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Title: The Descent of Man and Selection in Relation to Sex, Vol. I

Author: Charles Darwin

Release date: January 15, 2011 [eBook #34967]

Language: English

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*** START OF THE PROJECT GUTENBERG EBOOK THE DESCENT
OF MAN AND SELECTION IN RELATION TO SEX, VOL. I ***

THE

DESCENT OF MAN,
AND

SELECTION IN RELATION TO SEX.

By CHARLES DARWIN, M.A., F.R.S., &c.

IN TWO VOLUMES.—Vol. I.
WITH ILLUSTRATIONS.

LONDON:
JOHN MURRAY, ALBEMARLE STREET.
1871.
[The right of Translation is reserved.]

BY THE SAME AUTHOR.

ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL
SELECTION; or, The Preservation of Favoured Races in the
Struggle for Life; Fifth Edition (Tenth Thousand), with Additions and
Corrections. 1869. Murray.
THE VARIATION OF ANIMALS AND PLANTS UNDER
DOMESTICATION. In two vols. With Illustrations. 1868. Murray.
ON THE VARIOUS CONTRIVANCES by which BRITISH AND
FOREIGN ORCHIDS ARE FERTILISED BY INSECTS; and on the
Good Effects of Crossing. With numerous Woodcuts. Murray.
A NATURALIST‘S VOYAGE ROUND THE WORLD; or, A Journal of
Researches into the Natural History and Geology of the Countries
visited during the voyage of H.M.S. ‘Beagle,’ under the command of
Captain FitzRoy, R.N. Eleventh Thousand. Murray.
ON THE STRUCTURE AND DISTRIBUTION OF CORAL REEFS.
Smith, Elder, & Co.

GEOLOGICAL OBSERVATIONS ON VOLCANIC ISLANDS. Smith,
Elder, & Co.
GEOLOGICAL OBSERVATIONS ON SOUTH AMERICA. Smith, Elder
& Co.
A MONOGRAPH OF THE CIRRIPEDIA. With numerous Illustrations. 2
vols. 8vo. Hardwicke.
ON THE MOVEMENTS AND HABITS OF CLIMBING PLANTS. With
Woodcuts. Williams & Norgate.

LONDON: PRINTED BY WILLIAM CLOWES AND SONS, STAMFORD STREET, AND CHARING CROSS.

CONTENTS.

Introduction Page 1-5

PART I.

ON THE DESCENT OF MAN

CHAPTER I.
The Evidence of the Descent of man from some Lower form.
Nature of the evidence bearing on the origin of man—Homologous structures in man
and the lower animals—Miscellaneous points of correspondence—
Development—Rudimentary structures, muscles, sense-organs, hair, bones,
reproductive organs, &c.—The bearing of these three great classes of facts on
the origin of man 9-33

CHAPTER II.
Comparison of the Mental Powers of Man and the Lower Animals.
The difference in mental power between the highest ape and the lowest savage,
immense—Certain instincts in common—The emotions—Curiosity—Imitation
—Attention—Memory—Imagination—Reason—Progressive improvement—
Tools and weapons used by animals—Language—Self-consciousness—Sense
of beauty—Belief in God, spiritual agencies, superstitions 34-69

CHAPTER III.
Comparison of the Mental Powers of Man and the Lower Animals—continued.
The difference in mental power between the highest ape and the lowest savage,
immense—Certain instincts in common—The emotions—Curiosity—Imitation
—Attention—Memory—Imagination—Reason—Progressive improvement—
Tools and weapons used by animals—Language—Self-consciousness—Sense
of beauty—Belief in God, spiritual agencies, superstitions 70-106

CHAPTER IV.
On the Manner of Development of Man from some Lower Form.
Variability of body and mind in man—Inheritance—Causes of variability—Laws of
variation the same in man as in the lower animals—Direct action of the
conditions of life—Effects of the increased use and disuse of parts—Arrested
development—Reversion—Correlated variation—Rate of increase—Checks to
increase—Natural selection—Man the most dominant animal in the world—
Importance of his corporeal structure—The causes which have led to his
becoming erect—Consequent changes of structure—Decrease in size of the
canine teeth—Increased size and altered shape of the skull—Nakedness—
Absence of a tail—Defenceless condition of man 107-157

CHAPTER V.
On the Development of the Intellectual and Moral Faculties during Primeval
and Civilised Times.

The advancement of the intellectual powers through natural selection—Importance
of imitation—Social and moral faculties—Their development within the limits
of the same tribe—Natural selection as affecting civilised nations—Evidence
that civilised nations were once barbarous 158-184

CHAPTER VI.
On the Affinities and Genealogy of Man.
Position of man in the animal series—The natural system genealogical—Adaptive
characters of slight value—Various small points of resemblance between man
and the Quadrumana—Rank of man in the natural system—Birthplace and
antiquity of man—Absence of fossil connecting-links—Lower stages in the
genealogy of man, as inferred, firstly from his affinities and secondly from his
structure—Early androgynous condition of the Vertebrata—Conclusion 185-213

CHAPTER VII.
On the Races of Man.
The nature and value of specific characters—Application to the races of man—
Arguments in favour of, and opposed to, ranking the so-called races of man as
distinct species—Sub-species—Monogenists and polygenists—Convergence of
character—Numerous points of resemblance in body and mind between the
most distinct races of man—The state of man when he first spread over the
earth—Each race not descended from a single pair—The extinction of races—
The formation of races—The effects of crossing—Slight influence of the direct
action of the conditions of life—Slight or no influence of natural selection—
Sexual selection. 214-250

PART II.

SEXUAL SELECTION.

CHAPTER VIII.
Principles of Sexual Selection.
Secondary sexual characters—Sexual selection—Manner of action—Excess of males
—Polygamy—The male alone generally modified through sexual selection—
Eagerness of the male—Variability of the male—Choice exerted by the female
—Sexual compared with natural selection—Inheritance at corresponding
periods of life, at corresponding seasons of the year, and as limited by sex—
Relations between the several forms of inheritance—Causes why one sex and
the young are not modified through sexual selection—Supplement on the
proportional numbers of the two sexes throughout the animal kingdom—On the
limitation of the numbers of the two sexes through natural selection 253-320

CHAPTER IX.
Secondary Sexual Characters in the Lower Classes of the Animal Kingdom.
These characters absent in the lowest classes—Brilliant colours—Mollusca—
Annelids—Crustacea, secondary sexual characters strongly developed;
dimorphism; colour; characters not acquired before maturity—Spiders, sexual
colours of; stridulation by the males—Myriapoda 321-340

CHAPTER X.
Secondary Sexual Characters of Insects.
Diversified structures possessed by the males for seizing the females—Differences
between the sexes, of which the meaning is not understood—Difference in size
between the sexes—Thysanura—Diptera—Hemiptera—Homoptera, musical
powers possessed by the males alone—Orthoptera, musical instruments of the
males, much diversified in structure; pugnacity; colours—Neuroptera, sexual
differences in colour—Hymenoptera, pugnacity and colours—Coleoptera,
colours; furnished with great horns, apparently as an ornament; battles;
stridulating organs generally common to both sexes 341-385

CHAPTER XI.
Insects, continued.—Order Lepidoptera.
Courtship of butterflies—Battles—Ticking noise—Colours common to both sexes, 386-423
or more brilliant in the males—Examples—Not due to the direct action of the
conditions of life—Colours adapted for protection—Colours of moths—Display
—Perceptive powers of the Lepidoptera—Variability—Causes of the difference
in colour between the males and females—Mimickry, female butterflies more

brilliantly coloured than the males—Bright colours of caterpillars—Summary
and concluding remarks on the secondary sexual characters of insects—Birds
and insects compared

THE DESCENT OF MAN;
AND ON

SELECTION IN RELATION TO SEX.

INTRODUCTION.

The nature of the following work will be best understood by a brief account
of how it came to be written. During many years I collected notes on the
origin or descent of man, without any intention of publishing on the subject,
but rather with the determination not to publish, as I thought that I should
thus only add to the prejudices against my views. It seemed to me sufficient
to indicate, in the first edition of my ‘Origin of Species,’ that by this work
“light would be thrown on the origin of man and his history;” and this
implies that man must be included with other organic beings in any general
conclusion respecting his manner of appearance on this earth. Now the case
wears a wholly different aspect. When a naturalist like Carl Vogt ventures to
say in his address as President of the National Institution of Geneva (1869),
“personne, en Europe au moins, n’ose plus soutenir la création
indépendante et de toutes pièces, des espèces,” it is manifest that at least a
large number of naturalists must admit that species are the modified
descendants of other species; and this especially holds good with the
younger and rising naturalists. The greater number accept the agency of
natural selection; though some urge, whether with justice the future must
decide, that I have greatly overrated its importance. Of the older and
honoured chiefs in natural science, many unfortunately are still opposed to
evolution in every form.

In consequence of the views now adopted by most naturalists, and which
will ultimately, as in every other case, be followed by other men, I have
been led to put together my notes, so as to see how far the general
conclusions arrived at in my former works were applicable to man. This
seemed all the more desirable as I had never deliberately applied these
views to a species taken singly. When we confine our attention to any one
form, we are deprived of the weighty arguments derived from the nature of
the affinities which connect together whole groups of organisms—their
geographical distribution in past and present times, and their geological
succession. The homological structure, embryological development, and
rudimentary organs of a species, whether it be man or any other animal, to
which our attention may be directed, remain to be considered; but these
great classes of facts afford, as it appears to me, ample and conclusive
evidence in favour of the principle of gradual evolution. The strong support
derived from the other arguments should, however, always be kept before
the mind.
The sole object of this work is to consider, firstly, whether man, like every
other species, is descended from some pre-existing form; secondly, the
manner of his development; and thirdly, the value of the differences
between the so-called races of man. As I shall confine myself to these
points, it will not be necessary to describe in detail the differences between
the several races—an enormous subject which has been fully discussed in
many valuable works. The high antiquity of man has recently been
demonstrated by the labours of a host of eminent men, beginning with M.
Boucher de Perthes; and this is the indispensable basis for understanding his
origin. I shall, therefore, take this conclusion for granted, and may refer my
readers to the admirable treatises of Sir Charles Lyell, Sir John Lubbock,
and others. Nor shall I have occasion to do more than to allude to the
amount of difference between man and the anthropomorphous apes; for
Prof. Huxley, in the opinion of most competent judges, has conclusively
shewn that in every single visible character man differs less from the higher
apes than these do from the lower members of the same order of Primates.
This work contains hardly any original facts in regard to man; but as the
conclusions at which I arrived, after drawing up a rough draft, appeared to
me interesting, I thought that they might interest others. It has often and
confidently been asserted, that man’s origin can never be known: but

ignorance more frequently begets confidence than does knowledge: it is
those who know little, and not those who know much, who so positively
assert that this or that problem will never be solved by science. The
conclusion that man is the co-descendant with other species of some
ancient, lower, and extinct form, is not in any degree new. Lamarck long
ago came to this conclusion, which has lately been maintained by several
eminent naturalists and philosophers; for instance by Wallace, Huxley,
Lyell, Vogt, Lubbock, Büchner, Rolle, &c.,1 and especially by Häckel. This
last naturalist, besides his great work, 'Generelle Morphologie ‘(1866), has
recently (1868, with a second edit. in 1870), published his ‘Natürliche
Schöpfungsgeschichte, ‘in which he fully discusses the genealogy of man.
If this work had appeared before my essay had been written, I should
probably never have completed it. Almost all the conclusions at which I
have arrived I find confirmed by this naturalist, whose knowledge on many
points is much fuller than mine. Wherever I have added any fact or view
from Prof. Häckel’s writings, I give his authority in the text, other
statements I leave as they originally stood in my manuscript, occasionally
giving in the foot-notes references to his works, as a confirmation of the
more doubtful or interesting points.
During many years it has seemed to me highly probable that sexual
selection has played an important part in differentiating the races of man;
but in my ‘Origin of Species’ (first edition, p. 199) I contented myself by
merely alluding to this belief. When I came to apply this view to man, I
found it indispensable to treat the whole subject in full detail.2 Consequently
the second part of the present work, treating of sexual selection, has
extended to an inordinate length, compared with the first part; but this could
not be avoided.
I had intended adding to the present volumes an essay on the expression of
the various emotions by man and the lower animals. My attention was
called to this subject many years ago by Sir Charles Bell’s admirable work.
This illustrious anatomist maintains that man is endowed with certain
muscles solely for the sake of expressing his emotions. As this view is
obviously opposed to the belief that man is descended from some other and
lower form, it was necessary for me to consider it. I likewise wished to
ascertain how far the emotions are expressed in the same manner by the
different races of man. But owing to the length of the present work, I have

thought it better to reserve my essay, which is partially completed, for
separate publication.

Part I.

THE DESCENT OR ORIGIN OF MAN.

Part I.—THE DESCENT OF MAN.

CHAPTER I.

The Evidence of the Descent of Man from some Lower Form.
Nature of the evidence bearing on the origin of man—Homologous structures in man and the lower
animals—Miscellaneous points of correspondence—Development—Rudimentary structures,
muscles, sense-organs, hair, bones, reproductive organs, &c.—The bearing of these three great
classes of facts on the origin of man.

He who wishes to decide whether man is the modified descendant of some
pre-existing form, would probably first enquire whether man varies,
however slightly, in bodily structure and in mental faculties; and if so,
whether the variations are transmitted to his offspring in accordance with
the laws which prevail with the lower animals; such as that of the
transmission of characters to the same age or sex. Again, are the variations
the result, as far as our ignorance permits us to judge, of the same general
causes, and are they governed by the same general laws, as in the case of
other organisms; for instance by correlation, the inherited effects of use and
disuse, &c.? Is man subject to similar malconformations, the result of
arrested development, of reduplication of parts, &c., and does he display in
any of his anomalies reversion to some former and ancient type of
structure? It might also naturally be enquired whether man, like so many
other animals, has given rise to varieties and sub-races, differing but

slightly from each other, or to races differing so much that they must be
classed as doubtful species? How are such races distributed over the world;
and how, when crossed, do they react on each other, both in the first and
succeeding generations? And so with many other points.
The enquirer would next come to the important point, whether man tends to
increase at so rapid a rate, as to lead to occasional severe struggles for
existence, and consequently to beneficial variations, whether in body or
mind, being preserved, and injurious ones eliminated. Do the races or
species of men, whichever term may be applied, encroach on and replace
each other, so that some finally become extinct? We shall see that all these
questions, as indeed is obvious in respect to most of them, must be
answered in the affirmative, in the same manner as with the lower animals.
But the several considerations just referred to may be conveniently deferred
for a time; and we will first see how far the bodily structure of man shows
traces, more or less plain, of his descent from some lower form. In the two
succeeding chapters the mental powers of man, in comparison with those of
the lower animals, will be considered.

The Bodily Structure of Man.—It is notorious that man is constructed on the
same general type or model with other mammals. All the bones in his
skeleton can be compared with corresponding bones in a monkey, bat, or
seal. So it is with his muscles, nerves, blood-vessels and internal viscera.
The brain, the most important of all the organs, follows the same law, as
shewn by Huxley and other anatomists. Bischoff,3 who is a hostile witness,
admits that every chief fissure and fold in the brain of man has its analogy
in that of the orang; but he adds that at no period of development do their
brains perfectly agree; nor could this be expected, for otherwise their
mental powers would have been the same. Vulpian4 remarks: “Les
différences réelles qui existent entre l’encéphale de l’homme et celui des
singes supérieurs, sont bien minimes. Il ne faut pas se faire d’illusions à cet
égard. L’homme est bien plus près des singes anthropomorphes par les
caractères anatomiques de son cerveau que ceux-ci ne le sont non-
seulement des autres mammifères, mais mêmes de certains quadrumanes,
des guenons et des macaques.” But it would be superfluous here to give
further details on the correspondence between man and the higher mammals
in the structure of the brain and all other parts of the body.

It may, however, be worth while to specify a few points, not directly or
obviously connected with structure, by which this correspondence or
relationship is well shewn.
Man is liable to receive from the lower animals, and to communicate to
them, certain diseases as hydrophobia, variola, the glanders, &c.; and this
fact proves the close similarity of their tissues and blood, both in minute
structure and composition, far more plainly than does their comparison
under the best microscope, or by the aid of the best chemical analysis.
Monkeys are liable to many of the same non-contagious diseases as we are;
thus Rengger,5 who carefully observed for a long time the Cebus Azaræ in
its native land, found it liable to catarrh, with the usual symptoms, and
which when often recurrent led to consumption. These monkeys suffered
also from apoplexy, inflammation of the bowels, and cataract in the eye.
The younger ones when shedding their milk-teeth often died from fever.
Medicines produced the same effect on them as on us. Many kinds of
monkeys have a strong taste for tea, coffee, and spirituous liquors: they will
also, as I have myself seen, smoke tobacco with pleasure. Brehm asserts
that the natives of north-eastern Africa catch the wild baboons by exposing
vessels with strong beer, by which they are made drunk. He has seen some
of these animals, which he kept in confinement, in this state; and he gives a
laughable account of their behaviour and strange grimaces. On the
following morning they were very cross and dismal; they held their aching
heads with both hands and wore a most pitiable expression: when beer or
wine was offered them, they turned away with disgust, but relished the juice
of lemons.6 An American monkey, an Ateles, after getting drunk on brandy,
would never touch it again, and thus was wiser than many men. These
trifling facts prove how similar the nerves of taste must be in monkeys and
man, and how similarly their whole nervous system is affected.
Man is infested with internal parasites, sometimes causing fatal effects, and
is plagued by external parasites, all of which belong to the same genera or
families with those infesting other mammals. Man is subject like other
mammals, birds, and even insects, to that mysterious law, which causes
certain normal processes, such as gestation, as well as the maturation and
duration of various diseases, to follow lunar periods.7 His wounds are
repaired by the same process of healing; and the stumps left after the

amputation of his limbs occasionally possess, especially during an early
embryonic period, some power of regeneration, as in the lowest animals.8
The whole process of that most important function, the reproduction of the
species, is strikingly the same in all mammals, from the first act of
courtship by the male9 to the birth and nurturing of the young. Monkeys are
born in almost as helpless a condition as our own infants; and in certain
genera the young differ fully as much in appearance from the adults, as do
our children from their full-grown parents.10 It has been urged by some
writers as an important distinction, that with man the young arrive at
maturity at a much later age than with any other animal; but if we look to
the races of mankind which inhabit tropical countries the difference is not
great, for the orang is believed not to be adult till the age of from ten to
fifteen years.11 Man differs from woman in size, bodily strength, hairyness,
&c., as well as in mind, in the same manner as do the two sexes of many
mammals. It is, in short, scarcely possible to exaggerate the close
correspondence in general structure, in the minute structure of the tissues, in
chemical composition and in constitution, between man and the higher
animals, especially the anthropomorphous apes.

Embryonic Development.—Man is developed from an ovule, about the
125th of an inch in diameter, which differs in no respect from the ovules of
other animals. The embryo itself at a very early period can hardly be
distinguished from that of other members of the vertebrate kingdom. At this
period the arteries run in arch-like branches, as if to carry the blood to
branchiæ which are not present in the higher vertebrata, though the slits on
the sides of the neck still remain (f, g, fig. 1), marking their former position.
At a somewhat later period, when the extremities are developed, “the feet of
lizards and mammals,” as the illustrious Von Baer remarks, “the wings and
feet of birds, no less than the hands and feet of man, all arise from the same
fundamental form.” It is, says Prof. Huxley,12 “quite in the later stages of
development that the young human being presents marked differences from
the young ape, while the latter departs as much from the dog in its
developments, as the man does. Startling as this last assertion may appear to
be, it is demonstrably true.”

As some of my readers may never have seen a drawing of an embryo, I
have given one of man and another of a dog, at about the same early stage
of development, carefully copied from two works of undoubted accuracy.13

Fig. 1. Upper figure human embryo, from Ecker. Lower figure that of a dog, from
Bischoff.
a. Fore-brain, cerebral hemispheres, &c. g. Second visceral arch.
H. Vertebral columns and muscles in process of
b. Mid-brain, corpora quadrigemina.
development.
c. Hind-brain, cerebellum, medulla oblongata. i. Anterior ┐
│ extremities
┘

│
d. Eye. K. Posterior ┘
e. Ear. L. Tail or os coccyx.
f. First visceral arch.

After the foregoing statements made by such high authorities, it would be
superfluous on my part to give a number of borrowed details, shewing that
the embryo of man closely resembles that of other mammals. It may,
however, be added that the human embryo likewise resembles in various
points of structure certain low forms when adult. For instance, the heart at
first exists as a simple pulsating vessel; the excreta are voided through a
cloacal passage; and the os coccyx projects like a true tail, “extending
considerably beyond the rudimentary legs.”14 In the embryos of all air-
breathing vertebrates, certain glands called the corpora Wolffiana,
correspond with and act like the kidneys of mature fishes.15 Even at a later
embryonic period, some striking resemblances between man and the lower
animals may be observed. Bischoff says that the convolutions of the brain
in a human fœtus at the end of the seventh month reach about the same
stage of development as in a baboon when adult.16 The great toe, as Prof.
Owen remarks,17 “which forms the fulcrum when standing or walking, is
perhaps the most characteristic peculiarity in the human structure;” but in
an embryo, about an inch in length, Prof. Wyman18 found “that the great toe
was shorter than the others, and, instead of being parallel to them, projected
at an angle from the side of the foot, thus corresponding with the permanent
condition of this part in the quadrumana.” I will conclude with a quotation
from Huxley,19 who after asking, does man originate in a different way from
a dog, bird, frog or fish? says, “the reply is not doubtful for a moment;
without question, the mode of origin and the early stages of the
development of man are identical with those of the animals immediately
below him in the scale: without a doubt in these respects, he is far nearer to
apes, than the apes are to the dog.”

Rudiments.—This subject, though not intrinsically more important than the
two last, will for several reasons be here treated with more fullness.20 Not
one of the higher animals can be named which does not bear some part in a
rudimentary condition; and man forms no exception to the rule.
Rudimentary organs must be distinguished from those that are nascent;
though in some cases the distinction is not easy. The former are either

absolutely useless, such as the mammæ of male quadrupeds, or the incisor
teeth of ruminants which never cut through the gums; or they are of such
slight service to their present possessors, that we cannot suppose that they
were developed under the conditions which now exist. Organs in this latter
state are not strictly rudimentary, but they are tending in this direction.
Nascent organs, on the other hand, though not fully developed, are of high
service to their possessors, and are capable of further development.
Rudimentary organs are eminently variable; and this is partly intelligible, as
they are useless or nearly useless, and consequently are no longer subjected
to natural selection. They often become wholly suppressed. When this
occurs, they are nevertheless liable to occasional reappearance through
reversion; and this is a circumstance well worthy of attention.
Disuse at that period of life, when an organ is chiefly used, and this is
generally during maturity, together with inheritance at a corresponding
period of life, seem to have been the chief agents in causing organs to
become rudimentary. The term “disuse” does not relate merely to the
lessened action of muscles, but includes a diminished flow of blood to a
part or organ, from being subjected to fewer alternations of pressure, or
from becoming in any way less habitually active. Rudiments, however, may
occur in one sex of parts normally present in the other sex; and such
rudiments, as we shall hereafter see, have often originated in a distinct
manner. In some cases organs have been reduced by means of natural
selection, from having become injurious to the species under changed habits
of life. The process of reduction is probably often aided through the two
principles of compensation and economy of growth; but the later stages of
reduction, after disuse has done all that can fairly be attributed to it, and
when the saving to be effected by the economy of growth would be very
small,21 are difficult to understand. The final and complete suppression of a
part, already useless and much reduced in size, in which case neither
compensation nor economy can come into play, is perhaps intelligible by
the aid of the hypothesis of pangenesis, and apparently in no other way. But
as the whole subject of rudimentary organs has been fully discussed and
illustrated in my former works,22 I need here say no more on this head.
Rudiments of various muscles have been observed in many parts of the
human body;23 and not a few muscles, which are regularly present in some
of the lower animals can occasionally be detected in man in a greatly

reduced condition. Every one must have noticed the power which many
animals, especially horses, possess of moving or twitching their skin; and
this is effected by the panniculus carnosus. Remnants of this muscle in an
efficient state are found in various parts of our bodies; for instance, on the
forehead, by which the eyebrows are raised. The platysma myoides, which
is well developed on the neck, belongs to this system, but cannot be
voluntarily brought into action. Prof. Turner, of Edinburgh, has occasionally
detected, as he informs me, muscular fasciculi in five different situations,
namely in the axillæ, near the scapulæ, &c., all of which must be referred to
the system of the panniculus. He has also shewn24 that the musculus
sternalis or sternalis brutorum, which is not an extension of the rectus
abdominalis, but is closely allied to the panniculus, occurred in the
proportion of about 3 per cent. in upwards of 600 bodies: he adds, that this
muscle affords “an excellent illustration of the statement that occasional and
rudimentary structures are especially liable to variation in arrangement.”
Some few persons have the power of contracting the superficial muscles on
their scalps; and these muscles are in a variable and partially rudimentary
condition. M. A. de Candolle has communicated to me a curious instance of
the long-continued persistence or inheritance of this power, as well as of its
unusual development. He knows a family, in which one member, the
present head of a family, could, when a youth, pitch several heavy books
from his head by the movement of the scalp alone; and he won wagers by
performing this feat. His father, uncle, grandfather, and all his three children
possess the same power to the same unusual degree. This family became
divided eight generations ago into two branches; so that the head of the
above-mentioned branch is cousin in the seventh degree to the head of the
other branch. This distant cousin resides in another part of France, and on
being asked whether he possessed the same faculty, immediately exhibited
his power. This case offers a good illustration how persistently an
absolutely useless faculty may be transmitted.
The extrinsic muscles which serve to move the whole external ear, and the
intrinsic muscles which move the different parts, all of which belong to the
system of the panniculus, are in a rudimentary condition in man; they are
also variable in development, or at least in function. I have seen one man
who could draw his ears forwards, and another who could draw them
backwards;25

and from what one of these persons told me, it is probable that most of us
by often touching our ears and thus directing our attention towards them,
could by repeated trials recover some power of movement. The faculty of
erecting the ears and of directing them to different points of the compass, is
no doubt of the highest service to many animals, as they thus perceive the
point of danger; but I have never heard of a man who possessed the least
power of erecting his ears,—the one movement which might be of use to
him. The whole external shell of the ear may be considered a rudiment,
together with the various folds and prominences (helix and anti-helix,
tragus and anti-tragus, &c.) which in the lower animals strengthen and
support the ear when erect, without adding much to its weight. Some
authors, however, suppose that the cartilage of the shell serves to transmit
vibrations to the acoustic nerve; but Mr. Toynbee,26 after collecting all the
known evidence on this head, concludes that the external shell is of no
distinct use. The ears of the chimpanzee and orang are curiously like those
of man, and I am assured by the keepers in the Zoological Gardens that
these animals never move or erect them; so that they are in an equally
rudimentary condition, as far as function is concerned, as in man. Why
these animals, as well as the progenitors of man, should have lost the power
of erecting their ears we cannot say. It may be, though I am not quite
satisfied with this view, that owing to their arboreal habits and great
strength they were but little exposed to danger, and so during a lengthened
period moved their ears but little, and thus gradually lost the power of
moving them. This would be a parallel case with that of those large and
heavy birds, which from inhabiting oceanic islands have not been exposed
to the attacks of beasts of prey, and have consequently lost the power of
using their wings for flight.
The celebrated sculptor, Mr. Woolner, informs me of one little peculiarity in
the external ear, which he has often observed both in men and women, and
of which he perceived the full signification. His attention was first called to
the subject whilst at work on his figure of Puck, to which he had given
pointed ears. He was thus led to examine the ears of various monkeys, and
subsequently more carefully those of man. The peculiarity consists in a little
blunt point, projecting from the inwardly folded margin, or helix. Mr.
Woolner made an exact model of one such case, and has sent me the
accompanying drawing. (Fig. 2.) These points not only project inwards, but

often a little outwards, so that they are visible
when the head is viewed from directly in front
or behind. They are variable in size and
somewhat in position, standing either a little
higher or lower; and they sometimes occur on
one ear and not on the other. Now the meaning
of these projections is not, I think, doubtful; but
it may be thought that they offer too trifling a
character to be worth notice. This thought,
however, is as false as it is natural. Every
character, however slight, must be the result of
Fig. 2. Human Ear, modelled and some definite cause; and if it occurs in many
drawn by Mr. Woolner. individuals deserves consideration. The helix
a. The projecting point.
obviously consists of the extreme margin of the
ear folded inwards; and this folding appears to
be in some manner connected with the whole external ear being
permanently pressed backwards. In many monkeys, which do not stand
high in the order, as baboons and some species of macacus,27 the upper
portion of the ear is slightly pointed, and the margin is not at all folded
inwards; but if the margin were to be thus folded, a slight point would
necessarily project inwards and probably a little outwards. This could
actually be observed in a specimen of the Ateles beelzebuth in the
Zoological Gardens; and we may safely conclude that it is a similar
structure—a vestige of formerly pointed ears—which occasionally
reappears in man.
The nictitating membrane, or third eyelid, with its accessory muscles and
other structures, is especially well developed in birds, and is of much
functional importance to them, as it can be rapidly drawn across the whole
eye-ball. It is found in some reptiles and amphibians, and in certain fishes,
as in sharks. It is fairly well developed in the two lower divisions of the
mammalian series, namely, in the monotremata and marsupials, and in some
few of the higher mammals, as in the walrus. But in man, the quadrumana,
and most other mammals, it exists, as is admitted by all anatomists, as a
mere rudiment, called the semilunar fold.28
The sense of smell is of the highest importance to the greater number of
mammals—to some, as the ruminants, in warning them of danger; to others,

as the carnivora, in finding their prey; to others, as the wild boar, for both
purposes combined. But the sense of smell is of extremely slight service, if
any, even to savages, in whom it is generally more highly developed than in
the civilised races. It does not warn them of danger, nor guide them to their
food; nor does it prevent the Esquimaux from sleeping in the most fetid
atmosphere, nor many savages from eating half-putrid meat. Those who
believe in the principle of gradual evolution, will not readily admit that this
sense in its present state was originally acquired by man, as he now exists.
No doubt he inherits the power in an enfeebled and so far rudimentary
condition, from some early progenitor, to whom it was highly serviceable
and by whom it was continually used. We can thus perhaps understand how
it is, as Dr. Maudsley has truly remarked,29 that the sense of smell in man “is
singularly effective in recalling vividly the ideas and images of forgotten
scenes and places;” for we see in those animals, which have this sense
highly developed, such as dogs and horses, that old recollections of persons
and places are strongly associated with their odour.
Man differs conspicuously from all the other Primates in being almost
naked. But a few short straggling hairs are found over the greater part of the
body in the male sex, and fine down on that of the female sex, In
individuals belonging to the same race these hairs are highly variable, not
only in abundance, but likewise in position: thus the shoulders in some
Europeans are quite naked, whilst in others they bear thick tufts of hair.30
There can be little doubt that the hairs thus scattered over the body are the
rudiments of the uniform hairy coat of the lower animals. This view is
rendered all the more probable, as it is known that fine, short, and pale-
coloured hairs on the limbs and other parts of the body occasionally become
developed into “thickset, long, and rather coarse dark hairs,” when
abnormally nourished near old-standing inflamed surfaces.31
I am informed by Mr. Paget that persons belonging to the same family often
have a few hairs in their eyebrows much longer than the others; so that this
slight peculiarity seems to be inherited. These hairs apparently represent the
vibrissæ, which are used as organs of touch by many of the lower animals.
In a young chimpanzee I observed that a few upright, rather long, hairs,
projected above the eyes, where the true eyebrows, if present, would have
stood.

The fine wool-like hair, or so-called lanugo, with which the human fœtus
during the sixth month is thickly covered, offers a more curious case. It is
first developed, during the fifth month, on the eyebrows and face, and
especially round the mouth, where it is much longer than that on the head.
A moustache of this kind was observed by Eschricht32 on a female fœtus;
but this is not so surprising a circumstance as it may at first appear, for the
two sexes generally resemble each other in all external characters during an
early period of growth. The direction and arrangement of the hairs on all
parts of the fœtal body are the same as in the adult, but are subject to much
variability. The whole surface, including even the forehead and ears, is thus
thickly clothed; but it is a significant fact that the palms of the hands and
the soles of the feet are quite naked, like the inferior surfaces of all four
extremities in most of the lower animals. As this can hardly be an accidental
coincidence, we must consider the woolly covering of the fœtus to be the
rudimental representative of the first permanent coat of hair in those
mammals which are born hairy. This representation is much more complete,
in accordance with the usual law of embryological development, than that
afforded by the straggling hairs on the body of the adult.
It appears as if the posterior molar or wisdom-teeth were tending to become
rudimentary in the more civilised races of man. These teeth are rather
smaller than the other molars, as is likewise the case with the corresponding
teeth in the chimpanzee and orang; and they have only two separate fangs.
They do not cut through the gums till about the seventeenth year, and I am
assured by dentists that they are much more liable to decay, and are earlier
lost, than the other teeth. It is also remarkable that they are much more
liable to vary both in structure and in the period of their development than
the other teeth.33 In the Melanian races, on the other hand, the wisdom-teeth
are usually furnished with three separate fangs, and are generally sound:
they also differ from the other molars in size less than in the Caucasian
races.34 Prof. Schaaffhausen accounts for this difference between the races
by “the posterior dental portion of the jaw being always shortened” in those
that are civilised,35 and this shortening may, I presume, be safely attributed
to civilised men habitually feeding on soft, cooked food, and thus using
their jaws less. I am informed by Mr. Brace that it is becoming quite a
common practice in the United States to remove some of the molar teeth of

children, as the jaw does not grow large enough for the perfect development
of the normal number.
With respect to the alimentary canal I have met with an account of only a
single rudiment, namely the vermiform appendage of the cæcum. The
cæcum is a branch or diverticulum of the intestine, ending in a cul-de-sac,
and it is extremely long in many of the lower vegetable-feeding mammals.
In the marsupial koala it is actually more than thrice as long as the whole
body.36 It is sometimes produced into a long gradually-tapering point, and is
sometimes constricted in parts. It appears as if, in consequence of changed
diet or habits, the cæcum had become much shortened in various animals,
the vermiform appendage being left as a rudiment of the shortened part.
That this appendage is a rudiment, we may infer from its small size, and
from the evidence which Prof. Canestrini37 has collected of its variability in
man. It is occasionally quite absent, or again is largely developed. The
passage is sometimes completely closed for half or two-thirds of its length,
with the terminal part consisting of a flattened solid expansion. In the orang
this appendage is long and convoluted: in man it arises from the end of the
short cæcum, and is commonly from four to five inches in length, being
only about the third of an inch in diameter. Not only is it useless, but it is
sometimes the cause of death, of which fact I have lately heard two
instances: this is due to small hard bodies, such as seeds, entering the
passage and causing inflammation.38
In the Quadrumana and some other orders of mammals, especially in the
Carnivora, there is a passage near the lower end of the humerus, called the
supra-condyloid foramen, through which the great nerve of the fore limb
passes, and often the great artery. Now in the humerus of man, as Dr.
Struthers39 and others have shewn, there is generally a trace of this passage,
and it is sometimes fairly well developed, being formed by a depending
hook-like process of bone, completed by a band of ligament. When present
the great nerve invariably passes through it, and this clearly indicates that it
is the homologue and rudiment of the supra-condyloid foramen of the lower
animals. Prof. Turner estimates, as he informs me, that it occurs in about
one per cent. of recent skeletons; but during ancient times it appears to have
been much more common. Mr. Busk40 has collected the following evidence
on this head: Prof. Broca “noticed the perforation in four and a half per
cent. of the arm-bones collected in the ‘Cimetière du Sud’ at Paris; and in

the Grotto of Orrony, the contents of which are referred to the Bronze
period, as many as eight humeri out of thirty-two were perforated; but this
extraordinary proportion, he thinks, might be due to the cavern having been
a sort of ‘family vault.’ Again, M. Dupont found 30 per cent. of perforated
bones in the caves of the Valley of the Lesse, belonging to the Reindeer
period; whilst M. Leguay, in a sort of dolmen at Argenteuil, observed
twenty-five per cent. to be perforated; and M. Pruner-Bey found twenty-six
per cent. in the same condition in bones from Vauréal. Nor should it be left
unnoticed that M. Pruner-Bey states that this condition is common in
Guanche skeletons.” The fact that ancient races, in this and several other
cases, more frequently present structures which resemble those of the lower
animals than do the modern races, is interesting. One chief cause seems to
be that ancient races stand somewhat nearer than modern races in the long
line of descent to their remote animal-like progenitors.
The os coccyx in man, though functionless as a tail, plainly represents this
part in other vertebrate animals. At an early embryonic period it is free, and,
as we have seen, projects beyond the lower extremities. In certain rare and
anomalous cases it has been known, according to Isidore Geoffroy St.-
Hilaire and others,41 to form a small external rudiment of a tail. The os
coccyx is short, usually including only four vertebræ: and these are in a
rudimental condition, for they consist, with the exception of the basal one,
of the centrum alone.42 They are furnished with some small muscles; one of
which, as I am informed by Prof. Turner, has been expressly described by
Theile as a rudimentary repetition of the extensor of the tail, which is so
largely developed in many mammals.
The spinal cord in man extends only as far downwards as the last dorsal or
first lumbar vertebra; but a thread-like structure (the filum terminale) runs
down the axis of the sacral part of the spinal canal, and even along the back
of the coccygeal bones. The upper part of this filament, as Prof. Turner
informs me, is undoubtedly homologous with the spinal cord; but the lower
part apparently consists merely of the pia mater, or vascular investing
membrane. Even in this case the os coccyx may be said to possess a vestige
of so important a structure as the spinal cord, though no longer enclosed
within a bony canal. The following fact, for which I am also indebted to
Prof. Turner, shews how closely the os coccyx corresponds with the true tail
in the lower animals: Luschka has recently discovered at the extremity of

the coccygeal bones a very peculiar convoluted body, which is continuous
with the middle sacral artery; and this discovery led Krause and Meyer to
examine the tail of a monkey (Macacus) and of a cat, in both of which they
found, though not at the extremity, a similarly convoluted body.
The reproductive system offers various rudimentary structures; but these
differ in one important respect from the foregoing cases. We are not here
concerned with a vestige of a part which does not belong to the species in
an efficient state; but with a part which is always present and efficient in the
one sex, being represented in the other by a mere rudiment. Nevertheless,
the occurrence of such rudiments is as difficult to explain on the belief of
the separate creation of each species, as in the foregoing cases. Hereafter I
shall have to recur to these rudiments, and shall shew that their presence
generally depends merely on inheritance; namely, on parts acquired by one
sex having been partially transmitted to the other. Here I will only give
some instances of such rudiments. It is well known that in the males of all
mammals, including man, rudimentary mammæ exist. These in several
instances have become well developed, and have yielded a copious supply
of milk. Their essential identity in the two sexes is likewise shewn by their
occasional sympathetic enlargement in both during an attack of the measles.
The vesicula prostratica, which has been observed in many male mammals,
is now universally acknowledged to be the homologue of the female uterus,
together with the connected passage. It is impossible to read Leuckart’s able
description of this organ, and his reasoning, without admitting the justness
of his conclusion. This is especially clear in the case of those mammals in
which the true female uterus bifurcates, for in the males of these the
vesicula likewise bifurcates.43 Some additional rudimentary structures
belonging to the reproductive system might here have been adduced.44

The bearing of the three great classes of facts now given is unmistakeable.
But it would be superfluous here fully to recapitulate the line of argument
given in detail in my ‘Origin of Species.’ The homological construction of
the whole frame in the members of the same class is intelligible, if we admit
their descent from a common progenitor, together with their subsequent
adaptation to diversified conditions. On any other view the similarity of
pattern between the hand of a man or monkey, the foot of a horse, the
flipper of a seal, the wing of a bat, &c., is utterly inexplicable. It is no

scientific explanation to assert that they have all been formed on the same
ideal plan. With respect to development, we can clearly understand, on the
principle of variations supervening at a rather late embryonic period, and
being inherited at a corresponding period, how it is that the embryos of
wonderfully different forms should still retain, more or less perfectly, the
structure of their common progenitor. No other explanation has ever been
given of the marvellous fact that the embryo of a man, dog, seal, bat,
reptile, &c., can at first hardly be distinguished from each other. In order to
understand the existence of rudimentary organs, we have only to suppose
that a former progenitor possessed the parts in question in a perfect state,
and that under changed habits of life they became greatly reduced, either
from simple disuse, or through the natural selection of those individuals
which were least encumbered with a superfluous part, aided by the other
means previously indicated.
Thus we can understand how it has come to pass that man and all other
vertebrate animals have been constructed on the same general model, why
they pass through the same early stages of development, and why they
retain certain rudiments in common. Consequently we ought frankly to
admit their community of descent: to take any other view, is to admit that
our own structure and that of all the animals around us, is a mere snare laid
to entrap our judgment. This conclusion is greatly strengthened, if we look
to the members of the whole animal series, and consider the evidence
derived from their affinities or classification, their geographical distribution
and geological succession. It is only our natural prejudice, and that
arrogance which made our forefathers declare that they were descended
from demi-gods, which leads us to demur to this conclusion. But the time
will before long come when it will be thought wonderful, that naturalists,
who were well acquainted with the comparative structure and development
of man and other mammals, should have believed that each was the work of
a separate act of creation.

CHAPTER II.

Comparison of the Mental Powers of Man and the Lower Animals.

The difference in mental power between the highest ape and the lowest savage, immense—Certain
instincts in common—The emotions—Curiosity—Imitation—Attention—Memory—
Imagination—Reason—Progressive improvement—Tools and weapons used by animals—
Language—Self-consciousness—Sense of beauty—Belief in God, spiritual agencies,
superstitions.

We have seen in the last chapter that man bears in his bodily structure clear
traces of his descent from some lower form; but it may be urged that, as
man differs so greatly in his mental power from all other animals, there
must be some error in this conclusion. No doubt the difference in this
respect is enormous, even if we compare the mind of one of the lowest
savages, who has no words to express any number higher than four, and
who uses no abstract terms for the commonest objects or affections,45 with
that of the most highly organised ape. The difference would, no doubt, still
remain immense, even if one of the higher apes had been improved or
civilised as much as a dog has been in comparison with its parent-form, the
wolf or jackal. The Fuegians rank amongst the lowest barbarians; but I was
continually struck with surprise how closely the three natives on board
H.M.S. “Beagle,” who had lived some years in England and could talk a
little English, resembled us in disposition and in most of our mental
faculties. If no organic being excepting man had possessed any mental
power, or if his powers had been of a wholly different nature from those of
the lower animals, then we should never have been able to convince
ourselves that our high faculties had been gradually developed. But it can
be clearly shewn that there is no fundamental difference of this kind. We
must also admit that there is a much wider interval in mental power
between one of the lowest fishes, as a lamprey or lancelet, and one of the
higher apes, than between an ape and man; yet this immense interval is
filled up by numberless gradations.
Nor is the difference slight in moral disposition between a barbarian, such
as the man described by the old navigator Byron, who dashed his child on
the rocks for dropping a basket of sea-urchins, and a Howard or Clarkson;
and in intellect, between a savage who does not use any abstract terms, and
a Newton or Shakspeare. Differences of this kind between the highest men
of the highest races and the lowest savages, are connected by the finest
gradations. Therefore it is possible that they might pass and be developed
into each other.

My object in this chapter is solely to shew that there is no fundamental
difference between man and the higher mammals in their mental faculties.
Each division of the subject might have been extended into a separate essay,
but must here be treated briefly. As no classification of the mental powers
has been universally accepted, I shall arrange my remarks in the order most
convenient for my purpose; and will select those facts which have most
struck me, with the hope that they may produce some effect on the reader.
With respect to animals very low in the scale, I shall have to give some
additional facts under Sexual Selection, shewing that their mental powers
are higher than might have been expected. The variability of the faculties in
the individuals of the same species is an important point for us, and some
few illustrations will here be given. But it would be superfluous to enter
into many details on this head, for I have found on frequent enquiry, that it
is the unanimous opinion of all those who have long attended to animals of
many kinds, including birds, that the individuals differ greatly in every
mental characteristic. In what manner the mental powers were first
developed in the lowest organisms, is as hopeless an enquiry as how life
first originated. These are problems for the distant future, if they are ever to
be solved by man.
As man possesses the same senses with the lower animals, his fundamental
intuitions must be the same. Man has also some few instincts in common, as
that of self-preservation, sexual love, the love of the mother for her new-
born offspring, the power possessed by the latter of sucking, and so forth.
But man, perhaps, has somewhat fewer instincts than those possessed by the
animals which come next to him in the series. The orang in the Eastern
islands, and the chimpanzee in Africa, build platforms on which they sleep;
and, as both species follow the same habit, it might be argued that this was
due to instinct, but we cannot feel sure that it is not the result of both
animals having similar wants and possessing similar powers of reasoning.
These apes, as we may assume, avoid the many poisonous fruits of the
tropics, and man has no such knowledge; but as our domestic animals,
when taken to foreign lands and when first turned out in the spring, often
eat poisonous herbs, which they afterwards avoid, we cannot feel sure that
the apes do not learn from their own experience or from that of their parents
what fruits to select. It is however certain, as we shall presently see, that

apes have an instinctive dread of serpents, and probably of other dangerous
animals.
The fewness and the comparative simplicity of the instincts in the higher
animals are remarkable in contrast with those of the lower animals. Cuvier
maintained that instinct and intelligence stand in an inverse ratio to each
other; and some have thought that the intellectual faculties of the higher
animals have been gradually developed from their instincts. But Pouchet, in
an interesting essay,46 has shewn that no such inverse ratio really exists.
Those insects which possess the most wonderful instincts are certainly the
most intelligent. In the vertebrate series, the least intelligent members,
namely fishes and amphibians, do not possess complex instincts; and
amongst mammals the animal most remarkable for its instincts, namely the
beaver, is highly intelligent, as will be admitted by every one who has read
Mr. Morgan’s excellent account of this animal.47
Although the first dawnings of intelligence, according to Mr. Herbert
Spencer,48 have been developed through the multiplication and co-ordination
of reflex actions, and although many of the simpler instincts graduate into
actions of this kind and can hardly be distinguished from them, as in the
case of young animals sucking, yet the more complex instincts seem to have
originated independently of intelligence. I am, however, far from wishing to
deny that instinctive actions may lose their fixed and untaught character,
and be replaced by others performed by the aid of the free will. On the other
hand, some intelligent actions—as when, birds on oceanic islands first learn
to avoid man—after being performed during many generations, become
converted into instincts and are inherited. They may then be said to be
degraded in character, for they are no longer performed through reason or
from experience. But the greater number of the more complex instincts
appear to have been gained in a wholly different manner, through the
natural selection of variations of simpler instinctive actions. Such variations
appear to arise from the same unknown causes acting on the cerebral
organisation, which induce slight variations or individual differences in
other parts of the body; and these variations, owing to our ignorance, are
often said to arise spontaneously. We can, I think, come to no other
conclusion with respect to the origin of the more complex instincts, when
we reflect on the marvellous instincts of sterile worker-ants and bees, which

leave no offspring to inherit the effects of experience and of modified
habits.
Although a high degree of intelligence is certainly compatible with the
existence of complex instincts, as we see in the insects just named and in
the beaver, it is not improbable that they may to a certain extent interfere
with each other’s development. Little is known about the functions of the
brain, but we can perceive that as the intellectual powers become highly
developed, the various parts of the brain must be connected by the most
intricate channels of intercommunication; and as a consequence each
separate part would perhaps tend to become less well fitted to answer in a
definite and uniform, that is instinctive, manner to particular sensations or
associations.
I have thought this digression worth giving, because we may easily
underrate the mental powers of the higher animals, and especially of man,
when we compare their actions founded on the memory of past events, on
foresight, reason, and imagination, with exactly similar actions instinctively
performed by the lower animals; in this latter case the capacity of
performing such actions having been gained, step by step, through the
variability of the mental organs and natural selection, without any conscious
intelligence on the part of the animal during each successive generation. No
doubt, as Mr. Wallace has argued,49 much of the intelligent work done by
man is due to imitation and not to reason; but there is this great difference
between his actions and many of those performed by the lower animals,
namely, that man cannot, on his first trial, make, for instance, a stone
hatchet or a canoe, through his power of imitation. He has to learn his work
by practice; a beaver, on the other hand, can make its dam or canal, and a
bird its nest, as well, or nearly as well, the first time it tries, as when old and
experienced.
To return to our immediate subject: the lower animals, like man, manifestly
feel pleasure and pain, happiness and misery. Happiness is never better
exhibited than by young animals, such as puppies, kittens, lambs, &c., when
playing together, like our own children. Even insects play together, as has
been described by that excellent observer, P. Huber,50 who saw ants chasing
and pretending to bite each other, like so many puppies.

