DEPARTlvlEIIT OF PSYCEIATRY
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QHAaLES_DARWIN.

THE DESCENT OF MAN

And Selection in Relation to Sex

By CHARLES jDARWlN, M.A.,F.R.S.

Auth'orof -THE ORIGIN OF SPECIES," etc., etc '

Pi

printed from the Second English Edition,
Revised and Augmented

ILLUSTRATED

A. L. BURT COMPANY, ^ ^ ^ ^ ^
^ ^ ^ ^ PUBLISHERS, NEW YORK

>>)' n ^ to ->

'*'*" ""PftEFACE TO THE SECOND EDITION.

DuEiKG the successive reprints of the first edition of
this work, published in 1871, I was able to introduce sev-
eral important corrections; and now that more time has
elapsed I have endeavored to profit by the fiery ordeal
through which the book has passed, and have taken ad-
vantage of all the criticisms which seem to me sound. I
am also greatly indebted to a large number of correspond-
ents for the communication of a surprising number of new
facts and remarks. These have been so numerous that I
have been able to use only the more important ones; and
of these, as well as of the more important corrections, I
will append a list. Some new illustrations have been in-
troduced and four of the old drawings have been replaced
by better ones, done from life by Mr. T. W. Wood. I
must especially call attention to some observations which I
owe to the kindness of Prof. Huxley (given as a supple-
ment at the end of Part I), on the nature of the differences
between the brains of ma,n and the higher apes. I have
been particularly glad to give these observations, because
during the last few years several memoirs on the subject
have appeared on the Continent and their importance has
been, in some cases, greatly exaggerated by popular writers.

I may take this opportunity of remarking that my critics
frequently assume that I attribute all changes of corporeal
structure and mental power exclusively to the natural se-
lection of such variations as are often called spontaneous;
whereas, even in the first edition of the '* Origin of
Species," I distinctly stated that great weight muet l;)e at-

iv PREFACE,

tributed to the inherited effects of use and disuse, with re-
spect both to the body and mind. I also attributed some
amount of modification to the direct and prolonged action
of changed conditions of life. Some allowance, too, must
be made for occasional reversions of structure; nor must we
forget what I have called "correlated^' growth, meaning
thereby that various parts of the organization are in some
unknown manner so connected, that when one part varies
so do others; and if variations in the one are accumulated
by selection other parts will be modified. Again, it has
been said by several critics that when I found that many
details of structure in man could not be explained through
natural selection, I invented sexual selection; I gave, how-
ever, a tolerably clear sketch of this principle in the first
edition of the " Origin of Species, '^ and I there stated that
it was applicable to man. This subject of sexual selection
has been treated at full length in the present work, simply
because an opportunity was here first afforded me. I have
been struck with the likeness of many of the half -favorable
criticisms on sexual selection, with those which appeared
at first on natural selection; such as, that it would explain
some few details, but certainly was not applicable to the
extent to which I have employed it. My conviction of the
power of sexual selection remains unshaken ; but it is
probable, or almost certain, that several of my conclusions
will hereafter be found erroneous; this can hardly fail to
be the case in the first treatment of a subject. When
naturalists have become familiar with the idea of sexual
selection, it will, as I believe, be much more largely ac-
cepted; and it has already been fully and favorably re-
ceived by several capable judges.

Down, Bbckenham, Kent, September, 1874

CONTENTS.

pAas.
Intboduction 1

PART I.

THE DESCE]S^T OR ORIGIN" OF MAK.

CHAPTER I.
The Evidence of the Descent of Man from Some Lower Form. . 5

CHAPTER II.
On the Manner of Development of Man from Some Lower Form 29

CHAPTER III.

Comparison of the Mental Powers of Man and the Lower

Animals 73

CHAPTER IV.

Comparison of the Mental Powers of Man and the Lower

Animals — continued 110

CHAPTER V.

On the Development of the Intellectual and Moral Faculties

During Primeval and Civilized Times 144

CHAPTER VL
On the Affinities and Genealogy of Man • 166

CHAPTER VIL
On the Races of Man 189

n CONTENTS.

PART II.

SEXUAL SELECTION.

CHAPTER VIII.

Pagb.
Principles of Sexual Selection 234

CHAPTER IX.

Secondary Sexual Characters in the Lower Classes of tlie Ani-
mal Kingdom 294

CHAPTER X.
Secondary Sexual Characters of Insects 311

CHAPTER XI.
Insects, continued — Order Lepidoptera. Butterflies and Moths. 348

CHAPTER XII.

Secondary Sexual Characters of Fishes, Amphibians, and

peptiles 375

CHAPTER XIIL
Secondary Sexual Characters of Birds 407

CHAPTER XIV.
Birds — cantinued , 459

CHAPTER XV.
'Biix^&—contimied , 505

CHAPTER XVI.
'BudiQ— concluded 528

CHAPTER XVn.
Secondary Sexual Characters of Mammals 570

CONTENTS, vii

CHAPTER XVIII.

Page.

Secondary Sexual Characters of Mammals — continued 600

PART III.

SEXUAL SBLECTIOIT IK KBLATION TO MAN", AKD COKCLUSION".

CHAPTER XIX.
Secondary Sexual Characters of Man ^ 634

CHAPTER XX.
Secondary Sexual Characters of M.SiJi-— continued 668

CHAPTER XXI.
General Summary and Conclusion 693

Supplemental Note ,. 709

Index •••.. •••• 715

THE DESCENT OF MAN;

AKD

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 creation independ-
ante et de toutes pieces, des especes,'^ it is manifest that at
least a large number of naturalists must admit that species
are the modified descendants of other species; and this es-
pecially 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 honored chiefs in natural science, many un-
fortunately are still opposed to evolution in every form.

In consequence of the views now adopted by most natu-
ralists, and which will ultimately, as in every other case, be

3 TEE DESCENT OF MAK

followed by others who are not scientific, I have been led to
put together my notes, so as to see how far the general con-
clusions 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 de-
prived of the weighty arguments derived from the nature
of the affinities which connect together whole groups of
organisms — their geographical distribution in past and pres-
ent times, and their geological succession. The homologi-
cal structure, embryological development, and rudimentary
organs of a species remain to be considered, whether it be
man or any other animal, to which our attention may be
directed; but these great classes of facts afford, as it ap-
pears to me, ample and conclusive evidence in favor 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 devel-
opment; 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 sub-
ject which has been fully discussed in many valuable works.
The high antiquity of man has recently been demonstrated
by the labors 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 shown that in
every 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

INTRODUCTION'. 3

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 con-
clusion 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, Biichner, Rolle, etc.,* and especially by
Hackel. This last naturalist, besides his great work,
^^Generelle Morphologic" (1866), has recently (1868,
with a second edition in 1870), published his " Naturliche
Schopfungsgeschichte," 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 com-
pleted it. Almost all the conclusions at which I have
arrived I ttnd confirmed by this naturalist, whose knowl-
edge on many points is much fuller than mine. Wherever
I have added any fact or view from Prof. HackeFs writ-
ings, I give his authority in the text; other statements I
leave as they originally stood in my manuscript, occasion-
ally giving in the footnotes 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
diiferentiating the races of man; but in my " Origin
of Species" (first edition) 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

*As the works of the first-named authors are so well known, I
need not give the titles ; but as those of the latter are less well
known in England, I will give them : " Sechs Vorlesungen liber die
Darwin'sche Theorie," zweite Auflage, 1868, von Dr. L. Buchner ;
translated into French under the title " Conferences sur la Theorie
Darwinienne," 1869. " Der Mensch, im Lichte der Darwin'sche
Lehre," 1865, von Dr. F. Rolle. I will not attempt to give references
to all the authors who have taken the same side of the question.
Thus G. Canestrini has published (" Annuario della Soc. d. Nat.,"
Modena, 1867, p. 81), a very curious paper on rudimentary characters,
as bearing on the origin of man. Another work has (1869) been
published by Dr. Francesco Barrago, bearing in Italian the title
of " Man, made in the image of God. was also made in the image of
the ap©."

4 THE DESCENT OF MAK.

subject in full detail.* Consequently, the second pai^t 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 volume 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 BelFs admirable worJc.
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 re-
serve my essay for separate publication.

* Prof. Hackel was the only author, who, at the time when this
work first appeared, had discussed the subject of sexual selection,
and had seen its full importance, since the publication of the
"Origin;" and this he did in a very able manner in his various
works.

PART I.

THE DESCENT OR ORIGIN OF MAN.

CHAPTER I.

THE ETTPEXCE OF THE DESCEN^T OF MAK FKOM SOME
LOWER FORM.

Nature of the evidence bearing on tlie 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, etc. —
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
inquire 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. 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, etc. ? Is man subject to similar malcon-
formations, the result of arrested development, of reduplica-
tion of parts, etc. , and does he display in any of his anoma-
lies reversion to some former and ancient type of structure?
It might also naturally be inquired 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 in the
first and succeeding generations? And so with many other
points.

6 THE DESCENT OF MAN.

The inquirer 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 conse-
quently 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 one another, so that some finally
become extinct ? We shall see that all these questions, as
indeed is obvious in respect to most of them, n^aist be an-
swered 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 succeeding chapters the mental powers of man, in com-
parison 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 as 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 vis-
cera. The brain, the most important of all the organs,
follows the same law, as shown by Huxley and other anato-
mists. Bischoff,* 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 de-
velopment do their brains perfectly agree ; nor could per-
fect agreement be expected, for otherwise their mental pow-
ers would have been the same. Vulpianf remarks : " Les
differences reelles qui existent entre Tencephale de Fhomme
et celui des singes superieurs, sont bein minimes. II ne
faut pas se faire d^illu6ions d cet egard. L^homme est bein
plus pres des singes anthropomorphes par les caracteres
anatomiques de son cerveau que ceux-ci ne le sont non seul-
ement des autres mammif ^res, mais meme de certains quad-
rumanes, des guenons et des macaques. ''' But it would be

* " Grossliirnwindungen des Mensclien," 1868, s. 96. Tlie con-
clusions of this author, as well as those of Gratiolet and Aeby, con-
cerning the brain, will be discussed by Prof. Huxley in the Appendix
alluded to in the Preface to this edition.

f "Lee. sur la Phys.," 1866, p. 890, as quoted by M. Dally,
" t'Ordre des Primates et le Transformisme," 1868, p. 39.

HOMOLOGICAL STRUCTURES. 7

superfluous here to give further details on the correspond-
ence between man and the higher mammels 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 shown.

Man is liable to receive from the lower animals, and
to communicate to them, certain diseases, as hydrophobia,
variola, the glanders, syphilis, cholera, herpes, etc. ;* and
this fact proves the close similarity f of their tissues and
blood, both in minute structure and composition, far more
plainly than does their comparison under the best micro-
scope, or by the aid of the best chemical analysis. Mon-
keys are liable to many of the same non-contagious diseases
as we are; thus Kengger,! who carefully observed for a loug
time the Cehus Azarce 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 cata-
ract 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 m'onkeys
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
Afi-ica 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

* Dr. W. Lauder Lindsay has treated this subject at some length
in the "Journal of Mental Science," July, 1871; and in the "Edin-
burgh Veterinary Review," July, 1858.

f A Reviewer has criticised ("British Quarterly Review," Oct. 1,
1871, p. 472) what I have here said with much severity and contempt;
but as I do not use the term identity, I cannot see tliat I am greatly
in error. There appears to me a strong analogy between the same
infection or contagion producing the same result, or one closely simi-
lar, in two distinct animals, Liid the testing of two distinct fluids by
the same chemical reagent.

X " Naturgeschichte der Saugethiere von Paraguay," 1830, s. 50.

§ The same tastes are common to some animals much lower in the
scale. Mr, A. Nichols informs me that he kept in Queensland, in
Australia, three individuals of the Phaseolarctus cinereus ; and that,
without having been taught in any way, they acquired a strong tast©
Iqx rum aad smoking tobacco.

8 THE DESCENT OF MAN.

this state; and he gives a laughable account of their behav-
ior 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 dis-
gust, but relished the juice of lemons.* 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 De 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 as those infest-
ing other mammals, and in the case of scabies to the same
species, f Man is subject, like other mammals, birds, and
even insects, J to that mysterious law, which causes certain
normal processes, such as gestation, as well as the matura-
tion and duration of various diseases, to follow lunar periods.
His wounds are repaired by the same process of healing;
and the stumps left after the amputation of his limbs, es-
pecially during an early embryonic period, occasionally
possess some power of regeneration, as in the lowest
animals. §

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 male, | to

* Brehm, " Thierleben," B. i, 1864, s. 75, 86. On the Ateles, s.
105. For other analogous statements, see s. 25, 107.

f Dr. W. Lauder Lindsay, "Edinburgh Veterinary Review," July,
1858, p. 13.

X With respect to insects see Dr. Lay cock " On a General Law of
Vital Periodicity," *' British Association," 1842. Dr. Macculloch,
" Silliman's North American Journal of Science," vol. xvii, p. 305,
has seen a dog suffering from tertian ague. Hereafter I shall return
to this subject.

§1 have given the evidence on this head in ray "Variation of
Animals and Plants under Domestication," vol, ii, p. 15, and more
could be added.

\ Mares e diversis generibus Quadrumanorum sine dubio dignos-
cunt feminas humanas a maribus, Primum, credo, odoratu, postea
aspectu. Mr. Youatt, qui diu in Hortis Zoologicis (Bestiariis) medi-
cus animalium erat, vir in rebus observandis cautus et sagax, hoo
mihi certissime probavit, et curatores ejusdem loci et alii e ministris
COttfirmaverunt. Sir Andrew Smith et Brehm notabant idem in Cyno*

mUOLOGIGAL STRUGTUREh. 9

the birtli 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.* It has been urged by some writers, as an import-
ant 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 coun-
tries the difference is not great, for the orang is believed
not to be adult till the age of from ten to fifteen years. \
Man differs from woman in size, bodily strength, hairiness,
etc., as well as in mind, in the same manner as do the two
sexes of many mammals. So that the 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,
is extremely close.

Em'bryo7iic 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 distin-
guished from that of other members of the vertebrate king-
dom. At this period the arteries run in arch-like branches,
as if to carry the blood to branchiae which are not present
in the higher vertebrata, though the slits on the sides of the
neck still remain (/, g, fig. 1), marking their former posi-
tion. 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,];

ceplialo. Illustrissimus Cuvier etiam narrat multa de liac re, qua
ut opinor, niliil turpius potest indicari inter omnia liominibus et
Quadrumanis communia. Narrat enim Cynocephalum quendam in
f urorem incidere aspectu feminarum aliquarum, sed nequaquam ac-
cendi tanto furore ab omnibus. Semper eligebat juniores, et dignos-
cebat in turba, et advocabat voce gestuque.