The fact that the lower animals are excited by the same emotions as
ourselves is so well established, that it will not be necessary to weary the
reader by many details. Terror acts in the same manner on them as on us,
causing the muscles to tremble, the heart to palpitate, the sphincters to be
relaxed, and the hair to stand on end. Suspicion, the offspring of fear, is
eminently characteristic of most wild animals. Courage and timidity are
extremely variable qualities in the individuals of the same species, as is
plainly seen in our dogs. Some dogs and horses are ill-tempered and easily
turn sulky; others are good-tempered; and these qualities are certainly
inherited. Every one knows how liable animals are to furious rage, and how
plainly they show it. Many anecdotes, probably true, have been published
on the long-delayed and artful revenge of various animals. The accurate
Rengger and Brehm51 state that the American and African monkeys which
they kept tame, certainly revenged themselves. The love of a dog for his
master is notorious; in the agony of death he has been known to caress his
master, and every one has heard of the dog suffering under vivisection, who
licked the hand of the operator; this man, unless he had a heart of stone,
must have felt remorse to the last hour of his life. As Whewell52 has
remarked, “who that reads the touching instances of maternal affection,
related so often of the women of all nations, and of the females of all
animals, can doubt that the principle of action is the same in the two cases?”
We see maternal affection exhibited in the most trifling details; thus
Rengger observed an American monkey (a Cebus) carefully driving away
the flies which plagued her infant; and Duvaucel saw a Hylobates washing
the faces of her young ones in a stream. So intense is the grief of female
monkeys for the loss of their young, that it invariably caused the death of
certain kinds kept under confinement by Brehm in N. Africa. Orphan-
monkeys were always adopted and carefully guarded by the other monkeys,
both males and females. One female baboon had so capacious a heart that
she not only adopted young monkeys of other species, but stole young dogs
and cats, which she continually carried about. Her kindness, however, did
not go so far as to share her food with her adopted offspring, at which
Brehm was surprised, as his monkeys always divided everything quite fairly
with their own young ones. An adopted kitten scratched the above-
mentioned affectionate baboon, who certainly had a fine intellect, for she
was much astonished at being scratched, and immediately examined the

kitten’s feet, and without more ado bit off the claws. In the Zoological
Gardens, I heard from the keeper that an old baboon (C. chacma) had
adopted a Rhesus monkey; but when a young drill and mandrill were placed
in the cage, she seemed to perceive that these monkeys, though distinct
species, were her nearer relatives, for she at once rejected the Rhesus and
adopted both of them. The young Rhesus, as I saw, was greatly discontented
at being thus rejected, and it would, like a naughty child, annoy and attack
the young drill and mandrill whenever it could do so with safety; this
conduct exciting great indignation in the old baboon. Monkeys will also,
according to Brehm, defend their master when attacked by any one, as well
as dogs to whom they are attached, from the attacks of other dogs. But we
here trench on the subject of sympathy, to which I shall recur. Some of
Brehm’s monkeys took much delight in teasing, in various ingenious ways,
a certain old dog whom they disliked, as well as other animals.
Most of the more complex emotions are common to the higher animals and
ourselves. Every one has seen how jealous a dog is of his master’s
affection, if lavished on any other creature; and I have observed the same
fact with monkeys. This shews that animals not only love, but have the
desire to be loved. Animals manifestly feel emulation. They love
approbation or praise; and a dog carrying a basket for his master exhibits in
a high degree self-complacency or pride. There can, I think, be no doubt
that a dog feels shame, as distinct from fear, and something very like
modesty when begging too often for food. A great dog scorns the snarling
of a little dog, and this may be called magnanimity. Several observers have
stated that monkeys certainly dislike being laughed at; and they sometimes
invent imaginary offences. In the Zoological Gardens I saw a baboon who
always got into a furious rage when his keeper took out a letter or book and
read it aloud to him; and his rage was so violent that, as I witnessed on one
occasion, he bit his own leg till the blood flowed.
We will now turn to the more intellectual emotions and faculties, which are
very important, as forming the basis for the development of the higher
mental powers. Animals manifestly enjoy excitement and suffer from ennui,
as may be seen with dogs, and, according to Rengger, with monkeys. All
animals feel Wonder, and many exhibit Curiosity. They sometimes suffer
from this latter quality, as when the hunter plays antics and thus attracts
them; I have witnessed this with deer, and so it is with the wary chamois,

and with some kinds of wild-ducks. Brehm gives a curious account of the
instinctive dread which his monkeys exhibited towards snakes; but their
curiosity was so great that they could not desist from occasionally satiating
their horror in a most human fashion, by lifting up the lid of the box in
which the snakes were kept. I was so much surprised at his account, that I
took a stuffed and coiled-up snake into the monkey-house at the Zoological
Gardens, and the excitement thus caused was one of the most curious
spectacles which I ever beheld. Three species of Cercopithecus were the
most alarmed; they dashed about their cages and uttered sharp signal-cries
of danger, which were understood by the other monkeys. A few young
monkeys and one old Anubis baboon alone took no notice of the snake. I
then placed the stuffed specimen on the ground in one of the larger
compartments. After a time all the monkeys collected round it in a large
circle, and staring intently, presented a most ludicrous appearance. They
became extremely nervous; so that when a wooden ball, with which they
were familiar as a plaything, was accidently moved in the straw, under
which it was partly hidden, they all instantly started away. These monkeys
behaved very differently when a dead fish, a mouse, and some other new
objects were placed in their cages; for though at first frightened, they soon
approached, handled and examined them. I then placed a live snake in a
paper bag, with the mouth loosely closed, in one of the larger
compartments. One of the monkeys immediately approached, cautiously
opened the bag a little, peeped in, and instantly dashed away. Then I
witnessed what Brehm has described, for monkey after monkey, with head
raised high and turned on one side, could not resist taking momentary peeps
into the upright bag, at the dreadful object lying quiet at the bottom. It
would almost appear as if monkeys had some notion of zoological affinities,
for those kept by Brehm exhibited a strange, though mistaken, instinctive
dread of innocent lizards and frogs. An orang, also, has been known to be
much alarmed at the first sight of a turtle.53
The principle of Imitation is strong in man, and especially in man in a
barbarous state. Desor54 has remarked that no animal voluntarily imitates an
action performed by man, until in the ascending scale we come to monkeys,
which are well-known to be ridiculous mockers. Animals, however,
sometimes imitate each others’ actions: thus two species of wolves, which
had been reared by dogs, learned to bark, as does sometimes the jackal,55 but

whether this can be called voluntary imitation is another question. From one
account which I have read, there is reason to believe that puppies nursed by
cats sometimes learn to lick their feet and thus to clean their faces: it is at
least certain, as I hear from a perfectly trustworthy friend, that some dogs
behave in this manner. Birds imitate the songs of their parents, and
sometimes those of other birds; and parrots are notorious imitators of any
sound which they often hear.
Hardly any faculty is more important for the intellectual progress of man
than the power of Attention. Animals clearly manifest this power, as when a
cat watches by a hole and prepares to spring on its prey. Wild animals
sometimes become so absorbed when thus engaged, that they may be easily
approached. Mr. Bartlett has given me a curious proof how variable this
faculty is in monkeys. A man who trains monkeys to act used to purchase
common kinds from the Zoological Society at the price of five pounds for
each; but he offered to give double the price, if he might keep three or four
of them for a few days, in order to select one. When asked how he could
possibly so soon learn whether a particular monkey would turn out a good
actor, he answered that it all depended on their power of attention. If when
he was talking and explaining anything to a monkey, its attention was easily
distracted, as by a fly on the wall or other trifling object, the case was
hopeless. If he tried by punishment to make an inattentive monkey act, it
turned sulky. On the other hand, a monkey which carefully attended to him
could always be trained.
It is almost superfluous to state that animals have excellent Memories for
persons and places. A baboon at the Cape of Good Hope, as I have been
informed by Sir Andrew Smith, recognised him with joy after an absence of
nine months. I had a dog who was savage and averse to all strangers, and I
purposely tried his memory after an absence of five years and two days. I
went near the stable where he lived, and shouted to him in my old manner;
he showed no joy, but instantly followed me out walking and obeyed me,
exactly as if I had parted with him only half-an-hour before. A train of old
associations, dormant during five years, had thus been instantaneously
awakened in his mind. Even ants, as P. Huber56 has clearly shewn,
recognised their fellow-ants belonging to the same community after a
separation of four months. Animals can certainly by some means judge of
the intervals of time between recurrent events.

The Imagination is one of the highest prerogatives of man. By this faculty
he unites, independently of the will, former images and ideas, and thus
creates brilliant and novel results. A poet, as Jean Paul Richter remarks,57
“who must reflect whether he shall make a character say yes or no—to the
devil with him; he is only a stupid corpse.” Dreaming gives us the best
notion of this power; as Jean Paul again says, “The dream is an involuntary
art of poetry.” The value of the products of our imagination depends of
course on the number, accuracy, and clearness of our impressions; on our
judgment and taste in selecting or rejecting the involuntary combinations,
and to a certain extent on our power of voluntarily combining them. As
dogs, cats, horses, and probably all the higher animals, even birds, as is
stated on good authority,58 have vivid dreams, and this is shewn by their
movements and voice, we must admit that they possess some power of
imagination.
Of all the faculties of the human mind, it will, I presume, be admitted that
Reason stands at the summit. Few persons any longer dispute that animals
possess some power of reasoning. Animals may constantly be seen to pause,
deliberate, and resolve. It is a significant fact, that the more the habits of
any particular animal are studied by a naturalist, the more he attributes to
reason and the less to unlearnt instincts.59 In future chapters we shall see that
some animals extremely low in the scale apparently display a certain
amount of reason. No doubt it is often difficult to distinguish between the
power of reason and that of instinct. Thus Dr. Hayes, in his work on ‘The
Open Polar Sea,’ repeatedly remarks that his dogs, instead of continuing to
draw the sledges in a compact body, diverged and separated when they
came to thin ice, so that their weight might be more evenly distributed. This
was often the first warning and notice which the travellers received that the
ice was becoming thin and dangerous. Now, did the dogs act thus from the
experience of each individual, or from the example of the older and wiser
dogs, or from an inherited habit, that is from an instinct? This instinct might
possibly have arisen since the time, long ago, when dogs were first
employed by the natives in drawing their sledges; or the Arctic wolves, the
parent-stock of the Esquimaux dog, may have acquired this instinct,
impelling them not to attack their prey in a close pack when on thin ice.
Questions of this kind are most difficult to answer.

So many facts have been recorded in various works shewing that animals
possess some degree of reason, that I will here give only two or three
instances, authenticated by Rengger, and relating to American monkeys,
which stand low in their order. He states that when he first gave eggs to his
monkeys, they smashed them and thus lost much of their contents;
afterwards they gently hit one end against some hard body, and picked off
the bits of shell with their fingers. After cutting themselves only once with
any sharp tool, they would not touch it again, or would handle it with the
greatest care. Lumps of sugar were often given them wrapped up in paper;
and Rengger sometimes put a live wasp in the paper, so that in hastily
unfolding it they got stung; after this had once happened, they always first
held the packet to their ears to detect any movement within. Any one who is
not convinced by such facts as these, and by what he may observe with his
own dogs, that animals can reason, would not be convinced by anything
that I could add. Nevertheless I will give one case with respect to dogs, as it
rests on two distinct observers, and can hardly depend on the modification
of any instinct.
Mr. Colquhoun60 winged two wild-ducks, which fell on the opposite side of
a stream; his retriever tried to bring over both at once, but could not
succeed; she then, though never before known to ruffle a feather,
deliberately killed one, brought over the other, and returned for the dead
bird. Col. Hutchinson relates that two partridges were shot at once, one
being killed, the other wounded; the latter ran away, and was caught by the
retriever, who on her return came across the dead bird; “she stopped,
evidently greatly puzzled, and after one or two trials, finding she could not
take it up without permitting the escape of the winged bird, she considered
a moment, then deliberately murdered it by giving it a severe crunch, and
afterwards brought away both together. This was the only known instance
of her ever having wilfully injured any game.” Here we have reason, though
not quite perfect, for the retriever might have brought the wounded bird first
and then returned for the dead one, as in the case of the two wild-ducks.
The muleteers in S. America say, “I will not give you the mule whose step
is easiest, but la mas rational,—the one that reasons best;” and Humboldt61
adds, “this popular expression, dictated by long experience, combats the
system of animated machines, better perhaps than all the arguments of
speculative philosophy.”

It has, I think, now been shewn that man and the higher animals, especially
the Primates, have some few instincts in common. All have the same senses,
intuitions and sensations—similar passions, affections, and emotions, even
the more complex ones; they feel wonder and curiosity; they possess the
same faculties of imitation, attention, memory, imagination, and reason,
though in very different degrees. Nevertheless many authors have insisted
that man is separated through his mental faculties by an impassable barrier
from all the lower animals. I formerly made a collection of above a score of
such aphorisms, but they are not worth giving, as their wide difference and
number prove the difficulty, if not the impossibility, of the attempt. It has
been asserted that man alone is capable of progressive improvement; that he
alone makes use of tools or fire, domesticates other animals, possesses
property, or employs language; that no other animal is self-conscious,
comprehends itself, has the power of abstraction, or possesses general
ideas; that man alone has a sense of beauty, is liable to caprice, has the
feeling of gratitude, mystery, &c.; believes in God, or is endowed with a
conscience. I will hazard a few remarks on the more important and
interesting of these points.
Archbishop Sumner formerly maintained62 that man alone is capable of
progressive improvement. With animals, looking first to the individual,
every one who has had any experience in setting traps knows that young
animals can be caught much more easily than old ones; and they can be
much more easily approached by an enemy. Even with respect to old
animals, it is impossible to catch many in the same place and in the same
kind of trap, or to destroy them by the same kind of poison; yet it is
improbable that all should have partaken of the poison, and impossible that
all should have been caught in the trap. They must learn caution by seeing
their brethren caught or poisoned. In North America, where the fur-bearing
animals have long been pursued, they exhibit, according to the unanimous
testimony of all observers, an almost incredible amount of sagacity, caution,
and cunning; but trapping has been there so long carried on that inheritance
may have come into play.
If we look to successive generations, or to the race, there is no doubt that
birds and other animals gradually both acquire and lose caution in relation
to man or other enemies;63 and this caution is certainly in chief part an
inherited habit or instinct, but in part the result of individual experience. A

good observer, Leroy,64 states that in districts where foxes are much hunted,
the young when they first leave their burrows are incontestably much more
wary than the old ones in districts where they are not much disturbed.
Our domestic dogs are descended from wolves and jackals,65 and though
they may not have gained in cunning, and may have lost in waryness and
suspicion, yet they have progressed in certain moral qualities, such as in
affection, trust-worthiness, temper, and probably in general intelligence.
The common rat has conquered and beaten several other species throughout
Europe, in parts of North America, New Zealand, and recently in Formosa,
as well as on the mainland of China. Mr. Swinhoe,66 who describes these
latter cases, attributes the victory of the common rat over the large Mus
coninga to its superior cunning; and this latter quality may be attributed to
the habitual exercise of all its faculties in avoiding extirpation by man, as
well as to nearly all the less cunning or weak-minded rats having been
successively destroyed by him. To maintain, independently of any direct
evidence, that no animal during the course of ages has progressed in
intellect or other mental faculties, is to beg the question of the evolution of
species. Hereafter we shall see that, according to Lartet, existing mammals
belonging to several orders have larger brains than their ancient tertiary
prototypes.
It has often been said that no animal uses any tool; but the chimpanzee in a
state of nature cracks a native fruit, somewhat like a walnut, with a stone.67
Rengger68 easily taught an American monkey thus to break open hard palm-
nuts, and afterwards of its own accord it used stones to open other kinds of
nuts, as well as boxes. It thus also removed the soft rind of fruit that had a
disagreeable flavour. Another monkey was taught to open the lid of a large
box with a stick, and afterwards it used the stick as a lever to move heavy
bodies; and I have myself seen a young orang put a stick into a crevice, slip
his hand to the other end, and use it in the proper manner as a lever. In the
cases just mentioned stones and sticks were employed as implements; but
they are likewise used as weapons. Brehm69 states, on the authority of the
well-known traveller Schimper, that in Abyssinia when the baboons
belonging to one species (C. gelada) descend in troops from the mountains
to plunder the fields, they sometimes encounter troops of another species
(C. hamadryas), and then a fight ensues. The Geladas roll down great
stones, which the Hamadryas try to avoid, and then, both species, making a

great uproar, rush furiously against each other. Brehm, when accompanying
the Duke of Coburg-Gotha, aided in an attack with fire-arms on a troop of
baboons in the pass of Mensa in Abyssinia. The baboons in return rolled so
many stones down the mountain, some as large as a man’s head, that the
attackers had to beat a hasty retreat; and the pass was actually for a time
closed against the caravan. It deserves notice that these baboons thus acted
in concert. Mr. Wallace70 on three occasions saw female orangs,
accompanied by their young, “breaking off branches and the great spiny
fruit of the Durian tree, with every appearance of rage; causing such a
shower of missiles as effectually kept us from approaching too near the
tree.”
In the Zoological Gardens a monkey which had weak teeth used to break
open nuts with a stone; and I was assured by the keepers that this animal,
after using the stone, hid it in the straw, and would not let any other monkey
touch it. Here, then, we have the idea of property; but this idea is common
to every dog with a bone, and to most or all birds with their nests.
The Duke of Argyll71 remarks, that the fashioning of an implement for a
special purpose is absolutely peculiar to man; and he considers that this
forms an immeasurable gulf between him and the brutes. It is no doubt a
very important distinction, but there appears to me much truth in Sir J.
Lubbock’s suggestion,72 that when primeval man first used flint-stones for
any purpose, he would have accidentally splintered them, and would then
have used the sharp fragments. From this step it would be a small one to
intentionally break the flints, and not a very wide step to rudely fashion
them. This latter advance, however, may have taken long ages, if we may
judge by the immense interval of time which elapsed before the men of the
neolithic period took to grinding and polishing their stone tools. In breaking
the flints, as Sir J. Lubbock likewise remarks, sparks would have been
emitted, and in grinding them heat would have been evolved: “thus the two
usual methods of obtaining fire may have originated.” The nature of fire
would have been known in the many volcanic regions where lava
occasionally flows through forests. The anthropomorphous apes, guided
probably by instinct, build for themselves temporary platforms; but as many
instincts are largely controlled by reason, the simpler ones, such as this of
building a platform, might readily pass into a voluntary and conscious act.
The orang is known to cover itself at night with the leaves of the Pandanus;

and Brehm states that one of his baboons used to protect itself from the heat
of the sun by throwing a straw-mat over its head. In these latter habits, we
probably see the first steps towards some of the simpler arts; namely rude
architecture and dress, as they arose amongst the early progenitors of man.

Language.—This faculty has justly been considered as one of the chief
distinctions between man and the lower animals. But man, as a highly
competent judge, Archbishop Whately remarks, “is not the only animal that
can make use of language to express what is passing in his mind, and can
understand, more or less, what is so expressed by another.”73 In Paraguay
the Cebus Azaræ when excited utters at least six distinct sounds, which
excite in other monkeys similar emotions.74 The movements of the features
and gestures of monkeys are understood by us, and they partly understand
ours, as Rengger and others declare. It is a more remarkable fact that the
dog, since being domesticated, has learnt to bark75 in at least four or five
distinct tones. Although barking is a new art, no doubt the wild species, the
parents of the dog, expressed their feelings by cries of various kinds. With
the domesticated dog we have the bark of eagerness, as in the chase; that of
anger; the yelping or howling bark of despair, as when shut up; that of joy,
as when starting on a walk with his master; and the very distinct one of
demand or supplication, as when wishing for a door or window to be
opened.
Articulate language is, however, peculiar to man; but he uses in common
with the lower animals inarticulate cries to express his meaning, aided by
gestures and the movements of the muscles of the face.76 This especially
holds good with the more simple and vivid feelings, which are but little
connected with our higher intelligence. Our cries of pain, fear, surprise,
anger, together with their appropriate actions, and the murmur of a mother
to her beloved child, are more expressive than any words. It is not the mere
power of articulation that distinguishes man from other animals, for as
every one knows, parrots can talk; but it is his large power of connecting
definite sounds with definite ideas; and this obviously depends on the
development of the mental faculties.
As Horne Tooke, one of the founders of the noble science of philology,
observes, language is an art, like brewing or baking; but writing would have

been a much more appropriate simile. It certainly is not a true instinct, as
every language has to be learnt. It differs, however, widely from all
ordinary arts, for man has an instinctive tendency to speak, as we see in the
babble of our young children; whilst no child has an instinctive tendency to
brew, bake, or write. Moreover, no philologist now supposes that any
language has been deliberately invented; each has been slowly and
unconsciously developed by many steps. The sounds uttered by birds offer
in several respects the nearest analogy to language, for all the members of
the same species utter the same instinctive cries expressive of their
emotions; and all the kinds that have the power of singing exert this power
instinctively; but the actual song, and even the call-notes, are learnt from
their parents or foster-parents. These sounds, as Daines Barrington77 has
proved, “are no more innate than language is in man.” The first attempts to
sing “may be compared to the imperfect endeavour in a child to babble.”
The young males continue practising, or, as the bird-catchers say, recording,
for ten or eleven months. Their first essays show hardly a rudiment of the
future song; but as they grow older we can perceive what they are aiming
at; and at last they are said “to sing their song round.” Nestlings which have
learnt the song of a distinct species, as with the canary-birds educated in the
Tyrol, teach and transmit their new song to their offspring. The slight
natural differences of song in the same species inhabiting different districts
may be appositely compared, as Barrington remarks, “to provincial
dialects;” and the songs of allied, though distinct species may be compared
with the languages of distinct races of man. I have given the foregoing
details to shew that an instinctive tendency to acquire an art is not a
peculiarity confined to man.
With respect to the origin of articulate language, after having read on the
one side the highly interesting works of Mr. Hensleigh Wedgwood, the Rev.
F. Farrar, and Prof. Schleicher,78 and the celebrated lectures of Prof. Max
Müller on the other side, I cannot doubt that language owes its origin to the
imitation and modification, aided by signs and gestures, of various natural
sounds, the voices of other animals, and man’s own instinctive cries. When
we treat of sexual selection we shall see that primeval man, or rather some
early progenitor of man, probably used his voice largely, as does one of the
gibbon-apes at the present day, in producing true musical cadences, that is
in singing; we may conclude from a widely-spread analogy that this power

would have been especially exerted during the courtship of the sexes,
serving to express various emotions, as love, jealousy, triumph, and serving
as a challenge to their rivals. The imitation by articulate sounds of musical
cries might have given rise to words expressive of various complex
emotions. As bearing on the subject of imitation, the strong tendency in our
nearest allies, the monkeys, in microcephalous idiots,79 and in the barbarous
races of mankind, to imitate whatever they hear deserves notice. As
monkeys certainly understand much that is said to them by man, and as in a
state of nature they utter signal-cries of danger to their fellows,80 it does not
appear altogether incredible, that some unusually wise ape-like animal
should have thought of imitating the growl of a beast of prey, so as to
indicate to his fellow monkeys the nature of the expected danger. And this
would have been a first step in the formation of a language.
As the voice was used more and more, the vocal organs would have been
strengthened and perfected through the principle of the inherited effects of
use; and this would have reacted on the power of speech. But the relation
between the continued use of language and the development of the brain
has no doubt been far more important. The mental powers in some early
progenitor of man must have been more highly developed than in any
existing ape, before even the most imperfect form of speech could have
come into use; but we may confidently believe that the continued use and
advancement of this power would have reacted on the mind by enabling and
encouraging it to carry on long trains of thought. A long and complex train
of thought can no more be carried on without the aid of words, whether
spoken or silent, than a long calculation without the use of figures or
algebra. It appears, also, that even ordinary trains of thought almost require
some form of language, for the dumb, deaf, and blind girl, Laura Bridgman,
was observed to use her fingers whilst dreaming.81 Nevertheless a long
succession of vivid and connected ideas, may pass through the mind
without the aid of any form of language, as we may infer from the
prolonged dreams of dogs. We have, also, seen that retriever-dogs are able
to reason to a certain extent; and this they manifestly do without the aid of
language. The intimate connection between the brain, as it is now
developed in us, and the faculty of speech, is well shewn by those curious
cases of brain-disease, in which speech is specially affected, as when the
power to remember substantives is lost, whilst other words can be correctly

used.82 There is no more improbability in the effects of the continued use of
the vocal and mental organs being inherited, than in the case of
handwriting, which depends partly on the structure of the hand and partly
on the disposition of the mind; and handwriting is certainly inherited.83
Why the organs now used for speech should have been originally perfected
for this purpose, rather than any other organs, it is not difficult to see. Ants
have considerable powers of intercommunication by means of their
antennæ, as shewn by Huber, who devotes a whole chapter to their
language. We might have used our fingers as efficient instruments, for a
person with practice can report to a deaf man every word of a speech
rapidly delivered at a public meeting; but the loss of our hands, whilst thus
employed, would have been a serious inconvenience. As all the higher
mammals possess vocal organs constructed on the same general plan with
ours, and which are used as a means of communication, it was obviously
probable, if the power of communication had to be improved, that these
same organs would have been still further developed; and this has been
effected by the aid of adjoining and well-adapted parts, namely the tongue
and lips.84 The fact of the higher apes not using their vocal organs for
speech, no doubt depends on their intelligence not having been sufficiently
advanced. The possession by them of organs, which with long-continued
practice might have been used for speech, although not thus used, is
paralleled by the case of many birds which possess organs fitted for singing,
though they never sing. Thus, the nightingale and crow have vocal organs
similarly constructed, these being used by the former for diversified song,
and by the latter merely for croaking.85
The formation of different languages and of distinct species, and the proofs
that both have been developed through a gradual process, are curiously the
same.86 But we can trace the origin of many words further back than in the
case of species, for we can perceive that they have arisen from the imitation
of various sounds, as in alliterative poetry. We find in distinct languages
striking homologies due to community of descent, and analogies due to a
similar process of formation. The manner in which certain letters or sounds
change when others change is very like correlated growth. We have in both
cases the reduplication of parts, the effects of long-continued use, and so
forth. The frequent presence of rudiments, both in languages and in species,
is still more remarkable. The letter m in the word am, means I; so that in the

expression I am, a superfluous and useless rudiment has been retained. In
the spelling also of words, letters often remain as the rudiments of ancient
forms of pronunciation. Languages, like organic beings, can be classed in
groups under groups; and they can be classed either naturally according to
descent, or artificially by other characters. Dominant languages and dialects
spread widely and lead to the gradual extinction of other tongues. A
language, like a species, when once extinct, never, as Sir C. Lyell remarks,
reappears. The same language never has two birthplaces. Distinct languages
may be crossed or blended together.87 We see variability in every tongue,
and new words are continually cropping up; but as there is a limit to the
powers of the memory, single words, like whole languages, gradually
become extinct. As Max Müller88 has well remarked:—“A struggle for life is
constantly going on amongst the words and grammatical forms in each
language. The better, the shorter, the easier forms are constantly gaining the
upper hand, and they owe their success to their own inherent virtue.” To
these more important causes of the survival of certain words, mere novelty
may, I think, be added; for there is in the mind of man a strong love for
slight changes in all things. The survival or preservation of certain favoured
words in the struggle for existence is natural selection.
The perfectly regular and wonderfully complex construction of the
languages of many barbarous nations has often been advanced as a proof,
either of the divine origin of these languages, or of the high art and former
civilisation of their founders. Thus F. von Schlegel writes: “In those
languages which appear to be at the lowest grade of intellectual culture, we
frequently observe a very high and elaborate degree of art in their
grammatical structure. This is especially the case with the Basque and the
Lapponian, and many of the American languages.”89 But it is assuredly an
error to speak of any language as an art in the sense of its having been
elaborately and methodically formed. Philologists now admit that
conjugations, declensions, &c., originally existed as distinct words, since
joined together; and as such words express the most obvious relations
between objects and persons, it is not surprising that they should have been
used by the men of most races during the earliest ages. With respect to
perfection, the following illustration will best shew how easily we may err:
a Crinoid sometimes consists of no less than 150,000 pieces of shell,90 all
arranged with perfect symmetry in radiating lines; but a naturalist does not

consider an animal of this kind as more perfect than a bilateral one with
comparatively few parts, and with none of these alike, excepting on the
opposite sides of the body. He justly considers the differentiation and
specialisation of organs as the test of perfection. So with languages, the
most symmetrical and complex ought not to be ranked above irregular,
abbreviated, and bastardised languages, which have borrowed expressive
words and useful forms of construction from various conquering, or
conquered, or immigrant races.
From these few and imperfect remarks I conclude that the extremely
complex and regular construction of many barbarous languages, is no proof
that they owe their origin to a special act of creation.91 Nor, as we have seen,
does the faculty of articulate speech in itself offer any insuperable objection
to the belief that man has been developed from some lower form.

Self-consciousness, Individuality, Abstraction, General Ideas, &c.—It
would be useless to attempt discussing these high faculties, which,
according to several recent writers, make the sole and complete distinction
between man and the brutes, for hardly two authors agree in their
definitions. Such faculties could not have been fully developed in man until
his mental powers had advanced to a high standard, and this implies the use
of a perfect language. No one supposes that one of the lower animals
reflects whence he comes or whither he goes,—what is death or what is life,
and so forth. But can we feel sure that an old dog with an excellent memory
and some power of imagination, as shewn by his dreams, never reflects on
his past pleasures in the chase? and this would be a form of self-
consciousness. On the other hand, as Büchner92 has remarked, how little can
the hard-worked wife of a degraded Australian savage, who uses hardly any
abstract words and cannot count above four, exert her self-consciousness, or
reflect on the nature of her own existence.
That animals retain their mental individuality is unquestionable. When my
voice awakened a train of old associations in the mind of the above-
mentioned dog, he must have retained his mental individuality, although
every atom of his brain had probably undergone change more than once
during the interval of five years. This dog might have brought forward the
argument lately advanced to crush all evolutionists, and said, “I abide amid

all mental moods and all material changes.... The teaching that atoms leave
their impressions as legacies to other atoms falling into the places they have
vacated is contradictory of the utterance of consciousness, and is therefore
false; but it is the teaching necessitated by evolutionism, consequently the
hypothesis is a false one.”93

Sense of Beauty.—This sense has been declared to be peculiar to man. But
when we behold male birds elaborately displaying their plumes and
splendid colours before the females, whilst other birds not thus decorated
make no such display, it is impossible to doubt that the females admire the
beauty of their male partners. As women everywhere deck themselves with
these plumes, the beauty of such ornaments cannot be disputed. The Bower-
birds by tastefully ornamenting their playing-passages with gaily-coloured
objects, as do certain humming-birds their nests, offer additional evidence
that they possess a sense of beauty. So with the song of birds, the sweet
strains poured forth by the males during the season of love are certainly
admired by the females, of which fact evidence will hereafter be given. If
female birds had been incapable of appreciating the beautiful colours, the
ornaments, and voices of their male partners, all the labour and anxiety
exhibited by them in displaying their charms before the females would have
been thrown away; and this it is impossible to admit. Why certain bright
colours and certain sounds should excite pleasure, when in harmony,
cannot, I presume, be explained any more than why certain flavours and
scents are agreeable; but assuredly the same colours and the same sounds
are admired by us and by many of the lower animals.
The taste for the beautiful, at least as far as female beauty is concerned, is
not of a special nature in the human mind; for it differs widely in the
different races of man, as will hereafter be shewn, and is not quite the same
even in the different nations of the same race. Judging from the hideous
ornaments and the equally hideous music admired by most savages, it might
be urged that their æsthetic faculty was not so highly developed as in
certain animals, for instance, in birds. Obviously no animal would be
capable of admiring such scenes as the heavens at night, a beautiful
landscape, or refined music; but such high tastes, depending as they do on
culture and complex associations, are not enjoyed by barbarians or by
uneducated persons.

Many of the faculties, which have been of inestimable service to man for
his progressive advancement, such as the powers of the imagination,
wonder, curiosity, an undefined sense of beauty, a tendency to imitation,
and the love of excitement or novelty, could not fail to have led to the most
capricious changes of customs and fashions. I have alluded to this point,
because a recent writer94 has oddly fixed on Caprice “as one of the most
remarkable and typical differences between savages and brutes.” But not
only can we perceive how it is that roan is capricious, but the lower animals
are, as we shall hereafter see, capricious in their affections, aversions, and
sense of beauty. There is also good reason to suspect that they love novelty,
for its own sake.

Belief in God—Religion.—There is no evidence that man was aboriginally
endowed with the ennobling belief in the existence of an Omnipotent God.
On the contrary there is ample evidence, derived not from hasty travellers,
but from men who have long resided with savages, that numerous races
have existed and still exist, who have no idea of one or more gods, and who
have no words in their languages to express such an idea.95 The question is
of course wholly distinct from that higher one, whether there exists a
Creator and Ruler of the universe; and this has been answered in the
affirmative by the highest intellects that have ever lived.
If, however, we include under the term “religion” the belief in unseen or
spiritual agencies, the case is wholly different; for this belief seems to be
almost universal with the less civilised races. Nor is it difficult to
comprehend how it arose. As soon as the important faculties of the
imagination, wonder, and curiosity, together with some power of reasoning,
had become partially developed, man would naturally have craved to
understand what was passing around him, and have vaguely speculated on
his own existence. As Mr. M’Lennan96 has remarked, “Some explanation of
the phenomena of life, a man must feign for himself; and to judge from the
universality of it, the simplest hypothesis, and the first to occur to men,
seems to have been that natural phenomena are ascribable to the presence in
animals, plants, and things, and in the forces of nature, of such spirits
prompting to action as men are conscious they themselves possess.” It is
probable, as Mr. Tylor has clearly shewn, that dreams may have first given
rise to the notion of spirits; for savages do not readily distinguish between

subjective and objective impressions. When a savage dreams, the figures
which appear before him are believed to have come from a distance and to
stand over him; or “the soul of the dreamer goes out on its travels, and
comes home with a remembrance of what it has seen.”97 But until the above-
named faculties of imagination, curiosity, reason, &c., had been fairly well
developed in the mind of man, his dreams would not have led him to
believe in spirits, any more than in the case of a dog.
The tendency in savages to imagine that natural objects and agencies are
animated by spiritual or living essences, is perhaps illustrated by a little fact
which I once noticed: my dog, a full-grown and very sensible animal, was
lying on the lawn during a hot and still day; but at a little distance a slight
breeze occasionally moved an open parasol, which would have been wholly
disregarded by the dog, had any one stood near it. As it was, every time that
the parasol slightly moved, the dog growled fiercely and barked. He must, I
think, have reasoned to himself in a rapid and unconscious manner, that
movement without any apparent cause indicated the presence of some
strange living agent, and no stranger had a right to be on his territory.
The belief in spiritual agencies would easily pass into the belief in the
existence of one or more gods. For savages would naturally attribute to
spirits the same passions, the same love of vengeance or simplest form of
justice, and the same affections which they themselves experienced. The
Fuegians appear to be in this respect in an intermediate condition, for when
the surgeon on board the “Beagle” shot some young ducklings as
specimens, York Minster declared in the most solemn manner, “Oh! Mr.
Bynoe, much rain, much snow, blow much;” and this was evidently a
retributive punishment for wasting human food. So again he related how,
when his brother killed a “wild man,” storms long raged, much rain and
snow fell. Yet we could never discover that the Fuegians believed in what
we should call a God, or practised any religious rites; and Jemmy Button,
with justifiable pride, stoutly maintained that there was no devil in his land.
This latter assertion is the more remarkable, as with savages the belief in
bad spirits is far more common than the belief in good spirits.
The feeling of religious devotion is a highly complex one, consisting of
love, complete submission to an exalted and mysterious superior, a strong
sense of dependence,98 fear, reverence, gratitude, hope for the future, and

perhaps other elements. No being could experience so complex an emotion
until advanced in his intellectual and moral faculties to at least a moderately
high level. Nevertheless we see some distant approach to this state of mind,
in the deep love of a dog for his master, associated with complete
submission, some fear, and perhaps other feelings. The behaviour of a dog
when returning to his master after an absence, and, as I may add, of a
monkey to his beloved keeper, is widely different from that towards their
fellows. In the latter case the transports of joy appear to be somewhat less,
and the sense of equality is shewn in every action. Professor Braubach99
goes so far as to maintain that a dog looks on his master as on a god.
The same high mental faculties which first led man to believe in unseen
spiritual agencies, then in fetishism, polytheism, and ultimately in
monotheism, would infallibly lead him, as long as his reasoning powers
remained poorly developed, to various strange superstitions and customs.
Many of these are terrible to think of—such as the sacrifice of human
beings to a blood-loving god; the trial of innocent persons by the ordeal of
poison or fire; witchcraft, &c.—yet it is well occasionally to reflect on these
superstitions, for they shew us what an infinite debt of gratitude we owe to
the improvement of our reason, to science, and our accumulated
knowledge.100 As Sir J. Lubbock has well observed, “it is not too much to
say that the horrible dread of unknown evil hangs like a thick cloud over
savage life, and embitters every pleasure.” These miserable and indirect
consequences of our highest faculties may be compared with the incidental
and occasional mistakes of the instincts of the lower animals.

CHAPTER III.

Comparison of the Mental Powers of Man and the Lower Animals—
continued.
The moral sense—Fundamental proposition—The qualities of social animals—Origin of sociability
—Struggle between opposed instincts—Man a social animal—The more enduring social
instincts conquer other less persistent instincts—The social virtues alone regarded by savages—
The self-regarding virtues acquired at a later stage of development—The importance of the
judgment of the members of the same community on conduct—Transmission of moral
tendencies—Summary.

I fully subscribe to the judgment of those writers101 who maintain that of all
the differences between man and the lower animals, the moral sense or
conscience is by far the most important. This sense, as Mackintosh102
remarks, “has a rightful supremacy over every other principle of human
action;” it is summed up in that short but imperious word ought, so full of
high significance. It is the most noble of all the attributes of man, leading
him without a moment’s hesitation to risk his life for that of a fellow-
creature; or after due deliberation, impelled simply by the deep feeling of
right or duty, to sacrifice it in some great cause. Immanuel Kant exclaims,
“Duty! Wondrous thought, that workest neither by fond insinuation, flattery,
nor by any threat, but merely by holding up thy naked law in the soul, and
so extorting for thyself always reverence, if not always obedience; before
whom all appetites are dumb, however secretly they rebel; whence thy
original?”103
This great question has been discussed by many writers104 of consummate
ability; and my sole excuse for touching on it is the impossibility of here
passing it over, and because, as far as I know, no one has approached it
exclusively from the side of natural history. The investigation possesses,
also, some independent interest, as an attempt to see how far the study of
the lower animals can throw light on one of the highest psychical faculties
of man.
The following proposition seems to me in a high degree probable—namely,
that any animal whatever, endowed with well-marked social instincts,105
would inevitably acquire a moral sense or conscience, as soon as its
intellectual powers had become as well developed, or nearly as well
developed, as in man. For, firstly, the social instincts lead an animal to take
pleasure in the society of its fellows, to feel a certain amount of sympathy
with them, and to perform various services for them. The services may be
of a definite and evidently instinctive nature; or there may be only a wish
and readiness, as with most of the higher social animals, to aid their fellows
in certain general ways. But these feelings and services are by no means
extended to all the individuals of the same species, only to those of the
same association. Secondly, as soon as the mental faculties had become
highly developed, images of all past actions and motives would be
incessantly passing through the brain of each individual; and that feeling of
dissatisfaction which invariably results, as we shall hereafter see, from any

unsatisfied instinct, would arise, as often as it was perceived that the
enduring and always present social instinct had yielded to some other
instinct, at the time stronger, but neither enduring in its nature, nor leaving
behind it a very vivid impression. It is clear that many instinctive desires,
such as that of hunger, are in their nature of short duration; and after being
satisfied are not readily or vividly recalled. Thirdly, after the power of
language had been acquired and the wishes of the members of the same
community could be distinctly expressed, the common opinion how each
member ought to act for the public good, would naturally become to a large
extent the guide to action. But the social instincts would still give the
impulse to act for the good of the community, this impulse being
strengthened, directed, and sometimes even deflected by public opinion, the
power of which rests, as we shall presently see, on instinctive sympathy.
Lastly, habit in the individual would ultimately play a very important part in
guiding the conduct of each member; for the social instincts and impulses,
like all other instincts, would be greatly strengthened by habit, as would
obedience to the wishes and judgment of the community. These several
subordinate propositions must now be discussed; and some of them at
considerable length.
It may be well first to premise that I do not wish to maintain that any
strictly social animal, if its intellectual faculties were to become as active
and as highly developed as in man, would acquire exactly the same moral
sense as ours. In the same manner as various animals have some sense of
beauty, though they admire widely different objects, so they might have a
sense of right and wrong, though led by it to follow widely different lines of
conduct. If, for instance, to take an extreme case, men were reared under
precisely the same conditions as hive-bees, there can hardly be a doubt that
our unmarried females would, like the worker-bees, think it a sacred duty to
kill their brothers, and mothers would strive to kill their fertile daughters;
and no one would think of interfering. Nevertheless the bee, or any other
social animal, would in our supposed case gain, as it appears to me, some
feeling of right and wrong, or a conscience. For each individual would have
an inward sense of possessing certain stronger or more enduring instincts,
and others less strong or enduring; so that there would often be a struggle
which impulse should be followed; and satisfaction or dissatisfaction would
be felt, as past impressions were compared during their incessant passage

through the mind. In this case an inward monitor would tell the animal that
it would have been better to have followed the one impulse rather than the
other. The one course ought to have been followed: the one would have
been right and the other wrong; but to these terms I shall have to recur.

Sociability.—Animals of many kinds are social; we find even distinct
species living together, as with some American monkeys, and with the
united flocks of rooks, jackdaws, and starlings. Man shows the same feeling
in his strong love for the dog, which the dog returns with interest. Every
one must have noticed how miserable horses, dogs, sheep, &c. are when
separated from their companions; and what affection at least the two former
kinds show on their reunion. It is curious to speculate on the feelings of a
dog, who will rest peacefully for hours in a room with his master or any of
the family, without the least notice being taken of him; but if left for a short
time by himself, barks or howls dismally. We will confine our attention to
the higher social animals, excluding insects, although these aid each other
in many important ways. The most common service which the higher
animals perform for each other, is the warning each other of danger by
means of the united senses of all. Every sportsman knows, as Dr. Jaeger
remarks,106 how difficult it is to approach animals in a herd or troop. Wild
horses and cattle do not, I believe, make any danger-signal; but the attitude
of any one who first discovers an enemy, warns the others. Rabbits stamp
loudly on the ground with their hind-feet as a signal: sheep and chamois do
the same, but with their fore-feet, uttering likewise a whistle. Many birds
and some mammals post sentinels, which in the case of seals are said107
generally to be the females. The leader of a troop of monkeys acts as the
sentinel, and utters cries expressive both of danger and of safety.108 Social
animals perform many little services for each other: horses nibble, and cows
lick each other, on any spot which itches: monkeys search for each other’s
external parasites; and Brehm states that after a troop of the Cercopithecus
griseo-viridis has rushed through a thorny brake, each monkey stretches
itself on a branch, and another monkey sitting by “conscientiously”
examines its fur and extracts every thorn or burr.
Animals also render more important services to each other: thus wolves and
some other beasts of prey hunt in packs, and aid each other in attacking
their victims. Pelicans fish in concert. The Hamadryas baboons turn over

stones to find insects, &c.; and when they come to a large one, as many as
can stand round, turn it over together and share the booty. Social animals
mutually defend each other. The males of some ruminants come to the front
when there is danger and defend the herd with their horns. I shall also in a
future chapter give cases of two young wild bulls attacking an old one in
concert, and of two stallions together trying to drive away a third stallion
from a troop of mares. Brehm encountered in Abyssinia a great troop of
baboons which were crossing a valley: some had already ascended the
opposite mountain, and some were still in the valley: the latter were
attacked by the dogs, but the old males immediately hurried down from the
rocks, and with mouths widely opened roared so fearfully, that the dogs
precipitately retreated. They were again encouraged to the attack; but by
this time all the baboons had reascended the heights, excepting a young
one, about six months old, who, loudly calling for aid, climbed on a block
of rock and was surrounded. Now one of the largest males, a true hero,
came down again from the mountain, slowly went to the young one, coaxed
him, and triumphantly led him away—the dogs being too much astonished
to make an attack. I cannot resist giving another scene which was witnessed
by this same naturalist; an eagle seized a young Cercopithecus, which, by
clinging to a branch, was not at once carried off; it cried loudly for
assistance, upon which the other members of the troop with much uproar
rushed to the rescue, surrounded the eagle, and pulled out so many feathers,
that he no longer thought of his prey, but only how to escape. This eagle, as
Brehm remarks, assuredly would never again attack a monkey in a troop.
It is certain that associated animals have a feeling of love for each other
which is not felt by adult and non-social animals. How far in most cases
they actually sympathise with each other’s pains and pleasures is more
doubtful, especially with respect to the latter. Mr. Buxton, however, who
had excellent means of observation,109 states that his macaws, which lived
free in Norfolk, took “an extravagant interest” in a pair with a nest, and
whenever the female left it, she was surrounded by a troop “screaming
horrible acclamations in her honour.” It is often difficult to judge whether
animals have any feeling for each other’s sufferings. Who can say what
cows feel, when they surround and stare intently on a dying or dead
companion? That animals sometimes are far from feeling any sympathy is
too certain; for they will expel a wounded animal from the herd, or gore or

worry it to death. This is almost the blackest fact in natural history, unless
indeed the explanation which has been suggested is true, that their instinct
or reason leads them to expel an injured companion, lest beasts of prey,
including man, should be tempted to follow the troop. In this case their
conduct is not much worse than that of the North American Indians who
leave their feeble comrades to perish on the plains, or the Feegeans, who,
when their parents get old or fall ill, bury them alive.110
Many animals, however, certainly sympathise with each other’s distress or
danger. This is the case even with birds; Capt. Stansbury111 found on a salt
lake in Utah an old and completely blind pelican, which was very fat, and
must have been long and well fed by his companions. Mr. Blyth, as he
informs me, saw Indian crows feeding two or three of their companions
which were blind; and I have heard of an analogous case with the domestic
cock. We may, if we choose, call these actions instinctive; but such cases
are much too rare for the development of any special instinct.112 I have
myself seen a dog, who never passed a great friend of his, a cat which lay
sick in a basket, without giving her a few licks with his tongue, the surest
sign of kind feeling in a dog.
It must be called sympathy that leads a courageous dog to fly at any one
who strikes his master, as he certainly will. I saw a person pretending to
beat a lady who had a very timid little dog on her lap, and the trial had
never before been made. The little creature instantly jumped away, but after
the pretended beating was over, it was really pathetic to see how
perseveringly he tried to lick his mistress’s face and comfort her. Brehm113
states that when a baboon in confinement was pursued to be punished, the
others tried to protect him. It must have been sympathy in the cases above
given which led the baboons and Cercopitheci to defend their young
comrades from the dogs and the eagle. I will give only one other instance of
sympathetic and heroic conduct in a little American monkey. Several years
ago a keeper at the Zoological Gardens, showed me some deep and scarcely
healed wounds on the nape of his neck, inflicted on him whilst kneeling on
the floor by a fierce baboon. The little American monkey, who was a warm
friend of this keeper, lived in the same large compartment, and was
dreadfully afraid of the great baboon. Nevertheless, as soon as he saw his
friend the keeper in peril, he rushed to the rescue, and by screams and bites

so distracted the baboon that the man was able to escape, after running great
risk, as the surgeon who attended him thought, of his life.
Besides love and sympathy, animals exhibit other qualities which in us
would be called moral; and I agree with Agassiz114 that dogs possess
something very like a conscience. They certainly possess some power of
self-command, and this does not appear to be wholly the result of fear. As
Braubach115 remarks, a dog will refrain from stealing food in the absence of
his master. Dogs have long been accepted as the very type of fidelity and
obedience. All animals living in a body which defend each other or attack
their enemies in concert, must be in some degree faithful to each other; and
those that follow a leader must be in some degree obedient. When the
baboons in Abyssinia116 plunder a garden, they silently follow their leader;
and if an imprudent young animal makes a noise, he receives a slap from
the others to teach him silence and obedience; but as soon as they are sure
that there is no danger, all show their joy by much clamour.
With respect to the impulse which leads certain animals to associate
together, and to aid each other in many ways, we may infer that in most
cases they are impelled by the same sense of satisfaction or pleasure which
they experience in performing other instinctive actions; or by the same
sense of dissatisfaction, as in other cases of prevented instinctive actions.
We see this in innumerable instances, and it is illustrated in a striking
manner by the acquired instincts of our domesticated animals; thus a young
shepherd-dog delights in driving and running round a flock of sheep, but
not in worrying them; a young foxhound delights in hunting a fox, whilst
some other kinds of dogs as I have witnessed, utterly disregard foxes. What
a strong feeling of inward satisfaction must impel a bird, so full of activity,
to brood day after day over her eggs. Migratory birds are miserable if
prevented from migrating, and perhaps they enjoy starting on their long
flight. Some few instincts are determined solely by painful feelings, as by
fear, which leads to self-preservation, or is specially directed against certain
enemies. No one, I presume, can analyse the sensations of pleasure or pain.
In many cases, however, it is probable that instincts are persistently
followed from the mere force of inheritance, without the stimulus of either
pleasure or pain. A young pointer, when it first scents game, apparently
cannot help pointing. A squirrel in a cage who pats the nuts which it cannot
eat, as if to bury them in the ground, can hardly be thought to act thus either

from pleasure or pain. Hence the common assumption that men must be
impelled to every action by experiencing some pleasure or pain may be
erroneous. Although a habit may be blindly and implicitly followed,
independently of any pleasure or pain felt at the moment, yet if it be
forcibly and abruptly checked, a vague sense of dissatisfaction is generally
experienced; and this is especially true in regard to persons of feeble
intellect.
It has often been assumed that animals were in the first place rendered
social, and that they feel as a consequence uncomfortable when separated
from each other, and comfortable whilst together; but it is a more probable
view that these sensations were first developed, in order that those animals
which would profit by living in society, should be induced to live together.
In the same manner as the sense of hunger and the pleasure of eating were,
no doubt, first acquired in order to induce animals to eat. The feeling of
pleasure from society is probably an extension of the parental or filial
affections; and this extension may be in chief part attributed to natural
selection, but perhaps in part to mere habit. For with those animals which
were benefited by living in close association, the individuals which took the
greatest pleasure in society would best escape various dangers; whilst those
that cared least for their comrades and lived solitary would perish in greater
numbers. With respect to the origin of the parental and filial affections,
which apparently lie at the basis of the social affections, it is hopeless to
speculate; but we may infer that they have been to a large extent gained
through natural selection. So it has almost certainly been with the unusual
and opposite feeling of hatred between the nearest relations, as with the
worker-bees which kill their brother-drones, and with the queen-bees which
kill their daughter-queens; the desire to destroy, instead of loving, their
nearest relations having been here of service to the community.
The all-important emotion of sympathy is distinct from that of love. A
mother may passionately love her sleeping and passive infant, but she can
then hardly be said to feel sympathy for it. The love of a man for his dog is
distinct from sympathy, and so is that of a dog for his master. Adam Smith
formerly argued, as has Mr. Bain recently, that the basis of sympathy lies in
our strong retentiveness of former states of pain or pleasure. Hence, “the
sight of another person enduring hunger, cold, fatigue, revives in us some
recollection of these states, which are painful even in idea.” We are thus

impelled to relieve the sufferings of another, in order that our own painful
feelings may be at the same time relieved. In like manner we are led to
participate in the pleasures of others.117 But I cannot see how this view
explains the fact that sympathy is excited in an immeasurably stronger
degree by a beloved than by an indifferent person. The mere sight of
suffering, independently of love, would suffice to call up in us vivid
recollections and associations. Sympathy may at first have originated in the
manner above suggested; but it seems now to have become an instinct,
which is especially directed towards beloved objects, in the same manner as
fear with animals is especially directed against certain enemies. As
sympathy is thus directed, the mutual love of the members of the same
community will extend its limits. No doubt a tiger or lion feels sympathy
for the sufferings of its own young, but not for any other animal. With
strictly social animals the feeling will be more or less extended to all the
associated members, as we know to be the case. With mankind selfishness,
experience, and imitation probably add, as Mr. Bain has shewn, to the
power of sympathy; for we are led by the hope of receiving good in return
to perform acts of sympathetic kindness to others; and there can be no doubt
that the feeling of sympathy is much strengthened by habit. In however
complex a manner this feeling may have originated, as it is one of high
importance to all those animals which aid and defend each other, it will
have been increased, through natural selection; for those communities,
which included the greatest number of the most sympathetic members,
would flourish best and rear the greatest number of offspring.
In many cases it is impossible to decide whether certain social instincts
have been acquired through natural selection, or are the indirect result of
other instincts and faculties, such as sympathy, reason, experience, and a
tendency to imitation; or again, whether they are simply the result of long-
continued habit. So remarkable an instinct as the placing sentinels to warn
the community of danger, can hardly have been the indirect result of any
other faculty; it must therefore have been directly acquired. On the other
hand, the habit followed by the males of some social animals, of defending
the community and of attacking their enemies or their prey in concert, may
perhaps have originated from mutual sympathy; but courage, and in most
cases strength, must have been previously acquired, probably through
natural selection.