*This remark is made with respect to Cynocephalus and tlie
antbropomorplious apes by Geoffrey Saint-Hilaire and F. Cuvier,
" Hist. Nat. des Manimiferes," tom.i, 1824.

f Huxley, «* Man's Place in Nature." 1863, p. 34.

Jlbid., p. 67.

10 THE DESCENT OF MAN.

*' quite in the later stages of development ttiat 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 asser-
tion 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,*

After the foregoing statements made by such high
authorities, it would be superfluous on my part to give a
number of borrowed details, showing that the embryo of
man closely resembles that of other mammals. It may,
however, be added, that the human embryo likewise resem-
bles certain low forms when adult in various points of
structure. 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, ^' ex-
tending considerably beyond the rudimentary legs.^'^f In
the embryos of all air-breathing vertebrates, certain glands,
called the corpora Wolffiana, correspond with, and act
like the kidneys of mature fishes. | Even at a later
embryonic period, some striking resemblances between
man and the lower animals may be observed. Bischofl
says that " the convolutions of the brain in a human foetus
at the end of the seventh month reach about the same
stage of development as in a baboon when adult. "§
The great toe, -as Prof. Owen remarks, || " which forms
the fulcrum when standing or walking, is perhaps

*The human embryo (upper fig.) is from Ecker, "Icones Phys.,"
1851-1859, tab. xxx, fig. 2. This embryo was ten lines in length, so
that the drawing is much magnified. The embryo of the dog is from
BischofE, " Entwicklungsgeschichte des Hunde-Eies," 1845, tab. xi,
fig. 42 B. This drawing is five times magnified, the embryo being
twenty five days old. The internal viscer; have been omitted, and
the uterine appendages in both drawings removed. I was directed
to these figures by Prof. Huxley, from whose work, " Man's Place in
Nature," the idea of giving them was taken. Hackel has also given
analogous drawings in his " Schopfungsgeschichte."

f Prof. Wyman in ** Proc. of American Acad, of Sciences," vol, iv,
1860, p. 17.

X Owen, " Anatomy of Vertebrates," vol. i, p. 533.

§ " Die Qrosshirnwindungen des Menschen." 1868, s. 95.

I ** Anatomy of Vertebrates," vol. ii, p. 553.

EOMOLOQIGAL STBUCTUHm.

11

Fiff. 1. Upper figure human embryo, from Ecker.
^ *'*' » £j.Qj^ BischofE.

Lower figure that of a dog.

a. Pore-brain, cerebral hemispberes,

b'. Mid-brain, corpora quadrigemina.

c. Hind-brain, cerebellum, medulla
oblongata,

d. Eye.
I, £ar.

/. First visceral arch.
Q. Second visceral arch.
H. Vertebral columns and muscles
in process of development.
i Ajiterior j. extremities.
K. Posterior )
L. Tail or os coccyx.

1^ THE DESCENT OE MAN.

the most characteristic peculiarity in the human stmct-
ure;" but in an embryo, about an inch in length, Prof.
Wyman* 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, f 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 mpre
important than the two last, will for several reasons be
treated here more fully. X Not one of the higher animals
can be named which does not bear some part in a rudi-
mentary 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 mamm^ 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
can hardly 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 devel-
oped, are of high service to their possessors, and are capa-
ble of further development. Rudimentary organs are
eminently variable; and this is partly intelligible, as they
are useless, or nearly useless, and consequently are no

* "Proc. Soc. Nat. Hist.," Boston 1863, vol. ix, p. 185.

f "Man's Place in Nature," p, 65.

:j:I had written a rough copy of this chapter before reading- a valu-
able paper, " Caratteri rudimentali in ordine all' origine dell' uomo'*
(" Annuario della Soc. d. Nat.," Modena, 1867, p. 81), by G. Canes-
trini, to which paper I am considerably indebted. Hackel has given
admirable discussions on this whole subject, under the title of Dys-
teleology, in his " Generelle Morphologie" and ' ' SchOpf ungsge-
schichte."

nUDIMENTS, 13

longer subjected to natural selection. They often become
wholly suppressed. When this occurs, they are neverthe-
less liable to occasional reappearance through reversion — a
circumstance well worthy of attention.

The chief agents in causing organs to become rudiment-
ary seem to have been disuse at that period of life when
the organ is chiefly used (and this is generally during matu-
rity), and also inheritance at a corresponding period of life.
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 alterna-
tions of pressure, or from becoming in any way less habitu-
ally active. Eudiments, however, may occur in one sex
of those parts which are normally present in the other sex;
and such rudiments, as we shall hereafter see, have often
originated in a way distinct from those here referred to.
In some cases, organs have been reduced by means of nat-
ural 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 com-
pensation and economy of growth; bnt the later stages of
reduction, after disuse has done all that can fairly be at-
tributed to it, and when the saving to be effected by the
economy of growth would be very small,* 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 come into play, is
perhaps intelligible by the aid of the hypothesis of pangene-
sis. But as the whole subject of rudimentary organs has
been discussed and illustrated in my former works, f I need
here say no more on this head.

Eudiments of various muscles have been observed in
many parts of the human body ;J and not a few muscles,

* Some good criticisms on this subject have been given by Messrs.
Murie and Mivart, in '* Transact. Zoolog. Soc," 1869, vol. vii, p. 92.

\ " Variation of Animals and Plants under Domestication," vol. ii,
pp. 317 and 397. See also "Origin of Species."

X For instance M Richard (** Annales des Sciences Nat., 3d series,
Zoolog., 1852, torn, xviii, p. 13) describes and figures rudiments of
what he calls the "muscle pedieux de la main," which he says is
sometimes " infiniment petit." Another muscle, called " le tibial
posterieur," is generally quite absent in the hand, but appears froro
time to time in a more or less rudimentary conditioa, *

14 TEE DESCENT OF MAK.

which are regularly present in some of the lower animals,
can occasionally be detected in man in a greatly reduced con-
dition. 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, the muscle on the
forehead, by which the eyebrows are raised. The platysma
myoides, which is well developed on the neck, belongs to
this system. Prof. Turner, of Edinburgh, has occa-
sionally detected, as he informs me, muscular fasciculi in
five different situations, namely in the axillae, near the
scapulae, etc., all of which must be referred to the system
of the panniculus. He has also shown* that the musculus
sternalis or sternalis irutorum, which is not an extension
of the rectus ahdominalis, but is closely allied to ih.Q pan-
niculus, occurred in the proportion of about three 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 the 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, grand-
father, and his three children possess the same power to the
3ame 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 persistent
may be the transmission of an absolutely useless faculty,
probably derived from our remote semi-human progenitors;

*Prof. W Turaer, " Proc. Royal Soc. Edinburgh," 1866-67, p. 65.

RUDIMENTS. 15

since many monkeys have, and frequently use the power,
of largely moving tlieir scalps up and down. *

The extrinsic muscles which serve to move the external
ear, and the intrinsic muscles which move the different
parts, are in a rudimentary condition in man, and they all
belong to the system of the pa?iuicuhis ; they are also vari-
able in development, or at least in function. I have seen
one man who could draw the whole ear forward; other men
can draw it upward; another who could draw it backward;!
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 toward them, could recover some
power of movement by repeated trials. The power of erect-
ing and directing the shell of the ears to the various points
of the compass, is no doubt of the highest service to many
animals, as they thus perceive the direction of danger; but
I have never heard, on sufficient evidence, of a man who
possessed this power, the one which might be of use to him.
The whole external shell may be considered a rudiment, to-
gether with the various folds and prominences (helix and
anti-helix, tragus, and anti-tragus, etc.) which in the lower
animals strengthen and support the ear when erect, with-
out 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,J 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 the proper muscles are likewise but very slightly
developed. § I am also assured by the keepers in the
Zoological Gardens that these animals never move or erect
their ears; so that they are in an equally rudimentary condi-
tion with those of man, as far as function is concerned.