Of the various instincts and habits, some are much stronger than others, that
is, some either give more pleasure in their performance and more distress in
their prevention than others; or, which is probably quite as important, they
are more persistently followed through inheritance without exciting any
special feeling of pleasure or pain. We are ourselves conscious that some
habits are much more difficult to cure or change than others. Hence a
struggle may often be observed in animals between different instincts, or
between an instinct and some habitual disposition; as when a dog rushes
after a hare, is rebuked, pauses, hesitates, pursues again or returns ashamed
to his master; or as between the love of a female dog for her young puppies
and for her master, for she may be seen to slink away to them, as if half
ashamed of not accompanying her master. But the most curious instance
known to me of one instinct conquering another, is the migratory instinct
conquering the maternal instinct. The former is wonderfully strong; a
confined bird will at the proper season beat her breast against the wires of
her cage, until it is bare and bloody. It causes young salmon to leap out of
the fresh water, where they could still continue to live, and thus
unintentionally to commit suicide. Every one knows how strong the
maternal instinct is, leading even timid birds to face great danger, though
with hesitation and in opposition to the instinct of selfpreservation.
Nevertheless the migratory instinct is so powerful that late in the autumn
swallows and house-martins frequently desert their tender young, leaving
them to perish miserably in their nests.118
We can perceive that an instinctive impulse, if it be in any way more
beneficial to a species than some other or opposed instinct, would be
rendered the more potent of the two through natural selection; for the
individuals which had it most strongly developed would survive in larger
numbers. Whether this is the case with the migratory in comparison with
the maternal instinct, may well be doubted. The great persistence or steady
action of the former at certain seasons of the year during the whole day,
may give it for a time paramount force.

Man a social animal.—Most persons admit that man is a social being. We
see this in his dislike of solitude, and in his wish for society beyond that of
his own family. Solitary confinement is one of the severest punishments
which can be inflicted. Some authors suppose that man primevally lived in

single families; but at the present day, though single families, or only two or
three together, roam the solitudes of some savage lands, they are always, as
far as I can discover, friendly with other families inhabiting the same
district. Such families occasionally meet in council, and they unite for their
common defence. It is no argument against savage man being a social
animal, that the tribes inhabiting adjacent districts are almost always at war
with each other; for the social instincts never extend to all the individuals of
the same species. Judging from the analogy of the greater number of the
Quadrumana, it is probable that the early ape-like progenitors of man were
likewise social; but this is not of much importance for us. Although man, as
he now exists, has few special instincts, having lost any which his early
progenitors may have possessed, this is no reason why he should not have
retained from an extremely remote period some degree of instinctive love
and sympathy for his fellows. We are indeed all conscious that we do
possess such sympathetic feelings;119 but our consciousness does not tell us
whether they are instinctive, having originated long ago in the same manner
as with the lower animals, or whether they have been acquired by each of us
during our early years. As man is a social animal, it is also probable that he
would inherit a tendency to be faithful to his comrades, for this quality is
common to most social animals. He would in like manner possess some
capacity for self-command, and perhaps of obedience to the leader of the
community. He would from an inherited tendency still be willing to defend,
in concert with others, his fellow-men, and would be ready to aid them in
any way which did not too greatly interfere with his own welfare or his own
strong desires.
The social animals which stand at the bottom of the scale are guided almost
exclusively, and those which stand higher in the scale are largely guided, in
the aid which they give to the members of the same community, by special
instincts; but they are likewise in part impelled by mutual love and
sympathy, assisted apparently by some amount of reason. Although man, as
just remarked, has no special instincts to tell him how to aid his fellow-men,
he still has the impulse, and with his improved intellectual faculties would
naturally be much guided in this respect by reason and experience.
Instinctive sympathy would, also, cause him to value highly the approbation
of his fellow-men; for, as Mr. Bain has clearly shewn,120 the love of praise
and the strong feeling of glory, and the still stronger horror of scorn and

infamy, “are due to the workings of sympathy.” Consequently man would
be greatly influenced by the wishes, approbation, and blame of his fellow-
men, as expressed by their gestures and language. Thus the social instincts,
which must have been acquired by man in a very rude state, and probably
even by his early ape-like progenitors, still give the impulse to many of his
best actions; but his actions are largely determined by the expressed wishes
and judgment of his fellow-men, and unfortunately still oftener by his own
strong, selfish desires. But as the feelings of love and sympathy and the
power of self-command become strengthened by habit, and as the power of
reasoning becomes clearer so that man can appreciate the justice of the
judgments of his fellow-men, he will feel himself impelled, independently
of any pleasure or pain felt at the moment, to certain lines of conduct. He
may then say, I am the supreme judge of my own conduct, and in the words
of Kant, I will not in my own person violate the dignity of humanity.

The more enduring Social Instincts conquer the less Persistent Instincts.—
We have, however, not as yet considered the main point, on which the
whole question of the moral sense hinges. Why should a man feel that he
ought to obey one instinctive desire rather than another? Why does he
bitterly regret if he has yielded to the strong sense of self-preservation, and
has not risked his life to save that of a fellow-creature; or why does he
regret having stolen food from severe hunger?
It is evident in the first place, that with mankind the instinctive impulses
have different degrees of strength; a young and timid mother urged by the
maternal instinct will, without a moment’s hesitation, run the greatest
danger for her infant, but not for a mere fellow-creature. Many a man, or
even boy, who never before risked his life for another, but in whom courage
and sympathy were well developed, has, disregarding the instinct of self-
preservation, instantaneously plunged into a torrent to save a drowning
fellow-creature. In this case man is impelled by the same instinctive motive,
which caused the heroic little American monkey, formerly described, to
attack the great and dreaded baboon, to save his keeper. Such actions as the
above appear to be the simple result of the greater strength of the social or
maternal instincts than of any other instinct or motive; for they are
performed too instantaneously for reflection, or for the sensation of pleasure
or pain; though if prevented distress would be caused.

I am aware that some persons maintain that actions performed impulsively,
as in the above cases, do not come under the dominion of the moral sense,
and cannot be called moral. They confine this term to actions done
deliberately, after a victory over opposing desires, or to actions prompted by
some lofty motive. But it appears scarcely possible to draw any clear line of
distinction of this kind; though the distinction may be real. As far as exalted
motives are concerned, many instances have been recorded of barbarians,
destitute of any feeling of general benevolence towards mankind, and not
guided by any religious motive, who have deliberately as prisoners
sacrificed their lives,121 rather than betray their comrades; and surely their
conduct ought to be considered as moral. As far as deliberation and the
victory over opposing motives are concerned, animals may be seen
doubting between opposed instincts, as in rescuing their offspring or
comrades from danger; yet their actions, though done for the good of
others, are not called moral. Moreover, an action repeatedly performed by
us, will at last be done without deliberation or hesitation, and can then
hardly be distinguished from an instinct; yet surely no one will pretend that
an action thus done ceases to be moral. On the contrary, we all feel that an
act cannot be considered as perfect, or as performed in the most noble
manner, unless it be done impulsively, without deliberation or effort, in the
same manner as by a man in whom the requisite qualities are innate. He
who is forced to overcome his fear or want of sympathy before he acts,
deserves, however, in one way higher credit than the man whose innate
disposition leads him to a good act without effort. As we cannot distinguish
between motives, we rank all actions of a certain class as moral, when they
are performed by a moral being. A moral being is one who is capable of
comparing his past and future actions or motives, and of approving or
disapproving of them. We have no reason to suppose that any of the lower
animals have this capacity; therefore when a monkey faces danger to rescue
its comrade, or takes charge of an orphan-monkey, we do not call its
conduct moral. But in the case of man, who alone can with certainty be
ranked as a moral being, actions of a certain class are called moral, whether
performed deliberately after a struggle with opposing motives, or from the
effects of slowly-gained habit, or impulsively through instinct.
But to return to our more immediate subject; although some instincts are
more powerful than others, thus leading to corresponding actions, yet it

cannot be maintained that the social instincts are ordinarily stronger in man,
or have become stronger through long-continued habit, than the instincts,
for instance, of self-preservation, hunger, lust, vengeance, &c. Why then
does man regret, even though he may endeavour to banish any such regret,
that he has followed the one natural impulse, rather than the other; and why
does he further feel that he ought to regret his conduct? Man in this respect
differs profoundly from the lower animals. Nevertheless we can, I think, see
with some degree of clearness the reason of this difference.
Man, from the activity of his mental faculties, cannot avoid reflection: past
impressions and images are incessantly passing through his mind with
distinctness. Now with those animals which live permanently in a body, the
social instincts are ever present and persistent. Such animals are always
ready to utter the danger-signal, to defend the community, and to give aid to
their fellows in accordance with their habits; they feel at all times, without
the stimulus of any special passion or desire, some degree of love and
sympathy for them; they are unhappy if long separated from them, and
always happy to be in their company. So it is with ourselves. A man who
possessed no trace of such feelings would be an unnatural monster. On the
other hand, the desire to satisfy hunger, or any passion, such as vengeance,
is in its nature temporary, and can for a time be fully satisfied. Nor is it
easy, perhaps hardly possible, to call up with complete vividness the
feeling, for instance, of hunger; nor indeed, as has often been remarked, of
any suffering. The instinct of self-preservation is not felt except in the
presence of danger; and many a coward has thought himself brave until he
has met his enemy face to face. The wish for another man’s property is
perhaps as persistent a desire as any that can be named; but even in this case
the satisfaction of actual possession is generally a weaker feeling than the
desire: many a thief, if not an habitual one, after success has wondered why
he stole some article.
Thus, as man cannot prevent old impressions continually repassing through
his mind, he will be compelled to compare the weaker impressions of, for
instance, past hunger, or of vengeance satisfied or danger avoided at the
cost of other men, with the instinct of sympathy and good-will to his
fellows, which is still present and ever in some degree active in his mind.
He will then feel in his imagination that a stronger instinct has yielded to
one which now seems comparatively weak; and then that sense of

dissatisfaction will inevitably be felt with which man is endowed, like every
other animal, in order that his instincts may be obeyed. The case before
given, of the swallow, affords an illustration, though of a reversed nature, of
a temporary though for the time strongly persistent instinct conquering
another instinct which is usually dominant over all others. At the proper
season these birds seem all day long to be impressed with the desire to
migrate; their habits change; they become restless, are noisy, and
congregate in flocks. Whilst the mother-bird is feeding or brooding over her
nestlings, the maternal instinct is probably stronger than the migratory; but
the instinct which is more persistent gains the victory, and at last, at a
moment when her young ones are not in sight, she takes flight and deserts
them. When arrived at the end of her long journey, and the migratory
instinct ceases to act, what an agony of remorse each bird would feel, if,
from being endowed with great mental activity, she could not prevent the
image continually passing before her mind of her young ones perishing in
the bleak north from cold and hunger.
At the moment of action, man will no doubt be apt to follow the stronger
impulse; and though this may occasionally prompt him to the noblest deeds,
it will far more commonly lead him to gratify his own desires at the
expense of other men. But after their gratification, when past and weaker
impressions are contrasted with the ever-enduring social instincts,
retribution will surely come. Man will then feel dissatisfied with himself,
and will resolve with more or less force to act differently for the future.
This is conscience; for conscience looks backwards and judges past actions,
inducing that kind of dissatisfaction, which if weak we call regret, and if
severe remorse.
These sensations are, no doubt, different from those experienced when other
instincts or desires are left unsatisfied; but every unsatisfied instinct has its
own proper prompting sensation, as we recognise with hunger, thirst, &c.
Man thus prompted, will through long habit acquire such perfect self-
command, that his desires and passions will at last instantly yield to his
social sympathies, and there will no longer be a struggle between them. The
still hungry, or the still revengeful man will not think of stealing food, or of
wreaking his vengeance. It is possible, or, as we shall hereafter see, even
probable, that the habit of self-command may, like other habits, be
inherited. Thus at last man comes to feel, through acquired and perhaps

inherited habit, that it is best for him to obey his more persistent instincts.
The imperious word ought seems merely to imply the consciousness of the
existence of a persistent instinct, either innate or partly acquired, serving
him as a guide, though liable to be disobeyed. We hardly use the word
ought in a metaphorical sense, when we say hounds ought to hunt, pointers
to point, and retrievers to retrieve their game. If they fail thus to act, they
fail in their duty and act wrongly.
If any desire or instinct, leading to an action opposed to the good of others,
still appears to a man, when recalled to mind, as strong as, or stronger than,
his social instinct, he will feel no keen regret at having followed it; but he
will be conscious that if his conduct were known to his fellows, it would
meet with their disapprobation; and few are so destitute of sympathy as not
to feel discomfort when this is realised. If he has no such sympathy, and if
his desires leading to bad actions are at the time strong, and when recalled
are not overmastered by the persistent social instincts, then he is essentially
a bad man;122 and the sole restraining motive left is the fear of punishment,
and the conviction that in the long run it would be best for his own selfish
interests to regard the good of others rather than his own.
It is obvious that every one may with an easy conscience gratify his own
desires, if they do not interfere with his social instincts, that is with the
good of others; but in order to be quite free from self-reproach, or at least of
anxiety, it is almost necessary for him to avoid the disapprobation, whether
reasonable or not, of his fellow men. Nor must he break through the fixed
habits of his life, especially if these are supported by reason; for if he does,
he will assuredly feel dissatisfaction. He must likewise avoid the
reprobation of the one God or gods, in whom according to his knowledge or
superstition he may believe; but in this case the additional fear of divine
punishment often supervenes.

The strictly Social Virtues at first alone regarded.—The above view of the
first origin and nature of the moral sense, which tells us what we ought to
do, and of the conscience which reproves us if we disobey it, accords well
with what we see of the early and undeveloped condition of this faculty in
mankind. The virtues which must be practised, at least generally, by rude
men, so that they may associate in a body, are those which are still

recognised as the most important. But they are practised almost exclusively
in relation to the men of the same tribe; and their opposites are not regarded
as crimes in relation to the men of other tribes. No tribe could hold together
if murder, robbery, treachery, &c., were common; consequently such crimes
within the limits of the same tribe “are branded with everlasting infamy;”123
but excite no such sentiment beyond these limits. A North-American Indian
is well pleased with himself, and is honoured by others, when he scalps a
man of another tribe; and a Dyak cuts off the head of an unoffending person
and dries it as a trophy. The murder of infants has prevailed on the largest
scale throughout the world,124 and has met with no reproach; but infanticide,
especially of females, has been thought to be good for the tribe, or at least
not injurious. Suicide during former times was not generally considered as a
crime,125 but rather from the courage displayed as an honourable act; and it
is still largely practised by some semi-civilised nations without reproach,
for the loss to a nation of a single individual is not felt: whatever the
explanation may be, suicide, as I hear from Sir J. Lubbock, is rarely
practised by the lowest barbarians. It has been recorded that an Indian Thug
conscientiously regretted that he had not strangled and robbed as many
travellers as did his father before him. In a rude state of civilisation the
robbery of strangers is, indeed, generally considered as honourable.
The great sin of Slavery has been almost universal, and slaves have often
been treated in an infamous manner. As barbarians do not regard the
opinion of their women, wives are commonly treated like slaves. Most
savages are utterly indifferent to the sufferings of strangers, or even delight
in witnessing them. It is well known that the women and children of the
North-American Indians aided in torturing their enemies. Some savages
take a horrid pleasure in cruelty to animals,126 and humanity with them is an
unknown virtue. Nevertheless, feelings of sympathy and kindness are
common, especially during sickness, between the members of the same
tribe, and are sometimes extended beyond the limits of the tribe. Mungo
Park’s touching account of the kindness of the negro women of the interior
to him is well known. Many instances could be given of the noble fidelity
of savages towards each other, but not to strangers; common experience
justifies the maxim of the Spaniard, “Never, never trust an Indian.” There
cannot be fidelity without truth; and this fundamental virtue is not rare
between the members of the same tribe: thus Mungo Park heard the negro

women teaching their young children to love the truth. This, again, is one of
the virtues which becomes so deeply rooted in the mind that it is sometimes
practised by savages even at a high cost, towards strangers; but to lie to
your enemy has rarely been thought a sin, as the history of modern
diplomacy too plainly shews. As soon as a tribe has a recognised leader,
disobedience becomes a crime, and even abject submission is looked at as a
sacred virtue.
As during rude times no man can be useful or faithful to his tribe without
courage, this quality has universally been placed in the highest rank; and
although, in civilised countries, a good, yet timid, man may be far more
useful to the community than a brave one, we cannot help instinctively
honouring the latter above a coward, however benevolent. Prudence, on the
other hand, which does not concern the welfare of others, though a very
useful virtue, has never been highly esteemed. As no man can practise the
virtues necessary for the welfare of his tribe without self-sacrifice, self-
command, and the power of endurance, these qualities have been at all
times highly and most justly valued. The American savage voluntarily
submits without a groan to the most horrid tortures to prove and strengthen
his fortitude and courage; and we cannot help admiring him, or even an
Indian Fakir, who, from a foolish religious motive, swings suspended by a
hook buried in his flesh.
The other self-regarding virtues, which do not obviously, though they may
really, affect the welfare of the tribe, have never been esteemed by savages,
though now highly appreciated by civilised nations. The greatest
intemperance with savages is no reproach. Their utter licentiousness, not to
mention unnatural crimes, is something astounding.127 As soon, however, as
marriage, whether polygamous or monogamous, becomes common,
jealousy will lead to the inculcation of female virtue; and this being
honoured will tend to spread to the unmarried females. How slowly it
spreads to the male sex we see at the present day. Chastity eminently
requires self-command; therefore it has been honoured from a very early
period in the moral history of civilised man. As a consequence of this, the
senseless practice of celibacy has been ranked from a remote period as a
virtue.128 The hatred of indecency, which appears to us so natural as to be
thought innate, and which is so valuable an aid to chastity, is a modern
virtue, appertaining exclusively, as Sir G. Staunton remarks,129 to civilised

life. This is shewn by the ancient religious rites of various nations, by the
drawings on the walls of Pompeii, and by the practices of many savages.
We have now seen that actions are regarded by savages, and were probably
so regarded by primeval man, as good or bad, solely as they affect in an
obvious manner the welfare of the tribe,—not that of the species, nor that of
man as an individual member of the tribe. This conclusion agrees well with
the belief that the so-called moral sense is aboriginally derived from the
social instincts, for both relate at first exclusively to the community. The
chief causes of the low morality of savages, as judged by our standard, are,
firstly, the confinement of sympathy to the same tribe. Secondly,
insufficient powers of reasoning, so that the bearing of many virtues,
especially of the self-regarding virtues, on the general welfare of the tribe is
not recognised. Savages, for instance, fail to trace the multiplied evils
consequent on a want of temperance, chastity, &c. And, thirdly, weak power
of self-command; for this power has not been strengthened through long-
continued, perhaps inherited, habit, instruction and religion.
I have entered into the above details on the immorality of savages,130
because some authors have recently taken a high view of their moral nature,
or have attributed most of their crimes to mistaken benevolence.131 These
authors appear to rest their conclusion on savages possessing, as they
undoubtedly do possess, and often in a high degree, those virtues which are
serviceable, or even necessary, for the existence of a tribal community.

Concluding Remarks.—Philosophers of the derivative132 school of morals
formerly assumed that the foundation of morality lay in a form of
Selfishness; but more recently in the “Greatest Happiness principle.”
According to the view given above, the moral sense is fundamentally
identical with the social instincts; and in the case of the lower animals it
would be absurd to speak of these instincts as having been developed from
selfishness, or for the happiness of the community. They have, however,
certainly been developed for the general good of the community. The term,
general good, may be defined as the means by which the greatest possible
number of individuals can be reared in full vigour and health, with all their
faculties perfect, under the conditions to which they are exposed. As the
social instincts both of man and the lower animals have no doubt been

developed by the same steps, it would be advisable, if found practicable, to
use the same definition in both cases, and to take as the test of morality, the
general good or welfare of the community, rather than the general
happiness; but this definition would perhaps require some limitation on
account of political ethics.
When a man risks his life to save that of a fellow-creature, it seems more
appropriate to say that he acts for the general good or welfare, rather than
for the general happiness of mankind. No doubt the welfare and the
happiness of the individual usually coincide; and a contented, happy tribe
will flourish better than one that is discontented and unhappy. We have seen
that at an early period in the history of man, the expressed wishes of the
community will have naturally influenced to a large extent the conduct of
each member; and as all wish for happiness, the “greatest happiness
principle” will have become a most important secondary guide and object;
the social instincts, including sympathy, always serving as the primary
impulse and guide. Thus the reproach of laying the foundation of the most
noble part of our nature in the base principle of selfishness is removed;
unless indeed the satisfaction which every animal feels when it follows its
proper instincts, and the dissatisfaction felt when prevented, be called
selfish.
The expression of the wishes and judgment of the members of the same
community, at first by oral and afterwards by written language, serves, as
just remarked, as a most important secondary guide of conduct, in aid of the
social instincts, but sometimes in opposition to them. This latter fact is well
exemplified by the Law of Honour, that is the law of the opinion of our
equals, and not of all our countrymen. The breach of this law, even when
the breach is known to be strictly accordant with true morality, has caused
many a man more agony than a real crime. We recognise the same influence
in the burning sense of shame which most of us have felt even after the
interval of years, when calling to mind some accidental breach of a trifling
though fixed rule of etiquette. The judgment of the community will
generally be guided by some rude experience of what is best in the long run
for all the members; but this judgment will not rarely err from ignorance
and from weak powers of reasoning. Hence the strangest customs and
superstitions, in complete opposition to the true welfare and happiness of
mankind, have become all-powerful throughout the world. We see this in

the horror felt by a Hindoo who breaks his caste, in the shame of a
Mahometan woman who exposes her face, and in innumerable other
instances. It would be difficult to distinguish between the remorse felt by a
Hindoo who has eaten unclean food, from that felt after committing a theft;
but the former would probably be the more severe.
How so many absurd rules of conduct, as well as so many absurd religious
beliefs, have originated we do not know; nor how it is that they have
become, in all quarters of the world, so deeply impressed on the mind of
men; but it is worthy of remark that a belief constantly inculcated during the
early years of life, whilst the brain is impressible, appears to acquire almost
the nature of an instinct; and the very essence of an instinct is that it is
followed independently of reason. Neither can we say why certain
admirable virtues, such as the love of truth, are much more highly
appreciated by some savage tribes than by others;133 nor, again, why similar
differences prevail even amongst civilised nations. Knowing how firmly
fixed many strange customs and superstitions have become, we need feel no
surprise that the self-regarding virtues should now appear to us so natural,
supported as they are by reason, as to be thought innate, although they were
not valued by man in his early condition.
Notwithstanding many sources of doubt, man can generally and readily
distinguish between the higher and lower moral rules. The higher are
founded on the social instincts, and relate to the welfare of others. They are
supported by the approbation of our fellow-men and by reason. The lower
rules, though some of them when implying self-sacrifice hardly deserve to
be called lower, relate chiefly to self, and owe their origin to public opinion,
when matured by experience and cultivated; for they are not practised by
rude tribes.
As man advances in civilisation, and small tribes are united into larger
communities, the simplest reason would tell each individual that he ought to
extend his social instincts and sympathies to all the members of the same
nation, though personally unknown to him. This point being once reached,
there is only an artificial barrier to prevent his sympathies extending to the
men of all nations and races. If, indeed, such men are separated from him
by great differences in appearance or habits, experience unfortunately
shews us how long it is before we look at them as our fellow-creatures.

Sympathy beyond the confines of man, that is humanity to the lower
animals, seems to be one of the latest moral acquisitions. It is apparently
unfelt by savages, except towards their pets. How little the old Romans
knew of it is shewn by their abhorrent gladiatorial exhibitions. The very
idea of humanity, as far as I could observe, was new to most of the Gauchos
of the Pampas. This virtue, one of the noblest with which man is endowed,
seems to arise incidentally from our sympathies becoming more tender and
more widely diffused, until they are extended to all sentient beings. As soon
as this virtue is honoured and practised by some few men, it spreads
through instruction and example to the young, and eventually through
public opinion.
The highest stage in moral culture at which we can arrive, is when we
recognise that we ought to control our thoughts, and “not even in inmost
thought to think again the sins that made the past so pleasant to us.”134
Whatever makes any bad action familiar to the mind, renders its
performance by so much the easier. As Marcus Aurelius long ago said,
“Such as are thy habitual thoughts, such also will be the character of thy
mind; for the soul is dyed by the thoughts.”135
Our great philosopher, Herbert Spencer, has recently explained his views on
the moral sense. He says,136 “I believe that the experiences of utility
organised and consolidated through all past generations of the human race,
have been producing corresponding modifications, which, by continued
transmission and accumulation, have become in us certain faculties of
moral intuition—certain emotions responding to right and wrong conduct,
which have no apparent basis in the individual experiences of utility.” There
is not the least inherent improbability, as it seems to me, in virtuous
tendencies being more or less strongly inherited; for, not to mention the
various dispositions and habits transmitted by many of our domestic
animals, I have heard of cases in which a desire to steal and a tendency to
lie appeared to run in families of the upper ranks; and as stealing is so rare a
crime in the wealthy classes, we can hardly account by accidental
coincidence for the tendency occurring in two or three members of the same
family. If bad tendencies are transmitted, it is probable that good ones are
likewise transmitted. Excepting through the principle of the transmission of
moral tendencies, we cannot understand the differences believed to exist in

this respect between the various races of mankind. We have, however, as
yet, hardly sufficient evidence on this head.
Even the partial transmission of virtuous tendencies would be an immense
assistance to the primary impulse derived directly from the social instincts,
and indirectly from the approbation of our fellow-men. Admitting for the
moment that virtuous tendencies are inherited, it appears probable, at least
in such cases as chastity, temperance, humanity to animals, &c., that they
become first impressed on the mental organisation through habit,
instruction, and example, continued during several generations in the same
family, and in a quite subordinate degree, or not at all, by the individuals
possessing such virtues, having succeeded best in the struggle for life. My
chief source of doubt with respect to any such inheritance, is that senseless
customs, superstitions, and tastes, such as the horror of a Hindoo for
unclean food, ought on the same principle to be transmitted. Although this
in itself is perhaps not less probable than that animals should acquire
inherited tastes for certain kinds of food or fear of certain foes, I have not
met with any evidence in support of the transmission of superstitious
customs or senseless habits.

Finally, the social instincts which no doubt were acquired by man, as by the
lower animals, for the good of the community, will from the first have given
to him some wish to aid his fellows, and some feeling of sympathy. Such
impulses will have served him at a very early period as a rude rule of right
and wrong. But as man gradually advanced in intellectual power and was
enabled to trace the more remote consequences of his actions; as he
acquired sufficient knowledge to reject baneful customs and superstitions;
as he regarded more and more not only the welfare but the happiness of his
fellow-men; as from habit, following on beneficial experience, instruction,
and example, his sympathies became more tender and widely diffused, so as
to extend to the men of all races, to the imbecile, the maimed, and other
useless members of society, and finally to the lower animals,—so would the
standard of his morality rise higher and higher. And it is admitted by
moralists of the derivative school and by some intuitionists, that the
standard of morality has risen since an early period in the history of man.137

As a struggle may sometimes be seen going on between the various
instincts of the lower animals, it is not surprising that there should be a
struggle in man between his social instincts, with their derived virtues, and
his lower, though at the moment, stronger impulses or desires. This, as Mr.
Galton138 has remarked, is all the less surprising, as man has emerged from a
state of barbarism within a comparatively recent period. After having
yielded to some temptation we feel a sense of dissatisfaction, analogous to
that felt from other unsatisfied instincts, called in this case conscience; for
we cannot prevent past images and impressions continually passing through
our minds, and these in their weakened state we compare with the ever-
present social instincts, or with habits gained in early youth and
strengthened during our whole lives, perhaps inherited, so that they are at
last rendered almost as strong as instincts. Looking to future generations,
there is no cause to fear that the social instincts will grow weaker, and we
may expect that virtuous habits will grow stronger, becoming perhaps fixed
by inheritance. In this case the struggle between our higher and lower
impulses will be less severe, and virtue will be triumphant.

Summary of the two last Chapters.—There can be no doubt that the
difference between the mind of the lowest man and that of the highest
animal is immense. An anthropomorphous ape, if he could take a
dispassionate view of his own case, would admit that though he could form
an artful plan to plunder a garden—though he could use stones for fighting
or for breaking open nuts, yet that the thought of fashioning a stone into a
tool was quite beyond his scope. Still less, as he would admit, could he
follow out a train of metaphysical reasoning, or solve a mathematical
problem, or reflect on God, or admire a grand natural scene. Some apes,
however, would probably declare that they could and did admire the beauty
of the coloured skin and fur of their partners in marriage. They would
admit, that though they could make other apes understand by cries some of
their perceptions and simpler wants, the notion of expressing definite ideas
by definite sounds had never crossed their minds. They might insist that
they were ready to aid their fellow-apes of the same troop in many ways, to
risk their lives for them, and to take charge of their orphans; but they would
be forced to acknowledge that disinterested love for all living creatures, the
most noble attribute of man, was quite beyond their comprehension.

Nevertheless the difference in mind between man and the higher animals,
great as it is, is certainly one of degree and not of kind. We have seen that
the senses and intuitions, the various emotions and faculties, such as love,
memory, attention, curiosity, imitation, reason, &c., of which man boasts,
may be found in an incipient, or even sometimes in a well-developed
condition, in the lower animals. They are also capable of some inherited
improvement, as we see in the domestic dog compared with the wolf or
jackal. If it be maintained that certain powers, such as self-consciousness,
abstraction, &c., are peculiar to man, it may well be that these are the
incidental results of other highly-advanced intellectual faculties; and these
again are mainly the result of the continued use of a highly developed
language. At what age does the new-born infant possess the power of
abstraction, or become selfconscious and reflect on its own existence? We
cannot answer; nor can we answer in regard to the ascending organic scale.
The half-art and half-instinct of language still bears the stamp of its gradual
evolution. The ennobling belief in God is not universal with man; and the
belief in active spiritual agencies naturally follows from his other mental
powers. The moral sense perhaps affords the best and highest distinction
between man and the lower animals; but I need not say anything on this
head, as I have so lately endeavoured to shew that the social instincts,—the
prime principle of man’s moral constitution139—with the aid of active
intellectual powers and the effects of habit, naturally lead to the golden rule,
“As ye would that men should do to you, do ye to them likewise;” and this
lies at the foundation of morality.
In a future chapter I shall make some few remarks on the probable steps and
means by which the several mental and moral faculties of man have been
gradually evolved. That this at least is possible ought not to be denied,
when we daily see their development in every infant; and when we may
trace a perfect gradation from the mind of an utter idiot, lower than that of
the lowest animal, to the mind of a Newton.

CHAPTER IV.

On the Manner of Development of Man from some lower Form.

Variability of body and mind in man—Inheritance—Causes of variability—Laws of variation the
same in man as in the lower animals—Direct action of the conditions of life—Effects of the
increased use and disuse of parts—Arrested development—Reversion—Correlated variation—
Rate of increase—Checks to increase—Natural selection—Man the most dominant animal in
the world—Importance of his corporeal structure—The causes which have led to his becoming
erect—Consequent changes of structure—Decrease in size of the canine teeth—Increased size
and altered shape of the skull—Nakedness—Absence of a tail—Defenceless condition of man.

We have seen in the first chapter that the homological structure of man, his
embryological development and the rudiments which he still retains, all
declare in the plainest manner that he is descended from some lower form.
The possession of exalted mental powers is no insuperable objection to this
conclusion. In order that an ape-like creature should have been transformed
into man, it is necessary that this early form, as well as many successive
links, should all have varied in mind and body. It is impossible to obtain
direct evidence on this head; but if it can be shewn that man now varies—
that his variations are induced by the same general causes, and obey the
same general laws, as in the case of the lower animals—there can be little
doubt that the preceding intermediate links varied in a like manner. The
variations at each successive stage of descent must, also, have been in some
manner accumulated and fixed.
The facts and conclusions to be given in this chapter relate almost
exclusively to the probable means by which the transformation of man has
been effected, as far as his bodily structure is concerned. The following
chapter will be devoted to the development of his intellectual and moral
faculties. But the present discussion likewise bears on the origin of the
different races or species of mankind, whichever term may be preferred.
It is manifest that man is now subject to much variability. No two
individuals of the same race are quite alike. We may compare millions of
faces, and each will be distinct. There is an equally great amount of
diversity in the proportions and dimensions of the various parts of the body;
the length of the legs being one of the most variable points.140 Although in
some quarters of the world an elongated skull, and in other quarters a short
skull prevails, yet there is great diversity of shape even within the limits of
the same race, as with the aborigines of America and South Australia,—the
latter a race “probably as pure and homogeneous in blood, customs, and
language as any in existence”—and even with the inhabitants of so confined

an area as the Sandwich Islands.141 An eminent dentist assures me that there
is nearly as much diversity in the teeth, as in the features. The chief arteries
so frequently run in abnormal courses, that it has been found useful for
surgical purposes to calculate from 12,000 corpses how often each course
prevails.142 The muscles are eminently variable: thus those of the foot were
found by Prof. Turner143 not to be strictly alike in any two out of fifty bodies;
and in some the deviations were considerable. Prof. Turner adds that the
power of performing the appropriate movements must have been modified
in accordance with the several deviations. Mr. J. Wood has recorded144 the
occurrence of 295 muscular variations in thirty-six subjects, and in another
set of the same number no less than 558 variations, reckoning both sides of
the body as one. In the last set, not one body out of the thirty-six was
“found totally wanting in departures from the standard descriptions of the
muscular system given in anatomical text-books.” A single body presented
the extraordinary number of twenty-five distinct abnormalities. The same
muscle sometimes varies in many ways: thus Prof. Macalister describes145 no
less than twenty distinct variations in the palmaris accessorius.
The famous old anatomist, Wolff,146 insists that the internal viscera are more
variable than the external parts: Nulla particula est quæ non aliter et aliter
in aliis se habeat hominibus. He has even written a treatise on the choice of
typical examples of the viscera for representation. A discussion on the beau-
ideal of the liver, lungs, kidneys, &c., as of the human face divine, sounds
strange in our ears.
The variability or diversity of the mental faculties in men of the same race,
not to mention the greater differences between the men of distinct races, is
so notorious that not a word need here be said. So it is with the lower
animals, as has been illustrated by a few examples in the last chapter. All
who have had charge of menageries admit this fact, and we see it plainly in
our dogs and other domestic animals. Brehm especially insists that each
individual monkey of those which he kept under confinement in Africa had
its own peculiar disposition and temper: he mentions one baboon
remarkable for its high intelligence; and the keepers in the Zoological
Gardens pointed out to me a monkey, belonging to the New World division,
equally remarkable for intelligence. Rengger, also, insists on the diversity in
the various mental characters of the monkeys of the same species which he

kept in Paraguay; and this diversity, as he adds, is partly innate, and partly
the result of the manner in which they have been treated or educated.147
I have elsewhere148 so fully discussed the subject of Inheritance that I need
here add hardly anything. A greater number of facts have been collected
with respect to the transmission of the most trifling, as well as of the most
important characters in man than in any of the lower animals; though the
facts are copious enough with respect to the latter. So in regard to mental
qualities, their transmission is manifest in our dogs, horses, and other
domestic animals. Besides special tastes and habits, general intelligence,
courage, bad and good temper, &c., are certainly transmitted. With man we
see similar facts in almost every family; and we now know through the
admirable labours of Mr. Galton149 that genius, which implies a wonderfully
complex combination of high faculties, tends to be inherited; and, on the
other hand, it is too certain that insanity and deteriorated mental powers
likewise run in the same families.
With respect to the causes of variability we are in all cases very ignorant;
but we can see that in man as in the lower animals, they stand in some
relation with the conditions to which each species has been exposed during
several generations. Domesticated animals vary more than those in a state
of nature; and this is apparently due to the diversified and changing nature
of their conditions. The different races of man resemble in this respect
domesticated animals, and so do the individuals of the same race when
inhabiting a very wide area, like that of America. We see the influence of
diversified conditions in the more civilised nations, the members of which
belong to different grades of rank and follow different occupations,
presenting a greater range of character than the members of barbarous
nations. But the uniformity of savages has often been exaggerated, and in
some cases can hardly be said to exist.150 It is nevertheless an error to speak
of man, even if we look only to the conditions to which he has been
subjected, as “far more domesticated”151 than any other animal. Some savage
races, such as the Australians, are not exposed to more diversified
conditions than are many species which have very wide ranges. In another
and much more important respect, man differs widely from any strictly
domesticated animal; for his breeding has not been controlled, either
through methodical or unconscious selection. No race or body of men has
been so completely subjugated by other men, that certain individuals have

been preserved and thus unconsciously selected, from being in some way
more useful to their masters. Nor have certain male and female individuals
been intentionally picked out and matched, except in the well-known case
of the Prussian grenadiers; and in this case man obeyed, as might have been
expected, the law of methodical selection; for it is asserted that many tall
men were reared in the villages inhabited by the grenadiers with their tall
wives.
If we consider all the races of man, as forming a single species, his range is
enormous; but some separate races, as the Americans and Polynesians, have
very wide ranges. It is a well-known law that widely-ranging species are
much more variable than species with restricted ranges; and the variability
of man may with more truth be compared with that of widely-ranging
species, than with that of domesticated animals.
Not only does variability appear to be induced in man and the lower
animals by the same general causes, but in both the same characters are
affected in a closely analogous manner. This has been proved in such full
detail by Godron and Quatrefages, that I need here only refer to their
works.152 Monstrosities, which graduate into slight variations, are likewise
so similar in man and the lower animals, that the same classification and the
same terms can be used for both, as may be seen in Isidore Geoffroy St.-
Hilaire’s great work.153 This is a necessary consequence of the same laws of
change prevailing throughout the animal kingdom. In my work on the
variation of domestic animals, I have attempted to arrange in a rude fashion
the laws of variation under the following heads:—The direct and definite
action of changed conditions, as shewn by all or nearly all the individuals of
the same species varying in the same manner under the same circumstances.
The effects of the long-continued use or disuse of parts. The cohesion of
homologous parts. The variability of multiple parts. Compensation of
growth; but of this law I have found no good instances in the case of man.
The effects of the mechanical pressure of one part on another; as of the
pelvis on the cranium of the infant in the womb. Arrests of development,
leading to the diminution or suppression of parts. The reappearance of long-
lost characters through reversion. And lastly, correlated variation. All these
so-called laws apply equally to man and the lower animals; and most of
them even to plants. It would be superfluous here to discuss all of them;154

but several are so important for us, that they must be treated at considerable
length.

The direct and definite action of changed conditions.—This is a most
perplexing subject. It cannot be denied that changed conditions produce
some effect, and occasionally a considerable effect, on organisms of all
kinds; and it seems at first probable that if sufficient time were allowed this
would be the invariable result. But I have failed to obtain clear evidence in
favour of this conclusion; and valid reasons may be urged on the other side,
at least as far as the innumerable structures are concerned, which are
adapted for special ends. There can, however, be no doubt that changed
conditions induce an almost indefinite amount of fluctuating variability, by
which the whole organisation is rendered in some degree plastic.
In the United States, above 1,000,000 soldiers, who served in the late war,
were measured, and the States in which they were born and reared
recorded.155 From this astonishing number of observations it is proved that
local influences of some kind act directly on stature; and we further learn
that “the State where the physical growth has in great measure taken place,
and the State of birth, which indicates the ancestry, seem to exert a marked
influence on the stature.” For instance it is established, “that residence in
the Western States, during the years of growth, tends to produce increase of
stature.” On the other hand, it is certain that with sailors, their manner of
life delays growth, as shewn “by the great difference between the statures of
soldiers and sailors at the ages of 17 and 18 years.” Mr. B. A. Gould
endeavoured to ascertain the nature of the influences which thus act on
stature; but he arrived only at negative results, namely, that they did not
relate to climate, the elevation of the land, soil, nor even “in any controlling
degree” to the abundance or need of the comforts of life. This latter
conclusion is directly opposed to that arrived at by Villermé from the
statistics of the height of the conscripts in different parts of France. When
we compare the differences in stature between the Polynesian chiefs and the
lower orders within the same islands, or between the inhabitants of the
fertile volcanic and low barren coral islands of the same ocean,156 or again
between the Fuegians on the eastern and western shores of their country,
where the means of subsistence are very different, it is scarcely possible to
avoid the conclusion that better food and greater comfort do influence

stature. But the preceding statements shew how difficult it is to arrive at any
precise result. Dr. Beddoe has lately proved that, with the inhabitants of
Britain, residence in towns and certain occupations have a deteriorating
influence on height; and he infers that the result is to a certain extent
inherited, as is likewise the case in the United States. Dr. Beddoe further
believes that wherever a “race attains its maximum of physical
development, it rises highest in energy and moral vigour.”157
Whether external conditions produce any other direct effect on man is not
known. It might have been expected that differences of climate would have
had a marked influence, as the lungs and kidneys are brought into fuller
activity under a low temperature, and the liver and skin under a high one.158
It was formerly thought that the colour of the skin and the character of the
hair were determined by light or heat; and although it can hardly be denied
that some effect is thus produced, almost all observers now agree that the
effect has been very small, even after exposure during many ages. But this
subject will be more properly discussed when we treat of the different races
of mankind. With our domestic animals there are grounds for believing that
cold and damp directly affect the growth of the hair; but I have not met with
any evidence on this head in the case of man.

Effects of the increased Use and Disuse of Parts.—It is well known that use
strengthens the muscles in the individual, and complete disuse, or the
destruction of the proper nerve, weakens them. When the eye is destroyed
the optic nerve often becomes atrophied. When an artery is tied, the lateral
channels increase not only in diameter, but in the thickness and strength of
their coats. When one kidney ceases acting from disease, the other increases
in size and does double work. Bones increase not only in thickness, but in
length, from carrying a greater weight.159 Different occupations habitually
followed lead to changed proportions in various parts of the body. Thus it
was clearly ascertained by the United States Commission160 that the legs of
the sailors employed in the late war were longer by 0.217 of an inch than
those of the soldiers, though the sailors were on an average shorter men;
whilst their arms were shorter by 1.09 of an inch, and therefore out of
proportion shorter in relation to their lesser height. This shortness of the
arms is apparently due to their greater use, and is an unexpected result; but
sailors chiefly use their arms in pulling and not in supporting weights. The

girth of the neck and the depth of the instep are greater, whilst the
circumference of the chest, waist, and hips is less in sailors than in soldiers.
Whether the several foregoing modifications would become hereditary, if
the same habits of life were followed during many generations, is not
known, but is probable. Rengger161 attributes the thin legs and thick arms of
the Payaguas Indians to successive generations having passed nearly their
whole lives in canoes, with their lower extremities motionless. Other
writers have come to a similar conclusion in other analogous cases.
According to Cranz,162 who lived for a long time with the Esquimaux, “the
natives believe that ingenuity and dexterity in seal-catching (their highest
art and virtue) is hereditary; there is really something in it, for the son of a
celebrated seal-catcher will distinguish himself though he lost his father in
childhood.” But in this case it is mental aptitude, quite as much as bodily
structure, which appears to be inherited. It is asserted that the hands of
English labourers are at birth larger than those of the gentry.163 From the
correlation which exists, at least in some cases,164 between the development
of the extremities and of the jaws, it is possible that in those classes which
do not labour much with their hands and feet, the jaws would be reduced in
size from this cause. That they are generally smaller in refined and civilised
men than in hard-working men or savages, is certain. But with savages, as
Mr. Herbert Spencer165 has remarked, the greater use of the jaws in chewing
coarse, uncooked food, would act in a direct manner on the masticatory
muscles and on the bones to which they are attached. In infants long before
birth, the skin on the soles of the feet is thicker than on any other part of the
body;166 and it can hardly be doubted that this is due to the inherited effects
of pressure during a long series of generations.
It is familiar to every one that watchmakers and engravers are liable to
become short-sighted, whilst sailors and especially savages are generally
long-sighted. Short-sight and long-sight certainly tend to be inherited.167 The
inferiority of Europeans, in comparison with savages, in eyesight and in the
other senses, is no doubt the accumulated and transmitted effect of lessened
use during many generations; for Rengger168 states that he has repeatedly
observed Europeans, who had been brought up and spent their whole lives
with the wild Indians, who nevertheless did not equal them in the sharpness
of their senses. The same naturalist observes that the cavities in the skull for
the reception of the several sense-organs are larger in the American

aborigines than in Europeans; and this no doubt indicates a corresponding
difference in the dimensions of the organs themselves. Blumenbach has also
remarked on the large size of the nasal cavities in the skulls of the American
aborigines, and connects this fact with their remarkably acute power of
smell. The Mongolians of the plains of Northern Asia, according to Pallas,
have wonderfully perfect senses; and Prichard believes that the great
breadth of their skulls across the zygomas follows from their highly-
developed sense-organs.169
The Quechua Indians inhabit the lofty plateaux of Peru, and Alcide
d’Orbigny states170 that from continually breathing a highly rarefied
atmosphere they have acquired chests and lungs of extraordinary
dimensions. The cells, also, of the lungs are larger and more numerous than
in Europeans. These observations have been doubted; but Mr. D. Forbes
carefully measured many Aymaras, an allied race, living at the height of
between ten and fifteen thousand feet; and he informs me171 that they differ
conspicuously from the men of all other races seen by him, in the
circumference and length of their bodies. In his table of measurements, the
stature of each man is taken at 1000, and the other measurements are
reduced to this standard. It is here seen that the extended arms of the
Aymaras are shorter than those of Europeans, and much shorter than those
of Negroes. The legs are likewise shorter, and they present this remarkable
peculiarity, that in every Aymara measured the femur is actually shorter
than the tibia. On an average the length of the femur to that of the tibia is as
211 to 252; whilst in two Europeans measured at the same time, the femora
to the tibiæ were as 244 to 230; and in three Negroes as 258 to 241. The
humerus is likewise shorter relatively to the fore-arm. This shortening of
that part of the limb which is nearest to the body, appears to be, as
suggested to me by Mr. Forbes, a case of compensation in relation with the
greatly increased length of the trunk. The Aymaras present some other
singular points of structure, for instance, the very small projection of the
heel.
These men are so thoroughly acclimatised to their cold and lofty abode, that
when formerly carried down by the Spaniards to the low Eastern plains, and
when now tempted down by high wages to the gold-washings, they suffer a
frightful rate of mortality. Nevertheless Mr. Forbes found a few pure
families which had survived during two generations; and he observed that

they still inherited their characteristic peculiarities. But it was manifest,
even without measurement, that these peculiarities had all decreased; and
on measurement their bodies were found not to be so much elongated as
those of the men on the high plateau; whilst their femora had become
somewhat lengthened, as had their tibiæ but in a less degree. The actual
measurements may be seen by consulting Mr. Forbes‘ memoir. From these
valuable observations, there can, I think, be no doubt that residence during
many generations at a great elevation tends, both directly and indirectly, to
induce inherited modifications in the proportions of the body.172
Although man may not have been much modified during the latter stages of
his existence through the increased or decreased use of parts, the facts now
given shew that his liability in this respect has not been lost; and we
positively know that the same law holds good with the lower animals.
Consequently we may infer, that when at a remote epoch the progenitors of
man were in a transitional state, and were changing from quadrupeds into
bipeds, natural selection would probably have been greatly aided by the
inherited effects of the increased or diminished use of the different parts of
the body.

Arrests of Development.—Arrested development differs from arrested
growth, as parts in the former state continue to grow whilst still retaining
their early condition. Various monstrosities come under this head, and some
are known to be occasionally inherited, as a cleft-palate. It will suffice for
our purpose to refer to the arrested brain-development of microcephalous
idiots, as described in Vogt’s great memoir.173 Their skulls are smaller, and
the convolutions of the brain are less complex than in normal men. The
frontal sinus, or the projection over the eyebrows, is largely developed, and
the jaws are prognathous to an “effrayant” degree; so that these idiots
somewhat resemble the lower types of mankind. Their intelligence and
most of their mental faculties are extremely feeble. They cannot acquire the
power of speech, and are wholly incapable of prolonged attention, but are
much given to imitation. They are strong and remarkably active, continually
gamboling and jumping about, and making grimaces. They often ascend
stairs on all-fours; and are curiously fond of climbing up furniture or trees.
We are thus reminded of the delight shewn by almost all boys in climbing

trees; and this again reminds us how lambs and kids, originally alpine
animals, delight to frisk on any hillock, however small.