* See my *• Expression of tlie Emotions in Man and Animals," 1872,
p. 144.

f Canestrini quotes Hyrtl. ("Annuario della Soc. dei Naturalisti,"
Modena, 1867, p. 97) to the same effect.

i ''The Diseases of the Ear," by J. Toynbee, F. R. S., 1860, p. 12.
A distinguished physiologist, Prof. Preyer, informs me that he had
lately been experimenting on the function of the shell of the ear, and
has come to nearly the same conclusion as that given here.

SProf. A. Macalister, "Annals and Mag. of Nat. History," voL
vii, 1871, p. 342,

16 THE DESCENT OF MAX

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 satisfied with this view,
that owing to their arboreal habits and great strength they
were but little exposed to danger, and so during a length-
ened 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 inability to
move the ears in man and several apes is, however, partly
compensated by the freedom with which they can move the
head in a horizontal plane, so as to catch sounds from all
directions. It has been asserted that the ear of man alone
possesses a lobule; but "a rudiment of it is found in the
gorilla;"* and, as I hear from Prof. Preyer, it is not rarely
absent in the negro.

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 per-
ceived the full significance. His attention was first called
to the subject while at work on his figure of Puck, to
which he had given pointed ears. He was thus led to ex-
amine 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. When present, it is developed at birth, and, ac-
cording to Prof. Ludwig Meyer, more frequently in man
than in woman. Mr. Woolner made an exact model of one
such case, and sent me the accompanying drawing. (Fig. 2. )
These points not only project inward toward the center of
the ear, but often a little outward from its plane, so as to be
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. They are not con-
fined to mankind, for I observed a case in one of the spider-
monkeys (Ateles Beehebuth) in our Zoological Gardens;
and Mr. E. Kay Lankester informs me of another case in a
chimpanzee in the gardens at Hamburg. The helix ob-

*Mr. St. George Mivart, "Elementary Anatomy," 1873, p. 390.

MUDIMENTS.

viously consists of the extreme margin of the ear folded
inward ; and this folding appears to be in some manner
connected with the whole external ear being permanently
pressed backward. In many monkeys, which do not stand
high in the order, as baboons and some species of Macacus,*
the upper portion of the ear is slightly pointed, and the
margin is not at all folded inward ; but if the margin were,
to be thus folded, a slight point would necessarily project
inward toward the center, and probably a little outward
from the plane of the ear ; and this I believe to be their
origin in many cases. On the other hand. Prof. L. Meyer,
in an able paper recently published,! maintains that the
whole case is one of mere variability;
and that the projections are not real
ones, but are due to the internal
cartilage on each side of the points
not having been fully developed. I
am quite ready to admit that this is
the correct explanation in many in-
stances, as in those figured by Prof.
Meyer, in which there are several
minute points, or the whole margin
is sinuous. I have myself seen,
through the kindness of Dr. L. Down,
the ear of a microcephalous idiot,
on which there is a projection on the
outside of the helix, and not on the
inward folded edge, so that this point
can have no relation to a former apex
of the ear. Nevertheless in some
cases, my original view, that the points are vestiges of the tips
of formerly erect and pointed ears, still seems to me probable.
I think so from the frequency of their occurrence, and from the
general correspondence in position with that of the tip of a
pointed ear. In one case, of which a photograph has been
Bent me, the projection is so large, that supposing, in ac-
cordance with Prof. Meyer's view, the ear to be made per-

See also some remarks, and the drawings of the ears of the Lem-
uroidea, in Messrs. Murie and Mivart's excellent paper in *' Transact.
Zoolog. Soc," vol. vii, 1869, pp, 6 and 90.

f Ueber das Darwin'sche Spitzolur. "Archiv fur Path. Anat. und
Phys./' 1871, p. 485.

Fig. 2. Human Ear, mod-
eled and drawn X>y Mr.
Woolner.

o. The projecting point.

18 THE DESCENT OF MAN.

feet by the equal development of the cartilage throughout
the whole extent of the margin, it would have covered fully
one-third of the whole ear. Two cases have been commu-
nicated to me, one in North America and the other in
England, in which the upper margin is not at all folded
inward, but is pointed, so that it closely resembles the
pointed ear of an ordinary quadruped in outline. In one
of these cases, which was that of a young child, the father
compared the ear with the drawing which I have given* of

Mg. 8. Foetus x)f an Orang. Exact copy of a photograph, showing
the form of the ear- at this early age.

the ear of a monkey, the Cynopitliecus niger, and says that
their outlines are closely similar. If, in these two cases,
the margin had been folded inward in the normal manner,
an inward projection must have been formed. I may add
that in two other cases the outline still remains somewhat
pointed, although the margin of the upper part of the ear
is normally folded inward — in one of them, however, very
narrowly. The above wood-cut (Fig. 3) is an accurate
copy of a photograph of the foetus of an orang (kindly sent
me by Dr. Nitsche), in which it may be seen how different
the pointed outline of the ear is at this period from its
adult condition, when it bears a close general resemblance

*" Tlie Expression of the Emotions/* p. 136. . •

RUDIMENTS, 19

to that of man. It is evident that the folding over of the
tip of such an ear, unless it changed greatly during its
further development, would give rise to a point projecting
inward. On the whole, it still seems to me probable that
the points in question are in some cases, both in man and
apes, vestiges of a former condition.

The nictitating membrane, or third eyelid, with its ac-
cessory 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 ad-
mitted by all anatomists, as a mere rudiment, called the
semilunar fold.*

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, again, as the wild boar, for
both purposes combined. But the sense of smell is of
extremely slight service, if any, even to the dark colored
races of men, in whom it is much more highly developed
than in the white and civilized races, f Nevertheless it
does not warn them of danger, nor guide them to their

*Miiller's ** Elements of Pliysiology," Eng. translat., 1842, vol. ii,
p. 1117. Owen, ** Anatomy of Vertebrates," vol. iii, p. 260; ibid, on
tlie Walrus, **Proc. Zoolog. Soc," NovemlDer 8, 1854. See also R.
Knox, "Great Artists and Anatomists," p. 106. This rudiment ap-
parently is somewhat larger in Negroes and Australians than in Euro-
peans, see Carl Vogt, " Lectures on Man," Eng. translat., p. 129.

f The account given by Humboldt of the power of smell possessed
by the natives of South America is well known, and has been con-
firmed by others o M. Houzeau(" Etudes sur les Facultes Mentales,"
etc., torn, i, 1872, p. 91) asserts that he repeatedly made experiments,
and proved that Negroes and Indians could recognize persons in the
dark by their odor. Dr. W. Ogle has made some curious observa-
tions on the connection between the power of smell and the coloring
matter of the mucous membrane of the olfactory region, as well as of
the skin of the body. I have, therefore, spoken in the text of the
dark colored races having a finer sense of smell than the white races.
See his paper, " Medico-Chirurgical Transactions," London, vol. liii,
1870, p. 276.

20 THE DESCENT OF MAN.

food; nor does it prevent the Esquimaux from sleeping in
the most fetid atmosphere, nor many savages from eating
half -putrid meat. In Europeans the power differs greatly
in different individuals, as I am assured by an eminent
naturalist who possesses this sense highly developed, and
who has attended to the subject. Those who believe in the
principle of gradual evolution will not readily admit that
the sense of smell in its present state was originally acquired
by man as he now exists. He inherits the j)ower 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. In those animals which
have this sense highly developed, such as dogs and horses,
the recollection of persons and of places is strongly associ-
ated with their odor; and we can thus perhaps understand
how it is, as Dr. Maudsley has truly remarked,* that the
sense of smell in man *^is singularly effective in recalling
vividly the ideas and images of forgotten scenes and places."

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 man, and
fine down on that of the woman. The different races differ
much in hairiness; and in the individuals of the same race
the hairs are highly variable, not only in abundance, but
likewise in position; thus in some Europeans the shoulders
are quite naked, while in others they bear thick tufts of
hair. \ There can be little doubt that the hairs thus scat-
tered 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-
colored 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. X

I am informed by Sir James Paget that often several
members of a family have a few hairs in their eyebrows
much longer than the others; so that even this slight

* " The Physiology and Pathology of Mind," 2d edit., 1868, p. 134.

f Eschricht, Ueber die Richtung der Haare am menschlichen K6r-
per, "Miiller's Archiv fur Anat. und Phys.," 1837, s. 47. I shall
often have to refer to this very curious paper.

J Paget, ** Lectures on Surgical Pathology," 1853, vol. i, p. 71.

RUDIMENTS, 21

peculiarity seems to be inherited. These hairs, too, seem
to have their representatives; for in the chimpanzee, and in
certain species of Macacus, there are scattered hairs of con-
siderable length rising from the naked skin above the eyes,
and corresponding to our eyebrows; similar long hairs pro-
ject from the hairy covering of the superciliary ridges in
some baboons.

The fine wool-like hair, or so-called lanugo, with which
the human foetus during the sixth month is thickly cov-
ered, offers a more curious case. It is first developed, dur-
ing the fifth month, on the eyebrows and face, and espe-
cially round the mouth, where it is much longer than that
on the head. A mustache of this kind was observed by
Eschricht* on a female foetus; 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 foetal body are
the same as in the adult^ but are subject to much varia-
bility. 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 extremi-
ties in most of the lower animals. As this can hardly be
an accidental coincidence, the woolly covering of the foetus
probably represents the first permanent coat of hair in those
mammals which are born hairy. Three or four cases have
been recorded of persons born with their whole bodies and
faces thickly covered wdth fine long hairs; and this strange
condition is strongly inherited, and is correlated with an
abnormal condition of the teeth, f Prof. Alex. Brandt in-
forms me that he has compared the hair from the face of a
man thus characterized, aged thirty-five, with the lanugo
of a foetus, and finds it quite similar in texture; therefore,
as he remarks, the case may be attributed to an arrest of
development in the hair, together with its continued
growth. Many delicate children, as I have been assured
by a surgeon to a hospital for children, have their backs

* Eschricht, ibid., s. 40, 47.

f See my "Variation of Animals and Plants under Domestication,"
vol. ii, p. S27. Prof. Alex. Brandt has recently sent me an additional
case of a father and son, born in Russia, with tJbese peculiarities. I
nave received drawings of both from Patis*

22 THE DESCENT OF MAN,

covered by rather long silky hairs; and such cases probably
come under the same head.

It appears as if the posterior molar or wisdom teeth were
tending to become rudimentary in the more civilized 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 have been assured that
they are much more liable to decay, and are earlier lost
than the other teeth; but this is denied by some eminent
dentists. They are also much more liable to vary, both in
structure and in the period of their development, than the
other teeth.* 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, f
Prof. Schaaffhausen accounts for this difference between
the races by '^ the posterior dental portion of the jaw being
always shortened "in those that are civilized, J and this
shortening may, I presume, be attributed to civilized 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 caecum. The caecum is a branch or diver-
ticulum of the intestine, ending in a cul-de-sac, and is ex-
tremely long in many of the lower vegetable-feeding mam-

* Dr. Webb, ** Teeth in Man and the Anthropoid Apes," as quote 1
by Dr. C. Carter Blake in "Anthropological Review," July, 1867.
p. 299.

f Owen, ** Anatomy of Vertebrates. ** vol. iii, pp. 320, 321 and 325.

j ** On the Primitive Form of the Skull," Eng. translat. in" Anthrop-
ological Review," Oct. 1868, p. 426.

§ Prof. Montegazza writes to me from Florence, that he has lately
been studying the last molar teeth in the different races of man, and
has come to the same conclusion as that given in my text, viz. : that
in the higher or dTtlized races they are on the road toward atrophy
or eUmint^QQt

HmnMENTS. 23

mals. In the marsupial koala it is actually more than
thrice as long as the whole hody.* It is sometimes produced
into a long gradually tapering point, and is sometimes con-
stricted in parts. It appears as if, in consequence of
changed diet or habits, the caecum had become much short-
ened in various animals, the vermiform appendage being
left as a rudiment of the shortened part. That this ap-
pendage is a rudiment, we may infer from its small size, and
from the evidence which Prof. Canestrini f 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 caecum, 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 some-
times 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. J

In some of the lower Quadrumana, in the Lemuridae and
Carnivora, -as well as in many marsupials, there is a pas-
sage near the lower end of the humerus, called the supra-
condyloid foramen, through which the great nerve of the
fore limb and often the great artery pass. Now in the
humerus of man, there is generally a trace of this passage,
which is sometimes fairly well developed, being formed by
a depending hook-like process of bone, completed by a band
of ligament. Dr.. Struthers,§ who has closely attended to
the subject, has now shown that this peculiarity is some-
times inherited, as it has occurred in a father, and in no less

* Owen, ''Anatomy of Vertebrates," vol. iii, pp. 416, 434, 441.

t " Annuario della Soc. d. Nat.," Modena, 1867, p. 94.

JM. C. Martins ("De I'lTnite Organique," in "Revue d6s Deux
Mondes," June 15, 1863, p. 16), and Hackel ("Generelle Morpholo-
gie," B. ii, s. 278), liave botli remarked on the singular fact of this
rudiment sometimes causing death.

§ With respect to inheritance, see Dr. Struthers in the *• Lancet,"
Feb. 15, 1873, and another important paper, ibid., Jan. 34, 1863, p.
83. Dr. Knox, as I am informed, was the first anatomist who drew
attention to this peculiar structure in man ; see his ' ' G^reat Artists
and Anatomists," p. 63. See also an important meijioir on thitj pro-
cess by Dr. Gruber, in the " Bulletin de I'Acad. Imp. de S^. Patera-
bourg," torn, xii, 1867, p, 448-

24 THE DESCENT OF MAN.

than four out of his seven children. 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 if the occasional
development of this structure in man is, as seems probable,
due to reversion, it is a return to a very ancient state of
things, because in the higher Quadrumana it is absent.