Reversion.—Many of the cases to be here given might have been
introduced under the last heading. Whenever a structure is arrested in its
development, but still continues growing until it closely resembles a
corresponding structure in some lower and adult member of the same
group, we may in one sense consider it as a case of reversion. The lower
members in a group give us some idea how the common progenitor of the
group was probably constructed; and it is hardly credible that a part arrested
at an early phase of embryonic development should be enabled to continue
growing so as ultimately to perform its proper function, unless it had
acquired this power of continued growth during some earlier state of
existence, when the present exceptional or arrested structure was normal.
The simple brain of a microcephalous idiot, in as far as it resembles that of
an ape, may in this sense be said to offer a case of reversion. There are other
cases which come more strictly under our present heading of reversion.
Certain structures, regularly occurring in the lower members of the group to
which man belongs, occasionally make their appearance in him, though not
found in the normal human embryo; or, if present in the normal human
embryo, they become developed in an abnormal manner, though this
manner of development is proper to the lower members of the same group.
These remarks will be rendered clearer by the following illustrations.
In various mammals the uterus graduates from a double organ with two
distinct orifices and two passages, as in the marsupials, into a single organ,
showing no signs of doubleness except a slight internal fold, as in the
higher apes and man. The rodents exhibit a perfect series of gradations
between these two extreme states. In all mammals the uterus is developed
from two simple primitive tubes, the inferior portions of which form the
cornua; and it is in the words of Dr. Farre “by the coalescence of the two
cornua at their lower extremities that the body of the uterus is formed in
man; while in those animals in which no middle portion or body exists, the
cornua remain ununited. As the development of the uterus proceeds, the two
cornua become gradually shorter, until at length they are lost, or, as it were,
absorbed into the body of the uterus.” The angles of the uterus are still

produced into cornua, even so high in the scale as in the lower apes, and
their allies the lemurs.
Now in women anomalous cases are not very infrequent, in which the
mature uterus is furnished with cornua, or is partially divided into two
organs; and such cases, according to Owen, repeat “the grade of
concentrative development,” attained by certain rodents. Here perhaps we
have an instance of a simple arrest of embryonic development, with
subsequent growth and perfect functional development, for either side of
the partially double uterus is capable of performing the proper office of
gestation. In other and rarer cases, two distinct uterine cavities are formed,
each having its proper orifice and passage.174 No such stage is passed
through during the ordinary development of the embryo, and it is difficult to
believe, though perhaps not impossible, that the two simple, minute,
primitive tubes could know how (if such an expression may be used) to
grow into two distinct uteri, each with a well-constructed orifice and
passage, and each furnished with numerous muscles, nerves, glands and
vessels, if they had not formerly passed through a similar course of
development, as in the case of existing marsupials. No one will pretend that
so perfect a structure as the abnormal double uterus in woman could be the
result of mere chance. But the principle of reversion, by which long-lost
dormant structures are called back into existence, might serve as the guide
for the full development of the organ, even after the lapse of an enormous
interval of time.
Professor Canestrini,175 after discussing the foregoing and various analogous
cases, arrives at the same conclusion as that just given. He adduces, as
another instance, the malar bone, which, in some of the Quadrumana and
other mammals, normally consists of two portions. This is its condition in
the two-months-old human fœtus; and thus it sometimes remains, through
arrested development, in man when adult, more especially in the lower
prognathous races. Hence Canestrini concludes that some ancient
progenitor of man must have possessed this bone normally divided into two
portions, which subsequently became fused together. In man the frontal
bone consists of a single piece, but in the embryo and in children, and in
almost all the lower mammals, it consists of two pieces separated by a
distinct suture. This suture occasionally persists, more or less distinctly, in
man after maturity, and more frequently in ancient than in recent crania,

especially as Canestrini has observed in those exhumed from the Drift and
belonging to the brachycephalic type. Here again he comes to the same
conclusion as in the analogous case of the malar bones. In this and other
instances presently to be given, the cause of ancient races approaching the
lower animals in certain characters more frequently than do the modern
races, appears to be that the latter stand at a somewhat greater distance in
the long line of descent from their early semi-human progenitors.
Various other anomalies in man, more or less analogous with the foregoing,
have been advanced by different authors176 as cases of reversion; but these
seem not a little doubtful, for we have to descend extremely low in the
mammalian series before we find such structures normally present.177
In man the canine teeth are perfectly efficient instruments for mastication.
But their true canine character, as Owen178 remarks, “is indicated by the
conical form of the crown, which terminates in an obtuse point, is convex
outward and flat or sub-concave within, at the base of which surface there is
a feeble prominence. The conical form is best expressed in the Melanian
races, especially the Australian. The canine is more deeply implanted, and
by a stronger fang than the incisors.” Nevertheless this tooth no longer
serves man as a special weapon for tearing his enemies or prey; it may,
therefore, as far as its proper function is concerned, be considered as
rudimentary. In every large collection of human skulls some may be found,
as Häckel179 observes, with the canine teeth projecting considerably beyond
the others in the same manner, but in a less degree, as in the
anthropomorphous apes. In these cases, open spaces between the teeth in
the one jaw are left for the reception of the canines belonging to the
opposite jaw. An interspace of this kind in a Kaffir skull, figured by
Wagner, is surprisingly wide.180 Considering how few ancient skulls have
been examined in comparison with recent skulls, it is an interesting fact that
in at least three cases the canines project largely; and in the Naulette jaw
they are spoken of as enormous.181
The males alone of the anthropomorphous apes have their canines fully
developed; but in the female gorilla, and in a less degree in the female
orang, these teeth project considerably beyond the others; therefore the fact
that women sometimes have, as I have been assured, considerably
projecting canines, is no serious objection to the belief that their occasional

great development in man is a case of reversion to an ape-like progenitor.
He who rejects with scorn the belief that the shape of his own canines, and
their occasional great development in other men, are due to our early
progenitors having been provided with these formidable weapons, will
probably reveal by sneering the line of his descent. For though he no longer
intends, nor has the power, to use these teeth as weapons, he will
unconsciously retract his “snarling muscles” (thus named by Sir C. Bell)182
so as to expose them ready for action, like a dog prepared to fight.
Many muscles are occasionally developed in man, which are proper to the
Quadrumana or other mammals. Professor Vlacovich183 examined forty male
subjects, and found a muscle, called by him the ischiopubic, in nineteen of
them; in three others there was a ligament which represented this muscle;
and in the remaining eighteen no trace of it. Out of thirty female subjects
this muscle was developed on both sides in only two, but in three others the
rudimentary ligament was present. This muscle, therefore, appears to be
much more common in the male than in the female sex; and on the principle
of the descent of man from some lower form, its presence can be
understood; for it has been detected in several of the lower animals, and in
all of these it serves exclusively to aid the male in the act of reproduction.
Mr. J. Wood, in his valuable series of papers,184 has minutely described a
vast number of muscular variations in man, which resemble normal
structures in the lower animals. Looking only to the muscles which closely
resemble those regularly present in our nearest allies, the Quadrumana, they
are too numerous to be here even specified. In a single male subject, having
a strong bodily frame and well-formed skull, no less than seven muscular
variations were observed, all of which plainly represented muscles proper to
various kinds of apes. This man, for instance, had on both sides of his neck
a true and powerful “levator claviculæ,” such as is found in all kinds of
apes, and which is said to occur in about one out of sixty human subjects.185
Again, this man had “a special abductor of the metatarsal bone of the fifth
digit, such as Professor Huxley and Mr. Flower have shewn to exist
uniformly in the higher and lower apes.” The hands and arms of man are
eminently characteristic structures, but their muscles are extremely liable to
vary, so as to resemble the corresponding muscles in the lower animals.186
Such resemblances are either complete and perfect or imperfect, yet in this
latter case manifestly of a transitional nature. Certain variations are more

common in man, and others in woman, without our being able to assign any
reason. Mr. Wood, after describing numerous cases, makes the following
pregnant remark: “Notable departures from the ordinary type of the
muscular structures run in grooves or directions, which must be taken to
indicate some unknown factor, of much importance to a comprehensive
knowledge of general and scientific anatomy.”187
That this unknown factor is reversion to a former state of existence may be
admitted as in the highest degree probable. It is quite incredible that a man
should through mere accident abnormally resemble, in no less than seven of
his muscles, certain apes, if there had been no genetic connection between
them. On the other hand, if man is descended from some ape-like creature,
no valid reason can be assigned why certain muscles should not suddenly
reappear after an interval of many thousand generations, in the same
manner as with horses, asses, and mules, dark-coloured stripes suddenly
reappear on the legs and shoulders, after an interval of hundreds, or more
probably thousands, of generations.
These various cases of reversion are so closely related to those of
rudimentary organs given in the first chapter, that many of them might have
been indifferently introduced in either chapter. Thus a human uterus
furnished with cornua may be said to represent in a rudimentary condition
the same organ in its normal state in certain mammals. Some parts which
are rudimental in man, as the os coccyx in both sexes and the mammæ in
the male sex, are always present; whilst others, such as the supra-condyloid
foramen, only occasionally appear, and therefore might have been
introduced under the head of reversion. These several reversionary, as well
as the strictly rudimentary, structures reveal the descent of man from some
lower form in an unmistakeable manner.

Correlated Variation.—In man, as in the lower animals, many structures are
so intimately related, that when one part varies so does another, without our
being able, in most cases, to assign any reason. We cannot say whether the
one part governs the other, or whether both are governed by some earlier
developed part. Various monstrosities, as I. Geoffroy repeatedly insists, are
thus intimately connected. Homologous structures are particularly liable to
change together, as we see on the opposite sides of the body, and in the

upper and lower extremities. Meckel long ago remarked that when the
muscles of the arm depart from their proper type, they almost always
imitate those of the leg; and so conversely with the muscles of the legs. The
organs of sight and hearing, the teeth and hair, the colour of the skin and
hair, colour and constitution, are more or less correlated.188 Professor
Schaaffhausen first drew attention to the relation apparently existing
between a muscular frame and strongly-pronounced supra-orbital ridges,
which are so characteristic of the lower races of man.
Besides the variations which can be grouped with more or less probability
under the foregoing heads, there is a large class of variations which may be
provisionally called spontaneous, for they appear, owing to our ignorance,
to arise without any exciting cause. It can, however, be shewn that such
variations, whether consisting of slight individual differences, or of
strongly-marked and abrupt deviations of structure, depend much more on
the constitution of the organism than on the nature of the conditions to
which it has been subjected.189

Rate of Increase.—Civilised populations have been known under
favourable conditions, as in the United States, to double their number in
twenty-five years; and according to a calculation by Euler, this might occur
in a little over twelve years.190 At the former rate the present population of
the United States, namely, thirty millions, would in 657 years cover the
whole terraqueous globe so thickly, that four men would have to stand on
each square yard of surface. The primary or fundamental check to the
continued increase of man is the difficulty of gaining subsistence and of
living in comfort. We may infer that this is the case from what we see, for
instance, in the United States, where subsistence is easy and there is plenty
of room. If such means were suddenly doubled in Great Britain, our number
would be quickly doubled. With civilised nations the above primary check
acts chiefly by restraining marriages. The greater death-rate of infants in the
poorest classes is also very important; as well as the greater mortality at all
ages, and from various diseases, of the inhabitants of crowded and
miserable houses. The effects of severe epidemics and wars are soon
counterbalanced, and more than counterbalanced, in nations placed under
favourable conditions. Emigration also comes in aid as a temporary check,
but not to any great extent with the extremely poor classes.

There is reason to suspect, as Malthus has remarked, that the reproductive
power is actually less in barbarous than in civilised races. We know nothing
positively on this head, for with savages no census has been taken; but from
the concurrent testimony of missionaries, and of others who have long
resided with such people, it appears that their families are usually small,
and large ones rare. This may be partly accounted for, as it is believed, by
the women suckling their infants for a prolonged period; but it is highly
probable that savages, who often suffer much hardship, and who do not
obtain so much nutritious food as civilised men, would be actually less
prolific. I have shewn in a former work,191 that all our domesticated
quadrupeds and birds, and all our cultivated plants, are more fertile than the
corresponding species in a state of nature. It is no valid objection to this
conclusion that animals suddenly supplied with an excess of food, or when
rendered very fat, and that most plants when suddenly removed from very
poor to very rich soil, are rendered more or less sterile. We might, therefore,
expect that civilised men, who in one sense are highly domesticated, would
be more prolific than wild men. It is also probable that the increased
fertility of civilised nations would become, as with our domestic animals,
an inherited character: it is at least known that with mankind a tendency to
produce twins runs in families.192
Notwithstanding that savages appear to be less prolific than civilised
people, they would no doubt rapidly increase if their numbers were not by
some means rigidly kept down. The Santali, or hill-tribes of India, have
recently afforded a good illustration of this fact; for they have increased, as
shewn by Mr. Hunter,193 at an extraordinary rate since vaccination has been
introduced, other pestilences mitigated, and war sternly repressed. This
increase, however, would not have been possible had not these rude people
spread into the adjoining districts and worked for hire. Savages almost
always marry; yet there is some prudential restraint, for they do not
commonly marry at the earliest possible age. The young men are often
required to show that they can support a wife, and they generally have first
to earn the price with which to purchase her from her parents. With savages
the difficulty of obtaining subsistence occasionally limits their number in a
much more direct manner than with civilised people, for all tribes
periodically suffer from severe famines. At such times savages are forced to
devour much bad food, and their health can hardly fail to be injured. Many

accounts have been published of their protruding stomachs and emaciated
limbs after and during famines. They are then, also, compelled to wander
much about, and their infants, as I was assured in Australia, perish in large
numbers. As famines are periodical, depending chiefly on extreme seasons,
all tribes must fluctuate in number. They cannot steadily and regularly
increase, as there is no artificial increase in the supply of food. Savages
when hardly pressed encroach on each other’s territories, and war is the
result; but they are indeed almost always at war with their neighbours. They
are liable to many accidents on land and water in their search for food; and
in some countries they must suffer much from the larger beasts of prey.
Even in India, districts have been depopulated by the ravages of tigers.
Malthus has discussed these several checks, but he does not lay stress
enough on what is probably the most important of all, namely infanticide,
especially of female infants, and the habit of procuring abortion. These
practices now prevail in many quarters of the world, and infanticide seems
formerly to have prevailed, as Mr. M’Lennan194 has shewn, on a still more
extensive scale. These practices appear to have originated in savages
recognising the difficulty, or rather the impossibility of supporting all the
infants that are born. Licentiousness may also be added to the foregoing
checks; but this does not follow from failing means of subsistence; though
there is reason to believe that in some cases (as in Japan) it has been
intentionally encouraged as a means of keeping down the population.
If we look back to an extremely remote epoch, before man had arrived at
the dignity of manhood, he would have been guided more by instinct and
less by reason than are savages at the present time. Our early semi-human
progenitors would not have practised infanticide, for the instincts of the
lower animals are never so perverted as to lead them regularly to destroy
their own offspring. There would have been no prudential restraint from
marriage, and the sexes would have freely united at an early age. Hence the
progenitors of man would have tended to increase rapidly, but checks of
some kind, either periodical or constant, must have kept down their
numbers, even more severely than with existing savages. What the precise
nature of these checks may have been, we cannot say, any more than with
most other animals. We know that horses and cattle, which are not highly
prolific animals, when first turned loose in South America, increased at an
enormous rate. The slowest breeder of all known animals, namely the

elephant, would in a few thousand years stock the whole world. The
increase of every species of monkey must be checked by some means; but
not, as Brehm remarks, by the attacks of beasts of prey. No one will assume
that the actual power of reproduction in the wild horses and cattle of
America, was at first in any sensible degree increased; or that, as each
district became fully stocked, this same power was diminished. No doubt in
this case and in all others, many checks concur, and different checks under
different circumstances; periodical dearths, depending on unfavourable
seasons, being probably the most important of all. So it will have been with
the early progenitors of man.

Natural Selection.—We have now seen that man is variable in body and
mind; and that the variations are induced, either directly or indirectly, by the
same general causes, and obey the same general laws, as with the lower
animals. Man has spread widely over the face of the earth, and must have
been exposed, during his incessant migrations,195 to the most diversified
conditions. The inhabitants of Tierra del Fuego, the Cape of Good Hope,
and Tasmania in the one hemisphere, and of the Arctic regions in the other,
must have passed through many climates and changed their habits many
times, before they reached their present homes.196 The early progenitors of
man must also have tended, like all other animals, to have increased beyond
their means of subsistence; they must therefore occasionally have been
exposed to a struggle for existence, and consequently to the rigid law of
natural selection. Beneficial variations of all kinds will thus, either
occasionally or habitually, have been preserved, and injurious ones
eliminated. I do not refer to strongly-marked deviations of structure, which
occur only at long intervals of time, but to mere individual differences. We
know, for instance, that the muscles of our hands and feet, which determine
our powers of movement, are liable, like those of the lower animals,197 to
incessant variability. If then the ape-like progenitors of man which
inhabited any district, especially one undergoing some change in its
conditions, were divided into two equal bodies, the one half which included
all the individuals best adapted by their powers of movement for gaining
subsistence or for defending themselves, would on an average survive in
greater number and procreate more offspring than the other and less well
endowed half.

Man in the rudest state in which he now exists is the most dominant animal
that has ever appeared on the earth. He has spread more widely than any
other highly organised form; and all others have yielded before him. He
manifestly owes this immense superiority to his intellectual faculties, his
social habits, which lead him to aid and defend his fellows, and to his
corporeal structure. The supreme importance of these characters has been
proved by the final arbitrament of the battle for life. Through his powers of
intellect, articulate language has been evolved; and on this his wonderful
advancement has mainly depended. He has invented and is able to use
various weapons, tools, traps, &c., with which he defends himself, kills or
catches prey, and otherwise obtains food. He has made rafts or canoes on
which to fish or cross over to neighbouring fertile islands. He has
discovered the art of making fire, by which hard and stringy roots can be
rendered digestible, and poisonous roots or herbs innocuous. This last
discovery, probably the greatest, excepting language, ever made by man,
dates from before the dawn of history. These several inventions, by which
man in the rudest state has become so preeminent, are the direct result of
the development of his powers of observation, memory, curiosity,
imagination, and reason. I cannot, therefore, understand how it is that Mr.
Wallace198 maintains, that “natural selection could only have endowed the
savage with a brain a little superior to that of an ape.”
Although the intellectual powers and social habits of man are of paramount
importance to him, we must not underrate the importance of his bodily
structure, to which subject the remainder of this chapter will be devoted.
The development of the intellectual and social or moral faculties will be
discussed in the following chapter.
Even to hammer with precision is no easy matter, as every one who has
tried to learn carpentry will admit. To throw a stone with as true an aim as
can a Fuegian in defending himself, or in killing birds, requires the most
consummate perfection in the correlated action of the muscles of the hand,
arm, and shoulder, not to mention a fine sense of touch. In throwing a stone
or spear, and in many other actions, a man must stand firmly on his feet;
and this again demands the perfect coadaptation of numerous muscles. To
chip a flint into the rudest tool, or to form a barbed spear or hook from a
bone, demands the use of a perfect hand; for, as a most capable judge, Mr.
Schoolcraft,199 remarks, the shaping fragments of stone into knives, lances,

or arrow-heads, shews “extraordinary ability and long practice.” We have
evidence of this in primeval men having practised a division of labour; each
man did not manufacture his own flint tools or rude pottery; but certain
individuals appear to have devoted themselves to such work, no doubt
receiving in exchange the produce of the chase. Archæologists are
convinced that an enormous interval of time elapsed before our ancestors
thought of grinding chipped flints into smooth tools. A man-like animal
who possessed a hand and arm sufficiently perfect to throw a stone with
precision or to form a flint into a rude tool, could, it can hardly be doubted,
with sufficient practice make almost anything, as far as mechanical skill
alone is concerned, which a civilised man can make. The structure of the
hand in this respect may be compared with that of the vocal organs, which
in the apes are used for uttering various signal-cries, or, as in one species,
musical cadences; but in man closely similar vocal organs have become
adapted through the inherited effects of use for the utterance of articulate
language.
Turning now to the nearest allies of man, and therefore to the best
representatives of our early progenitors, we find that the hands in the
Quadrumana are constructed on the same general pattern as in us, but are
far less perfectly adapted for diversified uses. Their hands do not serve so
well as the feet of a dog for locomotion; as may be seen in those monkeys
which walk on the outer margins of the palms, or on the backs of their bent
fingers, as in the chimpanzee and orang.200 Their hands, however, are
admirably adapted for climbing trees. Monkeys seize thin branches or
ropes, with the thumb on one side and the fingers and palm on the other
side, in the same manner as we do. They can thus also carry rather large
objects, such as the neck of a bottle, to their mouths. Baboons turn over
stones and scratch up roots with their hands. They seize nuts, insects, or
other small objects with the thumb in opposition to the fingers, and no
doubt they thus extract eggs and the young from the nests of birds.
American monkeys beat the wild oranges on the branches until the rind is
cracked, and then tear it off with the fingers of the two hands. Other
monkeys open mussel-shells with the two thumbs. With their fingers they
pull out thorns and burrs, and hunt for each other’s parasites. In a state of
nature they break open hard fruits with the aid of stones. They roll down
stones or throw them at their enemies; nevertheless, they perform these

various actions clumsily, and they are quite unable, as I have myself seen,
to throw a stone with precision.
It seems to me far from true that because “objects are grasped clumsily” by
monkeys, “a much less specialised organ of prehension” would have served
them201 as well as their present hands. On the contrary, I see no reason to
doubt that a more perfectly constructed hand would have been an advantage
to them, provided, and it is important to note this, that their hands had not
thus been rendered less well adapted for climbing trees. We may suspect
that a perfect hand would have been disadvantageous for climbing; as the
most arboreal monkeys in the world, namely Ateles in America and
Hylobates in Asia, either have their thumbs much reduced in size and even
rudimentary, or their fingers partially coherent, so that their hands are
converted into mere grasping-hooks.202
As soon as some ancient member in the great series of the Primates came,
owing to a change in its manner of procuring subsistence, or to a change in
the conditions of its native country, to live somewhat less on trees and more
on the ground, its manner of progression would have been modified; and in
this case it would have had to become either more strictly quadrupedal or
bipedal. Baboons frequent hilly and rocky districts, and only from necessity
climb up high trees;203 and they have acquired almost the gait of a dog. Man
alone has become a biped; and we can, I think, partly see how he has come
to assume his erect attitude, which forms one of the most conspicuous
differences between him and his nearest allies. Man could not have attained
his present dominant position in the world without the use of his hands
which are so admirably adapted to act in obedience to his will. As Sir C.
Bell204 insists “the hand supplies all instruments, and by its correspondence
with the intellect gives him universal dominion.” But the hands and arms
could hardly have become perfect enough to have manufactured weapons,
or to have hurled stones and spears with a true aim, as long as they were
habitually used for locomotion and for supporting the whole weight of the
body, or as long as they were especially well adapted, as previously
remarked, for climbing trees. Such rough treatment would also have blunted
the sense of touch, on which their delicate use largely depends. From these
causes alone it would have been an advantage to man to have become a
biped; but for many actions it is almost necessary that both arms and the
whole upper part of the body should be free; and he must for this end stand

firmly on his feet. To gain this great advantage, the feet have been rendered
flat, and the great toe peculiarly modified, though this has entailed the loss
of the power of prehension. It accords with the principle of the division of
physiological labour, which prevails throughout the animal kingdom, that as
the hands became perfected for prehension, the feet should have become
perfected for support and locomotion. With some savages, however, the foot
has not altogether lost its prehensile power, as shewn by their manner of
climbing trees and of using them in other ways.205
If it be an advantage to man to have his hands and arms free and to stand
firmly on his feet, of which there can be no doubt from his preeminent
success in the battle of life, then I can see no reason why it should not have
been advantageous to the progenitors of man to have become more and
more erect or bipedal. They would thus have been better able to have
defended themselves with stones or clubs, or to have attacked their prey, or
otherwise obtained food. The best constructed individuals would in the long
run have succeeded best, and have survived in larger numbers. If the gorilla
and a few allied forms had become extinct, it might have been argued with
great force and apparent truth, that an animal could not have been gradually
converted from a quadruped into a biped; as all the individuals in an
intermediate condition would have been miserably ill-fitted for progression.
But we know (and this is well worthy of reflection) that several kinds of
apes are now actually in this intermediate condition; and no one doubts that
they are on the whole well adapted for their conditions of life. Thus the
gorilla runs with a sidelong shambling gait, but more commonly progresses
by resting on its bent hands. The long-armed apes occasionally use their
arms like crutches, swinging their bodies forward between them, and some
kinds of Hylobates, without having been taught, can walk or run upright
with tolerable quickness; yet they move awkwardly, and much less securely
than man. We see, in short, with existing monkeys various gradations
between a form of progression strictly like that of a quadruped and that of a
biped or man.
As the progenitors of man became more and more erect, with their hands
and arms more and more modified for prehension and other purposes, with
their feet and legs at the same time modified for firm support and
progression, endless other changes of structure would have been necessary.
The pelvis would have had to be made broader, the spine peculiarly curved

and the head fixed in an altered position, and all these changes have been
attained by man. Prof. Schaaffhausen206 maintains that “the powerful
mastoid processes of the human skull are the result of his erect position;”
and these processes are absent in the orang, chimpanzee, &c., and are
smaller in the gorilla than in man. Various other structures might here have
been specified, which appear connected with man’s erect position. It is very
difficult to decide how far all these correlated modifications are the result of
natural selection, and how far of the inherited effects of the increased use of
certain parts, or of the action of one part on another. No doubt these means
of change act and react on each other: thus when certain muscles, and the
crests of bone to which they are attached, become enlarged by habitual use,
this shews that certain fictions are habitually performed and must be
serviceable. Hence the individuals which performed them best, would tend
to survive in greater numbers.
The free use of the arms and hands, partly the cause and partly the result of
man’s erect position, appears to have led in an indirect manner to other
modifications of structure. The early male progenitors of man were, as
previously stated, probably furnished with great canine teeth; but as they
gradually acquired the habit of using stones, clubs, or other weapons, for
fighting with their enemies, they would have used their jaws and teeth less
and less. In this case, the jaws, together with the teeth, would have become
reduced in size, as we may feel sure from innumerable analogous cases. In a
future chapter we shall meet with a closely-parallel case, in the reduction or
complete disappearance of the canine teeth in male ruminants, apparently in
relation with the development of their horns; and in horses, in relation with
their habit of fighting with their incisor teeth and hoofs.
In the adult male anthropomorphous apes, as Rütimeyer,207 and others have
insisted, it is precisely the effect which the jaw-muscles by their great
development have produced on the skull, that causes it to differ so greatly in
many respects from that of man, and has given to it “a truly frightful
physiognomy.” Therefore as the jaws and teeth in the progenitors of man
gradually become reduced in size, the adult skull would have presented
nearly the same characters which it offers in the young of the
anthropomorphous apes, and would thus have come to resemble more
nearly that of existing man. A great reduction of the canine teeth in the

males would almost certainly, as we shall hereafter see, have affected
through inheritance the teeth of the females.
As the various mental faculties were gradually developed, the brain would
almost certainly have become larger. No one, I presume, doubts that the
large size of the brain in man, relatively to his body, in comparison with that
of the gorilla or orang, is closely connected with his higher mental powers.
We meet with closely analogous facts with insects, in which the cerebral
ganglia are of extraordinary dimensions in ants; these ganglia in all the
Hymenoptera being many times larger than in the less intelligent orders,
such as beetles.208 On the other hand, no one supposes that the intellect of
any two animals or of any two men can be accurately gauged by the cubic
contents of their skulls. It is certain that there may be extraordinary mental
activity with an extremely small absolute mass of nervous matter: thus the
wonderfully diversified instincts, mental powers, and affections of ants are
generally known, yet their cerebral ganglia are not so large as the quarter of
a small pin’s head. Under this latter point of view, the brain of an ant is one
of the most marvellous atoms of matter in the world, perhaps more
marvellous than the brain of man.
The belief that there exists in man some close relation between the size of
the brain and the development of the intellectual faculties is supported by
the comparison of the skulls of savage and civilised races, of ancient and
modern people, and by the analogy of the whole vertebrate series. Dr. J.
Barnard Davis has proved209 by many careful measurements, that the mean
internal capacity of the skull in Europeans is 92·3 cubic inches; in
Americans 87·5; in Asiatics 87·1; and in Australians only 81·9 inches.
Professor Broca210 found that skulls from graves in Paris of the nineteenth
century, were larger than those from vaults of the twelfth century, in the
proportion of 1484 to 1426; and Prichard is persuaded that the present
inhabitants of Britain have “much more capacious brain-cases” than the
ancient inhabitants. Nevertheless it must be admitted that some skulls of
very high antiquity, such as the famous one of Neanderthal, are well
developed and capacious. With respect to the lower animals, M. E. Lartet,211
by comparing the crania of tertiary and recent mammals, belonging to the
same groups, has come to the remarkable conclusion that the brain is
generally larger and the convolutions more complex in the more recent
form. On the other hand I have shewn212 that the brains of domestic rabbits

are considerably reduced in bulk, in comparison with those of the wild
rabbit or hare; and this may be attributed to their having been closely
confined during many generations, so that they have exerted but little their
intellect, instincts, senses, and voluntary movements.
The gradually increasing weight of the brain and skull in man must have
influenced the development of the supporting spinal column, more
especially whilst he was becoming erect. As this change of position was
being brought about, the internal pressure of the brain, will, also, have
influenced the form of the skull; for many facts shew how easily the skull is
thus affected. Ethnologists believe that it is modified by the kind of cradle
in which infants sleep. Habitual spasms of the muscles and a cicatrix from a
severe burn have permanently modified the facial bones. In young persons
whose heads from disease have become fixed either sideways or backwards,
one of the eyes has changed its position, and the bones of the skull have
been modified; and this apparently results from the brain pressing in a new
direction.213 I have shewn that with long-eared rabbits, even so trifling a
cause as the lopping forward of one ear drags forward on that side almost
every bone of the skull; so that the bones on the opposite sides no longer
strictly correspond. Lastly, if any animal were to increase or diminish much
in general size, without any change in its mental powers; or if the mental
powers were to be much increased or diminished without any great change
in the size of the body; the shape of the skull would almost certainly be
altered. I infer this from my observations on domestic rabbits, some kinds
of which have become very much larger than the wild animal, whilst others
have retained nearly the same size, but in both cases the brain has been
much reduced relatively to the size of the body. Now I was at first much
surprised by finding that in all these rabbits the skull had become elongated
or dolichocephalic; for instance, of two skulls of nearly equal breadth, the
one from a wild rabbit and the other from a large domestic kind, the former
was only 3·15 and the latter 4·3 inches in length.214 One of the most marked
distinctions in different races of man is that the skull in some is elongated,
and in others rounded; and here the explanation suggested by the case of the
rabbits may partially hold good; for Welcker finds that short “men incline
more to brachycephaly, and tall men to dolichocephaly;”215 and tall men may
be compared with the larger and longer-bodied rabbits, all of which have
elongated skulls, or are dolichocephalic.

From these several facts we can to a certain extent understand the means
through which the great size and more or less rounded form of the skull has
been acquired by man; and these are characters eminently distinctive of him
in comparison with the lower animals.
Another most conspicuous difference between man and the lower animals is
the nakedness of his skin. Whales and dolphins (Cetacea), dugongs
(Sirenia) and the hippopotamus are naked; and this may be advantageous to
them for gliding through the water; nor would it be injurious to them from
the loss of warmth, as the species which inhabit the colder regions are
protected by a thick layer of blubber, serving the same purpose as the fur of
seals and otters. Elephants and rhinoceroses are almost hairless; and as
certain extinct species which formerly lived under an arctic climate were
covered with long wool or hair, it would almost appear as if the existing
species of both genera had lost their hairy covering from exposure to heat.
This appears the more probable, as the elephants in India which live on
elevated and cool districts are more hairy216 than those on the lowlands. May
we then infer that man became divested of hair from having aboriginally
inhabited some tropical land? The fact of the hair being chiefly retained in
the male sex on the chest and face, and in both sexes at the junction of all
four limbs with the trunk, favours this inference, assuming that the hair was
lost before man became erect; for the parts which now retain most hair
would then have been most protected from the heat of the sun. The crown
of the head, however, offers a curious exception, for at all times it must
have been one of the most exposed parts, yet it is thickly clothed with hair.
In this respect man agrees with the great majority of quadrupeds, which
generally have their upper and exposed surfaces more thickly clothed than
the lower surface. Nevertheless, the fact that the other members of the order
of Primates, to which man belongs, although inhabiting various hot regions,
are well clothed with hair, generally thickest on the upper surface,217 is
strongly opposed to the supposition that man became naked through the
action of the sun. I am inclined to believe, as we shall see under sexual
selection, that man, or rather primarily woman, became divested of hair for
ornamental purposes; and according to this belief it is not surprising that
man should differ so greatly in hairiness from all his lower brethren, for
characters gained through sexual selection often differ in closely-related
forms to an extraordinary degree.

According to a popular impression, the absence of a tail is eminently
distinctive of man; but as those apes which come nearest to man are
destitute of this organ, its disappearance does not especially concern us.
Nevertheless it may be well to own that no explanation, as far as I am
aware, has ever been given of the loss of the tail by certain apes and man.
Its loss, however, is not surprising, for it sometimes differs remarkably in
length in species of the same genera: thus in some species of Macacus the
tail is longer than the whole body, consisting of twenty-four vertebræ; in
others it consists of a scarcely visible stump, containing only three or four
vertebræ. In some kinds of baboons there are twenty-five, whilst in the
mandrill there are ten very small stunted caudal vertebræ, or, according to
Cuvier,218 sometimes only five. This great diversity in the structure and
length of the tail in animals belonging to the same genera, and following
nearly the same habits of life, renders it probable that the tail is not of much
importance to them; and if so, we might have expected that it would
sometimes have become more or less rudimentary, in accordance with what
we incessantly see with other structures. The tail almost always tapers
towards the end whether it be long or short; and this, I presume, results
from the atrophy, through disuse, of the terminal muscles together with their
arteries and nerves, leading to the atrophy of the terminal bones. With
respect to the os coccyx, which in man and the higher apes manifestly
consists of the few basal and tapering segments of an ordinary tail, I have
heard it asked how could these have become completely embedded within
the body; but there is no difficulty in this respect, for in many monkeys the
basal segments of the true tail are thus embedded. For instance, Mr. Murie
informs me that in the skeleton of a not full-grown Macacus inornatus, he
counted nine or ten caudal vertebræ, which altogether were only 1·8 inch in
length. Of these the three basal ones appeared to have been embedded; the
remainder forming the free part of the tail, which was only one inch in
length, and half an inch in diameter. Here, then, the three embedded caudal
vertebræ plainly correspond with the four coalesced vertebræ of the human
os coccyx.

I have now endeavoured to shew that some of the most distinctive
characters of man have in all probability been acquired, either directly, or
more commonly indirectly, through natural selection. We should bear in
mind that modifications in structure or constitution, which are of no service

to an organism in adapting it to its habits of life, to the food which it
consumes, or passively to the surrounding conditions, cannot have been
thus acquired. We must not, however, be too confident in deciding what
modifications are of service to each being: we should remember how little
we know about the use of many parts, or what changes in the blood or
tissues may serve to fit an organism for a new climate or some new kind of
food. Nor must we forget the principle of correlation, by which, as Isidore
Geoffroy has shewn in the case of man, many fit-range deviations of
structure are tied together. Independently of correlation, a change in one
part often leads through the increased or decreased use of other parts, to
other changes of a quite unexpected nature. It is also well to reflect on such
facts, as the wonderful growth of galls on plants caused by the poison of an
insect, and on the remarkable changes of colour in the plumage of parrots
when fed on certain fishes, or inoculated with the poison of toads;219 for we
can thus see that the fluids of the system, if altered for some special
purpose, might induce other strange changes. We should especially bear in
mind that modifications acquired and continually used during past ages for
some useful purpose would probably become firmly fixed and might be
long inherited.
Thus a very large yet undefined extension may safely be given to the direct
and indirect results of natural selection; but I now admit, after reading the
essay by Nägeli on plants, and the remarks by various authors with respect
to animals, more especially those recently made by Professor Broca, that in
the earlier editions of my ‘Origin of Species’ I probably attributed too much
to the action of natural selection or the survival of the fittest. I have altered
the fifth edition of the Origin so as to confine my remarks to adaptive
changes of structure. I had not formerly sufficiently considered the
existence of many structures which appear to be, as far as we can judge,
neither beneficial nor injurious; and this I believe to be one of the greatest
oversights as yet detected in my work. I may be permitted to say as some
excuse, that I had two distinct objects in view, firstly, to shew that species
had not been separately created, and secondly, that natural selection had
been the chief agent of change, though largely aided by the inherited effects
of habit, and slightly by the direct action of the surrounding conditions.
Nevertheless I was not able to annul the influence of my former belief, then
widely prevalent, that each species had been purposely created; and this led

to my tacitly assuming that every detail of structure, excepting rudiments,
was of some special, though unrecognised, service. Any one with this
assumption in his mind would naturally extend the action of natural
selection, either during past or present times, too far. Some of those who
admit the principle of evolution, but reject natural selection, seem to forget,
when criticising my book, that I had the above two objects in view; hence if
I have erred in giving to natural selection great power, which I am far from
admitting, or in having exaggerated its power, which is in itself probable, I
have at least, as I hope, done good service in aiding to overthrow the dogma
of separate creations.
That all organic beings, including man, present many modifications of
structure which are of no service to them at present, nor have been formerly,
is, as I can now see, probable. We know not what produces the numberless
slight differences between the individuals of each species, for reversion
only carries the problem a few steps backwards; but each peculiarity must
have had its own efficient cause. If these causes, whatever they may be,
were to act more uniformly and energetically during a lengthened period
(and no reason can be assigned why this should not sometimes occur), the
result would probably be not mere slight individual differences, but well-
marked, constant modifications. Modifications which are in no way
beneficial cannot have been kept uniform through natural selection, though
any which were injurious would have been thus eliminated. Uniformity of
character would, however, naturally follow from, the assumed uniformity of
the exciting causes, and likewise from the free intercrossing of many
individuals. The same organism might acquire in this manner during
successive periods successive modifications, and these would be
transmitted in a nearly uniform state as long as the exciting causes remained
the same and there was free intercrossing. With respect to the exciting
causes we can only say, as when speaking of so-called spontaneous
variations, that they relate much more closely to the constitution of the
varying organism, than to the nature of the conditions to which it has been
subjected.

Conclusion.—In this chapter we have seen that as man at the present day is
liable, like every other animal, to multiform individual differences or slight
variations, so no doubt were the early progenitors of man; the variations

being then as now induced by the same general causes, and governed by the
same general and complex laws. As all animals tend to multiply beyond
their means of subsistence, so it must have been with the progenitors of
man; and this will inevitably have led to a struggle for existence and to
natural selection. This latter process will have been greatly aided by the
inherited effects of the increased use of parts; these two processes
incessantly reacting on each other. It appears, also, as we shall hereafter see,
that various unimportant characters have been acquired by man through
sexual selection. An unexplained residuum of change, perhaps a large one,
must be left to the assumed uniform action of those unknown agencies,
which occasionally induce strongly-marked and abrupt deviations of
structure in our domestic productions.
Judging from the habits of savages and of the greater number of the
Quadrumana, primeval men, and even the ape-like progenitors of man,
probably lived in society. With strictly social animals, natural selection
sometimes acts indirectly on the individual, through the preservation of
variations which are beneficial only to the community. A community
including a large number of well-endowed individuals increases in number
and is victorious over other and less well-endowed communities; although
each separate member may gain no advantage over the other members of
the same community. With associated insects many remarkable structures,
which are of little or no service to the individual or its own offspring, such
as the pollen-collecting apparatus, or the sting of the worker-bee, or the
great jaws of soldier-ants, have been thus acquired. With the higher social
animals, I am not aware that any structure has been modified solely for the
good of the community, though some are of secondary service to it. For
instance, the horns of ruminants and the great canine teeth of baboons
appear to have been acquired by the males as weapons for sexual strife, but
they are used in defence of the herd or troop. In regard to certain mental
faculties the case, as we shall see in the following chapter, is wholly
different; for these faculties have been chiefly, or even exclusively, gained
for the benefit of the community; the individuals composing the community
being at the same time indirectly benefited.
It has often been objected to such views as the foregoing, that man is one of
the most helpless and defenceless creatures in the world; and that during his
early and less well-developed condition he would have been still more

helpless. The Duke of Argyll, for instance, insists220 that “the human frame
has diverged from the structure of brutes, in the direction of greater physical
helplessness and weakness. That is to say, it is a divergence which of all
others it is most impossible to ascribe to mere natural selection.” He
adduces the naked and unprotected state of the body, the absence of great
teeth or claws for defence, the little strength of man, his small speed in
running, and his slight power of smell, by which to discover food or to
avoid danger. To these deficiencies there might have been added the still
more serious loss of the power of quickly climbing trees, so as to escape
from enemies. Seeing that the unclothed Fuegians can exist under their
wretched climate, the loss of hair would not have been a great injury to
primeval man, if he inhabited a warm country. When we compare
defenceless man with the apes, many of which are provided with
formidable canine teeth, we must remember that these in their fully-
developed condition are possessed by the males alone, being chiefly used
by them for fighting with their rivals; yet the females which are not thus
provided, are able to survive.
In regard to bodily size or strength, we do not know whether man is
descended from some comparatively small species, like the chimpanzee, or
from one as powerful as the gorilla; and, therefore, we cannot say whether
man has become larger and stronger, or smaller and weaker, in comparison
with his progenitors. We should, however, bear in mind that an animal
possessing great size, strength, and ferocity, and which, like the gorilla,
could defend itself from all enemies, would probably, though not
necessarily, have failed to become social; and this would most effectually
have checked the acquirement by man of his higher mental qualities, such
as sympathy and the love of his fellow-creatures. Hence it might have been
an immense advantage to man to have sprung from some comparatively
weak creature.
The slight corporeal strength of man, his little speed, his want of natural
weapons, &c., are more than counterbalanced, firstly by his intellectual
powers, through which he has, whilst still remaining in a barbarous state,
formed for himself weapons, tools, &c., and secondly by his social qualities
which lead him to give aid to his fellow-men and to receive it in return. No
country in the world abounds in a greater degree with dangerous beasts than
Southern Africa; no country presents more fearful physical hardships than

the Arctic regions; yet one of the puniest races, namely, the Bushmen,
maintain themselves in Southern Africa, as do the dwarfed Esquimaux in
the Arctic regions. The early progenitors of man were, no doubt, inferior in
intellect, and probably in social disposition, to the lowest existing savages;
but it is quite conceivable that they might have existed, or even flourished,
if, whilst they gradually lost their brute-like powers, such as climbing trees,
&c., they at the same time advanced in intellect. But granting that the
progenitors of man were far more helpless and defenceless than any
existing savages, if they had inhabited some warm continent or large island,
such as Australia or New Guinea, or Borneo (the latter island being now
tenanted by the orang), they would not have been exposed to any special
danger. In an area as large as one of these islands, the competition between
tribe and tribe would have been sufficient, under favourable conditions, to
have raised man, through the survival of the fittest, combined with the
inherited effects of habit, to his present high position in the organic scale.

CHAPTER V.

On the Development of the Intellectual and Moral Faculties during
Primeval and Civilised Times.
The advancement of the intellectual powers through natural selection—Importance of imitation—
Social and moral faculties—Their development within the limits of the same tribe—Natural
selection as affecting civilised nations—Evidence that civilised nations were once barbarous.

The subjects to be discussed in this chapter are of the highest interest, but
are treated by me in a most imperfect and fragmentary manner. Mr. Wallace,
in an admirable paper before referred to,221 argues that man after he had
partially acquired those intellectual and moral faculties which distinguish
him from the lower animals, would have been but little liable to have had
his bodily structure modified through natural selection or any other means.
For man is enabled through his mental faculties “to keep with an unchanged
body in harmony with the changing universe.” He has great power of
adapting his habits to new conditions of life. He invents weapons, tools and
various stratagems, by which he procures food and defends himself. When
he migrates into a colder climate he uses clothes, builds sheds, and makes

fires; and, by the aid of fire, cooks food otherwise indigestible. He aids his
fellow-men in many ways, and anticipates future events. Even at a remote
period he practised some subdivision of labour.
The lower animals, on the other hand, must have their bodily structure
modified in order to survive under greatly changed conditions. They must
be rendered stronger, or acquire more effective teeth or claws, in order to
defend themselves from new enemies; or they must be reduced in size so as
to escape detection and danger. When they migrate into a colder climate
they must become clothed with thicker fur, or have their constitutions
altered. If they fail to be thus modified, they will cease to exist.
The case, however, is widely different, as Mr. Wallace has with justice
insisted, in relation to the intellectual and moral faculties of man. These
faculties are variable; and we have every reason to believe that the
variations tend to be inherited. Therefore, if they were formerly of high
importance to primeval man and to his ape-like progenitors, they would
have been perfected or advanced through natural selection. Of the high
importance of the intellectual faculties there can be no doubt, for man
mainly owes to them his preeminent position in the world. We can see that,
in the rudest state of society, the individuals who were the most sagacious,
who invented and used the best weapons or traps, and who were best able to
defend themselves, would rear the greatest number of offspring. The tribes
which included the largest number of men thus endowed would increase in
number and supplant other tribes. Numbers depend primarily on the means
of subsistence, and this, partly on the physical nature of the country, but in a
much higher degree on the arts which are there practised. As a tribe
increases and is victorious, it is often still further increased by the
absorption of other tribes.222 The stature and strength of the men of a tribe
are likewise of some importance for its success, and these depend in part on
the nature and amount of the food which can be obtained. In Europe the
men of the Bronze period were supplanted by a more powerful and, judging
from their sword-handles, larger-handed race;223 but their success was
probably due in a much higher degree to their superiority in the arts.
All that we know about savages, or may infer from their traditions and from
old monuments, the history of which is quite forgotten by the present
inhabitants, shew that from the remotest times successful tribes have

supplanted other tribes. Relics of extinct or forgotten tribes have been
discovered throughout the civilised regions of the earth, on the wild plains
of America, and on the isolated islands in the Pacific Ocean. At the present
day civilised nations are everywhere supplanting barbarous nations,
excepting where the climate opposes a deadly barrier; and they succeed
mainly, though not exclusively, through their arts, which are the products of
the intellect. It is, therefore, highly probable that with mankind the
intellectual faculties have been gradually perfected through natural
selection; and this conclusion is sufficient for our purpose. Undoubtedly it
would have been very interesting to have traced the development of each
separate faculty from the state in which it exists in the lower animals to that
in which it exists in man; but neither my ability nor knowledge permit the
attempt.
It deserves notice that as soon as the progenitors of man became social (and
this probably occurred at a very early period), the advancement of the
intellectual faculties will have been aided and modified in an important
manner, of which we see only traces in the lower animals, namely, through
the principle of imitation, together with reason and experience. Apes are
much given to imitation, as are the lowest savages; and the simple fact
previously referred to, that after a time no animal can be caught in the same
place by the same sort of trap, shews that animals learn by experience, and
imitate each others’ caution. Now, if some one man in a tribe, more
sagacious than the others, invented a new snare or weapon, or other means
of attack or defence, the plainest self-interest, without the assistance of
much reasoning power, would prompt the other members to imitate him;
and all would thus profit. The habitual practice of each new art must
likewise in some slight degree strengthen the intellect. If the new invention
were an important one, the tribe would increase in number, spread, and
supplant other tribes. In a tribe thus rendered more numerous there would
always be a rather better chance of the birth of other superior and inventive
members. If such men left children to inherit their mental superiority, the
chance of the birth of still more ingenious members would be somewhat
better, and in a very small tribe decidedly better. Even if they left no
children, the tribe would still include their blood-relations; and it has been
ascertained by agriculturists224 that by preserving and breeding from the

family of an animal, which when slaughtered was found to be valuable, the
desired character has been obtained.
Turning now to the social and moral faculties. In order that primeval men,
or the ape-like progenitors of man, should have become social, they must
have acquired the same instinctive feelings which impel other animals to
live in a body; and they no doubt exhibited the same general disposition.
They would have felt uneasy when separated from their comrades, for
whom they would have felt some degree of love; they would have warned
each other of danger, and have given mutual aid in attack or defence. All
this implies some degree of sympathy, fidelity, and courage. Such social
qualities, the paramount importance of which to the lower animals is
disputed by no one, were no doubt acquired by the progenitors of man in a
similar manner, namely, through natural selection, aided by inherited habit.
When two tribes of primeval man, living in the same country, came into
competition, if the one tribe included (other circumstances being equal) a
greater number of courageous, sympathetic, and faithful members, who
were always ready to warn each other of danger, to aid and defend each
other, this tribe would without doubt succeed best and conquer the other.
Let it be borne in mind how all-important, in the never-ceasing wars of
savages, fidelity and courage must be. The advantage which disciplined
soldiers have over undisciplined hordes follows chiefly from the confidence
which each man feels in his comrades. Obedience, as Mr. Bagehot has well
shewn,225 is of the highest value, for any form of government is better than
none. Selfish and contentious people will not cohere, and without coherence
nothing can be effected. A tribe possessing the above qualities in a high
degree would spread and be victorious over other tribes; but in the course of
time it would, judging from all past history, be in its turn overcome by some
other and still more highly endowed tribe. Thus the social and moral
qualities would tend slowly to advance and be diffused throughout the
world.
But it may be asked, how within the limits of the same tribe did a large
number of members first become endowed with these social and moral
qualities, and how was the standard of excellence raised? It is extremely
doubtful whether the offspring of the more sympathetic and benevolent
parents, or of those which were the most faithful to their comrades, would
be reared in greater number than the children of selfish and treacherous

parents of the same tribe. He who was ready to sacrifice his life, as many a
savage has been, rather than betray his comrades, would often leave no
offspring to inherit his noble nature. The bravest men, who were always
willing to come to the front in war, and who freely risked their lives for
others, would on an average perish in larger number than other men.
Therefore it seems scarcely possible (bearing in mind that we are not here
speaking of one tribe being victorious over another) that the number of men
gifted with such virtues, or that the standard of their excellence, could be
increased through natural selection, that is, by the survival of the fittest.
Although the circumstances which lead to an increase in the number of men
thus endowed within the same tribe are too complex to be clearly followed
out, we can trace some of the probable steps. In the first place, as the
reasoning powers and foresight of the members became improved, each
man would soon learn from experience that if he aided his fellow-men, he
would commonly receive aid in return. From this low motive he might
acquire the habit of aiding his fellows; and the habit of performing
benevolent actions certainly strengthens the feeling of sympathy, which
gives the first impulse to benevolent actions. Habits, moreover, followed
during many generations probably tend to be inherited.
But there is another and much more powerful stimulus to the development
of the social virtues, namely, the praise and the blame of our fellow-men.
The love of approbation and the dread of infamy, as well as the bestowal of
praise or blame, are primarily due, as we have seen in the third chapter, to
the instinct of sympathy; and this instinct no doubt was originally acquired,
like all the other social instincts, through natural selection. At how early a
period the progenitors of man, in the course of their development, became
capable of feeling and being impelled by the praise or blame of their fellow-
creatures, we cannot, of course, say. But it appears that even dogs
appreciate encouragement, praise, and blame. The rudest savages feel the
sentiment of glory, as they clearly show by preserving the trophies of their
prowess, by their habit of excessive boasting, and even by the extreme care
which they take of their personal appearance and decorations; for unless
they regarded the opinion of their comrades, such habits would be
senseless.

They certainly feel shame at the breach of some of their lesser rules; but
how far they experience remorse is doubtful. I was at first surprised that I
could not recollect any recorded instances of this feeling in savages; and Sir
J. Lubbock226 states that he knows of none. But if we banish from our minds
all cases given in novels and plays and in death-bed confessions made to
priests, I doubt whether many of us have actually witnessed remorse;
though we may have often seen shame and contrition for smaller offences.
Remorse is a deeply hidden feeling. It is incredible that a savage, who will
sacrifice his life rather than betray his tribe, or one who will deliver himself
up as a prisoner rather than break his parole,227 would not feel remorse in his
inmost soul, though he might conceal it, if he had failed in a duty which he
held sacred.
We may therefore conclude that primeval man, at a very remote period,
would have been influenced by the praise and blame of his fellows. It is
obvious, that the members of the same tribe would approve of conduct
which appeared to them to be for the general good, and would reprobate
that which appeared evil. To do good unto others—to do unto others as ye
would they should do unto you,—is the foundation-stone of morality. It is,
therefore, hardly possible to exaggerate the importance during rude times of
the love of praise and the dread of blame. A man who was not impelled by
any deep, instinctive feeling, to sacrifice his life for the good of others, yet
was roused to such actions by a sense of glory, would by his example excite
the same wish for glory in other men, and would strengthen by exercise the
noble feeling of admiration. He might thus do far more good to his tribe
than by begetting offspring with a tendency to inherit his own high
character.
With increased experience and reason, man perceives the more remote
consequences of his actions, and the self-regarding virtues, such as
temperance, chastity, &c., which during early times are, as we have before
seen, utterly disregarded, come to be highly esteemed or even held sacred. I
need not, however, repeat what I have said on this head in the third chapter.
Ultimately a highly complex sentiment, having its first origin in the social
instincts, largely guided by the approbation of our fellow-men, ruled by
reason, self-interest, and in later times by deep religious feelings, confirmed
by instruction and habit, all combined, constitute our moral sense or
conscience.