There is another foramen or perforation in the humerus,
occasionally present in man, which may be called the inter-
condyloid. This occurs, but not constantly, in various an-
thropoid and other apes,* and likewise in many of the lower
animals. It is remarkable that this perforation seems to
have been present in man much more frequently during
ancient times than recently. Mr. Buskf 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 ' Oimetiere 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. D upon t found thirty per cent,
of perforated bones in the caves of the Valley of the Lesse,
belonging to the Reindeer period; while 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 Vaureal. Nor
should it be left unnoticed that M. Pruner-Bey states that
this condition is common in Guanche skeletons.^' It is an
interesting 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. One chief
cause seems to be that the ancient races stand somewhat

*Mr. St. George Mivart, *' Transact. Pliil. Soc," 1867, p. 310.

f " On tlie Caves of Gibraltar," "Transact. Internat. Congress of
Prehist. Arch." Third Session, 1869, p. 159. Prof. Wyman has lately
shown (Fourth Annual Report, Peabody Museum, 1871, p. 20), thai
this perforation is present in thirty-one per cent, of some human re-
mains from ancient mounds in the Western United States, and in
Florida. It frequently occurs in the negro.

RUDIMENTS. 25

nearer in the long line of descent to their remote animal-
like progenitors.

In man, the os coccyx, together with certain other verte-
bra3 hereafter to be described, though f unctionless as a tail,
plainly represent this part in other vertebrate animals. At
an early embryonic period it is free, and projects beyond
the lower extremities; as may be seen in the drawing (Fig.
1) of a human embryo. Even after birth it has been known,
in certain rare and anomalous cases,* to form a small ex-
ternal rudiment of a tail. The os coccyx is short, usually
including only four vertebrge, all anchylosed together; and
these are in a rudimentary condition, for they consist, with
the exception of the basal one, of the centrum alone, f
They are furnished with some small muscles; one of which,
as I am informed by Prof. Turner, has been expressly de-
scribed by Theile as a rudimentary repetition of the exten-
sor of the tail, a muscle which is so largely developed in
many mammals.

The spinal cord in man extends only as far downward 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 ves-
tige of so important a structure as the spinal cord, though
no longer inclosed within a bony canal. The following
fact, for which I am also indebted to Prof. Turner,
shows how closely the os coccyx corresponds with the
true tail in the lower animals: Luschka has recently dis-
covered at the extremity of the coccygeal bones a very pe-
culiar convoluted body, which is continuous with the mid-
dle sacral artery; and this discovery led Krause and Meyer

* Quatrefages lias lately collected the evidence on this subject.
"Revue des Cours Scienti'fiques," 1867-1868, p. 625. In 1840 Fleisch-
mann exhibited a human foetus bearing' a free tail, which, as is not
always the case, included vertebral bodies; and this tail was critically
examined by the many anatomists present at the meeting of natural-
ists at Erlangen (see Marshall in ' ' Niederlandischen Archiv f iir Zoolo-
gie," December, 1871).

t Owen, " On the Nature of Limbs," 1849, p. 114.

26 . THE DESCENT OF MAN.

to examine the tail of a monkey (Macacus), and of a cat,
in both of which they found a similarly convoluted body,
though not at the extremity.

The reproductive system offers various rudimentary struct-
ures; but these differ in one important respect from the
foregoing cases. Here we are not concerned with the ves-
tige of a part which does not belong to the species in
an efficient state, but with a part efficient in the one
sex, and represented in the other by a mere rudiment.
Nevertheless, the occurrence of such rudiments is as diffi-
cult 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 show that their
presence generally depends merely on inheritance, that is,
on parts acquired by one sex having been partially trans-
mitted to the other. I will in this place only give some in-
stances of such rudiments. It is well known that in the
males of all mammals, including man, rudimentary mammas
exist. These in several instances have become well de-
veloped, and have yielded a copious supply of milk. Their
essential identity in the two sexes is likewise shown by
their occasional sympathetic enlargement in both during
an attack of the measles. The vesicula j?rostatica, 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.* Some other rudi-
mentary structures belonging to the reproductive system
might have been here adduced, f

The bearing of the three great classes of facts now given
is unmistakable. But it Avould be superfluous fully to recap-
itulate the line of argument given in detail in my " Origin
of Species. ^^ The homological construction of the whole

*Leuckart, in Todd's '' Cyclop, of Anat.," 1849-52, vol. iv, p. 1415".
In man this organ is only from three to six lines in length, but, like
so many other rudimentary parts, it is variable in development as
well as in other characters.

fSee, on this subject, Owen, "Anatomy of Vertebrates," vol. iii,
np. 675, 676, 706.

RUDIMENTS. 27

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, etc., is utterly inexplicable.*
It is no scientific explanation to assert that they have all
been formed on the same ideal plan. With respect to de-
velopment, 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 marvelous fact that the embryos of a man, dog, seal,
bat, reptile, etc., can at first hardly be distinguished from
each other. In order to understand the existence of rudi-
mentary organs, we have only to suppose that a former pro-
genitor 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 pre-
viously indicated.

* Prof. Bianconi, in a recently published work, illustrated by ad-
mirable engravings (" La Tbeorie Darwinienne et la creation dite in-
dependante," 1874), endeavors to sliow that homological structures,
in the above and other cases, can be fully explained on mechanical
principles, in accordance with their uses. No one has shown so well,
how admirably such structures are adapted for their final purpose ;
and this adaptation can, as I believe, be explained through natural
selection. In considering the wing of a bat, he brings forward (p.
218) what appears to me (to use Auguste Comte's words) a mere met-
aphysical principle, namely, the preservation ' ' in its integrity of the
mammalian nature of the animal." In only a few cases does he dis-
cuss rudiments, and then only those parts which are partially
rudimentary, such as the little hoofs of the pig and ox, which do not
touch the ground ; these he shows clearly to be of service to the ani-
mal. It is unfortunate that he did not consider such cases as the
minute teeth, which never cut through the jaw in the ox, or the
mammae of male quadrupeds, or the wings of certain beetles, existing
under the soldered wing-covers, or the vestiges of the pistil and
stamens in various flowers, and many other such cases. Although I
greatly admire Prof. Bianconi's work, yet the belief now held by
most naturalists seems to me left unshaken, that homological struct-
ures are inexplicable on the principle of mere adaptation.

28 THE DESCENT OF MAN.

Thus we can understand how it has come to pass that
man and all other vertebrate animals have been con-
structed 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 con-
sider the evidence derived from their affinities or classifica-
tion, their geographical distribution and geological succes-
sion. It is only our natural prejudice, and that arrogance
which made our forefathers declare that they were de-
scended 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.

MANNER OF DEVELOPMENT, 29

CHAPTEE II.

OK THE MAN"NER OF DEVELOPMEl^T OF MAN FROM SOME
LOWER FORM.

Variability of body and mind in man — Inheritance — Causes of varia-
bility— Laws of variation the same in man as in the lower ani-
mals— 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.

It is manifest that man is now subject to much variabil-
ity. No two individuals of the same race are quite alike.
We may compare millions of faces, and each will be dis-
tinct. 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.*
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, f An eminent dentist assures me that

* ' ' Investigations in Military and Anthropolog. Statistics of Ameri-
can Soldiers," by B. A. Gould, 1869, p. 256.

f With respect to the ** Cranial forms of the American Aborigines,"
see Dr. Aitken Meigs in "Proc. Acad. Nat. Sci.," Philadelphia, May,
1868. On the Australians, see Huxley, in Lyell's "Antiquity of
Man," 1863, p. 87. On the Sandwich Islanders, Prof. J. Wyman,
*• Observations on Crania," Boston, 1868, p. 18.