It must not be forgotten that although a high standard of morality gives but
a slight or no advantage to each individual man and his children over the
other men of the same tribe, yet that an advancement in the standard of
morality and an increase in the number of well-endowed men will certainly
give an immense advantage to one tribe over another. There can be no doubt
that a tribe including many members who, from possessing in a high degree
the spirit of patriotism, fidelity, obedience, courage, and sympathy, were
always ready to give aid to each other and to sacrifice themselves for the
common good, would be victorious over most other tribes; and this would
be natural selection. At all times throughout the world tribes have
supplanted other tribes; and as morality is one element in their success, the
standard of morality and the number of well-endowed men will thus
everywhere tend to rise and increase.
It is, however, very difficult to form any judgment why one particular tribe
and not another has been successful and has risen in the scale of
civilisation. Many savages are in the same condition as when first
discovered several centuries ago. As Mr. Bagehot has remarked, we are apt
to look at progress as the normal rule in human society; but history refutes
this. The ancients did not even entertain the idea; nor do the oriental nations
at the present day. According to another high authority, Mr. Maine,228 “the
greatest part of mankind has never shewn a particle of desire that its civil
institutions should be improved.” Progress seems to depend on many
concurrent favourable conditions, far too complex to be followed out. But it
has often been remarked, that a cool climate from leading to industry and
the various arts has been highly favourable, or even indispensable for this
end. The Esquimaux, pressed by hard necessity, have succeeded in many
ingenious inventions, but their climate has been too severe for continued
progress. Nomadic habits, whether over wide plains, or through the dense
forests of the tropics, or along the shores of the sea, have in every case been
highly detrimental. Whilst observing the barbarous inhabitants of Tierra del
Fuego, it struck me that the possession of some property, a fixed abode, and
the union of many families under a chief, were the indispensable requisites
for civilisation. Such habits almost necessitate the cultivation of the ground;
and the first steps in cultivation would probably result, as I have elsewhere
shewn,229 from some such accident as the seeds of a fruit-tree falling on a
heap of refuse and producing an unusually fine variety. The problem,

however, of the first advance of savages towards civilisation is at present
much too difficult to be solved.

Natural Selection as affecting Civilised Nations.—In the last and present
chapters I have considered the advancement of man from a former semi-
human condition to his present state as a barbarian. But some remarks on
the agency of natural selection on civilised nations may be here worth
adding. This subject has been ably discussed by Mr. W. R. Greg,230 and
previously by Mr. Wallace and Mr. Galton.231 Most of my remarks are taken
from these three authors. With savages, the weak in body or mind are soon
eliminated; and those that survive commonly exhibit a vigorous state of
health. We civilised men, on the other hand, do our utmost to check the
process of elimination; we build asylums for the imbecile, the maimed, and
the sick; we institute poor-laws; and our medical men exert their utmost
skill to save the life of every one to the last moment. There is reason to
believe that vaccination has preserved thousands, who from a weak
constitution would formerly have succumbed to small-pox. Thus the weak
members of civilised societies propagate their kind. No one who has
attended to the breeding of domestic animals will doubt that this must be
highly injurious to the race of man. It is surprising how soon a want of care,
or care wrongly directed, leads to the degeneration of a domestic race; but
excepting in the case of man himself, hardly any one is so ignorant as to
allow his worst animals to breed.
The aid which we feel impelled to give to the helpless is mainly an
incidental result of the instinct of sympathy, which was originally acquired
as part of the social instincts, but subsequently rendered, in the manner
previously indicated, more tender and more widely diffused. Nor could we
check our sympathy, if so urged by hard reason, without deterioration in the
noblest part of our nature. The surgeon may harden himself whilst
performing an operation, for he knows that he is acting for the good of his
patient; but if we were intentionally to neglect the weak and helpless, it
could only be for a contingent benefit, with a certain and great present evil.
Hence we must bear without complaining the undoubtedly bad effects of
the weak surviving and propagating their kind; but there appears to be at
least one check in steady action, namely the weaker and inferior members
of society not marrying so freely as the sound; and this check might be

indefinitely increased, though this is more to be hoped for than expected, by
the weak in body or mind refraining from marriage.
In all civilised countries man accumulates property and bequeaths it to his
children. So that the children in the same country do not by any means start
fair in the race for success. But this is far from an unmixed evil; for without
the accumulation of capital the arts could not progress; and it is chiefly
through their power that the civilised races have extended, and are now
everywhere extending, their range, so as to take the place of the lower
races. Nor does the moderate accumulation of wealth interfere with the
process of selection. When a poor man becomes rich, his children enter
trades or professions in which there is struggle enough, so that the able in
body and mind succeed best. The presence of a body of well-instructed
men, who have not to labour for their daily bread, is important to a degree
which cannot be over-estimated; as all high intellectual work is carried on
by them, and on such work material progress of all kinds mainly depends,
not to mention other and higher advantages. No doubt wealth when very
great tends to convert men into useless drones, but their number is never
large; and some degree of elimination here occurs, as we daily see rich men,
who happen to be fools or profligate, squandering away all their wealth.
Primogeniture with entailed estates is a more direct evil, though it may
formerly have been a great advantage by the creation of a dominant class,
and any government is better than anarchy. The eldest sons, though they
may be weak in body or mind, generally marry, whilst the younger sons,
however superior in these respects, do not so generally marry. Nor can
worthless eldest sons with entailed estates squander their wealth. But here,
as elsewhere, the relations of civilised life are so complex that some
compensatory checks intervene. The men who are rich through
primogeniture are able to select generation after generation the more
beautiful and charming women; and these must generally be healthy in
body and active in mind. The evil consequences, such as they may be, of
the continued preservation of the same line of descent, without any
selection, are checked by men of rank always wishing to increase their
wealth and power; and this they effect by marrying heiresses. But the
daughters of parents who have produced single children, are themselves, as
Mr. Galton has shewn,232 apt to be sterile; and thus noble families are
continually cut off in the direct line, and their wealth flows into some side

channel; but unfortunately this channel is not determined by superiority of
any kind.
Although civilisation thus checks in many ways the action of natural
selection, it apparently favours, by means of improved food and the
freedom from occasional hardships, the better development of the body.
This may be inferred from civilised men having been found, wherever
compared, to be physically stronger than savages. They appear also to have
equal powers of endurance, as has been proved in many adventurous
expeditions. Even the great luxury of the rich can be but little detrimental;
for the expectation of life of our aristocracy, at all ages and of both sexes, is
very little inferior to that of healthy English lives in the lower classes.233
We will now look to the intellectual faculties alone. If in each grade of
society the members were divided into two equal bodies, the one including
the intellectually superior and the other the inferior, there can be little doubt
that the former would succeed best in all occupations and rear a greater
number of children. Even in the lowest walks of life, skill and ability must
be of some advantage, though in many occupations, owing to the great
division of labour, a very small one. Hence in civilised nations there will be
some tendency to an increase both in the number and in the standard of the
intellectually able. But I do not wish to assert that this tendency may not be
more than counterbalanced in other ways, as by the multiplication of the
reckless and improvident; but even to such as these, ability must be some
advantage.
It has often been objected to views like the foregoing, that the most eminent
men who have ever lived have left no offspring to inherit their great
intellect. Mr. Galton says,234 “I regret I am unable to solve the simple
question whether, and how far, men and women who are prodigies of genius
are infertile. I have, however, shewn that men of eminence are by no means
so.”
Great lawgivers, the founders of beneficent religions, great philosophers
and discoverers in science, aid the progress of mankind in a far higher
degree by their works than by leaving a numerous progeny. In the case of
corporeal structures, it is the selection of the slightly better-endowed and
the elimination of the slightly less well-endowed individuals, and not the

preservation of strongly-marked and rare anomalies, that leads to the
advancement of a species.235 So it will be with the intellectual faculties,
namely from the somewhat more able men in each grade of society
succeeding rather better than the less able, and consequently increasing in
number, if not otherwise prevented. When in any nation the standard of
intellect and the number of intellectual men have increased, we may expect
from the law of the deviation from an average, as shewn by Mr. Galton, that
prodigies of genius will appear somewhat more frequently than before.
In regard to the moral qualities, some elimination of the worst dispositions
is always in progress even in the most civilised nations. Malefactors are
executed, or imprisoned for long periods, so that they cannot freely transmit
their bad qualities. Melancholic and insane persons are confined, or commit
suicide. Violent and quarrelsome men often come to a bloody end. Restless
men who will not follow any steady occupation—and this relic of barbarism
is a great check to civilisation236—emigrate to newly-settled countries,
where they prove useful pioneers. Intemperance is so highly destructive,
that the expectation of life of the intemperate, at the age, for instance, of
thirty, is only 13.8 years; whilst for the rural labourers of England at the
same age it is 40·59 years.237 Profligate women bear few children, and
profligate men rarely marry; both suffer from disease. In the breeding of
domestic animals, the elimination of those individuals, though few in
number, which are in any marked manner inferior, is by no means an
unimportant element towards success. This especially holds good with
injurious characters which tend to reappear through reversion, such as
blackness in sheep; and with mankind some of the worst dispositions,
which occasionally without any assignable cause make their appearance in
families, may perhaps be reversions to a savage state, from which we are
not removed by very many generations. This view seems indeed recognised
in the common expression that such men are the black sheep of the family.
With civilised nations, as far as an advanced standard of morality, and an
increased number of fairly well-endowed men are concerned, natural
selection apparently effects but little; though the fundamental social
instincts were originally thus gained. But I have already said enough, whilst
treating of the lower races, on the causes which lead to the advance of
morality, namely, the approbation of our fellow-men—the strengthening of

our sympathies by habit—example and imitation—reason—experience and
even self-interest—instruction during youth, and religious feelings.
A most important obstacle in civilised countries to an increase in the
number of men of a superior class has been strongly urged by Mr. Greg and
Mr. Galton,238 namely, the fact that the very poor and reckless, who are often
degraded by vice, almost invariably marry early, whilst the careful and
frugal, who are generally otherwise virtuous, marry late in life, so that they
may be able to support themselves and their children in comfort. Those who
marry early produce within a given period not only a greater number of
generations, but, as shewn by Dr. Duncan,239 they produce many more
children. The children, moreover, that are born by mothers during the prime
of life are heavier and larger, and therefore probably more vigorous, than
those born at other periods. Thus the reckless, degraded, and often vicious
members of society, tend to increase at a quicker rate than the provident and
generally virtuous members. Or as Mr. Greg puts the case: “The careless,
squalid, unaspiring Irishman multiplies like rabbits: the frugal, foreseeing,
self-respecting, ambitious Scot, stern in his morality, spiritual in his faith,
sagacious and disciplined in his intelligence, passes his best years in
struggle and in celibacy, marries late, and leaves few behind him. Given a
land originally peopled by a thousand Saxons and a thousand Celts—and in
a dozen generations five-sixths of the population would be Celts, but five-
sixths of the property, of the power, of the intellect, would belong to the
one-sixth of Saxons that remained. In the eternal ‘struggle for existence,’ it
would be the inferior and less favoured race that had prevailed—and
prevailed by virtue not of its good qualities but of its faults.”
There are, however, some checks to this downward tendency. We have seen
that the intemperate suffer from a high rate of mortality, and the extremely
profligate leave few offspring. The poorest classes crowd into towns, and it
has been proved by Dr. Stark from the statistics of ten years in Scotland,240
that at all ages the death-rate is higher in towns than in rural districts, “and
during the first five years of life the town death-rate is almost exactly
double that of the rural districts.” As these returns include both the rich and
the poor, no doubt more than double the number of births would be
requisite to keep up the number of the very poor inhabitants in the towns,
relatively to those in the country. With women, marriage at too early an age
is highly injurious; for it has been found in France that, “twice as many

wives under twenty die in the year, as died out of the same number of the
unmarried.” The mortality, also, of husbands under twenty is “excessively
high,”241 but what the cause of this may be seems doubtful. Lastly, if the men
who prudently delay marrying until they can bring up their families in
comfort, were to select, as they often do, women in the prime of life, the
rate of increase in the better class would be only slightly lessened.
It was established from an enormous body of statistics, taken during 1853,
that the unmarried men throughout France, between the ages of twenty and
eighty, die in a much larger proportion than the married: for instance, out of
every 1000 unmarried men, between the ages of twenty and thirty, 11·3
annually died, whilst of the married only 6·5 died.242 A similar law was
proved to hold good, during the years 1863 and 1864, with the entire
population above the age of twenty in Scotland: for instance, out of every
1000 unmarried men, between the ages of twenty and thirty, 14·97 annually
died, whilst of the married only 7·24 died, that is less than half.243 Dr. Stark
remarks on this, “Bachelorhood is more destructive to life than the most
unwholesome trades, or than residence in an unwholesome house or district
where there has never been the most distant attempt at sanitary
improvement.” He considers that the lessened mortality is the direct result
of “marriage, and the more regular domestic habits which attend that state.”
He admits, however, that the intemperate, profligate, and criminal classes,
whose duration of life is low, do not commonly marry; and it must likewise
be admitted that men with a weak constitution, ill health, or any great
infirmity in body or mind, will often not wish to marry, or will be rejected.
Dr. Stark seems to have come to the conclusion that marriage in itself is a
main cause of prolonged life, from finding that aged married men still have
a considerable advantage in this respect over the unmarried of the same
advanced age; but every one must have known instances of men, who with
weak health during youth did not marry, and yet have survived to old age,
though remaining weak and therefore always with a lessened chance of life.
There is another remarkable circumstance which seems to support Dr.
Stark’s conclusion, namely, that widows and widowers in France suffer in
comparison with the married a very heavy rate of mortality; but Dr. Farr
attributes this to the poverty and evil habits consequent on the disruption of
the family, and to grief. On the whole we may conclude with Dr. Farr that
the lesser mortality of married than of unmarried men, which seems to be a

general law, “is mainly due to the constant elimination of imperfect types,
and to the skilful selection of the finest individuals out of each successive
generation;” the selection relating only to the marriage state, and acting on
all corporeal, intellectual, and moral qualities. We may, therefore, infer that
sound and good men who out of prudence remain for a time unmarried do
not suffer a high rate of mortality.
If the various checks specified in the two last paragraphs, and perhaps
others as yet unknown, do not prevent the reckless, the vicious and
otherwise inferior members of society from increasing at a quicker rate than
the better class of men, the nation will retrograde, as has occurred too often
in the history of the world. We must remember that progress is no invariable
rule. It is most difficult to say why one civilised nation rises, becomes more
powerful, and spreads more widely, than another; or why the same nation
progresses more at one time than at another. We can only say that it depends
on an increase in the actual number of the population, on the number of the
men endowed with high intellectual and moral faculties, as well as on their
standard of excellence. Corporeal structure, except so far as vigour of body
leads to vigour of mind, appears to have little influence.
It has been urged by several writers that as high intellectual powers are
advantageous to a nation, the old Greeks, who stood some grades higher in
intellect than any race that has ever existed,244 ought to have risen, if the
power of natural selection were real, still higher in the scale, increased in
number, and stocked the whole of Europe. Here we have the tacit
assumption, so often made with respect to corporeal structures, that there is
some innate tendency towards continued development in mind and body.
But development of all kinds depends on many concurrent favourable
circumstances. Natural selection acts only in a tentative manner. Individuals
and races may have acquired certain indisputable advantages, and yet have
perished from failing in other characters. The Greeks may have retrograded
from a want of coherence between the many small states, from the small
size of their whole country, from the practice of slavery, or from extreme
sensuality; for they did not succumb until “they were enervated and corrupt
to the very core.”245 The western nations of Europe, who now so
immeasurably surpass their former savage progenitors and stand at the
summit of civilisation, owe little or none of their superiority to direct

inheritance from the old Greeks; though they owe much to the written
works of this wonderful people.
Who can positively say why the Spanish nation, so dominant at one time,
has been distanced in the race. The awakening of the nations of Europe
from the dark ages is a still more perplexing problem. At this early period,
as Mr. Galton246 has remarked, almost all the men of a gentle nature, those
given to meditation or culture of the mind, had no refuge except in the
bosom of the Church which demanded celibacy; and this could hardly fail
to have had a deteriorating influence on each successive generation. During
this same period the Holy Inquisition selected with extreme care the freest
and boldest men in order to burn or imprison them. In Spain alone some of
the best men—those who doubted and questioned, and without doubting
there can be no progress—were eliminated during three centuries at the rate
of a thousand a year. The evil which the Catholic Church has thus effected,
though no doubt counterbalanced to a certain, perhaps large extent in other
ways, is incalculable; nevertheless, Europe has progressed at an
unparalleled rate.
The remarkable success of the English as colonists over other European
nations, which is well illustrated by comparing the progress of the
Canadians of English and French extraction, has been ascribed to their
“daring and persistent energy;” but who can say how the English gained
their energy. There is apparently much truth in the belief that the wonderful
progress of the United States, as well as the character of the people, are the
results of natural selection; the more energetic, restless, and courageous
men from all parts of Europe having emigrated during the last ten or twelve
generations to that great country, and having there succeeded best.247
Looking to the distant future, I do not think that the Rev. Mr. Zincke takes
an exaggerated view when he says:248 “All other series of events—as that
which resulted in the culture of mind in Greece, and that which resulted in
the empire of Rome—only appear to have purpose and value when viewed
in connection with, or rather as subsidiary to ... the great stream of Anglo-
Saxon emigration to the west.”
Obscure as is the problem of the advance of civilisation, we can at least see
that a nation which produced during a lengthened period the greatest

number of highly intellectual, energetic, brave, patriotic, and benevolent
men, would generally prevail over less favoured nations.
Natural selection follows from the struggle for existence; and this from a
rapid rate of increase. It is impossible not bitterly to regret, but whether
wisely is another question, the rate at which man tends to increase; for this
leads in barbarous tribes to infanticide and many other evils, and in civilised
nations to abject poverty, celibacy, and to the late marriages of the prudent.
But as man suffers from the same physical evils with the lower animals, he
has no right to expect an immunity from the evils consequent on the
struggle for existence. Had he not been subjected to natural selection,
assuredly he would never have attained to the rank of manhood. When we
see in many parts of the world enormous areas of the most fertile land
peopled by a few wandering savages, but which are capable of supporting
numerous happy homes, it might be argued that the struggle for existence
had not been sufficiently severe to force man upwards to his highest
standard. Judging from all that we know of man and the lower animals,
there has always been sufficient variability in the intellectual and moral
faculties, for their steady advancement through natural selection. No doubt
such advancement demands many favourable concurrent circumstances; but
it may well be doubted whether the most favourable would have sufficed,
had not the rate of increase been rapid, and the consequent struggle for
existence severe to an extreme degree.

On the evidence that all civilised nations were once barbarous.—As we
have had to consider the steps by which some semi-human creature has
been gradually raised to the rank of man in his most perfect state, the
present subject cannot be quite passed over. But it has been treated in so full
and admirable a manner by Sir J. Lubbock,249 Mr. Tylor, Mr. M’Lennan, and
others, that I need here give only the briefest summary of their results. The
arguments recently advanced by the Duke of Argyll250 and formerly by
Archbishop Whately, in favour of the belief that man came into the world as
a civilised being and that all savages have since undergone degradation,
seem to me weak in comparison with those advanced on the other side.
Many nations, no doubt, have fallen away in civilisation, and some may
have lapsed into utter barbarism, though on this latter head I have not met
with any evidence. The Fuegians were probably compelled by other

conquering hordes to settle in their inhospitable country, and they may have
become in consequence somewhat more degraded; but it would be difficult
to prove that they have fallen much below the Botocudos who inhabit the
finest parts of Brazil.
The evidence that all civilised nations are the descendants of barbarians,
consists, on the one side, of clear traces of their former low condition in
still-existing customs, beliefs, language, &c.; and on the other side, of
proofs that savages are independently able to raise themselves a few steps
in the scale of civilisation, and have actually thus risen. The evidence on the
first head is extremely curious, but cannot be here given: I refer to such
cases as that, for instance, of the art of enumeration, which, as Mr. Tylor
clearly shews by the words still used in some places, originated in counting
the fingers, first of one hand and then of the other, and lastly of the toes. We
have traces of this in our own decimal system, and in the Roman numerals,
which after reaching to the number V., change into VI., &c., when the other
hand no doubt was used. So again, “when we speak of three-score and ten,
we are counting by the vigesimal system, each score thus ideally made,
standing for 20—for ‘one man’ as a Mexican or Carib would put it.”251
According to a large and increasing school of philologists, every language
bears the marks of its slow and gradual evolution. So it is with the art of
writing, as letters are rudiments of pictorial representations. It is hardly
possible to read Mr. M’Lennan’s work252 and not admit that almost all
civilised nations still retain some traces of such rude habits as the forcible
capture of wives. What ancient nation, as the same author asks, can be
named that was originally monogamous? The primitive idea of justice, as
shewn by the law of battle and other customs of which traces still remain,
was likewise most rude. Many existing superstitions are the remnants of
former false religious beliefs. The highest form of religion—the grand idea
of God hating sin and loving righteousness—was unknown during primeval
times.
Turning to the other kind of evidence: Sir J. Lubbock has shewn that some
savages have recently improved a little in some of their simpler arts. From
the extremely curious account which he gives of the weapons, tools, and
arts, used or practised by savages in various parts of the world, it cannot be
doubted that these have nearly all been independent discoveries, excepting
perhaps the art of making fire.253 The Australian boomerang is a good

instance of one such independent discovery. The Tahitians when first visited
had advanced in many respects beyond the inhabitants of most of the other
Polynesian islands. There are no just grounds for the belief that the high
culture of the native Peruvians and Mexicans was derived from any foreign
source;254 many native plants were there cultivated, and a few native animals
domesticated. We should bear in mind that a wandering crew from some
semi-civilised land, if washed to the shores of America, would not, judging
from the small influence of most missionaries, have produced any marked
effect on the natives, unless they had already become somewhat advanced.
Looking to a very remote period in the history of the world, we find, to use
Sir J. Lubbock’s well-known terms, a paleolithic and neolithic period; and
no one will pretend that the art of grinding rough flint tools was a borrowed
one. In all parts of Europe, as far east as Greece, in Palestine, India, Japan,
New Zealand, and Africa, including Egypt, flint tools have been discovered
in abundance; and of their use the existing inhabitants retain no tradition.
There is also indirect evidence of their former use by the Chinese and
ancient Jews. Hence there can hardly be a doubt that the inhabitants of these
many countries, which include nearly the whole civilised world, were once
in a barbarous condition. To believe that man was aboriginally civilised and
then suffered utter degradation in so many regions, is to take a pitiably low
view of human nature. It is apparently a truer and more cheerful view that
progress has been much more general than retrogression; that man has
risen, though by slow and interrupted steps, from a lowly condition to the
highest standard as yet attained by him in knowledge, morals, and religion.

CHAPTER VI.

On the Affinities and Genealogy of Man.

Position of man in the animal series—The natural system genealogical—Adaptive characters of
slight value—Various small points of resemblance between man and the Quadrumana—Rank of
man in the natural system—Birthplace and antiquity of man—Absence of fossil connecting-
links—Lower stages in the genealogy of man, as inferred, firstly from his affinities and secondly
from his structure—Early androgynous condition of the Vertebrata—Conclusion.

Even if it be granted that the difference between man and his nearest allies
is as great in corporeal structure as some naturalists maintain, and although
we must grant that the difference between them is immense in mental
power, yet the facts given in the previous chapters declare, as it appears to
me, in the plainest manner, that man is descended from some lower form,
notwithstanding that connecting-links have not hitherto been discovered.
Man is liable to numerous, slight, and diversified variations, which are
induced by the same general causes, are governed and transmitted in
accordance with the same general laws, as in the lower animals. Man tends
to multiply at so rapid a rate that his offspring are necessarily exposed to a
struggle for existence, and consequently to natural selection. He has given
rise to many races, some of which are so different that they have often been
ranked by naturalists as distinct species. His body is constructed on the
same homological plan as that of other mammals, independently of the uses
to which the several parts may be put. He passes through the same phases of
embryological development. He retains many rudimentary and useless
structures, which no doubt were once serviceable. Characters occasionally
make their reappearance in him, which we have every reason to believe
were possessed by his early progenitors. If the origin of man had been
wholly different from that of all other animals, these various appearances
would be mere empty deceptions; but such an admission is incredible.
These appearances, on the other hand, are intelligible, at least to a large
extent, if man is the co-descendant with other mammals of some unknown
and lower form.
Some naturalists, from being deeply impressed with the mental and spiritual
powers of man, have divided the whole organic world into three kingdoms,
the Human, the Animal, and the Vegetable, thus giving to man a separate
kingdom.255 Spiritual powers cannot be compared or classed by the
naturalist; but he may endeavour to shew, as I have done, that the mental
faculties of man and the lower animals do not differ in kind, although
immensely in degree. A difference in degree, however great, does not justify

us in placing man in a distinct kingdom, as will perhaps be best illustrated
by comparing the mental powers of two insects, namely, a coccus or scale-
insect and an ant, which undoubtedly belong to the same class. The
difference is here greater, though of a somewhat different kind, than that
between man and the highest mammal. The female coccus, whilst young,
attaches itself by its proboscis to a plant; sucks the sap but never moves
again; is fertilised and lays eggs; and this is its whole history. On the other
hand, to describe the habits and mental powers of a female ant, would
require, as Pierre Huber has shewn, a large volume; I may, however, briefly
specify a few points. Ants communicate information to each other, and
several unite for the same work, or games of play. They recognise their
fellow-ants after months of absence. They build great edifices, keep them
clean, close the doors in the evening, and post sentries. They make roads,
and even tunnels under rivers. They collect food for the community, and
when an object, too large for entrance, is brought to the nest, they enlarge
the door, and afterwards build it up again.256 They go out to battle in regular
bands, and freely sacrifice their lives for the common weal. They emigrate
in accordance with a preconcerted plan. They capture slaves. They keep
Aphides as milch-cows. They move the eggs of their aphides, as well as
their own eggs and cocoons, into warm parts of the nest, in order that they
may be quickly hatched; and endless similar facts could be given. On the
whole, the difference in mental power between an ant and a coccus is
immense; yet no one has ever dreamed of placing them in distinct classes,
much less in distinct kingdoms. No doubt this interval is bridged over by
the intermediate mental powers of many other insects; and this is not the
case with man and the higher apes. But we have every reason to believe that
breaks in the series are simply the result of many forms having become
extinct.
Professor Owen, relying chiefly on the structure of the brain, has divided
the mammalian series into four sub-classes. One of these he devotes to man;
in another he places both the marsupials and the monotremata; so that he
makes man as distinct from all other mammals as are these two latter
groups conjoined. This view has not been accepted, as far as I am aware, by
any naturalist capable of forming an independent judgment, and therefore
need not here be further considered.

We can understand why a classification founded on any single character or
organ—even an organ so wonderfully complex and important as the brain—
or on the high development of the mental faculties, is almost sure to prove
unsatisfactory. This principle has indeed been tried with hymenopterous
insects; but when thus classed by their habits or instincts, the arrangement
proved thoroughly artificial.257 Classifications may, of course, be based on
any character whatever, as on size, colour, or the element inhabited; but
naturalists have long felt a profound conviction that there is a natural
system. This system, it is now generally admitted, must be, as far as
possible, genealogical in arrangement,—that is, the co-descendants of the
same form must be kept together in one group, separate from the co-
descendants of any other form; but if the parent-forms are related, so will be
their descendants, and the two groups together will form a larger group. The
amount of difference between the several groups—that is the amount of
modification which each has undergone—will be expressed by such terms
as genera, families, orders, and classes. As we have no record of the lines of
descent, these lines can be discovered only by observing the degrees of
resemblance between the beings which are to be classed. For this object
numerous points of resemblance are of much more importance than the
amount of similarity or dissimilarity in a few points. If two languages were
found to resemble each other in a multitude of words and points of
construction, they would be universally recognised as having sprung from a
common source, notwithstanding that they differed greatly in some few
words or points of construction. But with organic beings the points of
resemblance must not consist of adaptations to similar habits of life: two
animals may, for instance, have had their whole frames modified for living
in the water, and yet they will not be brought any nearer to each other in the
natural system. Hence we can see how it is that resemblances in
unimportant structures, in useless and rudimentary organs, and in parts not
as yet fully developed or functionally active, are by far the most serviceable
for classification; for they can hardly be due to adaptations within a late
period; and thus they reveal the old lines of descent or of true affinity.
We can further see why a great amount of modification in some one
character ought not to lead us to separate widely any two organisms. A part
which already differs much from the same part in other allied forms has
already, according to the theory of evolution, varied much; consequently it

would (as long as the organism remained exposed to the same exciting
conditions) be liable to further variations of the same kind; and these, if
beneficial, would be preserved, and thus continually augmented. In many
cases the continued development of a part, for instance, of the beak of a
bird, or of the teeth of a mammal, would not be advantageous to the species
for gaining its food, or for any other object; but with man we can see no
definite limit, as far as advantage is concerned, to the continued
development of the brain and mental faculties. Therefore in determining the
position of man in the natural or genealogical system, the extreme
development of his brain ought not to outweigh a multitude of resemblances
in other less important or quite unimportant points.
The greater number of naturalists who have taken into consideration the
whole structure of man, including his mental faculties, have followed
Blumenbach and Cuvier, and have placed man in a separate Order, under
the title of the Bimana, and therefore on an equality with the Orders of the
Quadrumana, Carnivora, &c. Recently many of our best naturalists have
recurred to the view first propounded by Linnæus, so remarkable for his
sagacity, and have placed man in the same Order with the Quadrumana,
under the title of the Primates. The justice of this conclusion will be
admitted if, in the first place, we bear in mind the remarks just made on the
comparatively small importance for classification of the great development
of the brain in man; bearing, also, in mind that the strongly-marked
differences between the skulls of man and the Quadrumana (lately insisted
upon by Bischoff, Aeby, and others) apparently follow from their differently
developed brains. In the second place, we must remember that nearly all the
other and more important differences between man and the Quadrumana are
manifestly adaptive in their nature, and relate chiefly to the erect position of
man; such as the structure of his hand, foot, and pelvis, the curvature of his
spine, and the position of his head. The family of seals offers a good
illustration of the small importance of adaptive characters for classification.
These animals differ from all other Carnivora in the form of their bodies
and in the structure of their limbs, far more than does man from the higher
apes; yet in every system, from that of Cuvier to the most recent one by Mr.
Flower,258 seals are ranked as a mere family in the Order of the Carnivora. If
man had not been his own classifier, he would never have thought of
founding a separate order for his own reception.

It would be beyond my limits, and quite beyond my knowledge, even to
name the innumerable points of structure in which man agrees with the
other Primates. Our great anatomist and philosopher, Prof. Huxley, has fully
discussed this subject,259 and has come to the conclusion that man in all parts
of his organisation differs less from the higher apes, than these do from the
lower members of the same group. Consequently there “is no justification
for placing man in a distinct order.”
In an early part of this volume I brought forward various facts, shewing
how closely man agrees in constitution with the higher mammals; and this
agreement, no doubt, depends on our close similarity in minute structure
and chemical composition. I gave, as instances, our liability to the same
diseases, and to the attacks of allied parasites; our tastes in common for the
same stimulants, and the similar effects thus produced, as well as by various
drugs; and other such facts.
As small unimportant points of resemblance between man and the higher
apes are not commonly noticed in systematic works, and as, when
numerous, they clearly reveal our relationship, I will specify a few such
points. The relative position of the features are manifestly the same in man
and the Quadrumana; and the various emotions are displayed by nearly
similar movements of the muscles and skin, chiefly above the eyebrows and
round the mouth. Some few expressions are, indeed, almost the same, as in
the weeping of certain kinds of monkeys, and in the laughing noise made by
others, during which the corners of the mouth are drawn backwards, and the
lower eyelids wrinkled. The external ears are curiously alike. In man the
nose is much more prominent than in most monkeys; but we may trace the
commencement of an aquiline curvature in the nose of the Hoolock Gibbon;
and this in the Semnopithecus nasica is carried to a ridiculous extreme.
The faces of many monkeys are ornamented with beards, whiskers, or
moustaches. The hair on the head grows to a great length in some species of
Semnopithecus;260 and in the Bonnet monkey (Macacus radiatus) it radiates
from a point on the crown, with a parting down the middle, as in man. It is
commonly said that the forehead gives to man his noble and intellectual
appearance; but the thick hair on the head of the Bonnet monkey terminates
abruptly downwards, and is succeeded by such short and fine hair, or down,
that at a little distance the forehead, with the exception of the eyebrows,

appears quite naked. It has been erroneously asserted that eyebrows are not
present in any monkey. In the species just named the degree of nakedness of
the forehead differs in different individuals; and Eschricht states261 that in
our children the limit between the hairy scalp and the naked forehead is
sometimes not well defined; so that here we seem to have a trifling case of
reversion to a progenitor, in whom the forehead had not as yet become quite
naked.
It is well known that the hair on our arms tends to converge from above and
below to a point at the elbow. This curious arrangement, so unlike that in
most of the lower mammals, is common to the gorilla, chimpanzee, orang,
some species of Hylobates, and even to some few American monkeys. But
in Hylobates agilis the hair on the fore-arm is directed downwards or
towards the wrist in the ordinary manner; and in H. lar it is nearly erect,
with only a very slight forward inclination; so that in this latter species it is
in a transitional state. It can hardly be doubted that with most mammals the
thickness of the hair and its direction on the back is adapted to throw off the
rain; even the transverse hairs on the fore-legs of a dog may serve for this
end when he is coiled up asleep. Mr. Wallace remarks that the convergence
of the hair towards the elbow on the arms of the orang (whose habits he has
so carefully studied) serves to throw off the rain, when, as is the custom of
this animal, the arms are bent, with the hands clasped round a branch or
over its own head. We should, however, bear in mind that the attitude of an
animal may perhaps be in part determined by the direction of the hair; and
not the direction of the hair by the attitude. If the above explanation is
correct in the case of the orang, the hair on our fore-arms offers a curious
record of our former state; for no one supposes that it is now of any use in
throwing off the rain, nor in our present erect condition is it properly
directed for this purpose.
It would, however, be rash to trust too much to the principle of adaptation in
regard to the direction of the hair in man or his early progenitors; for it is
impossible to study the figures given by Eschricht of the arrangement of the
hair on the human fœtus (this being the same as in the adult) and not agree
with this excellent observer that other and more complex causes have
intervened. The points of convergence seem to stand in some relation to
those points in the embryo which are last closed in during development.

There appears, also, to exist some relation between the arrangement of the
hair on the limbs, and the course of the medullary arteries.262
It must not be supposed that the resemblances between man and certain
apes in the above and many other points—such as in having a naked
forehead, long tresses on the head, &c.—are all necessarily the result of
unbroken inheritance from a common progenitor thus characterised, or of
subsequent reversion. Many of these resemblances are more probably due
to analogous variation, which follows, as I have elsewhere attempted to
shew,263 from co-descended organisms having a similar constitution and
having been acted on by similar causes inducing variability. With respect to
the similar direction of the hair on the fore-arms of man and certain
monkeys, as this character is common to almost all the anthropomorphous
apes, it may probably be attributed to inheritance; but not certainly so, as
some very distinct American monkeys are thus characterised. The same
remark is applicable to the tailless condition of man; for the tail is absent in
all the anthropomorphous apes. Nevertheless this character cannot with
certainty be attributed to inheritance, as the tail, though not absent, is
rudimentary in several other Old World and in some New World species,
and is quite absent in several species belonging to the allied group of
Lemurs.
Although, as we have now seen, man has no just right to form a separate
Order for his own reception, he may perhaps claim a distinct Sub-order or
Family. Prof. Huxley, in his last work,264 divides the Primates into three Sub-
orders; namely, the Anthropidæ with man alone, the Simiadæ including
monkeys of all kinds, and the Lemuridæ with the diversified genera of
lemurs. As far as differences in certain important points of structure are
concerned, man may no doubt rightly claim the rank of a Sub-order; and
this rank is too low, if we look chiefly to his mental faculties. Nevertheless,
under a genealogical point of view it appears that this rank is too high, and
that man ought to form merely a Family, or possibly even only a Sub-
family. If we imagine three lines of descent proceeding from a common
source, it is quite conceivable that two of them might after the lapse of ages
be so slightly changed as still to remain as species of the same genus; whilst
the third line might become so greatly modified as to deserve to rank as a
distinct Sub-family, Family, or even Order. But in this case it is almost
certain that the third line would still retain through inheritance numerous

small points of resemblance with the other two lines. Here then would occur
the difficulty, at present insoluble, how much weight we ought to assign in
our classifications to strongly-marked differences in some few points,—that
is to the amount of modification undergone; and how much to close
resemblance in numerous unimportant points, as indicating the lines of
descent or genealogy. The former alternative is the most obvious, and
perhaps the safest, though the latter appears the most correct as giving a
truly natural classification.
To form a judgment on this head, with reference to man we must glance at
the classification of the Simiadæ. This family is divided by almost all
naturalists into the Catarhine group, or Old World monkeys, all of which are
characterised (as their name expresses) by the peculiar structure of their
nostrils and by having four premolars in each jaw; and into the Platyrhine
group or New World monkeys (including two very distinct sub-groups), all
of which are characterised by differently-constructed nostrils and by having
six premolars in each jaw. Some other small differences might be
mentioned. Now man unquestionably belongs in his dentition, in the
structure of his nostrils, and some other respects, to the Catarhine or Old
World division; nor does he resemble the Platyrhines more closely than the
Catarhines in any characters, excepting in a few of not much importance
and apparently of an adaptive nature. Therefore it would be against all
probability to suppose that some ancient New World species had varied, and
had thus produced a man-like creature with all the distinctive characters
proper to the Old World division; losing at the same time all its own
distinctive characters. There can consequently hardly be a doubt that man is
an offshoot from the Old World Simian stem; and that under a genealogical
point of view, he must be classed with the Catarhine division.265
The anthropomorphous apes, namely the gorilla, chimpanzee, orang, and
hylobates, are separated as a distinct sub-group from the other Old World
monkeys by most naturalists. I am aware that Gratiolet, relying on the
structure of the brain, does not admit the existence of this sub-group, and no
doubt it is a broken one; thus the orang, as Mr. St. G. Mivart remarks,266 “is
one of the most peculiar and aberrant forms to be found in the Order.” The
remaining, non-anthropomorphous, Old World monkeys, are again divided
by some naturalists into two or three smaller sub-groups; the genus
Semnopithecus, with its peculiar sacculated stomach, being the type of one

such sub-group. But it appears from M. Gaudry’s wonderful discoveries in
Attica, that during the Miocene period a form existed there, which
connected Semnopithecus and Macacus; and this probably illustrates the
manner in which the other and higher groups were once blended together.
If the anthropomorphous apes be admitted to form a natural sub-group, then
as man agrees with them, not only in all those characters which he
possesses in common with the whole Catarhine group, but in other peculiar
characters, such as the absence of a tail and of callosities and in general
appearance, we may infer that some ancient member of the
anthropomorphous sub-group gave birth to man. It is not probable that a
member of one of the other lower sub-groups should, through the law of
analogous variation, have given rise to a man-like creature, resembling the
higher anthropomorphous apes in so many respects. No doubt man, in
comparison with most of his allies, has undergone an extraordinary amount
of modification, chiefly in consequence of his greatly developed brain and
erect position; nevertheless we should bear in mind that he “is but one of
several exceptional forms of Primates.”267
Every naturalist, who believes in the principle of evolution, will grant that
the two main divisions of the Simiadæ, namely the Catarhine and Platyrhine
monkeys, with their sub-groups, have all proceeded from some one
extremely ancient progenitor. The early descendants of this progenitor,
before they had diverged to any considerable extent from each other, would
still have formed a single natural group; but some of the species or incipient
genera would have already begun to indicate by their diverging characters
the future distinctive marks of the Catarhine and Platyrhine divisions.
Hence the members of this supposed ancient group would not have been so
uniform in their dentition or in the structure of their nostrils, as are the
existing Catarhine monkeys in one way and the Platyrhines in another way,
but would have resembled in this respect the allied Lemuridæ which differ
greatly from each other in the form of their muzzles,268 and to an
extraordinary degree in their dentition.
The Catarhine and Platyrhine monkeys agree in a multitude of characters,
as is shewn by their unquestionably belonging to one and the same Order.
The many characters which they possess in common can hardly have been
independently acquired by so many distinct species; so that these characters

must have been inherited. But an ancient form which possessed many
characters common to the Catarhine and Platyrhine monkeys, and others in
an intermediate condition, and some few perhaps distinct from those now
present in either group, would undoubtedly have been ranked, if seen by a
naturalist, as an ape or monkey. And as man under a genealogical point of
view belongs to the Catarhine or Old World stock, we must conclude,
however much the conclusion may revolt our pride, that our early
progenitors would have been properly thus designated.269 But we must not
fall into the error of supposing that the early progenitor of the whole Simian
stock, including man, was identical with, or even closely resembled, any
existing ape or monkey.

On the Birthplace and Antiquity of Man.—We are naturally led to enquire
where was the birthplace of man at that stage of descent when our
progenitors diverged from the Catarhine stock. The fact that they belonged
to this stock clearly shews that they inhabited the Old World; but not
Australia nor any oceanic island, as we may infer from the laws of
geographical distribution. In each great region of the world the living
mammals are closely related to the extinct species of the same region. It is
therefore probable that Africa was formerly inhabited by extinct apes
closely allied to the gorilla and chimpanzee; and as these two species are
now man’s nearest allies, it is somewhat more probable that our early
progenitors lived on the African continent than elsewhere. But it is useless
to speculate on this subject, for an ape nearly as large as a man, namely the
Dryopithecus of Lartet, which was closely allied to the anthropomorphous
Hylobates, existed in Europe during the Upper Miocene period; and since
so remote a period the earth has certainly undergone many great
revolutions, and there has been ample time for migration on the largest
scale.
At the period and place, whenever and wherever it may have been, when
man first lost his hairy covering, he probably inhabited a hot country; and
this would have been favourable for a frugiferous diet, on which, judging
from analogy, he subsisted. We are far from knowing how long ago it was
when man first diverged from the Catarhine stock; but this may have
occurred at an epoch as remote as the Eocene period; for the higher apes
had diverged from the lower apes as early as the Upper Miocene period, as

shewn by the existence of the Dryopithecus. We are also quite ignorant at
how rapid a rate organisms, whether high or low in the scale, may under
favourable circumstances be modified: we know, however, that some have
retained the same form during an enormous lapse of time. From what we
see going on under domestication, we learn that within the same period
some of the co-descendants of the same species may be not at all changed,
some a little, and some greatly changed. Thus it may have been with man,
who has undergone a great amount of modification in certain characters in
comparison with the higher apes.
The great break in the organic chain between man and his nearest allies,
which cannot be bridged over by any extinct or living species, has often
been advanced as a grave objection to the belief that man is descended from
some lower form; but this objection will not appear of much weight to those
who, convinced by general reasons, believe in the general principle of
evolution. Breaks incessantly occur in all parts of the series, some being
wide, sharp and defined, others less so in various degrees; as between the
orang and its nearest allies—between the Tarsius and the other Lemuridæ—
between the elephant and in a more striking manner between the
Ornithorhynchus or Echidna, and other mammals. But all these breaks
depend merely on the number of related forms which have become extinct.
At some future period, not very distant as measured by centuries, the
civilised races of man will almost certainly exterminate and replace
throughout the world the savage races. At the same time the
anthropomorphous apes, as Professor Schaaffhausen has remarked,270 will
no doubt be exterminated. The break will then be rendered wider, for it will
intervene between man in a more civilised state, as we may hope, than the
Caucasian, and some ape as low as a baboon, instead of as at present
between the negro or Australian and the gorilla.
With respect to the absence of fossil remains, serving to connect man with
his ape-like progenitors, no one will lay much stress on this fact, who will
read Sir C. Lyell’s discussion,271 in which he shews that in all the vertebrate
classes the discovery of fossil remains has been an extremely slow and
fortuitous process. Nor should it be forgotten that those regions which are
the most likely to afford remains connecting man with some extinct ape-like
creature, have not as yet been searched by geologists.

Lower Stages in the Genealogy of Man.—We have seen that man appears to
have diverged from the Catarhine or Old World division of the Simiadæ,
after these had diverged from the New World division. We will now
endeavour to follow the more remote traces of his genealogy, trusting in the
first place to the mutual affinities between the various classes and orders,
with some slight aid from the periods, as far as ascertained, of their
successive appearance on the earth. The Lemuridæ stand below and close to
the Simiadæ, constituting a very distinct family of the Primates, or,
according to Häckel, a distinct Order. This group is diversified and broken
to an extraordinary degree, and includes many aberrant forms. It has,
therefore, probably suffered much extinction. Most of the remnants survive
on islands, namely in Madagascar and in the islands of the Malayan
archipelago, where they have not been exposed to such severe competition
as they would have been on well-stocked continents. This group likewise
presents many gradations, leading, as Huxley remarks,272 “insensibly from
the crown and summit of the animal creation down to creatures from which
there is but a step, as it seems, to the lowest, smallest, and least intelligent
of the placental mammalia.” From these various considerations it is
probable that the Simiadæ were originally developed from the progenitors
of the existing Lemuridæ; and these in their turn from forms standing very
low in the mammalian series.

The Marsupials stand in many important characters below the placental
mammals. They appeared at an earlier geological period, and their range
was formerly much more extensive than what it now is. Hence the
Placentata are generally supposed to have been derived from the
Implacentata or Marsupials; not, however, from forms closely like the
existing Marsupials, but from their early progenitors. The Monotremata are
plainly allied to the Marsupials; forming a third and still lower division in
the great mammalian series. They are represented at the present day solely
by the Ornithorhynchus and Echidna; and these two forms may be safely
considered as relics of a much larger group which have been preserved in
Australia through some favourable concurrence of circumstances. The
Monotremata are eminently interesting, as in several important points of
structure they lead towards the class of reptiles.

In attempting to trace the genealogy of the Mammalia, and therefore of
man, lower down in the series, we become involved in greater and greater
obscurity. He who wishes to see what ingenuity and knowledge can effect,
may consult Prof. Häckel’s works.273 I will content myself with a few
general remarks. Every evolutionist will admit that the five great vertebrate
classes, namely, mammals, birds, reptiles, amphibians, and fishes, are all
descended from some one prototype; for they have much in common,
especially during their embryonic state. As the class of fishes is the most
lowly organised and appeared before the others, we may conclude that all
the members of the vertebrate kingdom are derived from some fish-like
animal, less highly organised than any as yet found in the lowest known
formations. The belief that animals so distinct as a monkey or elephant and
a humming-bird, a snake, frog, and fish, &c., could all have sprung from the
same parents, will appear monstrous to those who have not attended to the
recent progress of natural history. For this belief implies the former
existence of links closely binding together all these forms, now so utterly
unlike.
Nevertheless it is certain that groups of animals have existed, or do now
exist, which serve to connect more or less closely the several great
vertebrate classes. We have seen that the Ornithorhynchus graduates
towards reptiles; and Prof. Huxley has made the remarkable discovery,
confirmed by Mr. Cope and others, that the old Dinosaurians are
intermediate in many important respects between certain reptiles and certain
birds—the latter consisting of the ostrich-tribe (itself evidently a widely-
diffused remnant of a larger group) and of the Archeopteryx, that strange
Secondary bird having a long tail like that of the lizard. Again, according to
Prof. Owen,274 the Ichthyosaurians—great sea-lizards furnished with paddles
—present many affinities with fishes, or rather, according to Huxley, with
amphibians. This latter class (including in its highest division frogs and
toads) is plainly allied to the Ganoid fishes. These latter fishes swarmed
during the earlier geological periods, and were constructed on what is called
a highly generalised type, that is they presented diversified affinities with
other groups of organisms. The amphibians and fishes are also so closely
united by the Lepidosiren, that naturalists long disputed in which of these
two classes it ought to be placed. The Lepidosiren and some few Ganoid
fishes have been preserved from utter extinction by inhabiting our rivers,

which are harbours of refuge, bearing the same relation to the great waters
of the ocean that islands bear to continents.
Lastly, one single member of the immense and diversified class of fishes,
namely the lancelet or amphioxus, is so different from all other fishes, that
Häckel maintains that it ought to form a distinct class in the vertebrate
kingdom. This fish is remarkable for its negative characters; it can hardly be
said to possess a brain, vertebral column, or heart, &c.; so that it was
classed by the older naturalists amongst the worms. Many years ago Prof.
Goodsir perceived that the lancelet presented some affinities with the
Ascidians, which are invertebrate, hermaphrodite, marine creatures
permanently attached to a support. They hardly appear like animals, and
consist of a simple, tough, leathery sack, with two small projecting orifices.
They belong to the Molluscoida of Huxley—a lower division of the great
kingdom of the Mollusca; but they have recently been placed by some
naturalists amongst the Vermes or worms. Their larvæ somewhat resemble
tadpoles in shape,275 and have the power of swimming freely about. Some
observations lately made by M. Kowalevsky,276 since confirmed by Prof.
Kuppfer, will form a discovery of extraordinary interest, if still further
extended, as I hear from M. Kowalevsky in Naples he has now effected.
The discovery is that the larvæ of Ascidians are related to the Vertebrata, in
their manner of development, in the relative position of the nervous system,
and in possessing a structure closely like the chorda dorsalis of vertebrate
animals. It thus appears, if we may rely on embryology, which has always
proved the safest guide in classification, that we have at last gained a clue to
the source whence the Vertebrata have been derived. We should thus be
justified in believing that at an extremely remote period a group of animals
existed, resembling in many respects the larvæ of our present Ascidians,
which diverged into two great branches—the one retrograding in
development and producing the present class of Ascidians, the other rising
to the crown and summit of the animal kingdom by giving birth to the
Vertebrata.

We have thus far endeavoured rudely to trace the genealogy of the
Vertebrata by the aid of their mutual affinities. We will now look to man as
he exists; and we shall, I think, be able partially to restore during successive
periods, but not in due order of time, the structure of our early progenitors.