30 THE DESCENT OF MAN.

there is nearly as much diversity in the teeth as in the feat-
ures. The chief arteries so frequently run in abnormal
courses, that it has been found useful for surgical purposes
to calculate from 1040 corpses how often each course pre-
vails.* The muscles are eminently variable : thus those of
the foot were found by Prof. Turner f not to be strictly
alike in any two out of fifty bodies ; and in some the de-
viations were considerable. He adds, that the power of
performing the appropriate movements must have been
modified in accordance with the several deviations. Mr.
J. Wood has recorded J the occurrence of 295 muscular
variations in thirty-six subjects, and in another set of the
same number no less than 558 variations, those occurring
on both sides of the body being only reckoned as one. In
the last set, not one body out of the thirty-six was ^' found
totally wanting in departures from the standard descrip-
tions of the muscular system given in anatomical text
books." A single body presented the extraordinary num-
ber of twenty-five distinct abnormalities. The same mus-
cle sometimes varies in many ways : thus Prof. Macalister
describes § no less than twenty distinct .variations in the
palmaris accessorius.

The famous old anatomist, Wolff, || insists that the inter-
nal viscera are more variable than the external parts: Nulla
particula est qum no7i aliter et aliter in aliis se liabeat
ho7ninibus. 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,
etc., 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 differ-
ences between the men of distinct races, is so notorious that
not a word need here be caid. So it is with the lower ani-
mals. All who have had charge of menageries admit this
fact, and we see it plainly in our dogs and other domestic

* "Anatomy of the Arteries," by R. Quain. Preface, vol. i, 1844.
f "Transact. Royal Soc. Edinburgh," vol. xxiv, pp. 175, 189.
t*'Proc. Royal Soc," 1867, p. 544; also 1868, pp. 483, 524. There
is a previous paper, 1866, p. 229.

§"Proc. R. Irish Academy," vol. x, 1868, p. 141.
1 " Act. Acad. St. Petersburg," 1778, part ii, p. 217.

MANNER OF DEVELOPMENT. 31

animals. Brehm especially insists that each individual
monkey of those which he kept tame 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 intelli-
gence. Rengger, also, insists on the diversity in the vari-
ous 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.*

I have elsewhere f so fully discussed the subject of In-
heritance, that I need here add hardly any thing. 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 ani-
mals; though the facts are copious enough with respect to
the latter. So in regard to mental qualities, their trans-
mission is manifest in our dogs, horses, and other domestic
animals. Besides special tastes and habits, general intelli-
gence, courage, bad and good temper, etc., are certainly
transmitted. With man we see similar facts in almost
every family ; and we now know, through the admirable
labors of Mr. GaltonJ that genius which implies a wonder-
fully complex combination of high faculties, tends to be
inherited; and, on the other hand, it is too certain that in-
sanity and deteriorated mental powers likewise run in
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 to the conditions
to which each species has been exposed during several gen-
erations. Domesticated animals vary more than those in a
state of nature; and this is apparently due to the diversified
and changing nature of the conditions to which they have
been subjected. In this respect the different races of man

* Brehm, " Thierleben," B. i, s. 58, 87. tlengger, " Saugetliiere
von Paraguay," s. 57.

f ' ' Variation of Animals and Plants under Domestication," vol. ii,
cLiap. xii.

t" Hereditary Genius: an Inquiry into its Laws and Conse-
quences," 1869.

SH THE DESCENT OF MAN.

resemble 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 con-
ditions in the more civilized nations; for the members be-
longing to different grades of rank, and following different
occupations, present a greater range of character than do
the members of barbarous nations. But the uniformity of
savages has often been exaggerated, and in some cases can
hardly be said to exist.* It is, nevertheless, an error to
speak of man, even if we look only to the conditions to
which he has been exposed, as '^'^far more domesticated ''f
than any other animal. Some savage races, such as the
Australians, are not exposed to more diversified conditions
than are many species which have a wide range. In an-
other and much more important respect, man differs widely
from any strictly domesticated animal; for his breeding has
never long been controlled, either by methodical or uncon-
scious selection. No race or body of men has been so com-
pletely subjugated by other men, as that certain individuals
should be preserved, and thus unconsciously selected, from
somehow excelling in utility 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 and their tall wives.
In Sparta, also,, a form of selection was followed, for it was
enacted that all children should be examined shortly after
birth; the well-formed and vigorous being preserved, the
others left to perish. |

*Mr. Bates remarks (" The Naturalist on the Amazons," 1863, vol.
ii, p. 159), with respect to the Indians of the same South American
tribe, " No two of them were at all similar in the shape of the head ;
one man had an oval visage with fine features, and another was
quite Mongolian in breadth and prominence of cheek, spread of nos-
trils, and obliquity of eyes."

f Blumenbach, •* Treatises on Anthropolog.," Eug. translat., 1865,
p. 205.

ifMitford's "History of Greece," vol. i, p. 282. It appears also
from a passage in Xenophon's "Memorabilia," B. ii, 4 (to which my
attention has been called by the Rev. J. N. Hoare), that it was a well
recognized principle with the Greeks, that men ought to select their
wives with a view to the health and vigor of their children. The

MANNER OF DEVELOPMENT- 33

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 Pol3^nesians, 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 mere truth be compared with
that of widely ranging species, than with that of domesti-
cated animals.

Not only does variability appear to be in(Juced in man
and the lower animals by the same general causes, but in
both the same parts of the body are affected in a closely
analogous manner. This has been proved in such full de-
tail by Godron and Quatrefages, that I need here only refer
to their works.* 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 has been shown by Isidore Geoffrey
St.-Hilaire.f 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 exhibited by

Grecian poet, Tlieognis, who lived 550 B.C., clearly saw how import-
ant selection, if carefully applied, would be for the improvement of
mankind. He saw, likewise, that wealth often checks the proper
action of sexual selection. He thus writes :

** With kine and horses, Kurnus! we proceed
By reasonable rules, and choose a breed
For profit and increase, at any price;
Of a sound stock, without defect or vice.
But, in the daily matches that we make,
The price is every thing: for money's sake,
Men marry: women are in marriage given
The churl or ruffian, that in wealth has thriven.
May match his offspring with the proudest race:
Thus every thing is mix'd, noble and base!
If then in outward manner, form, and mind.
You find us a degraded, motley kind,
Wonder no more, my friend! the cause is plain,
And to lament the consequence is vain."
(The works of J. Hookham Frere, vol. ii, 1872, p. 334.)

*Godron, "De I'Espece," 1859, tom. ii, livre 3. Quatrefages,
"Unite de I'Espece Humaine," 1861. Also Lectures on Anthropol-
og.y. given in the " Revue des Cours Scientifiques," 1866-1868.

f " Hist. Gen. et Part, des Anomalies de I'Organisation," in three
volumes, tom. i, 183^.

34 THE DESCENT OF MAN.

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 instance 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. And 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; * but several are so important,
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, 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 favor of this conclusion; and valid reasons
may be urged on the other side, at least as far as the in-
numerable 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 organization 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 were recorded, f 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,

*I have fully discussed tliese laws in my "Variation of Animals
and Plants under Domestication," vol. ii, chap, xxii and xxiii. M. J.
P. Durand has lately (1868) published a valuable essay ** De I'lnfiu-
ence des Milieux," etc. He lays much stress, in the case of plants,
on the nature of the soil.

f "Investigations in Military and Anthrop. Statistics/' etc., 1869,
by B. A. Gould, pp. 93, 107, 136, 131, 134.