This can be effected by means of the rudiments which man still retains, by
the characters which occasionally make their appearance in him through
reversion, and by the aid of the principles of morphology and embryology.
The various facts, to which I shall here allude, have been given in the
previous chapters. The early progenitors of man were no doubt once
covered with hair, both sexes having beards; their ears were pointed and
capable of movement; and their bodies were provided with a tail, having the
proper muscles. Their limbs and bodies were also acted on by many
muscles which now only occasionally reappear, but are normally present in
the Quadrumana. The great artery and nerve of the humerus ran through a
supra-condyloid foramen. At this or some earlier period, the intestine gave
forth a much larger diverticulum or cæcum than that now existing. The foot,
judging from the condition of the great toe in the fœtus, was then
prehensile; and our progenitors, no doubt, were arboreal in their habits,
frequenting some warm, forest-clad land. The males were provided with
great canine teeth, which served them as formidable weapons.
At a much earlier period the uterus was double; the excreta were voided
through a cloaca; and the eye was protected by a third eyelid or nictitating
membrane. At a still earlier period the progenitors of man must have been
aquatic in their habits; for morphology plainly tells us that our lungs consist
of a modified swim-bladder, which once served as a float. The clefts on the
neck in the embryo of man show where the branchiæ once existed. At about
this period the true kidneys were replaced by the corpora Wolffiana. The
heart existed as a simple pulsating vessel; and the chorda dorsalis took the
place of a vertebral column. These early predecessors of man, thus seen in
the dim recesses of time, must have been as lowly organised as the lancelet
or amphioxus, or even still more lowly organised.
There is one other point deserving a fuller notice. It has long been known
that in the vertebrate kingdom one sex bears rudiments of various accessory
parts, appertaining to the reproductive system, which properly belong to the
opposite sex; and it has now been ascertained that at a very early embryonic
period both sexes possess true male and female glands. Hence some
extremely remote progenitor of the whole vertebrate kingdom appears to
have been hermaphrodite or androgynous.277 But here we encounter a
singular difficulty. In the mammalian class the males possess in their
vesiculæ prostraticæ rudiments of a uterus with the adjacent passage; they

bear also rudiments of mammæ, and some male marsupials have rudiments
of a marsupial sack.278 Other analogous facts could be added. Are we, then,
to suppose that some extremely ancient mammal possessed organs proper to
both sexes, that is, continued androgynous after it had acquired the chief
distinctions of its proper class, and therefore after it had diverged from the
lower classes of the vertebrate kingdom? This seems improbable in the
highest degree; for had this been the case, we might have expected that
some few members of the two lower classes, namely fishes279 and
amphibians, would still have remained androgynous. We must, on the
contrary, believe that when the five vertebrate classes diverged from their
common progenitor the sexes had already become separated. To account,
however, for male mammals possessing rudiments of the accessory female
organs, and for female mammals possessing rudiments of the masculine
organs, we need not suppose that their early progenitors were still
androgynous after they had assumed their chief mammalian characters. It is
quite possible that as the one sex gradually acquired the accessory organs
proper to it, some of the successive steps or modifications were transmitted
to the opposite sex. When we treat of sexual selection, we shall meet with
innumerable instances of this form of transmission,—as in the case of the
spurs, plumes, and brilliant colours, acquired by male birds for battle or
ornament, and transferred to the females in an imperfect or rudimentary
condition.
The possession by male mammals of functionally imperfect mammary
organs is, in some respects, especially curious. The Monotremata have the
proper milk-secreting glands with orifices, but no nipples; and as these
animals stand at the very base of the mammalian series, it is probable that
the progenitors of the class possessed, in like manner, the milk-secreting
glands, but no nipples. This conclusion is supported by what is known of
their manner of development; for Professor Turner informs me, on the
authority of Kölliker and Lauger, that in the embryo the mammary glands
can be distinctly traced before the nipples are in the least visible; and it
should be borne in mind that the development of successive parts in the
individual generally seems to represent and accord with the development of
successive beings in the same line of descent. The Marsupials differ from
the Monotremata by possessing nipples; so that these organs were probably
first acquired by the Marsupials after they had diverged from, and risen

above, the Monotremata, and were then transmitted to the placental
mammals. No one will suppose that after the Marsupials had approximately
acquired their present structure, and therefore at a rather late period in the
development of the mammalian series, any of its members still remained
androgynous. We seem, therefore, compelled to recur to the foregoing view,
and to conclude that the nipples were first developed in the females of some
very early marsupial form, and were then, in accordance with a common
law of inheritance, transferred in a functionally imperfect condition to the
males.
Nevertheless a suspicion has sometimes crossed my mind that long after the
progenitors of the whole mammalian class had ceased to be androgynous,
both sexes might have yielded milk and thus nourished their young; and in
the case of the Marsupials, that both sexes might have carried their young in
marsupial sacks. This will not appear utterly incredible, if we reflect that the
males of syngnathous fishes receive the eggs of the females in their
abdominal pouches, hatch them, and afterwards, as some believe, nourish
the young;280—that certain other male fishes hatch the eggs within their
mouths or branchial cavities;—that certain male toads take the chaplets of
eggs from the females and wind them round their own thighs, keeping them
there until the tadpoles are born;—that certain male birds undertake the
whole duty of incubation, and that male pigeons, as well as the females,
feed their nestlings with a secretion from their crops. But the above
suspicion first occurred to me from the mammary glands in male mammals
being developed so much more perfectly than the rudiments of those other
accessory reproductive parts, which are found in the one sex though proper
to the other. The mammary glands and nipples, as they exist in male
mammals, can indeed hardly be called rudimentary; they are simply not
fully developed and not functionally active. They are sympathetically
affected under the influence of certain diseases, like the same organs in the
female. At birth they often secrete a few drops of milk; and they have been
known occasionally in man and other mammals to become well developed,
and to yield a fair supply of milk. Now if we suppose that during a former
prolonged period male mammals aided the females in nursing their
offspring, and that afterwards from some cause, as from a smaller number
of young being produced, the males ceased giving this aid, disuse of the
organs during maturity would lead to their becoming inactive; and from two

well-known principles of inheritance this state of inactivity would probably
be transmitted to the males at the corresponding age of maturity. But at all
earlier ages these organs would be left unaffected, so that they would be
equally well developed in the young of both sexes.

Conclusion.—The best definition of advancement or progress in the organic
scale ever given, is that by Von Baer; and this rests on the amount of
differentiation and specialisation of the several parts of the same being,
when arrived, as I should be inclined to add, at maturity. Now as organisms
have become slowly adapted by means of natural selection for diversified
lines of life, their parts will have become, from the advantage gained by the
division of physiological labour, more and more differentiated and
specialised for various functions. The same part appears often to have been
modified first for one purpose, and then long afterwards for some other and
quite distinct purpose; and thus all the parts are rendered more and more
complex. But each organism will still retain the general type of structure of
the progenitor from which it was aboriginally derived. In accordance with
this view it seems, if we turn to geological evidence, that organisation on
the whole has advanced throughout the world by slow and interrupted steps.
In the great kingdom of the Vertebrata it has culminated in man. It must not,
however, be supposed that groups of organic beings are always supplanted
and disappear as soon as they have given birth to other and more perfect
groups. The latter, though victorious over their predecessors, may not have
become better adapted for all places in the economy of nature. Some old
forms appear to have survived from inhabiting protected sites, where they
have not been exposed to very severe competition; and these often aid us in
constructing our genealogies, by giving us a fair idea of former and lost
populations. But we must not fall into the error of looking at the existing
members of any lowly-organised group as perfect representatives of their
ancient predecessors.

The most ancient progenitors in the kingdom of the Vertebrata, at which we
are able to obtain an obscure glance, apparently consisted of a group of
marine animals,281 resembling the larvæ of existing Ascidians. These animals
probably gave rise to a group of fishes, as lowly organised as the lancelet;
and from these the Ganoids, and other fishes like the Lepidosiren, must

have been developed. From such fish a very small advance would carry us
on to the amphibians. We have seen that birds and reptiles were once
intimately connected together; and the Monotremata now, in a slight degree,
connect mammals with reptiles. But no one can at present say by what line
of descent the three higher and related classes, namely, mammals, birds, and
reptiles, were derived from either of the two lower vertebrate classes,
namely amphibians and fishes. In the class of mammals the steps are not
difficult to conceive which led from the ancient Monotremata to the ancient
Marsupials; and from these to the early progenitors of the placental
mammals. We may thus ascend to the Lemuridæ; and the interval is not
wide from these to the Simiadæ. The Simiadæ then branched off into two
great stems, the New World and Old World monkeys; and from the latter, at
a remote period, Man, the wonder and glory of the Universe, proceeded.
Thus we have given to man a pedigree of prodigious length, but not, it may
be said, of noble quality. The world, it has often been remarked, appears as
if it had long been preparing for the advent of man; and this, in one sense is
strictly true, for he owes his birth to a long line of progenitors. If any single
link in this chain had never existed, man would not have been exactly what
he now is. Unless we wilfully close our eyes, we may, with our present
knowledge, approximately recognise our parentage; nor need we feel
ashamed of it. The most humble organism is something much higher than
the inorganic dust under our feet; and no one with an unbiassed mind can
study any living creature, however humble, without being struck with
enthusiasm at its marvellous structure and properties.

CHAPTER VII.

On the Races of Man.
The nature and value of specific characters—Application to the races of man—Arguments in favour
of, and opposed to, ranking the so-called races of man as distinct species—Sub-species—
Monogenists and polygenists—Convergence of character—Numerous points of resemblance in
body and mind between the most distinct races of man—The state of man when he first spread
over the earth—Each race not descended from a single pair—The extinction of races—The
formation of races—The effects of crossing—Slight influence of the direct action of the
conditions of life—Slight or no influence of natural selection—Sexual selection.

It is not my intention here to describe the several so-called races of men;
but to inquire what is the value of the differences between them under a
classificatory point of view, and how they have originated. In determining
whether two or more allied forms ought to be ranked as species or varieties,
naturalists are practically guided by the following considerations; namely,
the amount of difference between them, and whether such differences relate
to few or many points of structure, and whether they are of physiological
importance; but more especially whether they are constant. Constancy of
character is what is chiefly valued and sought for by naturalists. Whenever
it can be shewn, or rendered probable, that the forms in question have
remained distinct for a long period, this becomes an argument of much
weight in favour of treating them as species. Even a slight degree of sterility
between any two forms when first crossed, or in their offspring, is generally
considered as a decisive test of their specific distinctness; and their
continued persistence without blending within the same area, is usually
accepted as sufficient evidence, either of some degree of mutual sterility, or
in the case of animals of some repugnance to mutual pairing.
Independently of blending from intercrossing, the complete absence, in a
well-investigated region, of varieties linking together any two closely-allied
forms, is probably the most important of all the criterions of their specific
distinctness; and this is a somewhat different consideration from mere
constancy of character, for two forms may be highly variable and yet not
yield intermediate varieties. Geographical distribution is often
unconsciously and sometimes consciously brought into play; so that forms
living in two widely separated areas, in which most of the other inhabitants
are specifically distinct, are themselves usually looked at as distinct; but in
truth this affords no aid in distinguishing geographical races from so-called
good or true species.
Now let us apply these generally-admitted principles to the races of man,
viewing him in the same spirit as a naturalist would any other animal. In
regard to the amount of difference between the races, we must make some
allowance for our nice powers of discrimination gained by the long habit of
observing ourselves. In India, as Elphinstone remarks,282 although a newly-
arrived European cannot at first distinguish the various native races, yet
they soon appear to him extremely dissimilar; and the Hindoo cannot at first
perceive any difference between the several European nations. Even the

most distinct races of man, with the exception of certain negro tribes, are
much more like each other in form than would at first be supposed. This is
well shewn by the French photographs in the Collection Anthropologique
du Muséum of the men belonging to various races, the greater number of
which, as many persons to whom I have shown them have remarked, might
pass for Europeans. Nevertheless, these men if seen alive would
undoubtedly appear very distinct, so that we are clearly much influenced in
our judgment by the mere colour of the skin and hair, by slight differences
in the features, and by expression.
There is, however, no doubt that the various races, when carefully
compared and measured, differ much from each other,—as in the texture of
the hair, the relative proportions of all parts of the body,283 the capacity of
the lungs, the form and capacity of the skull, and even in the convolutions
of the brain.284 But it would be an endless task to specify the numerous
points of structural difference. The races differ also in constitution, in
acclimatisation, and in liability to certain diseases. Their mental
characteristics are likewise very distinct; chiefly as it would appear in their
emotional, but partly in their intellectual, faculties. Every one who has had
the opportunity of comparison, must have been struck with the contrast
between the taciturn, even morose, aborigines of S. America and the light-
hearted, talkative negroes. There is a nearly similar contrast between the
Malays and the Papuans,285 who live under the same physical conditions,
and are separated from each other only by a narrow space of sea.
We will first consider the arguments which may be advanced in favour of
classing the races of man as distinct species, and then those on the other
side. If a naturalist, who had never before seen such beings, were to
compare a Negro, Hottentot, Australian, or Mongolian, he would at once
perceive that they differed in a multitude of characters, some of slight and
some of considerable importance. On inquiry he would find that they were
adapted to live under widely different climates, and that they differed
somewhat in bodily constitution and mental disposition. If he were then told
that hundreds of similar specimens could be brought from the same
countries, he would assuredly declare that they were as good species as
many to which he had been in the habit of affixing specific names. This
conclusion would be greatly strengthened as soon as he had ascertained that
these forms had all retained the same character for many centuries; and that

negroes, apparently identical with existing negroes, had lived at least 4000
years ago.286 He would also hear from an excellent observer, Dr. Lund,287 that
the human skulls found in the caves of Brazil, entombed with many extinct
mammals, belonged to the same type as that now prevailing throughout the
American Continent.
Our naturalist would then perhaps turn to geographical distribution, and he
would probably declare that forms differing not only in appearance, but
fitted for the hottest and dampest or driest countries, as well as for the arctic
regions, must be distinct species. He might appeal to the fact that no one
species in the group next to man, namely the Quadrumana, can resist a low
temperature or any considerable change of climate; and that those species
which come nearest to man have never been reared to maturity, even under
the temperate climate of Europe. He would be deeply impressed with the
fact, first noticed by Agassiz,288 that the different races of man are
distributed over the world in the same zoological provinces, as those
inhabited by undoubtedly distinct species and genera of mammals. This is
manifestly the case with the Australian, Mongolian, and Negro races of
man; in a less well-marked manner with the Hottentots; but plainly with the
Papuans and Malays, who are separated, as Mr. Wallace has shewn, by
nearly the same line which divides the great Malayan and Australian
zoological provinces. The aborigines of America range throughout the
Continent; and this at first appears opposed to the above rule, for most of
the productions of the Southern and Northern halves differ widely; yet some
few living forms, as the opossum, range from the one into the other, as did
formerly some of the gigantic Edentata. The Esquimaux, like other Arctic
animals, extend round the whole polar regions. It should be observed that
the mammalian forms which inhabit the several zoological provinces, do
not differ from each other in the same degree; so that it can hardly be
considered as an anomaly that the Negro differs more, and the American
much less, from the other races of man than do the mammals of the same
continents from those of the other provinces. Man, it may be added, does
not appear to have aboriginally inhabited any oceanic island; and in this
respect he resembles the other members of his class.
In determining whether the varieties of the same kind of domestic animal
should be ranked as specifically distinct, that is, whether any of them are
descended from distinct wild species, every naturalist would lay much

stress on the fact, if established, of their external parasites being specifically
distinct. All the more stress would be laid on this fact, as it would be an
exceptional one, for I am informed by Mr. Denny that the most different
kinds of dogs, fowls, and pigeons, in England, are infested by the same
species of Pediculi or lice. Now Mr. A. Murray has carefully examined the
Pediculi collected in different countries from the different races of man;289
and he finds that they differ, not only in colour, but in the structure of their
claws and limbs. In every case in which numerous specimens were obtained
the differences were constant. The surgeon of a whaling ship in the Pacific
assured me that when the Pediculi, with which some Sandwich Islanders on
board swarmed, strayed on to the bodies of the English sailors, they died in
the course of three or four days. These Pediculi were darker coloured and
appeared different from those proper to the natives of Chiloe in South
America, of which he gave me specimens. These, again, appeared larger
and much softer than European lice. Mr. Murray procured four kinds from
Africa, namely from the Negroes of the Eastern and Western coasts, from
the Hottentots and Caffres; two kinds from the natives of Australia; two
from North, and two from South America. In these latter cases it may be
presumed that the Pediculi came from natives inhabiting different districts.
With insects slight structural differences, if constant, are generally esteemed
of specific value: and the fact of the races of man being infested by
parasites, which appear to be specifically distinct, might fairly be urged as
an argument that the races themselves ought to be classed as distinct
species.
Our supposed naturalist having proceeded thus far in his investigation,
would next inquire whether the races of men, when crossed, were in any
degree sterile. He might consult the work290 of a cautious and philosophical
observer, Professor Broca; and in this he would find good, evidence that
some races were quite fertile together; but evidence of an opposite nature in
regard to other races. Thus it has been asserted that the native women of
Australia and Tasmania rarely produce children to European men; the
evidence, however, on this head has now been shewn to be almost
valueless. The half-castes are killed by the pure blacks; and an account has
lately been published of eleven half-caste youths murdered and burnt at the
same time, whose remains were found by the police.291 Again, it has often
been said that when mulattoes intermarry they produce few children; on the

other hand, Dr. Bachman of Charlestown292 positively asserts that he has
known mulatto families which have intermarried for several generations,
and have continued on an average as fertile as either pure whites or pure
blacks. Inquiries formerly made by Sir C. Lyell on this subject led him, as
he informs me, to the same conclusion. In the United States the census for
the year 1854 included, according to Dr. Bachman, 405,751 mulattoes; and
this number, considering all the circumstances of the case, seems small; but
it may partly be accounted for by the degraded and anomalous position of
the class, and by the profligacy of the women. A certain amount of
absorption of mulattoes into negroes must always be in progress; and this
would lead to an apparent diminution of the former. The inferior vitality of
mulattoes is spoken of in a trustworthy work293 as a well-known
phenomenon; but this is a different consideration from their lessened
fertility; and can hardly be advanced as a proof of the specific distinctness
of the parent races. No doubt both animal and vegetable hybrids, when
produced from extremely distinct species, are liable to premature death; but
the parents of mulattoes cannot be put under the category of extremely
distinct species. The common Mule, so notorious for long life and vigour,
and yet so sterile, shews how little necessary connection there is in hybrids
between lessened fertility and vitality: other analogous cases could be
added.
Even if it should hereafter be proved that all the races of men were perfectly
fertile together, he who was inclined from other reasons to rank them as
distinct species, might with justice argue that fertility and sterility are not
safe criterions of specific distinctness. We know that these qualities are
easily affected by changed conditions of life or by close inter-breeding, and
that they are governed by highly complex laws, for instance that of the
unequal fertility of reciprocal crosses between the same two species. With
forms which must be ranked as undoubted species, a perfect series exists
from those which are absolutely sterile when crossed, to those which are
almost or quite fertile. The degrees of sterility do not coincide strictly with
the degrees of difference in external structure or habits of life. Man in many
respects may be compared with those animals which have long been
domesticated, and a large body of evidence can be advanced in favour of
the Pallasian doctrine294 that domestication tends to eliminate the sterility
which is so general a result of the crossing of species in a state of nature.

From these several considerations, it may be justly urged that the perfect
fertility of the intercrossed races of man, if established, would not
absolutely preclude us from ranking them as distinct species.
Independently of fertility, the character of the offspring from a cross has
sometimes been thought to afford evidence whether the parent-forms ought
to be ranked as species or varieties; but after carefully studying the
evidence, I have come to the conclusion that no general rules of this kind
can be trusted. Thus with mankind the offspring of distinct races resemble
in all respects the offspring of true species and of varieties. This is shewn,
for instance, by the manner in which the characters of both parents are
blended, and by one form absorbing another through repeated crosses. In
this latter case the progeny both of crossed species and varieties retain for a
long period a tendency to revert to their ancestors, especially to that one
which is prepotent in transmission. When any character has suddenly
appeared in a race or species as the result of a single act of variation, as is
general with monstrosities,295 and this race is crossed with another not thus
characterised, the characters in question do not commonly appear in a
blended condition in the young, but are transmitted to them either perfectly
developed or not at all. As with the crossed races of man cases of this kind
rarely or never occur, this may be used as an argument against the view
suggested by some ethnologists, namely that certain characters, for instance
the blackness of the negro, first appeared as a sudden variation or sport.
Had this occurred, it is probable that mulattoes would often have been born,
either completely black or completely white.
We have now seen that a naturalist might feel himself fully justified in
ranking the races of man as distinct species; for he has found that they are
distinguished by many differences in structure and constitution, some being
of importance. These differences have, also, remained nearly constant for
very long periods of time. He will have been in some degree influenced by
the enormous range of man, which is a great anomaly in the class of
mammals, if mankind be viewed as a single species. He will have been
struck with the distribution of the several so-called races, in accordance
with that of other undoubtedly distinct species of mammals. Finally he
might urge that the mutual fertility of all the races has not as yet been fully
proved; and even if proved would not be an absolute proof of their specific
identity.

On the other side of the question, if our supposed naturalist were to enquire
whether the forms of man kept distinct like ordinary species, when mingled
together in large numbers in the same country, he would immediately
discover that this was by no means the case. In Brazil he would behold an
immense mongrel population of Negroes and Portuguese; in Chiloe and
other parts of South America, he would behold the whole population
consisting of Indians and Spaniards blended in various degrees.296 In many
parts of the same continent he would meet with the most complex crosses
between Negroes, Indians, and Europeans; and such triple crosses afford the
severest test, judging from the vegetable kingdom, of the mutual fertility of
the parent-forms. In one island of the Pacific he would find a small
population of mingled Polynesian and English blood; and in the Viti
Archipelago a population of Polynesians and Negritos crossed in all
degrees. Many analogous cases could be added, for instance, in South
Africa. Hence the races of man are not sufficiently distinct to co-exist
without fusion; and this it is, which in all ordinary cases affords the usual
test of specific distinctness.
Our naturalist would likewise be much disturbed as soon as he perceived
that the distinctive characters of every race of man were highly variable.
This strikes every one when he first beholds the negro-slaves in Brazil, who
have been imported from all parts of Africa. The same remark holds good
with the Polynesians, and with many other races. It may be doubted
whether any character can be named which is distinctive of a race and is
constant. Savages, even within the limits of the same tribe, are not nearly so
uniform in character, as has often been said. Hottentot women offer certain
peculiarities, more strongly marked than those occurring in any other race,
but these are known not to be of constant occurrence. In the several
American tribes, colour and hairyness differ considerably; as does colour to
a certain degree, and the shape of the features greatly, in the Negroes of
Africa. The shape of the skull varies much in some races;297 and so it is with
every other character. Now all naturalists have learnt by dearly-bought
experience, how rash it is to attempt to define species by the aid of
inconstant characters.
But the most weighty of all the arguments against treating the races of man
as distinct species, is that they graduate into each other, independently in
many cases, as far as we can judge, of their having intercrossed. Man has

been studied more carefully than any other organic being, and yet there is
the greatest possible diversity amongst capable judges whether he should be
classed as a single species or race, or as two (Virey), as three (Jacquinot), as
four (Kant), five (Blumenbach), six (Buffon), seven (Hunter), eight
(Agassiz), eleven (Pickering), fifteen (Bory St. Vincent), sixteen
(Desmoulins), twenty-two (Morton), sixty (Crawfurd), or as sixty-three,
according to Burke.298 This diversity of judgment does not prove that the
races ought not to be ranked as species, but it shews that they graduate into
each other, and that it is hardly possible to discover clear distinctive
characters between them.
Every naturalist who has had the misfortune to undertake the description of
a group of highly varying organisms, has encountered cases (I speak after
experience) precisely like that of man; and if of a cautious disposition, he
will end by uniting all the forms which graduate into each other as a single
species; for he will say to himself that he has no right to give names to
objects which he cannot define. Cases of this kind occur in the Order which
includes man, namely in certain genera of monkeys; whilst in other genera,
as in Cercopithecus, most of the species can be determined with certainty.
In the American genus Cebus, the various forms are ranked by some
naturalists as species, by others as mere geographical races. Now if
numerous specimens of Cebus were collected from all parts of South
America, and those forms which at present appear to be specifically
distinct, were found to graduate into each other by close steps, they would
be ranked by most naturalists as mere varieties or races; and thus the greater
number of naturalists have acted with respect to the races of man.
Nevertheless it must be confessed that there are forms, at least in the
vegetable kingdom,299 which we cannot avoid naming as species, but which
are connected together, independently of intercrossing, by numberless
gradations.
Some naturalists have lately employed the term “sub-species” to designate
forms which possess many of the characteristics of true species, but which
hardly deserve so high a rank. Now if we reflect on the weighty arguments,
above given, for raising the races of man to the dignity of species, and the
insuperable difficulties on the other side in defining them, the term “sub-
species” might here be used with much propriety. But from long habit the
term “race” will perhaps always be employed. The choice of terms is only

so far important as it is highly desirable to use, as far as that may be
possible, the same terms for the same degrees of difference. Unfortunately
this is rarely possible; for within the same family the larger genera generally
include closely-allied forms, which can be distinguished only with much
difficulty, whilst the smaller genera include forms that are perfectly distinct;
yet all must equally be ranked as species. So again the species within the
same large genus by no means resemble each other to the same degree: on
the contrary, in most cases some of them can be arranged in little groups
round other species, like satellites round planets.300

The question whether mankind consists of one or several species has of late
years been much agitated by anthropologists, who are divided into two
schools of monogenists and polygenists. Those who do not admit the
principle of evolution, must look at species either as separate creations or as
in some manner distinct entities; and they must decide what forms to rank
as species by the analogy of other organic beings which are commonly thus
received. But it is a hopeless endeavour to decide this point on sound
grounds, until some definition of the term “species” is generally accepted;
and the definition must not include an element which cannot possibly be
ascertained, such as an act of creation. We might as well attempt without
any definition to decide whether a certain number of houses should be
called a village, or town, or city. We have a practical illustration of the
difficulty in the never-ending doubts whether many closely-allied
mammals, birds, insects, and plants, which represent each other in North
America and Europe, should be ranked species or geographical races; and
so it is with the productions of many islands situated at some little distance
from the nearest continent.
Those naturalists, on the other hand, who admit the principle of evolution,
and this is now admitted by the greater number of rising men, will feel no
doubt that all the races of man are descended from a single primitive stock;
whether or not they think fit to designate them as distinct species, for the
sake of expressing their amount of difference.301 With our domestic animals
the question whether the various races have arisen from one or more species
is different. Although all such races, as well as all the natural species within
the same genus, have undoubtedly sprung from the same primitive stock,
yet it is a fit subject for discussion, whether, for instance, all the domestic

races of the dog have acquired their present differences since some one
species was first domesticated and bred by man; or whether they owe some
of their characters to inheritance from distinct species, which had already
been modified in a state of nature. With mankind no such question can
arise, for he cannot be said to have been domesticated at any particular
period.
When the races of man diverged at an extremely remote epoch from their
common progenitor, they will have differed but little from each other, and
been few in number; consequently they will then, as far as their
distinguishing characters are concerned, have had less claim to rank as
distinct species, than the existing so-called races. Nevertheless such early
races would perhaps have been ranked by some naturalists as distinct
species, so arbitrary is the term, if their differences, although extremely
slight, had been more constant than at present, and had not graduated into
each other.
It is, however, possible, though far from probable, that the early progenitors
of man might at first have diverged much in character, until they became
more unlike each other than are any existing races; but that subsequently, as
suggested by Vogt,302 they converged in character. When man selects for the
same object the offspring of two distinct species, he sometimes induces, as
far as general appearance is concerned, a considerable amount of
convergence. This is the case, as shewn by Von Nathusius,303 with the
improved breeds of pigs, which are descended from two distinct species;
and in a less well-marked manner with the improved breeds of cattle. A
great anatomist, Gratiolet, maintains that the anthropomorphous apes do not
form a natural sub-group; but that the orang is a highly developed gibbon or
semnopithecus; the chimpanzee a highly developed macacus; and the
gorilla a highly developed mandrill. If this conclusion, which rests almost
exclusively on brain-characters, be admitted, we should have a case of
convergence at least in external characters, for the anthropomorphous apes
are certainly more like each other in many points than they are to other
apes. All analogical resemblances, as of a whale to a fish, may indeed be
said to be cases of convergence; but this term has never been applied to
superficial and adaptive resemblances. It would be extremely rash in most
cases to attribute to convergence close similarity in many points of structure
in beings which had once been widely different. The form of a crystal is

determined solely by the molecular forces, and it is not surprising that
dissimilar substances should sometimes assume the same form; but with
organic beings we should bear in mind that the form of each depends on an
infinitude of complex relations, namely on the variations which have arisen,
these being due to causes far too intricate to be followed out,—on the
nature of the variations which have been preserved, and this depends on the
surrounding physical conditions, and in a still higher degree on the
surrounding organisms with which each has come into competition,—and
lastly, on inheritance (in itself a fluctuating element) from innumerable
progenitors, all of which have had their forms determined through equally
complex relations. It appears utterly incredible that two organisms, if
differing in a marked manner, should ever afterwards converge so closely as
to lead to a near approach to identity throughout their whole organisation.
In the case of the convergent pigs above referred to, evidence of their
descent from two primitive stocks is still plainly retained, according to Von
Nathusius, in certain bones of their skulls. If the races of man were
descended, as supposed by some naturalists, from two or more distinct
species, which had differed as much, or nearly as much, from each other, as
the orang differs from the gorilla, it can hardly be doubted that marked
differences in the structure of certain bones would still have been
discoverable in man as he now exists.
Although the existing races of man differ in many respects, as in colour,
hair, shape of skull, proportions of the body, &c., yet if their whole
organisation be taken into consideration they are found to resemble each
other closely in a multitude of points. Many of these points are of so
unimportant or of so singular a nature, that it is extremely improbable that
they should have been independently acquired by aboriginally distinct
species or races. The same remark holds good with equal or greater force
with respect to the numerous points of mental similarity between the most
distinct races of man. The American aborigines, Negroes and Europeans
differ as much from each other in mind as any three races that can be
named; yet I was incessantly struck, whilst living with the Fuegians on
board the “Beagle,” with the many little traits of character, shewing how
similar their minds were to ours; and so it was with a full-blooded negro
with whom I happened once to be intimate.

He who will carefully read Mr. Tylor’s and Sir J. Lubbock’s interesting
works304 can hardly fail to be deeply impressed with the close similarity
between the men of all races in tastes, dispositions and habits. This is shewn
by the pleasure which they all take in dancing, rude music, acting, painting,
tattooing, and otherwise decorating themselves,—in their mutual
comprehension of gesture-language—and, as I shall be able to shew in a
future essay, by the same expression in their features, and by the same
inarticulate cries, when they are excited by various emotions. This
similarity, or rather identity, is striking, when contrasted with the different
expressions which may be observed in distinct species of monkeys. There is
good evidence that the art of shooting with bows and arrows has not been
handed down from any common progenitor of mankind, yet the stone
arrow-heads, brought from the most distant parts of the world and
manufactured at the most remote periods, are, as Nilsson has shewn,305
almost identical; and this fact can only be accounted for by the various
races having similar inventive or mental powers. The same observation has
been made by archæologists306 with respect to certain widely-prevalent
ornaments, such as zigzags, &c.; and with respect to various simple beliefs
and customs, such as the burying of the dead under megalithic structures. I
remember observing in South America,307 that there, as in so many other
parts of the world, man has generally chosen the summits of lofty hills, on
which to throw up piles of stones, either for the sake of recording some
remarkable event, or for burying his dead.
Now when naturalists observe a close agreement in numerous small details
of habits, tastes and dispositions between two or more domestic races, or
between nearly-allied natural forms, they use this fact as an argument that
all are descended from a common progenitor who was thus endowed; and
consequently that all should be classed under the same species. The same
argument may be applied with much force to the races of man.
As it is improbable that the numerous and unimportant points of
resemblance between the several races of man in bodily structure and
mental faculties (I do not here refer to similar customs) should all have been
independently acquired, they must have been inherited from progenitors
who were thus characterised. We thus gain some insight into the early state
of man, before he had spread step by step over the face of the earth. The
spreading of man to regions widely separated by the sea, no doubt,

preceded any considerable amount of divergence of character in the several
races; for otherwise we should sometimes meet with the same race in
distinct continents; and this is never the case. Sir J. Lubbock, after
comparing the arts now practised by savages in all parts of the world,
specifies those which man could not have known, when he first wandered
from his original birthplace; for if once learnt they would never have been
forgotten.308 He thus shews that “the spear, which is but a development of
the knife-point, and the club, which is but a long hammer, are the only
things left.” He admits, however, that the art of making fire probably had
already been discovered, for it is common to all the races now existing, and
was known to the ancient cave-inhabitants of Europe. Perhaps the art of
making rude canoes or rafts was likewise known; but as man existed at a
remote epoch, when the land in many places stood at a very different level,
he would have been able, without the aid of canoes, to have spread widely.
Sir J. Lubbock further remarks how improbable it is that our earliest
ancestors could have “counted as high as ten, considering that so many
races now in existence cannot get beyond four.” Nevertheless, at this early
period, the intellectual and social faculties of man could hardly have been
inferior in any extreme degree to those now possessed by the lowest
savages; otherwise primeval man could not have been so eminently
successful in the struggle for life, as proved by his early and wide diffusion.
From the fundamental differences between certain languages, some
philologists have inferred that when man first became widely diffused he
was not a speaking animal; but it may be suspected that languages, far less
perfect than any now spoken, aided by gestures, might have been used, and
yet have left no traces on subsequent and more highly-developed tongues.
Without the use of some language, however imperfect, it appears doubtful
whether man’s intellect could have risen to the standard implied by his
dominant position at an early period.
Whether primeval man, when he possessed very few arts of the rudest kind,
and when his power of language was extremely imperfect, would have
deserved to be called man, must depend on the definition which we employ.
In a series of forms graduating insensibly from some ape-like creature to
man as he now exists, it would be impossible to fix on any definite point
when the term “man” ought to be used. But this is a matter of very little
importance. So again it is almost a matter of indifference whether the so-

called races of man are thus designated, or are ranked as species or sub-
species; but the latter term appears the most appropriate. Finally, we may
conclude that when the principles of evolution are generally accepted, as
they surely will be before long, the dispute between the monogenists and
the polygenists will die a silent and unobserved death.

One other question ought not to be passed over without notice, namely,
whether, as is sometimes assumed, each sub-species or race of man has
sprung from a single pair of progenitors. With our domestic animals a new
race can readily be formed from a single pair possessing some new
character, or even from a single individual thus characterised, by carefully
matching the varying offspring; but most of our races have been formed,
not intentionally from a selected pair, but unconsciously by the preservation
of many individuals which have varied, however slightly, in some useful or
desired manner. If in one country stronger and heavier horses, and in
another country lighter and fleeter horses, were habitually preferred, we
may feel sure that two distinct sub-breeds would, in the course of time, be
produced, without any particular pairs or individuals having been separated
and bred from in either country. Many races have been thus formed, and
their manner of formation is closely analogous with that of natural species.
We know, also, that the horses which have been brought to the Falkland
Islands have become, during successive generations, smaller and weaker,
whilst those which have run wild on the Pampas have acquired larger and
coarser heads; and such changes are manifestly due, not to any one pair, but
to all the individuals having been subjected to the same conditions, aided,
perhaps, by the principle of reversion. The new sub-breeds in none of these
cases are descended from any single pair, but from many individuals which
have varied in different degrees, but in the same general manner; and we
may conclude that the races of man have been similarly produced, the
modifications being either the direct result of exposure to different
conditions, or the indirect result of some form of selection. But to this latter
subject we shall presently return.

On the Extinction of the Races of Man.—The partial and complete
extinction of many races and sub-races of man are historically known
events. Humboldt saw in South America a parrot which was the sole living

creature that could speak the language of a lost tribe. Ancient monuments
and stone implements found in all parts of the world, of which no tradition
is preserved by the present inhabitants, indicate much extinction. Some
small and broken tribes, remnants of former races, still survive in isolated
and generally mountainous districts. In Europe the ancient races were all,
according to Schaaffhausen,309 “lower in the scale than the rudest living
savages;” they must therefore have differed, to a certain extent, from any
existing race. The remains described by Professor Broca310 from Les Eyzies,
though they unfortunately appear to have belonged to a single family,
indicate a race with a most singular combination of low or simious and high
characteristics, and is “entirely different from any other race, ancient or
modern, that we have ever heard of.” It differed, therefore, from the
quaternary race of the caverns of Belgium.
Unfavourable physical conditions appear to have had but little effect in the
extinction of races.311 Man has long lived in the extreme regions of the
North, with no wood wherewith to make his canoes or other implements,
and with blubber alone for burning and giving him warmth, but more
especially for melting the snow. In the Southern extremity of America the
Fuegians survive without the protection of clothes, or of any building
worthy to be called a hovel. In South Africa the aborigines wander over the
most arid plains, where dangerous beasts abound. Man can withstand the
deadly influence of the Terai at the foot of the Himalaya, and the pestilential
shores of tropical Africa.
Extinction follows chiefly from the competition of tribe with tribe, and race
with race. Various checks are always in action, as specified in a former
chapter, which serve to keep down the numbers of each savage tribe,—such
as periodical famines, the wandering of the parents and the consequent
deaths of infants, prolonged suckling, the stealing of women, wars,
accidents, sickness, licentiousness, especially infanticide, and, perhaps,
lessened fertility from less nutritious food, and many hardships. If from any
cause any one of these checks is lessened, even in a slight degree, the tribe
thus favoured will tend to increase; and when one of two adjoining tribes
becomes more numerous and powerful than the other, the contest is soon
settled by war, slaughter, cannibalism, slavery, and absorption. Even when a
weaker tribe is not thus abruptly swept away, if it once begins to decrease, it
generally goes on decreasing until it is extinct.312

When civilised nations come into contact with barbarians the struggle is
short, except where a deadly climate gives its aid to the native race. Of the
causes which lead to the victory of civilised nations, some are plain and
some very obscure. We can see that the cultivation of the land will be fatal
in many ways to savages, for they cannot, or will not, change their habits.
New diseases and vices are highly destructive; and it appears that in every
nation a new disease causes much death, until those who are most
susceptible to its destructive influence are gradually weeded out;313 and so it
may be with the evil effects from spirituous liquors, as well as with the
unconquerably strong taste for them shewn by so many savages. It further
appears, mysterious as is the fact, that the first meeting of distinct and
separated people generates disease.314 Mr. Sproat, who in Vancouver Island
closely attended to the subject of extinction, believes that changed habits of
life, which always follow from the advent of Europeans, induces much ill-
health. He lays, also, great stress on so trifling a cause as that the natives
become “bewildered and dull by the new life around them; they lose the
motives for exertion, and get no new ones in their place.”315
The grade of civilisation seems a most important element in the success of
nations which come in competition. A few centuries ago Europe feared the
inroads of Eastern barbarians; now, any such fear would be ridiculous. It is
a more curious fact, that savages did not formerly waste away, as Mr.
Bagehot has remarked, before the classical nations, as they now do before
modern civilised nations; had they done so, the old moralists would have
mused over the event; but there is no lament in any writer of that period
over the perishing barbarians.316
Although the gradual decrease and final extinction of the races of man is an
obscure problem, we can see that it depends on many causes, differing in
different places and at different times. It is the same difficult problem as
that presented by the extinction of one of the higher animals—of the fossil
horse, for instance, which disappeared from South America, soon
afterwards to be replaced, within the same districts, by countless troops of
the Spanish horse. The New Zealander seems conscious of this parallelism,
for he compares his future fate with that of the native rat almost
exterminated by the European rat. The difficulty, though great to our
imagination, and really great if we wish to ascertain the precise causes,
ought not to be so to our reason, as long as we keep steadily in mind that

the increase of each species and each race is constantly hindered by various
checks; so that if any new check, or cause of destruction, even a slight one,
be superadded, the race will surely decrease in number; and as it has
everywhere been observed that savages are much opposed to any change of
habits, by which means injurious checks could be counterbalanced,
decreasing numbers will sooner or later lead to extinction; the end, in most
cases, being promptly determined by the inroads of increasing and
conquering tribes.

On the Formation of the Races of Man.—It may be premised that when we
find the same race, though broken up into distinct tribes, ranging over a
great area, as over America, we may attribute their general resemblance to
descent from a common stock. In some cases the crossing of races already,
distinct has led to the formation of new races. The singular fact that
Europeans and Hindoos, who belong to the same Aryan stock and speak a
language fundamentally the same, differ widely in appearance, whilst
Europeans differ but little from Jews, who belong to the Semitic stock and
speak quite another language, has been accounted for by Broca317 through
the Aryan branches having been largely crossed during their wide diffusion
by various indigenous tribes. When two races in close contact cross, the
first result is a heterogeneous mixture: thus Mr. Hunter, in describing the
Santali or hill-tribes of India, says that hundreds of imperceptible gradations
may be traced “from the black, squat tribes of the mountains to the tall
olive-coloured Brahman, with his intellectual brow, calm eyes, and high but
narrow head;” so that it is necessary in courts of justice to ask the witnesses
whether they are Santalis or Hindoos.318 Whether a heterogeneous people,
such as the inhabitants of some of the Polynesian islands, formed by the
crossing of two distinct races, with few or no pure members left, would ever
become homogeneous, is not known from direct evidence. But as with our
domesticated animals, a crossed breed can certainly, in the course of a few
generations, be fixed and made uniform by careful selection,319 we may infer
that the free and prolonged intercrossing during many generations of a
heterogeneous mixture would supply the place of selection, and overcome
any tendency to reversion, so that a crossed race would ultimately become
homogeneous, though it might not partake in an equal degree of the
characters of the two parent-races.

Of all the differences between the races of man, the colour of the skin is the
most conspicuous and one of the best marked. Differences of this kind, it
was formerly thought, could be accounted for by long exposure under
different climates; but Pallas first shewed that this view is not tenable, and
he has been followed by almost all anthropologists.320 The view has been
rejected chiefly because the distribution of the variously coloured races,
most of whom must have long inhabited their present homes, does not
coincide with corresponding differences of climate. Weight must also be
given to such cases as that of the Dutch families, who, as we hear on
excellent authority,321 have not undergone the least change of colour, after
residing for three centuries in South Africa. The uniform appearance in
various parts of the world of gypsies and Jews, though the uniformity of the
latter has been somewhat exaggerated,322 is likewise an argument on the
same side. A very damp or a very dry atmosphere has been supposed to be
more influential in modifying the colour of the skin than mere heat; but as
D’Orbigny in South America, and Livingstone in Africa, arrived at
diametrically opposite conclusions with respect to dampness and dryness,
any conclusion on this head must be considered as very doubtful.323
Various facts, which I have elsewhere given, prove that the colour of the
skin and hair is sometimes correlated in a surprising manner with a
complete immunity from the action of certain vegetable poisons and from
the attacks of certain parasites. Hence it occurred to me, that negroes and
other dark races might have acquired their dark tints by the darker
individuals escaping during a long series of generations from the deadly
influence of the miasmas of their native countries.
I afterwards found that the same idea had long ago occurred to Dr. Wells.324
That negroes, and even mulattoes, are almost completely exempt from the
yellow-fever, which is so destructive in tropical America, has long been
known.325 They likewise escape to a large extent the fatal intermittent fevers
that prevail along, at least, 2600 miles of the shores of Africa, and which
annually cause one-fifth of the white settlers to die, and another fifth to
return home invalided.326 This immunity in the negro seems to be partly
inherent, depending on some unknown peculiarity of constitution, and
partly the result of acclimatisation. Pouchet327 states that the negro
regiments, borrowed from the Viceroy of Egypt for the Mexican war, which
had been recruited near the Soudan, escaped the yellow-fever almost

equally well with the negroes originally brought from various parts of
Africa, and accustomed to the climate of the West Indies. That
acclimatisation plays a part is shewn by the many cases in which negroes,
after having resided for some time in a colder climate, have become to a
certain extent liable to tropical fevers.328 The nature of the climate under
which the white races have long resided, likewise has some influence on
them; for during the fearful epidemic of yellow-fever in Demerara during
1837, Dr. Blair found that the death-rate of the immigrants was proportional
to the latitude of the country whence they had come. With the negro the
immunity, as far as it is the result of acclimatisation, implies exposure
during a prodigious length of time; for the aborigines of tropical America,
who have resided there from time immemorial, are not exempt from
yellow-fever; and the Rev. B. Tristram states, that there are districts in
Northern Africa which the native inhabitants are compelled annually to
leave, though the negroes can remain with safety.
That the immunity of the negro is in any degree correlated with the colour
of his skin is a mere conjecture: it may be correlated with some difference
in his blood, nervous system, or other tissues. Nevertheless, from the facts
above alluded to, and from some connection apparently existing between
complexion and a tendency to consumption, the conjecture seemed to me
not improbable. Consequently I endeavoured, with but little success,329 to
ascertain how far it held good. The late Dr. Daniell, who had long lived on
the West Coast of Africa, told me that he did not believe in any such
relation. He was himself unusually fair, and had withstood the climate in a
wonderful manner. When he first arrived as a boy on the coast, an old and
experienced negro chief predicted from his appearance that this would
prove the case. Dr. Nicholson, of Antigua, after having attended to this
subject, wrote to me that he did not think that dark-coloured Europeans
escaped the yellow-fever better than those that were light-coloured. Mr. J.
M. Harris altogether denies330 that Europeans with dark hair withstand a hot
climate better than other men; on the contrary, experience has taught him in
making a selection of men for service on the coast of Africa, to choose
those with red hair. As far, therefore, as these slight indications serve, there
seems no foundation for the hypothesis, which has been accepted by several
writers, that the colour of the black races may have resulted from darker

and darker individuals having survived in greater numbers, during their
exposure to the fever-generating miasmas of their native countries.
Although with our present knowledge we cannot account for the strongly-
marked differences in colour between the races of man, either through
correlation with constitutional peculiarities, or through the direct action of
climate; yet we must not quite ignore the latter agency, for there is good
reason to believe that some inherited effect is thus produced.331
We have seen in our third chapter that the conditions of life, such as
abundant food and general comfort, affect in a direct manner the
development of the bodily frame, the effects being transmitted. Through the
combined influences of climate and changed habits of life, European
settlers, in the United States undergo, as is generally admitted, a slight but
extraordinarily rapid change of appearance. There is, also, a considerable
body of evidence shewing that in the Southern States the house-slaves of
the third generation present a markedly different appearance from the field-
slaves.332
If, however, we look to the races of man, as distributed over the world, we
must infer that their characteristic differences cannot be accounted for by
the direct action of different conditions of life, even after exposure to them
for an enormous period of time. The Esquimaux live exclusively on animal
food; they are clothed in thick fur, and are exposed to intense cold and to
prolonged darkness; yet they do not differ in any extreme degree from the
inhabitants of Southern China, who live entirely on vegetable food and are
exposed almost naked to a hot, glaring climate. The unclothed Fuegians live
on the marine productions of their inhospitable shores; the Botocudos of
Brazil wander about the hot forests of the interior and live chiefly on
vegetable productions; yet these tribes resemble each other so closely that
the Fuegians on board the “Beagle” were mistaken by some Brazilians for
Botocudos. The Botocudos again, as well as the other inhabitants of tropical
America, are wholly different from the Negroes who inhabit the opposite
shores of the Atlantic, are exposed to a nearly similar climate, and follow
nearly the same habits of life.
Nor can the differences between the races of man be accounted for, except
to a quite insignificant degree, by the inherited effects of the increased or

decreased use of parts. Men who habitually live in canoes, may have their
legs somewhat stunted; those who inhabit lofty regions have their chests
enlarged; and those who constantly use certain sense-organs have the
cavities in which they are lodged somewhat increased in size, and their
features consequently a little modified. With civilised nations, the reduced
size of the jaws from lessened use, the habitual play of different muscles
serving to express different emotions, and the increased size of the brain
from greater intellectual activity, have together produced a considerable
effect on their general appearance in comparison with savages.333 It is also
possible that increased bodily stature, with no corresponding increase in the
size of the brain, may have given to some races (judging from the
previously adduced cases of the rabbits) an elongated skull of the
dolichocephalic type.
Lastly, the little-understood principle of correlation will almost certainly
have come into action, as in the case of great muscular development and
strongly projecting supra-orbital ridges. It is not improbable that the texture
of the hair, which differs much in the different races, may stand in some
kind of correlation with the structure of the skin; for the colour of the hair
and skin are certainly correlated, as is its colour and texture with the
Mandans.334 The colour of the skin and the odour emitted by it are likewise
in some manner connected. With the breeds of sheep the number of hairs
within a given space and the number of the excretory pores stand in some
relation to each other.335 If we may judge from the analogy of our
domesticated animals, many modifications of structure in man probably
come under this principle of correlated growth.

We have now seen that the characteristic differences between the races of
man cannot be accounted for in a satisfactory manner by the direct action of
the conditions of life, nor by the effects of the continued use of parts, nor
through the principle of correlation. We are therefore led to inquire whether
slight individual differences, to which man is eminently liable, may not
have been preserved and augmented during a long series of generations
through natural selection. But here we are at once met by the objection that
beneficial variations alone can be thus preserved; and as far as we are
enabled to judge (although always liable to error on this head) not one of
the external differences between the races of man are of any direct or

special service to him. The intellectual and moral or social faculties must of
course be excepted from this remark; but differences in these faculties can
have had little or no influence on external characters. The variability of all
the characteristic differences between the races, before referred to, likewise
indicates that these differences cannot be of much importance; for, had they
been important, they would long ago have been either fixed and preserved,
or eliminated. In this respect man resembles those forms, called by
naturalists protean or polymorphic, which have remained extremely
variable, owing, as it seems, to their variations being of an indifferent
nature, and consequently to their having escaped the action of natural
selection.
We have thus far been baffled in all our attempts to account for the
differences between the races of man; but there remains one important
agency, namely Sexual Selection, which appears to have acted as
powerfully on man, as on many other animals. I do not intend to assert that
sexual selection will account for all the differences between the races. An
unexplained residuum is left, about which we can in our ignorance only say,
that as individuals are continually born with, for instance, heads a little
rounder or narrower, and with noses a little longer or shorter, such slight
differences might become fixed and uniform, if the unknown agencies
which induced them were to act in a more constant manner, aided by long-
continued intercrossing. Such modifications come under the provisional
class, alluded to in our fourth chapter, which for the want of a better term
have been called spontaneous variations. Nor do I pretend that the effects of
sexual selection can be indicated with scientific precision; but it can be
shewn that it would be an inexplicable fact if man had not been modified by
this agency, which has acted so powerfully on innumerable animals, both
high and low in the scale. It can further be shewn that the differences
between the races of man, as in colour, hairyness, form of features, &c., are
of the nature which it might have been expected would have been acted on
by sexual selection. But in order to treat this subject in a fitting manner, I
have found it necessary to pass the whole animal kingdom in review; I have
therefore devoted to it the Second Part of this work. At the close I shall
return to man, and, after attempting to shew how far he has been modified
through sexual selection, will give a brief summary of the chapters in this
First Part.

Part II.—SEXUAL SELECTION.

CHAPTER VIII.

Principles of Sexual Selection.
Secondary sexual characters—Sexual selection—Manner of action—Excess of males—Polygamy—
The male alone generally modified through sexual selection—Eagerness of the male—
Variability of the male—Choice exerted by the female—Sexual compared with natural selection
—Inheritance, at corresponding periods of life, at corresponding seasons of the year, and as
limited by sex—Relations between the several forms of inheritance—Causes why one sex and
the young are not modified through sexual selection—Supplement on the proportional numbers
of the two sexes throughout the animal kingdom—On the limitation of the numbers of the two
sexes through natural selection.

With animals which have their sexes separated, the males necessarily differ
from the females in their organs of reproduction; and these afford the
primary sexual characters. But the sexes often differ in what Hunter has
called secondary sexual characters, which are not directly connected with
the act of reproduction; for instance, in the male possessing certain organs
of sense or locomotion, of which the female is quite destitute, or in having
them more highly-developed, in order that he may readily find or reach her;
or again, in the male having special organs of prehension so as to hold her
securely. These latter organs of infinitely diversified kinds graduate into,
and in some cases can hardly be distinguished from, those which are
commonly ranked as primary, such as the complex appendages at the apex
of the abdomen in male insects. Unless indeed we confine the term
“primary” to the reproductive glands, it is scarcely possible to decide, as far
as the organs of prehension are concerned, which ought to be called primary
and which secondary.
The female often differs from the male in having organs for the
nourishment or protection of her young, as the mammary glands of
mammals, and the abdominal sacks of the marsupials. The male, also, in

some few cases differs from the female in possessing analogous organs, as
the receptacles for the ova possessed by the males of certain fishes, and
those temporarily developed in certain male frogs. Female bees have a
special apparatus for collecting and carrying pollen, and their ovipositor is
modified into a sting for the defence of their larvæ and the community. In
the females of many insects the ovipositor is modified in the most complex
manner for the safe placing of the eggs. Numerous similar cases could be
given, but they do not here concern us. There are, however, other sexual
differences quite disconnected with the primary organs with which we are
more especially concerned—such as the greater size, strength, and
pugnacity of the male, his weapons of offence or means of defence against
rivals, his gaudy colouring and various ornaments, his power of song, and
other such characters.
Besides the foregoing primary and secondary sexual differences, the male
and female sometimes differ in structures connected with different habits of
life, and not at all, or only indirectly, related to the reproductive functions.
Thus the females of certain flies (Culicidæ and Tabanidæ) are blood-
suckers, whilst the males live on flowers and have their mouths destitute of
mandibles.336 The males alone of certain moths and of some crustaceans
(e.g. Tanais) have imperfect, closed mouths, and cannot feed. The
Complemental males of certain cirripedes live like epiphytic plants either
on the female or hermaphrodite form, and are destitute of a mouth and
prehensile limbs. In these cases it is the male which has been modified and
has lost certain important organs, which the other members of the same
group possess. In other cases it is the female which has lost such parts; for
instance, the female glow-worm is destitute of wings, as are many female
moths, some of which never leave their cocoons. Many female parasitic
crustaceans have lost their natatory legs. In some weevil-beetles
(Curculionidæ) there is a great difference between the male and female in
the length of the rostrum or snout;337 but the meaning of this and of many
analogous differences, is not at all understood. Differences of structure
between the two sexes in relation to different habits of life are generally
confined to the lower animals; but with some few birds the beak of the male
differs from that of the female. No doubt in most, but apparently not in all
these cases, the differences are indirectly connected with the propagation of
the species: thus a female which has to nourish a multitude of ova will

require more food than the male, and consequently will require special
means for procuring it. A male animal which lived for a very short time
might without detriment lose through disuse its organs for procuring food;
but he would retain his locomotive organs in a perfect state, so that he
might reach the female. The female, on the other hand, might safely lose her
organs for flying, swimming, or walking, if she gradually acquired habits
which rendered such powers useless.
We are, however, here concerned only with that kind of selection, which I
have called sexual selection. This depends on the advantage which certain
individuals have over other individuals of the same sex and species, in
exclusive relation to reproduction. When the two sexes differ in structure in
relation to different habits of life, as in the cases above mentioned, they
have no doubt been modified through natural selection, accompanied by
inheritance limited to one and the same sex. So again the primary sexual
organs, and those for nourishing or protecting the young, come under this
same head; for those individuals which generated or nourished their
offspring best, would leave, cæteris paribus, the greatest number to inherit
their superiority; whilst those which generated or nourished their offspring
badly, would leave but few to inherit their weaker powers. As the male has
to search for the female, he requires for this purpose organs of sense and
locomotion, but if these organs are necessary for the other purposes of life,
as is generally the case, they will have been developed through natural
selection. When the male has found the female he sometimes absolutely
requires prehensile organs to hold her; thus Dr. Wallace informs me that the
males of certain moths cannot unite with the females if their tarsi or feet are
broken. The males of many oceanic crustaceans have their legs and antennæ
modified in an extraordinary manner for the prehension of the female;
hence we may suspect that owing to these animals being washed about by
the waves of the open sea, they absolutely require these organs in order to
propagate their kind, and if so their development will have been the result
of ordinary or natural selection.
When the two sexes follow exactly the same habits of life, and the male has
more highly developed sense or locomotive organs than the female, it may
be that these in their perfected state are indispensable to the male for
finding the female; but in the vast majority of cases, they serve only to give
one male an advantage over another, for the less well-endowed males, if

time were allowed them, would succeed in pairing with the females; and
they would in all other respects, judging from the structure of the female, be
equally well adapted for their ordinary habits of life. In such cases sexual
selection must have come into action, for the males have acquired their
present structure, not from being better fitted to survive in the struggle for
existence, but from having gained an advantage over other males, and from
having transmitted this advantage to their male offspring alone. It was the
importance of this distinction which led me to designate this form of
selection as sexual selection. So again, if the chief service rendered to the
male by his prehensile organs is to prevent the escape of the female before
the arrival of other males, or when assaulted by them, these organs will
have been perfected through sexual selection, that is by the advantage
acquired by certain males over their rivals. But in most cases it is scarcely
possible to distinguish between the effects of natural and sexual selection.
Whole chapters could easily be filled with details on the differences
between the sexes in their sensory, locomotive, and prehensile organs. As,
however, these structures are not more interesting than others adapted for
the ordinary purposes of life, I shall almost pass them over, giving only a
few instances under each class.
There are many other structures and instincts which must have been
developed through sexual selection—such as the weapons of offence and
the means of defence possessed by the males for fighting with and driving
away their rivals—their courage and pugnacity—their ornaments of many
kinds—their organs for producing vocal or instrumental music—and their
glands for emitting odours; most of these latter structures serving only to
allure or excite the female. That these characters are the result of sexual and
not of ordinary selection is clear, as unarmed, unornamented, or unattractive
males would succeed equally well in the battle for life and in leaving a
numerous progeny, if better endowed males were not present. We may infer
that this would be the case, for the females, which are unarmed and
unornamented, are able to survive and procreate their kind. Secondary
sexual characters of the kind just referred to, will be fully discussed in the
following chapters, as they are in many respects interesting, but more
especially as they depend on the will, choice, and rivalry of the individuals
of either sex. When we behold two males fighting for the possession of the
female, or several male birds displaying their gorgeous plumage, and

performing the strangest antics before an assembled body of females, we
cannot doubt that, though led by instinct, they know what they are about,
and consciously exert their mental and bodily powers.
In the same manner as man can improve the breed of his game-cocks by the
selection of those birds which are victorious in the cockpit, so it appears
that the strongest and most vigorous males, or those provided with the best
weapons, have prevailed under nature, and have led to the improvement of
the natural breed or species. Through repeated deadly contests, a slight
degree of variability, if it led to some advantage, however slight, would
suffice for the work of sexual selection; and it is certain that secondary
sexual characters are eminently variable. In the same manner as man can
give beauty, according to his standard of taste, to his male poultry—can
give to the Sebright bantam a new and elegant plumage, an erect and
peculiar carriage—so it appears that in a state of nature female birds, by
having long selected the more attractive males, have added to their beauty.
No doubt this implies powers of discrimination and taste on the part of the
female which will at first appear extremely improbable; but I hope hereafter
to shew that this is not the case.
From our ignorance on several points, the precise manner in which sexual
selection acts is to a certain extent uncertain. Nevertheless if those
naturalists who already believe in the mutability of species, will read the
following chapters, they will, I think, agree with me that sexual selection
has played an important part in the history of the organic world. It is certain
that with almost all animals there is a struggle between the males for the
possession of the female. This fact is so notorious that it would be
superfluous to give instances. Hence the females, supposing that their
mental capacity sufficed for the exertion of a choice, could select one out of
several males. But in numerous cases it appears as if it had been specially
arranged that there should be a struggle between many males. Thus with
migratory birds, the males generally arrive before the females at their place
of breeding, so that many males are ready to contend for each female. The
bird-catchers assert that this is invariably the case with the nightingale and
blackcap, as I am informed by Mr. Jenner Weir, who confirms the statement
with respect to the latter species.

Mr. Swaysland of Brighton, who has been in the habit, during the last forty
years, of catching our migratory birds on their first arrival, writes to me that
he has never known the females of any species to arrive before their males.
During one spring he shot thirty-nine males of Ray’s wagtail (Budytes Raii)
before he saw a single female. Mr. Gould has ascertained by dissection, as
he informs me, that male snipes arrive in this country before the females. In
the case of fish, at the period when the salmon ascend our rivers, the males
in large numbers are ready to breed before the females. So it apparently is
with frogs and toads. Throughout the great class of insects the males almost
always emerge from the pupal state before the other sex, so that they
generally swarm for a time before any females can be seen.338 The cause of
this difference between the males and females in their periods of arrival and
maturity is sufficiently obvious. Those males which annually first migrated
into any country, or which in the spring were first ready to breed, or were
the most eager, would leave the largest number of offspring; and these
would tend to inherit similar instincts and constitutions. On the whole there
can be no doubt that with almost all animals, in which the sexes are
separate, there is a constantly recurrent struggle between the males for the
possession of the females.
Our difficulty in regard to sexual selection lies in understanding how it is
that the males which conquer other males, or those which prove the most
attractive to the females, leave a greater number of offspring to inherit their
superiority than the beaten and less attractive males. Unless this result
followed, the characters which gave to certain males an advantage over
others, could not be perfected and augmented through sexual selection.
When the sexes exist in exactly equal numbers, the worst-endowed males
will ultimately find females (excepting where polygamy prevails), and
leave as many offspring, equally well fitted for their general habits of life,
as the best-endowed males. From various facts and considerations, I
formerly inferred that with most animals, in which secondary sexual
characters were well developed, the males considerably exceeded the
females in number; and this does hold good in some few cases. If the males
were to the females as two to one, or as three to two, or even in a somewhat
lower ratio, the whole affair would be simple; for the better-armed or more
attractive males would leave the largest number of offspring. But after
investigating, as far as possible, the numerical proportions of the sexes, I do

not believe that any great inequality in number commonly exists. In most
cases sexual selection appears to have been effective in the following
manner.
Let us take any species, a bird for instance, and divide the females
inhabiting a district into two equal bodies: the one consisting of the more
vigorous and better-nourished individuals, and the other of the less vigorous
and healthy. The former, there can be little doubt, would be ready to breed
in the spring before the others; and this is the opinion of Mr. Jenner Weir,
who has during many years carefully attended to the habits of birds. There
can also be no doubt that the most vigorous, healthy, and best-nourished
females would on an average succeed in rearing the largest number of
offspring. The males, as we have seen, are generally ready to breed before
the females; of the males the strongest, and with some species the best
armed, drive away the weaker males; and the former would then unite with
the more vigorous and best-nourished females, as these are the first to
breed. Such vigorous pairs would surely rear a larger number of offspring
than the retarded females, which would be compelled, supposing the sexes
to be numerically equal, to unite with the conquered and less powerful
males; and this is all that is wanted to add, in the course of successive
generations, to the size, strength and courage of the males, or to improve
their weapons.
But in a multitude of cases the males which conquer other males, do not
obtain possession of the females, independently of choice on the part of the
latter. The courtship of animals is by no means so simple and short an affair
as might be thought. The females are most excited by, or prefer pairing
with, the more ornamented males, or those which are the best songsters, or
play the best antics; but it is obviously probable, as has been actually
observed in some cases, that they would at the same time prefer the more
vigorous and lively males.339 Thus the more vigorous females, which are the
first to breed, will have the choice of many males; and though they may not
always select the strongest or best armed, they will select those which are
vigorous and well armed, and in other respects the most attractive. Such
early pairs would have the same advantage in rearing offspring on the
female side as above explained, and nearly the same advantage on the male
side. And this apparently has sufficed during a long course of generations to

add not only to the strength and fighting-powers of the males, but likewise
to their various ornaments or other attractions.
In the converse and much rarer case of the males selecting particular
females, it is plain that those which were the most vigorous and had
conquered others, would have the freest choice; and it is almost certain that
they would select vigorous as well as attractive females. Such pairs would
have an advantage in rearing offspring, more especially if the male had the
power to defend the female during the pairing-season, as occurs with some
of the higher animals, or aided in providing for the young. The same
principles would apply if both sexes mutually preferred and selected certain
individuals of the opposite sex; supposing that they selected not only the
more attractive, but likewise the more vigorous individuals.
Numerical Proportion of the Two Sexes.—I have remarked that sexual
selection would be a simple affair if the males considerably exceeded in
number the females. Hence I was led to investigate, as far as I could, the
proportions between the two sexes of as many animals as possible; but the
materials are scanty. I will here give only a brief abstract of the results,
retaining the details for a supplementary discussion, so as not to interfere
with the course of my argument. Domesticated animals alone afford the
opportunity of ascertaining the proportional numbers at birth; but no
records have been specially kept for this purpose. By indirect means,
however, I have collected a considerable body of statistical data, from
which it appears that with most of our domestic animals the sexes are nearly
equal at birth. Thus with race-horses, 25,560 births have been recorded
during twenty-one years, and the male births have been to the female births
as 99·7 to 100. With greyhounds the inequality is greater than with any
other animal, for during twelve years, out of 6878 births, the male births
have been as 110·1 to 100 female births. It is, however, in some degree
doubtful whether it is safe to infer that the same proportional numbers
would hold good under natural conditions as under domestication; for slight
and unknown differences in the conditions affect to a certain extent the
proportion of the sexes. Thus with mankind, the male births in England are
as 104·5, in Russia as 108·9, and with the Jews of Livornia as 120 to 100
females. The proportion is also mysteriously affected by the circumstance
of the births being legitimate or illegitimate.

For our present purpose we are concerned with the proportion of the sexes,
not at birth, but at maturity, and this adds another element of doubt; for it is
a well ascertained fact that with man a considerably larger proportion of
males than of females die before or during birth, and during the first few
years of infancy. So it almost certainly is with male lambs, and so it may be
with the males of other animals. The males of some animals kill each other
by fighting; or they drive each other about until they become greatly
emaciated. They must, also, whilst wandering about in eager search for the
females, be often exposed to various dangers. With many kinds of fish the
males are much smaller than the females, and they are believed often to be
devoured by the latter or by other fishes. With some birds the females
appear to die in larger proportion than the males: they are also liable to be
destroyed on their nests, or whilst in charge of their young. With insects the
female larvæ are often larger than those of the males, and would
consequently be more likely to be devoured: in some cases the mature
females are less active and less rapid in their movements than the males,
and would not be so well able to escape from danger. Hence, with animals
in a state of nature, in order to judge of the proportions of the sexes at
maturity, we must rely on mere estimation; and this, except perhaps when
the inequality is strongly marked, is but little trustworthy. Nevertheless, as
far as a judgment can be formed, we may conclude from the facts given in
the supplement, that the males of some few mammals, of many birds, of
some fish and insects, considerably exceed in number the females.
The proportion between the sexes fluctuates slightly during successive
years: thus with race-horses, for every 100 females born, the males varied
from 1O7.1 in one year to 92.6 in another year, and with greyhounds from
116.3 to 95.3. But had larger numbers been tabulated throughout a more
extensive area than England, these fluctuations would probably have
disappeared; and such as they are, they would hardly suffice to lead under a
state of nature to the effective action of sexual selection. Nevertheless with
some few wild animals, the proportions seem, as shewn in the supplement,
to fluctuate either during different seasons or in different localities in a
sufficient degree to lead to such action. For it should be observed that any
advantage gained during certain years or in certain localities by those males
which were able to conquer other males, or were the most attractive to the
females, would probably be transmitted to the offspring and would not

subsequently be eliminated. During the succeeding seasons, when from the
equality of the sexes every male was everywhere able to procure a female,
the stronger or more attractive males previously produced would still have
at least as good a chance of leaving offspring as the less strong or less
attractive.
Polygamy.—The practice of polygamy leads to the same results as would
follow from an actual inequality in the number of the sexes; for if each male
secures two or more females, many males will not be able to pair; and the
latter assuredly will be the weaker or less attractive individuals. Many
mammals and some few birds are polygamous, but with animals belonging
to the lower classes I have found no evidence of this habit. The intellectual
powers of such animals are, perhaps, not sufficient to lead them to collect
and guard a harem of females. That some relation exists between polygamy
and the development of secondary sexual characters, appears nearly certain;
and this supports the view that a numerical preponderance of males would
be eminently favourable to the action of sexual selection. Nevertheless
many animals, especially birds, which are strictly monogamous, display
strongly-marked secondary sexual characters; whilst some few animals,
which are polygamous, are not thus characterised.

We will first briefly run through the class of mammals, and then turn to
birds. The gorilla seems to be a polygamist, and the male differs
considerably from the female; so it is with some baboons which live in
herds containing twice as many adult females as males. In South America
the Mycetes caraya presents well-marked sexual differences in colour,
beard, and vocal organs, and the male generally lives with two or three
wives: the male of the Cebus capucinus differs somewhat from the female,
and appears to be polygamous.340 Little is known on this head with respect to
most other monkeys, but some species are strictly monogamous. The
ruminants are eminently polygamous, and they more frequently present
sexual differences than almost any other group of mammals, especially in
their weapons, but likewise in other characters. Most deer, cattle, and sheep
are polygamous; as are most antelopes, though some of the latter are
monogamous. Sir Andrew Smith, in speaking of the antelopes of South
Africa, says that in herds of about a dozen there was rarely more than one
mature male. The Asiatic Antilope saiga appears to be the most inordinate

polygamist in the world; for Pallas341 states that the male drives away all
rivals, and collects a herd of about a hundred, consisting of females and
kids: the female is hornless and has softer hair, but does not otherwise differ
much from the male. The horse is polygamous, but, except in his greater
size and in the proportions of his body, differs but little from the mare. The
wild boar, in his great tusks and some other characters, presents well-
marked sexual characters; in Europe and in India he leads a solitary life,
except during the breeding-season; but at this season he consorts in India
with several females, as Sir W. Elliot, who has had large experience in
observing this animal, believes: whether this holds good in Europe is
doubtful, but is supported by some statements. The adult male Indian
elephant, like the boar, passes much of his time in solitude; but when
associating with others, “it is rare to find,” as Dr. Campbell states, “more
than one male with a whole herd of females.” The larger males expel or kill
the smaller and weaker ones. The male differs from the female by his
immense tusks and greater size, strength, and endurance; so great is the
difference in these latter respects, that the males when caught are valued at
twenty per cent. above the females.342 With other pachydermatous animals
the sexes differ very little or not at all, and they are not, as far as known,
polygamists. Hardly a single species amongst the Cheiroptera and Edentata,
or in the great Orders of the Rodents and Insectivora, presents well-
developed secondary sexual differences; and I can find no account of any
species being polygamous, excepting, perhaps, the common rat, the males
of which, as some rat-catchers affirm, live with several females.
The lion in South Africa, as I hear from Sir Andrew Smith, sometimes lives
with a single female, but generally with more than one, and, in one case,
was found with as many as five females, so that he is polygamous. He is, as
far as I can discover, the sole polygamist in the whole group of the
terrestrial Carnivora, and he alone presents well-marked sexual characters.
If, however, we turn to the marine Carnivora, the case is widely different;
for many species of seals offer, as we shall hereafter see, extraordinary
sexual differences, and they are eminently polygamous. Thus the male sea-
elephant of the Southern Ocean, always possesses, according to Péron,
several females, and the sea-lion of Forster is said to be surrounded by from
twenty to thirty females. In the North, the male sea-bear of Steller is
accompanied by even a greater number of females.

With respect to birds, many species, the sexes of which differ greatly from
each other, are certainly monogamous. In Great Britain we see well-marked
sexual differences in, for instance, the wild-duck which pairs with a single
female, with the common blackbird, and with the bullfinch which is said to
pair for life. So it is, as I am informed by Mr. Wallace, with the Chatterers
or Cotingidæ of South America, and numerous other birds. In several
groups I have not been able to discover whether the species are polygamous
or monogamous. Lesson says that birds of paradise, so remarkable for their
sexual differences, are polygamous, but Mr. Wallace doubts whether he had
sufficient evidence. Mr. Salvin informs me that he has been led to believe
that humming-birds are polygamous. The male widow-bird; remarkable for
his caudal plumes, certainly seems to be a polygamist.343 I have been assured
by Mr. Jenner Weir and by others, that three starlings not rarely frequent the
same nest; but whether this is a case of polygamy or polyandry has not been
ascertained.
The Gallinaceæ present almost as strongly marked sexual differences as
birds of paradise or humming-birds, and many of the species are, as is well
known, polygamous; others being strictly monogamous. What a contrast is
presented between the sexes by the polygamous peacock or pheasant, and
the monogamous guinea-fowl or partridge! Many similar cases could be
given, as in the grouse tribe, in which the males of the polygamous
capercailzie and black-cock differ greatly from the females; whilst the sexes
of the monogamous red grouse and ptarmigan differ very little. Amongst the
Cursores, no great number of species offer strongly-marked sexual
differences, except the bustards, and the great bustard (Otis tarda), is said to
be polygamous. With the Grallatores, extremely few species differ sexually,
but the ruff (Machetes pugnax) affords a strong exception, and this species
is believed by Montagu to be a polygamist. Hence it appears that with birds
there often exists a close relation between polygamy and the development
of strongly-marked sexual differences. On asking Mr. Bartlett, at the
Zoological Gardens, who has had such large experience with birds, whether
the male tragopan (one of the Gallinaceæ) was polygamous, I was struck by
his answering, “I do not know, but should think so from his splendid
colours.”
It deserves notice that the instinct of pairing with a single female is easily
lost under domestication. The wild-duck is strictly monogamous, the

domestic-duck highly polygamous. The Rev. W. D. Fox informs me that
with some half-tamed wild-ducks, kept on a large pond in his
neighbourhood, so many mallards were shot by the gamekeeper that only
one was left for every seven or eight females; yet unusually large broods
were reared. The guinea-fowl is strictly monogamous; but Mr. Fox finds
that his birds succeed best when he keeps one cock to two or three hens.344
Canary-birds pair in a state of nature, but the breeders in England
successfully put one male to four or five females; nevertheless the first
female, as Mr. Fox has been assured, is alone treated as the wife, she and
her young ones being fed by him; the others are treated as concubines. I
have noticed these cases, as it renders it in some degree probable that
monogamous species, in a state of nature, might readily become either
temporarily or permanently polygamous.
With respect to reptiles and fishes, too little is known of their habits to
enable us to speak of their marriage arrangements. The stickle-back
Gasterosteus, however, is said to be a polygamist;345 and the male during the
breeding-season differs conspicuously from the female.
To sum up on the means through which, as far as we can judge, sexual
selection has led to the development of secondary sexual characters. It has
been shewn that the largest number of vigorous offspring will be reared
from the pairing of the strongest and best-armed males, which have
conquered other males, with the most vigorous and best-nourished females,
which are the first to breed in the spring. Such females, if they select the
more attractive, and at the same time vigorous, males, will rear a larger
number of offspring than the retarded females, which must pair with the
less vigorous and less attractive males. So it will be if the more vigorous
males select the more attractive and at the same time healthy and vigorous
females; and this will especially hold good if the male defends the female,
and aids in providing food for the young. The advantage thus gained by the
more vigorous pairs in rearing a larger number of offspring has apparently
sufficed to render sexual selection efficient. But a large preponderance in
number of the males over the females would be still more efficient; whether
the preponderance was only occasional and local, or permanent; whether it
occurred at birth, or subsequently from the greater destruction of the
females; or whether it indirectly followed from the practice of polygamy.

The Male generally more modified than the Female.—Throughout the
animal kingdom, when the sexes differ from each other in external
appearance, it is the male which, with rare exceptions, has been chiefly
modified; for the female still remains more like the young of her own
species, and more like the other members of the same group. The cause of
this seems to lie in the males of almost all animals having stronger passions
than the females. Hence it is the males that fight together and sedulously
display their charms before the females; and those which are victorious
transmit their superiority to their male offspring. Why the males do not
transmit their characters to both sexes will hereafter be considered. That the
males of all mammals eagerly pursue the females is notorious to every one.
So it is with birds; but many male birds do not so much pursue the female,
as display their plumage, perform strange antics, and pour forth their song,
in her presence. With the few fish which have been observed, the male
seems much more eager than the female; and so it is with alligators, and
apparently with Batrachians. Throughout the enormous class of insects, as
Kirby remarks,346 “the law is, that the male shall seek the female.” With
spiders and crustaceans, as I hear from two great authorities, Mr. Blackwall
and Mr. C. Spence Bate, the males are more active and more erratic in their
habits than the females. With insects and crustaceans, when the organs of
sense or locomotion are present in the one sex and absent in the other, or
when, as is frequently the case, they are more highly developed in the one
than the other, it is almost invariably the male, as far as I can discover,
which retains such organs, or has them most developed; and this shews that
the male is the more active member in the courtship of the sexes.347

The female, on the other hand, with the rarest exception, is less eager than
the male. As the illustrious Hunter348 long ago observed, she generally
“requires to be courted;” she is coy, and may often be seen endeavouring for
a long time to escape from the male. Every one who has attended to the
habits of animals will be able to call to mind instances of this kind. Judging
from various facts, hereafter to be given, and from the results which may
fairly be attributed to sexual selection, the female, though comparatively
passive, generally exerts some choice and accepts one male in preference to
others. Or she may accept, as appearances would sometimes lead us to
believe, not the male which is the most attractive to her, but the one which

is the least distasteful. The exertion of some choice on the part of the female
seems almost as general a law as the eagerness of the male.
We are naturally led to enquire why the male in so many and such widely
distinct classes has been rendered more eager than the female, so that he
searches for her and plays the more active part in courtship. It would be no
advantage and some loss of power if both sexes were mutually to search for
each other; but why should the male almost always be the seeker? With
plants, the ovules after fertilisation have to be nourished for a time; hence
the pollen is necessarily brought to the female organs—being placed on the
stigma, through the agency of insects or of the wind, or by the spontaneous
movements of the stamens; and with the Algæ, &c., by the locomotive
power of the antherozooids. With lowly-organised animals permanently
affixed to the same spot and having their sexes separate, the male element is
invariably brought to the female; and we can see the reason; for the ova,
even if detached before being fertilised and not requiring subsequent
nourishment or protection, would be, from their larger relative size, less
easily transported than the male element. Hence plants349 and many of the
lower animals are, in this respect, analogous. In the case of animals not
affixed to the same spot, but enclosed within a shell with no power of
protruding any part of their bodies, and in the case of animals having little
power of locomotion, the males must trust the fertilising element to the risk
of at least a short transit through the waters of the sea. It would, therefore,
be a great advantage to such animals, as their organisation became
perfected, if the males when ready to emit the fertilising element, were to
acquire the habit of approaching the female as closely as possible. The
males of various lowly-organised animals having thus aboriginally acquired
the habit of approaching and seeking the females, the same habit would
naturally be transmitted to their more highly developed male descendants;
and in order that they should become efficient seekers, they would have to
be endowed with strong passions. The acquirement of such passions would
naturally follow from the more eager males leaving a larger number of
offspring than the less eager.
The great eagerness of the male has thus indirectly led to the much more
frequent development of secondary sexual characters in the male than in the
female. But the development of such characters will have been much aided,
if the conclusion at which I arrived after studying domesticated animals,

can be trusted, namely, that the male is more liable to vary than the female.
I am aware how difficult it is to verify a conclusion of this kind. Some
slight evidence, however, can be gained by comparing the two sexes in
mankind, as man has been more carefully observed than any other animal.
During the Novara Expedition350 a vast number of measurements of various
parts of the body in different races were made, and the men were found in
almost every case to present a greater range of variation than the women;
but I shall have to recur to this subject in a future chapter. Mr. J. Wood,351
who has carefully attended to the variation of the muscles in man, puts in
italics the conclusion that “the greatest number of abnormalities in each
subject is found in the males.” He had previously remarked that “altogether
in 102 subjects the varieties of redundancy were found to be half as many
again as in females, contrasting widely with the greater frequency of
deficiency in females before described.” Professor Macalister like wise
remarks352 that variations in the muscles “are probably more common in
males than females.” Certain muscles which are not normally present in
mankind are also more frequently developed in the male than in the female
sex, although exceptions to this rule are said to occur. Dr. Burt Wilder353 has
tabulated the cases of 152 individuals with supernumerary digits, of which
86 were males, and 39, or less than half, females; the remaining 27 being of
unknown sex. It should not, however, be overlooked that women would
more frequently endeavour to conceal a deformity of this kind than men.
Whether the large proportional number of deaths of the male offspring of
man and apparently of sheep, compared with the female offspring, before,
during, and shortly after birth (see supplement), has any relation to a
stronger tendency in the organs of the male to vary and thus to become
abnormal in structure or function, I will not pretend to conjecture.
In various classes of animals a few exceptional cases occur, in which the
female instead of the male has acquired well pronounced secondary sexual
characters, such as brighter colours, greater size, strength, or pugnacity.
With birds, as we shall hereafter see, there has sometimes been a complete
transposition of the ordinary characters proper to each sex; the females
having become the more eager in courtship, the males remaining
comparatively passive, but apparently selecting, as we may infer from the
results, the more attractive females. Certain female birds have thus been
rendered more highly coloured or otherwise ornamented, as well as more

powerful and pugnacious than the males, these characters being transmitted
to the female offspring alone.
It may be suggested that in some cases a double process of selection has
been carried on; the males having selected the more attractive females, and
the latter the more attractive males. This process however, though it might
lead to the modification of both sexes, would not make the one sex different
from the other, unless indeed their taste for the beautiful differed; but this is
a supposition too improbable in the case of any animal, excepting man, to
be worth considering. There are, however, many animals, in which the
sexes resemble each other, both being furnished with the same ornaments,
which analogy would lead us to attribute to the agency of sexual selection.
In such cases it may be suggested with more plausibility, that there has been
a double or mutual process of sexual selection; the more vigorous and
precocious females having selected the more attractive and vigorous males,
the latter having rejected all except the more attractive females. But from
what we know of the habits of animals, this view is hardly probable, the
male being generally eager to pair with any female. It is more probable that
the ornaments common to both sexes were acquired by one sex, generally
the male, and then transmitted to the offspring of both sexes. If, indeed,
during a lengthened period the males of any species were greatly to exceed
the females in number, and then during another lengthened period under
different conditions the reverse were to occur, a double, but not
simultaneous, process of sexual selection might easily be carried on, by
which the two sexes might be rendered widely different.
We shall hereafter see that many animals exist, of which neither sex is
brilliantly coloured or provided with special ornaments, and yet the
members of both sexes or of one alone have probably been modified
through sexual selection. The absence of bright tints or other ornaments
may be the result of variations of the right kind never having occurred, or of
the animals themselves preferring simple colours, such as plain black or
white. Obscure colours have often been acquired through natural selection
for the sake of protection, and the acquirement through sexual selection of
conspicuous colours, may have been checked from the danger thus
incurred. But in other cases the males have probably struggled together
during long ages, through brute force, or by the display of their charms, or
by both means combined, and yet no effect will have been produced unless

a larger number of offspring were left by the more successful males to
inherit their superiority, than by the less successful males; and this, as
previously shewn, depends on various complex contingencies.
Sexual selection acts in a less rigorous manner than natural selection. The
latter produces its effects by the life or death at all ages of the more or less
successful individuals. Death, indeed, not rarely ensues from the conflicts
of rival males. But generally the less successful male merely fails to obtain
a female, or obtains later in the season a retarded and less vigorous female,
or, if polygamous, obtains fewer females; so that they leave fewer, or less
vigorous, or no offspring. In regard to structures acquired through ordinary
or natural selection, there is in most cases, as long as the conditions of life
remain the same, a limit to the amount of advantageous modification in
relation to certain special ends; but in regard to structures adapted to make
one male victorious over another, either in fighting or in charming the
female, there is no definite limit to the amount of advantageous
modification; so that as long as the proper variations arise the work of
sexual selection will go on. This circumstance may partly account for the
frequent and extraordinary amount of variability presented by secondary
sexual characters. Nevertheless, natural selection will determine that
characters of this kind shall not be acquired by the victorious males, which
would be injurious to them in any high degree, either by expending too
much of their vital powers, or by exposing them to any great danger. The
development, however, of certain structures—of the horns, for instance, in
certain stags—has been carried to a wonderful extreme; and in some
instances to an extreme which, as far as the general conditions of life are
concerned, must be slightly injurious to the male. From this fact we learn
that the advantages which favoured males have derived from conquering
other males in battle or courtship, and thus leaving a numerous progeny,
have been in the long run greater than those derived from rather more
perfect adaptation to the external conditions of life. We shall further see,
and this could never have been anticipated, that the power to charm the
female has been in some few instances more important than the power to
conquer other males in battle.

LAWS OF INHERITANCE.

In order to understand how sexual selection has acted, and in the course of
ages has produced conspicuous results with many animals of many classes,
it is necessary to bear in mind the laws of inheritance, as far as they are
known. Two distinct elements are included under the term “inheritance,”
namely the transmission and the development of characters; but as these
generally go together, the distinction is often overlooked. We see this
distinction in those characters which are transmitted through the early years
of life, but are developed only at maturity or during old age. We see the
same distinction more clearly with secondary sexual characters, for these
are transmitted through both sexes, though developed in one alone. That
they are present in both sexes, is manifest when two species, having
strongly-marked sexual characters, are crossed, for each transmits the
characters proper to its own male and female sex to the hybrid offspring of
both sexes. The same fact is likewise manifest, when characters proper to
the male are occasionally developed in the female when she grows old or
becomes diseased; and so conversely with the male. Again, characters
occasionally appear, as if transferred from the male to the female, as when,
in certain breeds of the fowl, spurs regularly appear in the young and
healthy females; but in truth they are simply developed in the female; for in
every breed each detail in the structure of the spur is transmitted through the
female to her male offspring. In all cases of reversion, characters are
transmitted through two, three, or many generations, and are then under
certain unknown favourable conditions developed. This important
distinction between transmission and development will be easiest kept in
mind by the aid of the hypothesis of pangenesis, whether or not it be
accepted as true. According to this hypothesis, every unit or cell of the body
throws off gemmules or undeveloped atoms, which are transmitted to the
offspring of both sexes, and are multiplied by self-division. They may
remain undeveloped during the early years of life or during successive
generations; their development into units or cells, like those from which
they were derived, depending on their affinity for, and union with, other
units or cells previously developed in the due order of growth.

Inheritance at Corresponding Periods of Life.—This tendency is well
established. If a new character appears in an animal whilst young, whether
it endures throughout life or lasts only for a time, it will reappear, as a
general rule, at the same age and in the same manner in the offspring. If, on

the other hand, a new character appears at maturity, or even during old age,
it tends to reappear in the offspring at the same advanced age. When
deviations from this rule occur, the transmitted characters much oftener
appear before than after the corresponding age. As I have discussed this
subject at sufficient length in another work,354 I will here merely give two or
three instances, for the sake of recalling the subject to the reader’s mind. In
several breeds of the Fowl, the chickens whilst covered with down, in their
first true plumage, and in their adult plumage, differ greatly from each
other, as well as from their common parent-form, the Gallus bankiva; and
these characters are faithfully transmitted by each breed to their offspring at
the corresponding period of life. For instance, the chickens of spangled
Hamburghs, whilst covered with down, have a few dark spots on the head
and rump, but are not longitudinally striped, as in many other breeds; in
their first true plumage, “they are beautifully pencilled,” that is each feather
is transversely marked by numerous dark bars; but in their second plumage
the feathers all become spangled or tipped with a dark round spot.355 Hence
in this breed variations have occurred and have been transmitted at three
distinct periods of life. The Pigeon offers a more remarkable case, because
the aboriginal parent-species does not undergo with advancing age any
change of plumage, excepting that at maturity the breast becomes more
iridescent; yet there are breeds which do not acquire their characteristic
colours until they have moulted two, three, or four times; and these
modifications of plumage are regularly transmitted.

Inheritance at Corresponding Seasons of the Year.—With animals in a state
of nature innumerable instances occur of characters periodically appearing
at different seasons. We see this with the horns of the stag, and with the fur
of arctic animals which becomes thick and white during the winter.
Numerous birds acquire bright colours and other decorations during the
breeding-season alone. I can throw but little light on this form of
inheritance from facts observed under domestication. Pallas states,356 that in
Siberia domestic cattle and horses periodically become lighter-coloured
during the winter; and I have observed a similar marked change of colour in
certain ponies in England. Although I do not know that this tendency to
assume a differently coloured coat during different seasons of the year is
transmitted, yet it probably is so, as all shades of colour are strongly

inherited by the horse. Nor is this form of inheritance, as limited by season,
more remarkable than inheritance as limited by age or sex.

Inheritance as Limited by Sex.—The equal transmission of characters to
both, sexes is the commonest form of inheritance, at least with those
animals which do not present strongly-marked sexual differences, and
indeed with many of these. But characters are not rarely transferred
exclusively to that sex, in which they first appeared. Ample evidence on this
head has been advanced in my work on Variation under Domestication; but
a few instances may here be given. There are breeds of the sheep and goat,
in which the horns of the male differ greatly in shape from those of the
female; and these differences, acquired under domestication, are regularly
transmitted to the same sex. With tortoise-shell cats the females alone, as a
general rule, are thus coloured, the males being rusty-red. With most breeds
of the fowl, the characters proper to each sex are transmitted to the same
sex alone. So general is this form of transmission that it is an anomaly when
we see in certain breeds variations transmitted equally to both sexes. There
are also certain sub-breeds of the fowl in which the males can hardly be
distinguished from each other, whilst the females differ considerably in
colour. With the pigeon the sexes of the parent-species do not differ in any
external character; nevertheless in certain domesticated breeds the male is
differently coloured from the female.357 The wattle in the English Carrier
pigeon and the crop in the Pouter are more highly developed in the male
than in the female; and although these characters have been gained through
long-continued selection by man, the difference between the two sexes is
wholly due to the form of inheritance which has prevailed; for it has arisen,
not from, but rather in opposition to, the wishes of the breeder.
Most of our domestic races have been formed by the accumulation of many
slight variations; and as some of the successive steps have been transmitted
to one sex alone, and some to both sexes, we find in the different breeds of
the same species all gradations between great sexual dissimilarity and
complete similarity. Instances have already been given with the breeds of
the fowl and pigeon; and under nature analogous cases are of frequent
occurrence. With animals under domestication, but whether under nature I
will not venture to say, one sex may lose characters proper to it, and may
thus come to resemble to a certain extent the opposite sex; for instance, the

males of some breeds of the fowl have lost their masculine plumes and
hackles. On the other hand the differences between the sexes may be
increased under domestication, as with merino sheep, in which the ewes
have lost their horns. Again, characters proper to one sex may suddenly
appear in the other sex; as with those sub-breeds of the fowl in which the
hens whilst young acquire spurs; or, as in certain Polish sub-breeds, in
which the females, as there is reason to believe, originally acquired a crest,
and subsequently transferred it to the males. All these cases are intelligible
on the hypothesis of pangenesis; for they depend on the gemmules of
certain units of the body, although present in both sexes, becoming through
the influence of domestication dormant in the one sex; or if naturally
dormant, becoming developed.
There is one difficult question which it will be convenient to defer to a
future chapter; namely, whether a character at first developed in both sexes,
can be rendered through selection limited in its development to one sex
alone. If, for instance, a breeder observed that some of his pigeons (in
which species characters are usually transferred in an equal degree to both
sexes) varied into pale blue; could he by long-continued selection make a
breed, in which the males alone should be of this tint, whilst the females
remained unchanged? I will here only say, that this, though perhaps not
impossible, would be extremely difficult; for the natural result of breeding
from the pale-blue males would be to change his whole stock, including
both sexes, into this tint. If, however, variations of the desired tint appeared,
which were from the first limited in their development to the male sex,
there would not be the least difficulty in making a breed characterised by
the two sexes being of a different colour, as indeed has been effected with a
Belgian breed, in which the males alone are streaked with black. In a
similar manner, if any variation appeared in a female pigeon, which was
from the first sexually limited in its development, it would be easy to make
a breed with the females alone thus characterised; but if the variation was
not thus originally limited, the process would be extremely difficult,
perhaps impossible.

On the Relation between the period of Development of a Character and its
transmission to one sex or to both sexes.—Why certain characters should be
inherited by both sexes, and other characters by one sex alone, namely by

that sex in which the character first appeared, is in most cases quite
unknown. We cannot even conjecture why with certain sub-breeds of the
pigeon, black striæ, though transmitted through the female, should be
developed in the male alone, whilst every other character is equally
transferred to both sexes. Why, again, with cats, the tortoise-shell colour
should, with rare exceptions, be developed in the female alone. The very
same characters, such as deficient or supernumerary digits, colour-
blindness, &c., may with mankind be inherited by the males alone of one
family, and in another family by the females alone, though in both cases
transmitted through the opposite as well as the same sex.358 Although we are
thus ignorant, two rules often hold good, namely that variations which, first
appear in either sex at a late period of life, tend to be developed in the same
sex alone; whilst variations which first appear early in life in either sex tend
to be developed in both sexes. I am, however, far from supposing that this is
the sole determining cause. As I have not elsewhere discussed this subject,
and as it has an important bearing on sexual selection, I must here enter into
lengthy and somewhat intricate details.
It is in itself probable that any character appearing at an early age would
tend to be inherited equally by both sexes, for the sexes do not differ much
in constitution, before the power of reproduction is gained. On the other
hand, after this power has been gained and the sexes have come to differ in
constitution, the gemmules (if I may again use the language of pangenesis)
which are cast off from each varying part in the one sex would be much
more likely to possess the proper affinities for uniting with the tissues of the
same sex, and thus becoming developed, than with those of the opposite
sex.
I was first led to infer that a relation of this kind exists, from the fact that
whenever and in whatever manner the adult male has come to differ from
the adult female, he differs in the same manner from the young of both
sexes. The generality of this fact is quite remarkable: it holds good with
almost all mammals, birds, amphibians, and fishes; also with many
crustaceans, spiders and some few insects, namely certain orthoptera and
libellulæ. In all these cases the variations, through the accumulation of
which the male acquired his proper masculine characters, must have
occurred at a somewhat late period of life; otherwise the young males
would have been similarly characterised; and conformably with our rule,

they are transmitted to and developed in the adult males alone. When, on
the other hand, the adult male closely resembles the young of both sexes
(these, with rare exceptions, being alike), he generally resembles the adult
female; and in most of these cases the variations through which the young
and old acquired their present characters, probably occurred in conformity
with our rule during youth. But there is here room for doubt, as characters
are sometimes transferred to the offspring at an earlier age than that at
which they first appeared in the parents, so that the parents may have varied
when adult, and have transferred their characters to their offspring whilst
young. There are, moreover, many animals, in which the two sexes closely
resemble each other, and yet both differ from their young; and here the
characters of the adults must have been acquired late in life; nevertheless,
these characters in apparent contradiction to our rule, are transferred to both
sexes. We must not, however, overlook the possibility or even probability of
successive variations of the same nature sometimes occurring, under
exposure to similar conditions, simultaneously in both sexes at a rather late
period of life; and in this case the variations would be transferred to the
offspring of both sexes at a corresponding late age; and there would be no
real contradiction to our rule of the variations which occur late in life being
transferred exclusively to the sex in which they first appeared. This latter
rule seems to hold true more generally than the second rule, namely, that
variations which occur in either sex early in life tend to be transferred to
both sexes. As it was obviously impossible even to estimate in how large a
number of cases throughout the animal kingdom these two propositions
hold good, it occurred to me to investigate some striking or crucial
instances, and to rely on the result.
An excellent case for investigation is afforded by the Deer Family. In all the
species, excepting one, the horns are developed in the male alone, though
certainly transmitted through the female, and capable of occasional
abnormal development in her. In the reindeer, on the other hand, the female
is provided with horns; so that in this species, the horns ought, according to
our rule, to appear early in life, long before the two sexes had arrived at
maturity and had come to differ much in constitution. In all the other
species of deer the horns ought to appear later in life, leading to their
development in that sex alone, in which they first appeared in the progenitor
of the whole Family. Now in seven species, belonging to distinct sections of

the family and inhabiting different regions, in which the stags alone bear
horns, I find that the horns first appear at periods varying from nine months
after birth in the roebuck to ten or twelve or even more months in the stags
of the six other larger species.359 But with the reindeer the case is widely
different, for as I hear from Prof. Nilsson, who kindly made special
enquiries for me in Lapland, the horns appear in the young animals within
four or five weeks after birth, and at the same time in both sexes. So that
here we have a structure, developed at a most unusually early age in one
species of the family, and common to both sexes in this one species.
In several kinds of antelopes the males alone are provided with horns,
whilst in the greater number both sexes have horns. With respect to the
period of development, Mr. Blyth informs me that there lived at one time in
the Zoological Gardens a young koodoo (Ant. strepsiceros), in which
species the males alone are horned, and the young of a closely-allied
species, viz. the eland (Ant. oreas), in which both sexes are horned. Now in
strict conformity with our rule, in the young male koodoo, although arrived
at the age of ten months, the horns were remarkably small considering the
size ultimately attained by them: whilst in the young male eland, although
only three months old, the horns were already very much larger than in the
koodoo. It is also worth notice that in the prong-horned antelope,360 in which
species the horns, though present in both sexes, are almost rudimentary in
the female, they do not appear until about five or six months after birth.
With sheep, goats, and cattle, in which the horns are well developed in both
sexes, though not quite equal in size, they can be felt, or even seen, at birth
or soon afterwards.361 Our rule, however, fails in regard to some breeds of
sheep, for instance merinos, in which the rams alone are horned; for I
cannot find on enquiry,362 that the horns are developed later in life in this
breed than in ordinary sheep in which both sexes are horned. But with
domesticated sheep the presence or absence of horns is not a firmly fixed
character; a certain proportion of the merino ewes bearing small horns, and
some of the rams being hornless; whilst with ordinary sheep hornless ewes
are occasionally produced.
In most of the species of the splendid family of the Pheasants, the males
differ conspicuously from the females, and they acquire their ornaments at a
rather late period of life. The eared pheasant (Crossoptilon auritum),
however, offers a remarkable exception, for both sexes possess the fine

caudal plumes, the large ear-tufts and the crimson velvet about the head;
and I find on enquiry in the Zoological Gardens that all these characters, in
accordance with our rule, appear very early in life. The adult male can,
however, be distinguished from the adult female by one character, namely
by the presence of spurs; and conformably with our rule, these do not begin
to be developed, as I am assured by Mr. Bartlett, before the age of six
months, and even at this age, can hardly be distinguished in the two sexes.363
The male and female Peacock differ conspicuously from each other in
almost every part of their plumage, except in the elegant head-crest, which
is common to both sexes; and this is developed very early in life, long
before the other ornaments which are confined to the male. The wild-duck
offers an analogous case, for the beautiful green speculum on the wings is
common to both sexes, though duller and somewhat smaller in the female,
and it is developed early in life, whilst the curled tail-feathers and other
ornaments peculiar to the male are developed later.364 Between such extreme
cases of close sexual resemblance and wide dissimilarity, as those of the
Crossoptilon and peacock, many intermediate ones could be given, in which
the characters follow in their order of development our two rules.
As most insects emerge from their pupal state in a mature condition, it is
doubtful whether the period of development determines the transference of
their characters to one or both sexes. But we do not know that the coloured
scales, for instance, in two species of butterflies, in one of which the sexes
differ in colour, whilst in the other they are alike, are developed at the same
relative age in the cocoon. Nor do we know whether all the scales are
simultaneously developed on the wings of the same species of butterfly, in
which certain coloured marks are confined to one sex, whilst other marks
are common to both sexes. A difference of this kind in the period of
development is not so improbable as it may at first appear; for with the
Orthoptera, which assume their adult state, not by a single metamorphosis,
but by a succession of moults, the young males of some species at first
resemble the females, and acquire their distinctive masculine characters
only during a later moult. Strictly analogous cases occur during the
successive moults of certain male crustaceans.
We have as yet only considered the transference of characters, relatively to
their period of development, with species in a natural state; we will now
turn to domesticated animals; first touching on monstrosities and diseases.

The presence of supernumerary digits, and the absence of certain phalanges,
must be determined at an early embryonic period—the tendency to profuse
bleeding is at least congenital, as is probably colour-blindness—yet these
peculiarities, and other similar ones, are often limited in their transmission
to one sex; so that the rule that characters which are developed at an early
period tend to be transmitted to both sexes, here wholly fails. But this rule,
as before remarked, does not appear to be nearly so generally true as the
converse proposition, namely, that characters which appear late in life in
one sex are transmitted exclusively to the same sex. From the fact of the
above abnormal peculiarities becoming attached to one sex. long before the
sexual functions are active, we may infer that there must be a difference of
some kind between the sexes at an extremely early age. With respect to
sexually-limited diseases, we know too little of the period at which they
originate, to draw any fair conclusion. Gout, however, seems to fall under
our rule; for it is generally caused by intemperance after early youth, and is
transmitted from the father to his sons in a much more marked manner than
to his daughters.
In the various domestic breeds of sheep, goats, and cattle, the males differ
from their respective females in the shape or development of their horns,
forehead, mane, dewlap, tail, and hump on the shoulders; and these
peculiarities, in accordance with our rule, are not fully developed until
rather late in life. With dogs, the sexes do not differ, except that in certain
breeds, especially in the Scotch deer-hound, the male is much larger and
heavier than the female; and as we shall see in a future chapter, the male
goes on increasing in size to an unusually late period of life, which will
account, according to our rule, for his increased size being transmitted to
his male offspring alone. On the other hand, the tortoise-shell colour of the
hair, which is confined to female cats, is quite distinct at birth, and this case
violates our rule. There is a breed of pigeons in which the males alone are
streaked with black, and the streaks can be detected even in the nestlings;
but they become more conspicuous at each successive moult, so that this
case partly opposes and partly supports the rule. With the English Carrier
and Pouter pigeon the full development of the wattle and the crop occurs
rather late in life, and these characters, conformably with our rule, are
transmitted in full perfection to the males alone. The following cases
perhaps come within the class previously alluded to, in which the two sexes

have varied in the same manner at a rather late period of life, and have
consequently transferred their new characters to both sexes at a
corresponding late period; and if so, such cases are not opposed to our rule.
Thus there are sub-breeds of the pigeon, described by Neumeister,365 both
sexes of which change colour after moulting twice or thrice, as does
likewise the Almond Tumbler; nevertheless these changes, though occurring
rather late in life, are common to both sexes. One variety of the Canary-
bird, namely the London Prize, offers a nearly analogous case.
With the breeds of the Fowl the inheritance of various characters by one sex
or by both sexes, seems generally determined by the period at which such
characters are developed. Thus in all the many breeds in which the adult
male differs greatly in colour from the female and from the adult male
parent-species, he differs from the young male, so that the newly acquired
characters must have appeared at a rather late period of life. On the other
hand with most of the breeds in which the two sexes resemble each other,
the young are coloured in nearly the same manner as their parents, and this
renders it probable that their colours first appeared early in life. We have
instances of this fact in all black and white breeds, in which the young and
old of both sexes are alike; nor can it be maintained that there is something
peculiar in a black or white plumage, leading to its transference to both
sexes; for the males alone of many natural species are either black or white,
the females being very differently coloured. With the so-called Cuckoo sub-
breeds of the fowl, in which the feathers are transversely pencilled with
dark stripes, both sexes and the chickens are coloured in nearly the same
manner. The laced plumage of the Sebright bantam is the same in both
sexes, and in the chickens the feathers are tipped with black, which makes a
near approach to lacing. Spangled Hamburghs, however, offer a partial
exception, for the two sexes, though not quite alike, resemble each other
more closely than do the sexes of the aboriginal parent-species, yet they
acquire their characteristic plumage late in life, for the chickens are
distinctly pencilled. Turning to other characters besides colour: the males
alone of the wild parent-species and of most domestic breeds possess a
fairly well developed comb, but in the young of the Spanish fowl it is
largely developed at a very early age, and apparently in consequence of this
it is of unusual size in the adult females. In the Game breeds pugnacity is
developed at a wonderfully early age, of which curious proofs could be

given; and this character is transmitted to both sexes, so that the hens, from
their extreme pugnacity, are now generally exhibited in separate pens. With
the Polish breeds the bony protuberance of the skull which supports the
crest is partially developed even before the chickens are hatched, and the
crest itself soon begins to grow, though at first feebly;366 and in this breed a
great bony protuberance and an immense crest characterise the adults of
both sexes.
Finally, from what we have now seen of the relation which exists in many
natural species and domesticated races, between the period of the
development of their characters and the manner of their transmission—for
example the striking fact of the early growth of the horns in the reindeer, in
which both sexes have horns, in comparison with their much later growth in
the other species in which the male alone bears horns—we may conclude
that one cause, though not the sole cause, of characters being exclusively
inherited by one sex, is their development at a late age. And secondly, that
one, though apparently a less efficient, cause of characters being inherited
by both sexes is their development at an early age, whilst the sexes differ
but little in constitution. It appears, however, that some difference must
exist between the sexes even during an early embryonic period, for
characters developed at this age not rarely become attached to one sex.

Summary and concluding remarks.—From the foregoing discussion on the
various laws of inheritance, we learn that characters often or even generally
tend to become developed in the same sex, at the same age, and periodically
at the same season of the year, in which they first appeared in the parents.
But these laws, from unknown causes, are very liable to change. Hence the
successive steps in the modification of a species might readily be
transmitted in different ways; some of the steps being transmitted to one
sex, and some to both; some to the offspring at one age, and some at all
ages. Not only are the laws of inheritance extremely complex, but so are the
causes which induce and govern variability. The variations thus caused are
preserved and accumulated by sexual selection, which is in itself an
extremely complex affair, depending, as it does, on ardour in love, courage,
and the rivalry of the males, and on the powers of perception, taste, and will
of the female. Sexual selection will also be dominated by natural selection
for the general welfare of the species. Hence the manner in which the

individuals of either sex or of both sexes are affected through sexual
selection cannot fail to be complex in the highest degree.
When variations occur late in life in one sex, and are transmitted to the
same sex at the same age, the other sex and the young are necessarily left
unmodified. When they occur late in life, but are transmitted to both sexes
at the same age, the young alone are left unmodified. Variations, however,
may occur at any period of life in one sex or in both, and be transmitted to
both sexes at all ages, and then all the individuals of the species will be
similarly modified. In the following chapters it will be seen that all these
cases frequently occur under nature.
Sexual selection can never act on any animal whilst young, before the age
for reproduction has arrived. From the great eagerness of the male it has
generally acted on this sex and not on the females. The males have thus
become provided with weapons for fighting with their rivals, or with organs
for discovering and securely holding the female, or for exciting and
charming her. When the sexes differ in these respects, it is also, as we have
seen, an extremely general law that the adult male differs more or less from
the young male; and we may conclude from this fact that the successive
variations, by which the adult male became modified, cannot have occurred
much before the age for reproduction. How then are we to account for this
general and remarkable coincidence between the period of variability and
that of sexual selection,—principles which are quite independent of each
other? I think we can see the cause: it is not that the males have never
varied at an early age, but that such variations have commonly been lost,
whilst those occurring at a later age have been preserved.
All animals produce more offspring than can survive to maturity; and we
have every reason to believe that death falls heavily on the weak and
inexperienced young. If then a certain proportion of the offspring were to
vary at birth or soon afterwards, in some manner which at this age was of
no service to them, the chance of the preservation of such variations would
be small. We have good evidence under domestication how soon variations
of all kinds are lost, if not selected. But variations which occurred at or near
maturity, and which were of immediate service to either sex, would
probably be preserved; as would similar variations occurring at an earlier
period in any individuals which happened to survive. As this principle has

an important bearing on sexual selection, it may be advisable to give an
imaginary illustration. We will take a pair of animals, neither very fertile
nor the reverse, and assume that after arriving at maturity they live on an
average for five years, producing each year five young. They would thus
produce 25 offspring; and it would not, I think, be an unfair estimate to
assume that 18 or 20 out of the 25 would perish before maturity, whilst still
young and inexperienced; the remaining seven or five sufficing to keep up
the stock of mature individuals. If so, we can see that variations which
occurred during youth, for instance in brightness, and which were not of the
least service to the young, would run a good chance of being utterly lost.
Whilst similar variations, which occurring at or near maturity in the
comparatively few individuals surviving to this age, and which immediately
gave an advantage to certain males, by rendering them more attractive to
the females, would be likely to be preserved. No doubt some of the
variations in brightness which occurred at an earlier age would by chance
be preserved, and eventually give to the male the same advantage as those
which appeared later; and this will account for the young males commonly
partaking to a certain extent (as may be observed with many birds) of the
bright colours of their adult male parents. If only a few of the successive
variations in brightness were to occur at a late age, the adult male would be
only a little brighter than the young male; and such cases are common.
In this illustration I have assumed that the young varied in a manner which
was of no service to them; but many characters proper to the adult male
would be actually injurious to the young,—as bright colours from making
them conspicuous, or horns of large size from expending much vital force.
Such variations in the young would promptly be eliminated through natural
selection. With the adult and experienced males, on the other hand, the
advantage thus derived in their rivalry with other males would often more
than counterbalance exposure to some degree of danger. Thus we can
understand how it is that variations which must originally have appeared
rather late in life have alone or in chief part been preserved for the
development of secondary sexual characters; and the remarkable
coincidence between the periods of variability and of sexual selection is
intelligible.
As variations which give to the male an advantage in lighting with other
males, or in finding, securing, or charming the female, would be of no use

to the female, they will not have been preserved in this sex either during
youth or maturity. Consequently such variations would be extremely liable
to be lost; and the female, as far as these characters are concerned, would be
left unmodified, excepting in so far as she may have received them by
transference from the male. No doubt if the female varied and transferred
serviceable characters to her male offspring, these would be favoured
through sexual selection; and then both sexes would thus far be modified in
the same manner. But I shall hereafter have to recur to these more intricate
contingencies.
In the following chapters, I shall treat of the secondary sexual characters in
animals of all classes, and shall endeavour in each case to apply the
principles explained in the present chapter. The lowest classes will detain us
for a very short time, but the higher animals, especially birds, must be
treated at considerable length. It should be borne in mind that for reasons
already assigned, I intend to give only a few illustrative instances of the
innumerable structures by the aid of which the male finds the female, or,
when found, holds her. On the other hand, all structures and instincts by
which the male conquers other males, and by which he allures or excites the
female, will be fully discussed, as these are in many ways the most
interesting.

Supplement on the proportional numbers of the two sexes in animals
belonging to various classes.

As no one, as far as I can discover, has paid attention to the relative
numbers of the two sexes throughout the animal kingdom, I will here give
such materials as I have been able to collect, although they are extremely
imperfect. They consist in only a few instances of actual enumeration, and
the numbers are not very large. As the proportions are known with certainty
on a large scale in the case of man alone, I will first give them, as a standard
of comparison.

Man.—In England during ten years (from 1857 to 1866) 707,120 children
on an annual average have been born alive, in the proportion of 104.5 males
to 100 females. But in 1857 the male births throughout England were as
105.2, and in 1865 as 104.0 to 100. Looking to separate districts, in

Buckinghamshire (where on an average 5000 children are annually born)
the mean proportion of male to female births, during the whole period of
the above ten years, was as 102.8 to 100; whilst in N. Wales (where the
average annual births are 12,873) it was as high as 106.2 to 100. Taking a
still smaller district, viz., Rutlandshire (where the annual births average
only 739), in 1864 the male births were as 114.6, and in 1862 as 97.0 to
100; but even in this small district the average of the 7385 births during the
whole ten years was as 104.5 to 100; that is in the same ratio as throughout
England.367 The proportions are sometimes slightly disturbed by unknown
causes; thus Prof. Faye states “that in some districts of Norway there has
been during a decennial period a steady deficiency of boys, whilst in others
the opposite condition has existed.” In France during forty-four years the
male to the female births have been as 106.2 to 100; but during this period
it has occurred five times in one department, and six times in another, that
the female births have exceeded the males. In Russia the average proportion
is as high as 108.9 to 100.368 It is a singular fact that with Jews the
proportion of male births is decidedly larger than with Christians: thus in
Prussia the proportion is as 113, in Breslau as 114, and in Livonia as 120 to
100; the Christian births in these countries being the same as usual, for
instance, in Livonia as 104 to 100.369 It is a still more singular fact that in
different nations, under different conditions and climates, in Naples,
Prussia, Westphalia, France and England, the excess of male over female
births is less when they are illegitimate than when legitimate.370
In various parts of Europe, according to Prof. Faye and other authors, “a
still greater preponderance of males would be met with, if death struck both
sexes in equal proportion in the womb and during birth. But the fact is, that
for every 100 still-born females, we have in several countries from 134.6 to
144.9 still-born males.” Moreover during the first four or five years of life
more male children die than females; “for example in England, during the
first year, 126 boys die for every 100 girls,—a proportion which in France
is still more unfavourable.”371 As a consequence of this excess in the death-
rate of male children, and of the exposure of men when adult to various
dangers, and of their tendency to emigrate, the females in all old-settled
countries, where statistical records have been kept,372 are found to
preponderate considerably over the males.

It has often been supposed that the relative ages of the parents determine the
sex of the offspring; and Prof. Leuckart373 has advanced what he considers
sufficient evidence, with respect to man and certain domesticated animals,
to shew that this is one important factor in the result. So again the period of
impregnation has been thought to be the efficient cause; but recent
observations discountenance this belief. Again, with mankind polygamy has
been supposed to lead to the birth of a greater proportion of female infants;
but Dr. J. Campbell374 carefully attended to this subject in the harems of
Siam, and he concludes that the proportion of male to female births is the
same as from monogamous unions. Hardly any animal has been rendered so
highly polygamous as our English race-horses, and we shall immediately
see that their male and female offspring are almost exactly equal in number.

Horses.—Mr. Tegetmeier has been so kind as to tabulate for me from the ‘Racing Calendar’ the
births of race-horses during a period of twenty-one years, viz. from 1846 to 1867; 1849 being
omitted, as no returns were that year published. The total births have been 25,560,375 consisting of
12,763 males and 12,797 females, or in the proportion of 99.7 males to 100 females. As these
numbers are tolerably large, and as they are drawn from all parts of England, during several years, we
may with much confidence conclude that with the domestic horse, or at least with the race-horse, the
two sexes are produced in almost equal numbers. The fluctuations in the proportions during
successive years are closely like those which occur with mankind, when a small and thinly-populated
area is considered: thus in 1856 the male horses were as 107.1, and in 1867 as only 92.6 to 100
females. In the tabulated returns the proportions vary in cycles, for the males exceeded the females
during six successive years; and the females exceeded the males during two periods each of four
years: this, however, may be accidental; at least I can detect nothing of the kind with man in the
decennial table in the Registrar’s Report for 1866. I may add that certain, mares, and this holds good
with certain cows and with women, tend to produce more of one sex than of the other; Mr. Wright of
Yeldersley House, informs me that one of his Arab mares, though put seven times to different horses,
produced seven fillies.

Dogs.—During a period of twelve years, from 1857 to 1868, the births of a large number of
greyhounds, throughout England, have been sent to the ‘Field’ newspaper; and I am again indebted to
Mr. Tegetmeier for carefully tabulating the results. The recorded, births have been 6878, consisting of
3605 males and 3273 females, that is, in the proportion of 110.1 males to 100 females. The greatest
fluctuations occurred in 1864, when the proportion was as 95.3 males, and in 1867, as 116.3 males to
100 females. The above average proportion of 110.1 to 100 is probably nearly correct in the case of
the greyhound, but whether it would hold with other domesticated breeds is in some degree doubtful.
Mr. Cupples has enquired from several great breeders of dogs, and finds that all without exception
believe that females are produced in excess; he suggests that this belief may have arisen from females
being less valued and the consequent disappointment producing a stronger impression on the mind.

Sheep.—The sexes of sheep are not ascertained by agriculturists until several months after birth, at
the period when the males are castrated; so that the following returns do not give the proportions at
birth. Moreover, I find that several great breeders in Scotland, who annually raise some thousand
sheep, are firmly convinced that a larger proportion of males than of females die during the first one
or two years; therefore the proportion of males would be somewhat greater at birth than at the age of
castration. This is a remarkable coincidence with what occurs, as we have seen, with mankind, and
both cases probably depend on some common cause. I have received returns from four gentlemen in
England who have bred lowland sheep, chiefly Leicesters, during the last ten or sixteen years; they
amount altogether to 8965 births, consisting of 4407 males and 4558 females; that is in the
proportion of 96.7 males to 100 females. With respect to Cheviot and black-faced sheep bred in
Scotland, I have received returns from six breeders, two of them on a large scale, chiefly for the years
1867-1869, but some of the returns extending back to 1862. The total number recorded amounts to
50,685, consisting of 25,071 males and 25,614 females, or in the proportion of 97.9 males to 100
females. If we take the English and Scotch returns together, the total number amounts to 59,650,
consisting of 29,478 males and 30,172 females, or as 97·7 to 100. So that with sheep at the age of
castration the females are certainly in excess of the males; but whether this would hold good at birth
is doubtful, owing to the greater liability in the males to early death.376

Of Cattle I have received returns from nine gentlemen of 982 births, too few to be trusted; these
consisted of 477 bull-calves and 505 cow-calves; i.e. in the proportion of 94·4 males to 100 females.
The Rev. W. D. Fox informs me that in 1867 out of 34 calves born on a farm in Derbyshire only one

was a bull. Mr. Harrison Weir writes to me that he has enquired from several breeders of Pigs, and
most of them estimate the male to the female births as about 7 to 6. This same gentleman has bred
Rabbits for many years, and has noticed that a far greater number of bucks are produced than does.

Of mammalia in a state of nature I have been able to learn very little. In regard to the common rat, I
have received conflicting statements. Mr. R. Elliot of Laighwood, informs me that a rat-catcher
assured him that he had always found the males in great excess, even with the young in the nest. In
consequence of this, Mr. Elliot himself subsequently examined some hundred old ones, and found the
statement true. Mr. F. Buckland has bred a large number of white rats, and he also believes that the
males greatly exceed the females. In regard to Moles, it is said that “the males are much more
numerous than the females;”377 and as the catching of these animals is a special occupation, the
statement may perhaps be trusted. Sir A. Smith, in describing an antelope of S. Africa378 (Kobus
ellipsiprymnus), remarks, that in the herds of this and other species, the males are few in number
compared with the females: the natives believe that they are born in this proportion; others believe
that the younger males are expelled from the herds, and Sir A. Smith says, that though he has himself
never seen herds consisting of young males alone, others affirm that this does occur. It appears
probable that the young males when expelled from the herd, would be likely to fell a prey to the
many beasts of prey of the country.

BIRDS.
With respect to the Fowl, I have received only one account, namely, that out of 1001 chickens of a
highly-bred stock of Cochins, reared during eight years by Mr. Stretch, 487 proved males and 514
females: i.e. as 94.7 to 100. In regard to domestic pigeons there is good evidence that the males are
produced in excess, or that their lives are longer; for these birds invariably pair, and single males, as
Mr. Tegetmeier informs me, can always be purchased cheaper than females. Usually the two birds
reared from the two eggs laid in the same nest consist of a male and female; but Mr. Harrison Weir,
who has been so large a breeder, says that he has often bred two cocks from the same nest, and
seldom two hens; moreover the hen is generally the weaker of the two, and more liable to perish.
With respect to birds in a state of nature, Mr. Gould and others379 are convinced that the males are
generally the more numerous; and as the young males of many species resemble the females, the
latter would naturally appear to be the most numerous. Large numbers of pheasants are reared by Mr.
Baker of Leadenhall from eggs laid by wild birds, and he informs Mr. Jenner Weir that four or five
males to one female are generally produced. An experienced observer remarks380 that in Scandinavia
the broods of the capercailzie and black-cock contain more males than females; and that with the
Dal-ripa (a kind of ptarmigan) more males than females attend the leks or places of courtship; but this
latter circumstance is accounted for by some observers by a greater number of hen birds being killed
by vermin. From various facts given by White of Selbourne,381 it seems clear that the males of the
partridge must be in considerable excess in the south of England; and I have been assured that this is
the case in Scotland. Mr. Weir on enquiring from the dealers who receive at certain seasons large
numbers of ruffs (Machetes pugnax) was told that the males are much the most numerous. This same
naturalist has also enquired for me from the bird-catchers, who annually catch an astonishing number
of various small species alive for the London market, and he was unhesitatingly answered by an old
and trustworthy man, that with the chaffinch the males are in large excess; he thought as high as 2
males to 1 female, or at least as high as 5 to 3.382 The males of the blackbird, he likewise maintained,
were by far the most numerous, whether caught by traps or by netting at night. These statements may
apparently be trusted, because the same man said that the sexes are about equal with the lark, the
twite (Linaria montana), and goldfinch. On the other hand he is certain that with the common linnet,

the females preponderate greatly, but unequally during different years; during some years he has
found the females to the males as four to one. It should, however, be borne in mind, that the chief
season for catching birds does not begin till September, so that with some species partial migrations
may have begun, and the flocks at this period often consist of hens alone. Mr. Salvin paid particular
attention to the sexes of the humming-birds in Central America, and he is convinced that with most of
the species the males are in excess; thus one year he procured 204 specimens belonging to ten
species, and these consisted of 166 males and of 38 females. With two other species the females were
in excess: but the proportions apparently vary either during different seasons or in different localities;
for on one occasion the males of Campylopterus hemileucurus were to the females as five to two, and
on another occasion383 in exactly the reversed ratio. As bearing on this latter point, I may add, that Mr.
Powys found in Corfu and Epirus the sexes of the chaffinch keeping apart, and “the females by far
the most numerous;” whilst in Palestine Mr. Tristram found “the male flocks appearing greatly to
exceed the female in number.”384 So again with the Quiscalus major, Mr. G. Taylor385 says, that in
Florida there were “very few females in proportion to the males,” whilst in Honduras the proportion
was the other way, the species there having the character of a polygamist.

FISH.
With Fish the proportional numbers of the sexes can be ascertained only by catching them in the
adult or nearly adult state; and there are many difficulties in arriving at any just conclusion.386
Infertile females might readily be mistaken for males, as Dr. Günther has remarked to me in regard to
trout. With some species the males are believed to die soon after fertilising the ova. With many
species the males are of much smaller size than the females, so that a large number of males would
escape from the same net by which the females were caught. M. Carbonnier,387 who has especially
attended to the natural history of the pike (Esox lucius) states that many males, owing to their small
size, are devoured by the larger females; and he believes that the males of almost all fish are exposed
from the same cause to greater danger than the females. Nevertheless in the few cases in which the
proportional numbers have been actually observed, the males appear to be largely in excess. Thus Mr.
R. Buist, the superintendent of the Stormontfield experiments, says that in 1865, out of 70 salmon
first landed for the purpose of obtaining the ova, upwards of 60 were males. In 1867 he again “calls
attention to the vast disproportion of the males to the females. We had at the outset at least ten males
to one female.” Afterwards sufficient females for obtaining ova were procured. He adds, “from the
great proportion of the males, they are constantly fighting and tearing each other on the spawning-
beds.”388 This disproportion, no doubt, can be accounted for in part, but whether wholly is very
doubtful, by the males ascending the rivers before the females. Mr. F. Buckland remarks in regard to
trout, that “it is a curious fact that the males preponderate very largely in number over the females. It
invariably happens that when the first rush of fish is made to the net, there will be at least seven or
eight males to one female found captive. I cannot quite account for this; either the males are more
numerous than the females, or the latter seek safety by concealment rather than flight.” He then adds,
that by carefully searching the banks, sufficient females for obtaining ova can be found.389 Mr. H. Lee
informs me that out of 212 trout, taken for this purpose in Lord Portsmouth’s park, 150 were males
and 62 females.
With the Cyprinidæ the males likewise seem to be in excess; but several members of this Family,
viz., the carp, tench, bream and minnow, appear regularly to follow the practice, rare in the animal
kingdom, of polyandry; for the female whilst spawning is always attended by two males, one on each
side, and in the case of the bream by three or four males. This fact is so well known, that it is always
recommended to stock a pond with two male tenches to one female, or at least with three males to
two females. With the minnow, an excellent observer states, that on the spawning-beds the males are

ten times as numerous as the females; when a female comes amongst the males, “she is immediately
pressed closely by a male on each side; and when they have been in that situation for a time, are
superseded by other two males.”390

INSECTS.
In this class, the Lepidoptera alone afford the means of judging of the proportional numbers of the
sexes; for they have been collected with special care by many good observers, and have been largely
bred from the egg or caterpillar state. I had hoped that some breeders of silk-moths might have kept
an exact record, but after writing to France and Italy, and consulting various treatises, I cannot find
that this has ever been done. The general opinion appears to be that the sexes are nearly equal, but in
Italy as I hear from Professor Canestrini, many breeders are convinced that the females are produced
in excess. The same naturalist, however, informs me, that in the two yearly broods of the Ailanthus
silk-moth (Bombyx cynthia), the males greatly preponderate in the first, whilst in the second the two
sexes are nearly equal, or the females rather in excess.
In regard to Butterflies in a state of nature, several observers have been much struck by the
apparently enormous preponderance of the males.391 Thus Mr. Bates,392 in speaking of the species, no
less than about a hundred in number, which inhabit the Upper Amazons, says that the males are much
more numerous than the females, even in the proportion of a hundred to one. In North America,
Edwards, who had great experience, estimates in the genus Papilio the males to the females as four to
one; and Mr. Walsh, who informed me of this statement, says that with P. turnus this is certainly the
case. In South Africa, Mr. R. Trimen found the males in excess in 19 species;393 and in one of these,
which swarms in open places, he estimated the number of males as fifty to one female. With another
species, in which the males are numerous in certain localities, he collected during seven years only
five females. In the island of Bourbon, M. Maillard states that the males of one species of Papilio are
twenty times as numerous as the females.394 Mr. Trimen informs me that as far as he has himself seen,
or heard from others, it is rare for the females of any butterfly to exceed in number the males; but this
is perhaps the case with three South African species. Mr. Wallace395 states that the females of
Ornithoptera crœsus, in the Malay archipelago, are more common and more easily caught than the
males; but this is a rare butterfly. I may here add, that in Hyperythra, a genus of moths, Guenée says,
that from four to five females are sent in collections from India for one male.
When this subject of the proportional numbers of the sexes of insects was brought before the
Entomological Society,396 it was generally admitted that the males of most Lepidoptera, in the adult
or imago state, are caught in greater numbers than the females; but this fact was attributed by various
observers to the more retiring habits of the females, and to the males emerging earlier from the
cocoon. This latter circumstance is well known to occur with most Lepidoptera, as well as with other
insects. So that, as M. Personnat remarks, the males of the domesticated Bombyx yamamai, are lost at
the beginning of the season, and the females at the end, from the want of mates.397 I cannot however
persuade myself that these causes suffice to explain the great excess of males in the cases, above
given, of butterflies which are extremely common in their native countries. Mr. Stainton, who has
paid such close attention during many years to the smaller moths, informs me that when he collected
them in the imago state, he thought that the males were ten times as numerous as the females, but that
since he has reared them on a large scale from the caterpillar state, he is convinced that the females
are the most numerous. Several entomologists concur in this view. Mr. Doubleday, however, and
some others, take an opposite view, and are convinced that they have reared from the egg and
caterpillar states a larger proportion of males than of females.

Besides the more active habits of the males, their earlier emergence from the cocoon, and their
frequenting in some cases more open stations, other causes may be assigned for an apparent or real
difference in the proportional numbers of the sexes of Lepidoptera, when captured in the imago state,
and when reared from the egg or caterpillar state. It is believed by many breeders in Italy, as I hear
from Professor Canestrini, that the female caterpillar of the silk-moth suffers more from the recent
disease than the male; and Dr. Staudinger informs me that in rearing Lepidoptera more females die in
the cocoon than males. With many species the female caterpillar is larger than the male, and a
collector would naturally choose the finest specimens, and thus unintentionally collect a larger
number of females. Three collectors have told me that this was their practice; but Dr. Wallace is sure
that most collectors take all the specimens which they can find of the rarer kinds, which alone are
worth the trouble of rearing. Birds when surrounded by caterpillars would probably devour the
largest; and Professor Canestrini informs me that in Italy some breeders believe, though on
insufficient evidence, that in the first brood of the Ailanthus silk-moth, the wasps destroy a larger
number of the female than of the male caterpillars. Dr. Wallace further remarks that female
caterpillars, from being larger than the males, require more time for their development and consume
more food and moisture; and thus they would be exposed during a longer time to danger from
ichneumons, birds, &c., and in times of scarcity would perish in greater numbers. Hence it appears
quite possible that, in a state of nature, fewer female Lepidoptera may reach maturity than males; and
for our special object we are concerned with the numbers at maturity, when the sexes are ready to
propagate their kind.
The manner in which the males of certain moths congregate in extraordinary numbers round a single
female, apparently indicates a great excess of males, though this fact may perhaps be accounted for
by the earlier emergence of the males from their cocoons. Mr. Stainton informs me that from twelve
to twenty males may often be seen congregated round a female Elachista rufocinerea. It is well
known that if a virgin Lasiocampa quercus or Saturnia carpini be exposed in a cage, vast numbers of
males collect round her, and if confined in a room will even come down the chimney to her. Mr.
Doubleday believes that he has seen from fifty to a hundred males of both these species attracted in
the course of a single day by a female under confinement. Mr. Trimen exposed in the Isle of Wight a
box in which a female of the Lasiocampa had been confined on the previous day, and five males soon
endeavoured to gain admittance. M. Verreaux, in Australia, having placed the female of a small
Bombyx in a box in his pocket, was followed by a crowd of males, so that about 200 entered the
house with him.398
Mr. Doubleday has called my attention to Dr. Staudinger’s399 list of Lepidoptera, which gives the
prices of the males and females of 300 species or well-marked varieties of (Rhopalocera) butterflies.
The prices for both sexes of the very common species are of course the same; but with 114 of the
rarer species they differ; the males being in all cases, excepting one, the cheapest. On an average of
the prices of the 113 species, the price of the male to that of the female is as 100 to 149; and this
apparently indicates that inversely the males exceed the females in number in the same proportion.
About 2000 species or varieties of moths (Heterocera) are catalogued, those with wingless females
being here excluded on account of the difference in habits of the two sexes: of these 2000 species,
141 differ in price according to sex, the males of 130 being cheaper, and the males of only 11 being
dearer than the females. The average price of the males of the 130 species, to that of the females, is
as 100 to 143. With respect to the butterflies in this priced list, Mr. Doubleday thinks (and no man in
England has had more experience), that there is nothing in the habits of the species which can
account for the difference in the prices of the two sexes, and that it can be accounted for only by an
excess in the numbers of the males. But I am bound to add that Dr. Staudinger himself, as he informs
me, is of a different opinion. He thinks that the less active habits of the females and the earlier
emergence of the males will account for his collectors securing a larger number of males than of
females, and consequently for the lower prices of the former With respect to specimens reared from

the caterpillar-state, Dr. Staudinger believes, as previously stated, that a greater number of females
than of males die under confinement in the cocoons. He adds that with certain species one sex seems
to preponderate over the other during certain years.
Of direct observations on the sexes of Lepidoptera, reared either from eggs or caterpillars, I have
received only the few following cases:—

Males. Females.
The Rev. J. Hellins400 of Exeter reared, during 1868, imagos of 73 species,
which consisted of 153 137
Mr. Albert Jones of Eltham reared, during 1868, imagos of 9 species, which,
consisted of 159 126
During 1869 he reared imagos from 4 species, consisting of 114 112
Mr. Buckler of Emsworth, Hants, during 1869, reared imagos from 74 species,
consisting of 180 169
Dr. Wallace of Colchester reared from one brood of Bombyx cynthia 52 48
Dr. Wallace raised, from cocoons of Bombyx Pernyi sent from China, during
1869 224 123
Dr. Wallace raised, during 1868 and 1869, from two lots of cocoons of Bombyx
Yamamai 52 46
—— ——
Total 934 761

So that in these eight lots of cocoons and eggs, males were produced in excess. Taken together the
proportion of males is as 122.7 to 100 females. But the numbers are hardly large enough to be
trustworthy.
On the whole, from the above various sources of evidence, all pointing to the same direction, I infer
that with most species of Lepidoptera, the males in the imago state generally exceed the females in
number, whatever the proportions may be at their first emergence from the egg.
With reference to the other Orders of insects, I have been able to collect very little reliable
information. With the stag-beetle (Lucanus cervus) “the males appear to be much more numerous
than the females;” but when, as Cornelius remarked during 1867, an unusual number of these beetles
appeared in one part of Germany, the females appeared to exceed the males as six so one. With one
of the Elateridæ, the males are said to be much more numerous than the females, and “two or three
are often found united with one female;”401 so that here polyandry seems to prevail. With Siagonium
(Staphylinidæ), in which the males are furnished with horns, “the females are far more numerous
than the opposite sex.” Mr. Janson stated at the Entomological Society that the females of the bark-
feeding Tomicus villosus are so common as to be a plague, whilst the males are so rare as to be hardly
known. In other Orders, from unknown causes, but apparently in some instances owing to
parthenogenesis, the males of certain species have never been discovered or are excessively rare, as
with several of the Cynipidæ.402 In all the gall-making Cynipidæ known to Mr. Walsh, the females are
four or five times as numerous as the males; and so it is, as he informs me, with the gall-making
Cecidomyiiæ (Diptera). With some common species of Saw-flies (Tenthredinæ) Mr. F. Smith has
reared hundreds of specimens from larvæ of all sizes, but has never reared a single male: on the other
hand Curtis says,403 that with certain species (Athalia), bred by him, the males to the females were as

six to one; whilst exactly the reverse occurred with the mature insects of the same species caught in
the fields. With the Neuroptera, Mr. Walsh states that in many, but by no means in all, the species of
the Odonatous groups (Ephemerina), there is a great overplus of males: in the genus Hetærina, also,
the males are generally at least four times as numerous as the females. In certain species in the genus
Gomphus the males are equally numerous, whilst in two other species, the females are twice or thrice
as numerous as the males. In some European species of Psocus thousands of females may be
collected without a single male, whilst with other species of the same genus both sexes are
common.404 In England, Mr. MacLachlan has captured hundreds of the female Apatania muliebris,
but has never seen the male; and of Boreus hyemalis only four or five males have been here seen.405
With most of these species (excepting, as I have heard, with the Tenthredinæ) there is no reason to
suppose that the females are subject to parthenogenesis; and thus we see how ignorant we are on the
causes of the apparent discrepancy in the proportional numbers of the two sexes.
In the other Classes of the Articulata I have been able to collect still less information. With Spiders,
Mr. Blackwall, who has carefully attended to this class during many years, writes to me that the
males from their more erratic habits are more commonly seen, and therefore appear to be the more
numerous. This is actually the case with a few species; but he mentions several species in six genera,
in which the females appear to be much more numerous than the males.406 The small size of the males
in comparison with the females, which is sometimes carried to an extreme degree, and their widely
different appearance, may account in some instances for their rarity in collections.407
Some of the lower Crustaceans are able to propagate their kind asexually, and this will account for
the extreme rarity of the males. With some other forms (as with Tanais and Cypris) there is reason to
believe, as Fritz Müller informs me, that the male is much shorter-lived than the female, which,
supposing the two sexes to be at first equal in number, would explain the scarcity of the males. On
the other hand this same naturalist has invariably taken, on the shores of Brazil, far more males than
females of the Diastylidæ and of Cypridina; thus with a species in the latter genus, 63 specimens
caught the same day, included 57 males; but he suggests that this preponderance may be due to some
unknown difference in the habits of the two sexes. With one of the higher Brazilian crabs, namely a
Gelasimus, Fritz Müller found the males to be more numerous than the females. The reverse seems to
be the case, according to the large experience of Mr. C. Spence Bate, with six common British crabs,
the names of which he has given me.

On the Power of Natural Selection to regulate the proportional Numbers of
the Sexes, and General Fertility.—In some peculiar cases, an excess in the
number of one sex over the other might be a great advantage to a species, as
with the sterile females of social insects, or with those animals in which
more than one male is requisite to fertilise the female, as with certain
cirripedes and perhaps certain fishes. An inequality between the sexes in
these cases might have been acquired through natural selection, but from
their rarity they need not here be further considered. In all ordinary cases an
inequality would be no advantage or disadvantage to certain individuals
more than to others; and therefore it could hardly have resulted from natural
selection. We must attribute the inequality to the direct action of those
unknown conditions, which with mankind lead to the males being born in a
somewhat larger excess in certain countries than in others, or which cause

the proportion between the sexes to differ slightly in legitimate and
illegitimate births.
Let us now take the case of a species producing from the unknown causes
just alluded to, an excess of one sex—we will say of males—these being
superfluous and useless, or nearly useless. Could the sexes be equalised
through natural selection? We may feel sure, from all characters being
variable, that certain pairs would produce a somewhat less excess of males
over females than other pairs. The former, supposing the actual number of
the offspring to remain constant, would necessarily produce more females,
and would therefore be more productive. On the doctrine of chances a
greater number of the offspring of the more productive pairs would survive;
and these would inherit a tendency to procreate fewer males and more
females. Thus a tendency towards the equalisation of the sexes would be
brought about. But our supposed species would by this process be rendered,
as just remarked, more productive; and this would in many cases be far
from an advantage; for whenever the limit to the numbers which exist,
depends, not on destruction by enemies, but on the amount of food,
increased fertility will lead to severer competition and to most of the
survivors being badly fed. In this case, if the sexes were equalised by an
increase in the number of the females, a simultaneous decrease in the total
number of the offspring would be beneficial, or even necessary, for the
existence of the species; and this, I believe, could be effected through
natural selection in the manner hereafter to be described. The same train of
reasoning is applicable in the above, as well as in the following case, if we
assume that females instead of males are produced in excess, for such
females from not uniting with males would be superfluous and useless. So it
would be with polygamous species, if we assume the excess of females to
be inordinately great.
An excess of either sex, we will again say of the males, could, however,
apparently be eliminated through natural selection in another and indirect
manner, namely by an actual diminution of the males, without any increase
of the females, and consequently without any increase in the productiveness
of the species. From the variability of all characters, we may feel assured
that some pairs, inhabiting any locality, would produce a rather smaller
excess of superfluous males, but an equal number of productive females.
When the offspring from the more and the less male-productive parents

were all mingled together, none would have any direct advantage over the
others; but those that produced few superfluous males would have one great
indirect advantage, namely that their ova or embryos would probably be
larger and finer, or their young better nurtured in the womb and afterwards.
We see this principle illustrated with plants; as those which bear a vast
number of seed produce small ones; whilst those which bear comparatively
few seeds, often produce large ones well-stocked with nutriment for the use
of the seedlings.408 Hence the offspring of the parents which had wasted least
force in producing superfluous males would be the most likely to survive,
and would inherit the same tendency not to produce superfluous males,
whilst retaining their full fertility in the production of females. So it would
be with the converse case of the female sex. Any slight excess, however, of
either sex could hardly be checked in so indirect a manner. Nor indeed has a
considerable inequality between the sexes been always prevented, as we
have seen in some of the cases given in the previous discussion. In these
cases the unknown causes which determine the sex of the embryo, and
which under certain conditions lead to the production of one sex in excess
over the other, have not been mastered by the survival of those varieties
which were subjected to the least waste of organised matter and force by the
production of superfluous individuals of either sex. Nevertheless we may
conclude that natural selection will always tend, though sometimes
inefficiently, to equalise the relative numbers of the two sexes.
Having said this much on the equalisation of the sexes, it may be well to
add a few remarks on the regulation through natural selection of the
ordinary fertility of species. Mr. Herbert Spencer has shewn in an able
discussion409 that with all organisms a ratio exists between what he calls
individuation and genesis; whence it follows that beings which consume
much matter or force in their growth, complicated structure or activity, or
which produce ova and embryos of large size, or which expend much
energy in nurturing their young, cannot be so productive as beings of an
opposite nature. Mr. Spencer further shews that minor differences in fertility
will be regulated through natural selection. Thus the fertility of each species
will tend to increase, from the more fertile pairs producing a larger number
of offspring, and these from their mere number will have the best chance of
surviving, and will transmit their tendency to greater fertility. The only
check to a continued augmentation of fertility in each organism seems to be

either the expenditure of more power and the greater risks run by the
parents that produce a more numerous progeny, or the contingency of very
numerous eggs and young being produced of smaller size, or less vigorous,
or subsequently not so well nurtured. To strike a balance in any case
between the disadvantages which follow from the production of a numerous
progeny, and the advantages (such as the escape of at least some individuals
from various dangers) is quite beyond our power of judgment.
When an organism has once been rendered extremely fertile, how its
fertility can be reduced through natural selection is not so clear as how this
capacity was first acquired. Yet it is obvious that if individuals of a species,
from a decrease of their natural enemies, were habitually reared in larger
numbers than could be supported, all the members would suffer.
Nevertheless the offspring from the less fertile parents would have no direct
advantage over the offspring from the more fertile parents, when all were
mingled together in the same district. All the individuals would mutually
tend to starve each other. The offspring indeed of the less fertile parents
would lie under one great disadvantage, for from the simple fact of being
produced in smaller numbers, they would be the most liable to
extermination. Indirectly, however, they would partake of one great
advantage; for under the supposed condition of severe competition, when
all were pressed for food, it is extremely probable that those individuals
which from some variation in their constitution produced fewer eggs or
young, would produce them of greater size or vigour; and the adults reared
from such eggs or young would manifestly have the best chance of
surviving, and would inherit a tendency towards lessened fertility. The
parents, moreover, which had to nourish or provide for fewer offspring
would themselves be exposed to a less severe strain in the struggle for
existence, and would have a better chance of surviving. By these steps, and
by no others as far as I can see, natural selection under the above conditions
of severe competition for food, would lead to the formation of a new race
less fertile, but better adapted for survival, than the parent-race.

CHAPTER IX.

Secondary Sexual Characters in the Lower Classes of the Animal
Kingdom.
These characters absent in the lowest classes—Brilliant colours—Mollusca—Annelids—Crustacea,
secondary sexual characters strongly developed; dimorphism; colour; characters not acquired
before maturity—Spiders, sexual colours of; stridulation by the males—Myriapoda.

In the lowest classes the two sexes are not rarely united in the same
individual, and therefore secondary sexual characters cannot be developed.
In many cases in which the two sexes are separate, both are permanently
attached to some support, and the one cannot search or struggle for the
other. Moreover it is almost certain that these animals have too imperfect
senses and much too low mental powers to feel mutual rivalry, or to
appreciate each other’s beauty or other attractions.
Hence in these classes, such as the Protozoa, Cœlenterata, Echinodermata,
Scolecida, true secondary sexual characters do not occur; and this fact
agrees with the belief that such characters in the higher classes have been
acquired through sexual selection, which depends on the will, desires, and
choice of either sex. Nevertheless some few apparent exceptions occur;
thus, as I hear from Dr. Baird, the males of certain Entozoa, or internal
parasitic worms, differ slightly in colour from the females; but we have no
reason to suppose that such differences have been augmented through
sexual selection.
Many of the lower animals, whether hermaphrodites or with the sexes
separate, are ornamented with the most brilliant tints, or are shaded and
striped in an elegant manner. This is the case with many corals and sea-
anemonies (Actineæ), with some jelly-fish (Medusæ, Porpita, &c.), with
some Planariæ, Ascidians, numerous Star-fishes, Echini, &c.; but we may
conclude from the reasons already indicated, namely the union of the two
sexes in some of these animals, the permanently affixed condition of others,
and the low mental powers of all, that such colours do not serve as a sexual
attraction, and have not been acquired through sexual selection. With the
higher animals the case is very different; for with them when one sex is
much more brilliantly or conspicuously coloured than the other, and there is
no difference in the habits of the two sexes which will account for this
difference, we have reason to believe in the influence of sexual selection;
and this belief is strongly confirmed when the more ornamented

individuals, which are almost always the males, display their attractions
before the other sex. We may also extend this conclusion to both sexes,
when coloured alike, if their colours are plainly analogous to those of one
sex alone in certain other species of the same group.
How, then, are we to account for the beautiful or even gorgeous colours of
many animals in the lowest classes? It appears very doubtful whether such
colours usually serve as a protection; but we are extremely liable to err in
regard to characters of all kinds in relation to protection, as will be admitted
by every one who has read Mr. Wallace’s excellent essay on this subject. It
would not, for instance, at first occur to any one that the perfect
transparency of the Medusæ, or jelly-fishes, was of the highest service to
them as a protection; but when we are reminded by Häckel that not only the
medusæ but many floating mollusca, crustaceans, and even small oceanic
fishes partake of this same glass-like structure, we can hardly doubt that
they thus escape the notice of pelagic birds and other enemies.
Notwithstanding our ignorance how far colour in many cases serves as a
protection, the most probable view in regard to the splendid tints of many of
the lowest animals seems to be that their colours are the direct result either
of the chemical nature or the minute structure of their tissues, independently
of any benefit thus derived. Hardly any colour is finer than that of arterial
blood; but there is no reason to suppose that the colour of the blood is in
itself any advantage; and though it adds to the beauty of the maiden’s
cheek, no one will pretend that it has been acquired for this purpose. So
again with many animals, especially the lower ones, the bile is richly
coloured; thus the extreme beauty of the Eolidæ (naked sea-slugs) is chiefly
due, as I am informed by Mr. Hancock, to the biliary glands seen through
the translucent integuments; this beauty being probably of no service to
these animals. The tints of the decaying leaves in an American forest are
described by every one as gorgeous; yet no one supposes that these tints are
of the least advantage to the trees. Bearing in mind how many substances
closely analogous to natural organic compounds have been recently formed
by chemists, and which exhibit the most splendid colours, it would have
been a strange fact if substances similarly coloured had not often originated,
independently of any useful end being thus gained, in the complex
laboratory of living organisms.

The sub-kingdom of the Mollusca.—Throughout this great division (taken
in its largest acceptation) of the animal kingdom, secondary sexual
characters, such as we are here considering, never, as far as I can discover,
occur. Nor could they be expected in the three lowest classes, namely in the
Ascidians, Polyzoa, and Brachiopods (constituting the Molluscoida of
Huxley), for most of these animals are permanently affixed to a support or
have their sexes united in the same individual. In the Lamellibranchiata, or
bivalve shells, hermaphroditism is not rare. In the next higher class of the
Gasteropoda, or marine univalve shells, the sexes are either united or
separate. But in this latter case the males never possess special organs for
finding, securing, or charming the females, or for fighting with other males.
The sole external difference between the sexes consists, as I am informed
by Mr. Gwyn Jeffreys, in the shell sometimes differing a little in form; for
instance, the shell of the male periwinkle (Littorina littorea) is narrower and
has a more elongated spire than that of the female. But differences of this
nature, it may be presumed, are directly connected with the act of
reproduction or with the development of the ova.
The Gasteropoda, though capable of locomotion and furnished with
imperfect eyes, do not appear to be endowed with sufficient mental powers
for the members of the same sex to struggle together in rivalry, and thus to
acquire secondary sexual characters. Nevertheless with the pulmoniferous
gasteropods, or land-shells, the pairing is preceded by courtship; for these
animals, though hermaphrodites, are compelled by their structure to pair
together. Agassiz remarks,410 “Quiconque a eu l’occasion d’observer les
amours des limaçons, ne saurait mettre en doute la séduction déployée dans
les mouvements et les allures qui préparent et accomplissent le double
embrassement de ces hermaphrodites.” These animals appear also
susceptible of some degree of permanent attachment: an accurate observer,
Mr. Lonsdale, informs me that he placed a pair of land-shells (Helix
pomatia), one of which was weakly, into a small and ill-provided garden.
After a short time the strong and healthy individual disappeared, and was
traced by its track of slime over a wall into an adjoining well-stocked
garden. Mr. Lonsdale concluded that it had deserted its sickly mate; but
after an absence of twenty-four hours it returned, and apparently
communicated the result of its successful exploration, for both then started
along the same track and disappeared over the wall.

Even in the highest class of the Mollusca, namely the Cephalopoda or
cuttle-fishes, in which the sexes are separate, secondary sexual characters of
the kind which we are here considering, do not, as far as I can discover,
occur. This is a surprising circumstance, as these animals possess highly-
developed sense-organs and have considerable mental powers, as will be
admitted by every one who has watched their artful endeavours to escape
from an enemy.411 Certain Cephalopoda, however, are characterised by one
extraordinary sexual character, namely, that the male element collects
within one of the arms or tentacles, which is then cast off, and, clinging by
its sucking-discs to the female, lives for a time an independent life. So
completely does the cast-off arm resemble a separate animal, that it was
described by Cuvier as a parasitic worm under the name of Hectocotyle.
But this marvellous structure may be classed as a primary rather than as a
secondary sexual character.
Although with the Mollusca sexual selection does not seem to have come
into play; yet many univalve and bivalve shells, such as volutes, cones,
scallops, &c., are beautifully coloured and shaped. The colours do not
appear in most cases to be of any use as a protection; they are probably the
direct result, as in the lowest classes, of the nature of the tissues; the
patterns and the sculpture of the shell depending on its manner of growth.
The amount of light seems to a certain extent to be influential; for although,
as repeatedly stated by Mr. Gwyn Jeffreys, the shells of some species living
at a profound depth are brightly coloured, yet we generally see the lower
surfaces and the parts covered by the mantle less highly coloured than the
upper and exposed surfaces.412 In some cases, as with shells living amongst
corals or brightly-tinted sea-weeds, the bright colours may serve as a
protection. But many of the nudibranch mollusca, or sea-slugs, are as
beautifully coloured as any shells, as may be seen in Messrs. Alder and
Hancock’s magnificent work; and from information kindly given me by Mr.
Hancock, it is extremely doubtful whether these colours usually serve as a
protection. With some species this may be the case, as with one which lives
on the green leaves of algæ, and is itself bright-green. But many brightly-
coloured, white or otherwise conspicuous species, do not seek concealment;
whilst again some equally conspicuous species, as well as other dull-
coloured kinds, live under stones and in dark recesses. So that with these

nudibranch molluscs, colour apparently does not stand in any close relation
to the nature of the places which they inhabit.
These naked sea-slugs are hermaphrodites, yet they pair together, as do
land-snails, many of which have extremely pretty shells. It is conceivable
that two hermaphrodites, attracted by each others’ greater beauty, might
unite and leave offspring which would inherit their parents’ greater beauty.
But with such lowly-organised creatures this is extremely improbable. Nor
is it at all obvious how the offspring from the more beautiful pairs of
hermaphrodites would have any advantage, so as to increase in numbers,
over the offspring of the less beautiful, unless indeed vigour and beauty
generally coincided. We have not here a number of males becoming mature
before the females, and the more beautiful ones selected by the more
vigorous females. If, indeed, brilliant colours were beneficial to an
hermaphrodite animal in relation to its general habits of life, the more
brightly-tinted individuals would succeed best and would increase in
number; but this would be a case of natural and not of sexual selection.

Sub-kingdom of the Vermes or Annulosa: Class, Annelida (or Sea-worms).
—In this class, although the sexes (when separate) sometimes differ from
each other in characters of such importance that they have been placed
under distinct genera or even families, yet the differences do not seem of
the kind which can be safely attributed to sexual selection. These animals,
like those in the preceding classes, apparently stand too low in the scale, for
the individuals of either sex to exert any choice in selecting a partner, or for
the individuals of the same sex to struggle together in rivalry.
Sub-kingdom of the Arthropoda: Class, Crustacea.—In this great class we
first meet with undoubted secondary sexual characters, often developed in a
remarkable manner. Unfortunately the habits of crustaceans are very
imperfectly known, and we cannot explain the uses of many structures
peculiar to one sex. With the lower parasitic species the males are of small
size, and they alone are furnished with perfect swimming-legs, antennæ and
sense-organs; the females being destitute of these organs, with their bodies
often consisting of a mere distorted mass. But these extraordinary
differences between the two sexes are no doubt related to their widely
different habits of life, and consequently do not concern us. In various

crustaceans, belonging to distinct families, the
anterior antennæ are furnished with peculiar
thread-like bodies, which are believed to act
as smelling-organs, and these are much more
numerous in the males than in the females. As
the males, without any unusual development
of their olfactory organs, would almost
certainly be able sooner or later to find the
females, the increased number of the
smelling-threads has probably been acquired
through sexual selection, by the better
provided males having been the most
successful in finding partners and in leaving
offspring. Fritz Müller has described a
remarkable dimorphic species of Tanais, in
which the male is represented by two distinct
forms, never graduating into each other. In the
one form the male is furnished with more
numerous smelling-threads, and in the other
form with more powerful and more elongated Fig. 3. Labidocera Darwinii,
chelæ or pincers which serve to hold the (from Lubbock).
female. Fritz Müller suggests that these a. Part of right-hand anterior
differences between the two male forms of antenna of male, forming a
the same species must have originated in prehensile organ.
certain individuals having varied in the b. Posterior pair of thoracic legs of
number of the smelling-threads, whilst other male.
individuals varied in the shape and size of c. Ditto of female.
their chelæ; so that of the former, those which were best able to find the
female, and of the latter, those which were best able to hold her when
found, have left the greater number of progeny to inherit their respective
advantages.413

In some of the lower crustaceans, the right-hand anterior antenna of the
male differs greatly in structure from the left-hand one, the latter resembling
in its simple tapering joints the antennæ of the female. In the male the
modified antenna is either swollen in the middle or angularly bent, or
converted (fig. 3) into an elegant, and sometimes wonderfully complex,

prehensile organ.414 It serves, as I hear from Sir J. Lubbock, to hold the
female, and for this same purpose one of the two posterior legs (b) on the
same side of the body is converted into a forceps. In another family the
inferior or posterior antennæ are “curiously zigzagged” in the males alone.

Fig. 4. Anterior part of body of Callianassa (from Milne-Edwards), showing the
unequal and differently-constructed right and left-hand chelæ of the male.
N.B.—The artist by mistake has reversed the drawing, and made the left-hand chela
the largest.

Fig. 5. Fig. 6.

Fig. 5. Second leg of male Orchestia Tucuratinga (from Fritz Müller).

Fig. 6. Ditto of female.

In the higher crustaceans the anterior legs form a pair of chelæ or pincers,
and these are generally larger in the male than in the female. In many
species the chelæ on the opposite sides of the body are of unequal size, the
right-hand one being, as I am informed by Mr. C. Spence Bate, generally,
though not invariably, the largest. This inequality is often much greater in
the male than in the female. The two chelæ also often differ in structure
(figs. 4 and 5), the smaller one resembling those of the female. What
advantage is gained by their inequality in size on the opposite sides of the
body, and by the inequality being much greater in the male than in the
female; and why, when they are of equal size, both are often much larger in
the male than in the female, is not known. The chelæ are sometimes of such
length and size that they cannot possibly be used, as I hear from Mr. Spence
Bate, for carrying food to the mouth. In the males of certain freshwater
prawns (Palæmon) the right leg is actually longer than the whole body.415 It
is probable that the great size of one leg with its chelæ may aid the male in
fighting with his rivals; but this use will not account for their inequality in
the female on the opposite sides of the body. In Gelasimus, according to a
statement quoted by Milne-Edwards,416 the male and female live in the same
burrow, which is worth notice, as shewing that they pair, and the male