MANNER OF DEVELOPMENT. 35

which indicates the ancestry, seem to exert a marked in-
fluence 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 life delays
growth, as shown ^^'^by the great difference between the
statures of soldiers and sailors at the ages of seventeen and
eighteen years." Mr. B. A. Gould endeavored 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 the
need of the comforts of life. This latter conclusion is
directly opposed to that arrived at by Villerme, 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 ban en coral islands of the same ocean,*
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 show 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 vigor, "f

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 influ-
ence, inasmuch as the lungs and kidneys are brought into

*For tlie Polynesians, see Pricliard's "Physical Hist, of Man-
kind," vol. V, 1847, pp. 145, 283. Also Godron, "De I'Espece," torn,
ii, p. 289. There is also a remarkable difference in appearance be-
tween the closely allied Hindoos inhabiting the Upper Ganges and
Bengal ; see Elphinstone's " History of India," vol. i, p. 824.

t " Memoirs, Anthropolog. Soc." vol. iii, 1867-69, pp. 561, 065,
567.

36 THE DESCENT OF MAN.

activity under a low temperature, and the liver and skin
under a high one. * It was formerly thought that the color
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
M^ell known that use strengthens the muscles in the individ-
ual, 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 kid-
ney ceases to act from disease, the other increases in size,
and does double work. Bones increase not only in thick-
ness, but in length, from carrying a greater weight, f Dif-
ferent occupations, habitually followed, lead to changed
proportions in various parts of the body. Thus it was as-
certained by the United States Commission;!; 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 ; while their arms were
shorter by 1.09 of an inch, and therefore, out of proportion,
shorter in relation to their lesser heiglit. This shortness of
the arms is apparently due to their greater use, and is an
unexpected result: but sailors chiefly use their arms in pull-
ing, and not in supporting weights. With sailors, the girth
of the neck and the depth of the instep are greater, while

*Dr. Brakenridge, "Theory of Diathesis," *' Medical Times,"
June 19 and July 17, 1869.

f I have given authorities for these several statements in my
"Variation of Animals under Domestication," vol. ii, pp. 297-800
Dr. Jaeger, "Ueber das Langenwachsthum der Knochen," " Jenais
chen Zeitschrift," B. v, Heft. i.

X " Investigations," etc. By B. A. Gould, 1869, p. 233.

MANNER OF DBVBLOPMBNT. 37

the circumference of the chest, waist, and hips is less than
in soldiers.

Whether the several foregoing modifications would be-
come hereditary, if the same habits of life were followed
during many generations, is not known, but it is probable.
Kengger* 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 extremi-
ties motionless. Other writers have come to a similar con-
clusion in analogous cases. According to Cranz,f 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 laborers are at birth larger than
those of the gentry. X From the correlation which exists,
at least in some cases, § between the de^'elopment of the ex-
tremities and of the jaws, it is possible that in those classes
which do not labor much with their hands and feet, the
jaws would be reduced in size from this cause. That they
are generally smaller in refined and civilized men than in
hard-working men or savages, is certain. But with savages,
as Mr. Herbert Spencer || 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 ;^ 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 engrav-
ers are liable to be short-sighted, while men living much
out of doors, and especially savages, are generally long-

* *' Saugethiere von Paraguay," 1830, s. 4.

f "History of Greenland," Eng. translat., 1767, vol. i, p. 230.

X "Intermarriage." By Alex. Walker, 1838, p. 377.

§ *' The Variation of Animals under Domestication," vol. I, p. 173.

\ "Principles of Biology," vol. i, p. 455.

Tf Paget, " Lectures on Surgical Pathology," vol, ii, 1853, p. 309.

38 THE DESCENT OF MAN,

sighted.* Short-sight and long-sight certainly tend to
be inherited, f 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 Rengger X 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 probably 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 Mon-
golians 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. §

The Quechua Indians inhabit the lofty plateaux of Peru;
and Alcide d^Orbigny states || that, from continually breath-
ing 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.

* It is a singular and unexpected fact that sailors are inferior to
landsmen in their mean distance of distinct vision. Dr. B. A. Gould
(" Sanitary Memoirs of the War of the Rebellion," 1869, p. 530), has
proved this to be the case ; and he accounts for it by the ordinary
range of vision in sailors being " restricted to the length of the vessel
and the height of the masts."

f " The Variation of Animals under Domestication," vol. i, p. 8.

X " Saugethiere von Paraguay," s. 8, 10. I have had good oppor-
tunities for observing the extraordinary power of eyesight in the
Fuegians. See also Lawrence (" Lectures on Physiology," etc. , 1822,
p. 404) on this same subject. M. Giraud-Teulon has recently col-
lected (" Revue des Cours Scientifiques," 1870, p. 625) a large and
valuable body of evidence proving that the cause of short-sight,
•* Ceat le travail assidu, de pres."

% Prichard, " Phys. Hist, of Mankind," on the authority of Blum-
enbach, vol. i, 1851» p. 311 ; for the statement by Pallas, vol. iv,
1844, p. 407.

I Quoted by Prichard, •* Researches into the Phys. Hist, of Man-
tod," VOL 7, j>. 463.

MANNER OF BE VELOPMENT, 39

These observations have been doubted ; but Mr. D. Forbes
carefully measured many Aymaras, an allied race, living at
the height of between 10,000 and 15,000 feet ; and he in-
forms me * 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 1,000, and the other measurements
are reduced to this standard. It is here seen that the ex-
tended 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 ; while in two Europeans, measured at the same
time, the femora to the tibiae were as 244 to 230 ; and in
three Negroes as 258 to 241. The humerus is likewise
shorter relatively to the forearm. 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 compensa-
tion 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 acclimatized 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 genera-
tions : and he observed that they still inherited their char-
acteristic 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 ;
while their femora had become somewhat lengthened, as
had their tibiag, although in a less degree. The actual
measurements may be seen by consulting Mr. Forbes'
memoir. From these observations, there can, I think, be
no doubt that residence during many generations at a great

*Mr. Forbes' valuable paper is now published in the "Journal of
^be Ethnological Soc. of London," new series, vol. ii, 1870, p. 193.

40 'fBE DESCENT OF MAN.

elevation tends, both directly and indirectly, to induce in-
herited modifications in the proportions of the body.*

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 show 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 selec-
tion would probably have been greatly aided by the in-
herited effects of the increased or diminished use of the dif-
ferent parts of the body.

Arrests of Developmejit. — There is a difference between
arrested development and arrested growth, for parts in the
former state continue to grow while still retaining their
early condition. Various monstrosities come under this
head; and some, as a cleft-palate, are known to be occa-
sionally inherited. It will suffice for our purpose to refer
to the arrested brain-development of microcephalous idiots,
as described in Vogt's memoir, f 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
eye-brows, is largely developed, and the jaws are pro-
gnathous to an '' eff ray a7if degree; so that these idiots
somewhat resemble the lower types of mankind. Their in-
telligence, 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 ac-
tive, continually gambolling and jumping about, and mak-
ing 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 shown 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. Idiots also resemble the lower

*Dr. WilckensC'Landwirtliscliaft. Woclienblatt," No. 10,
has lately published an interesting Essay showing how domestic ani-
mals, which live in mountainous regions, have their frames modified.

f'Memoire sur les Microcephales/' 1867, pp. 50, 125, 169, 171,
1^198.

MANNER OP DEVELOPMENT. 41

animals in some other respects; thus several cases are re-
corded of their carefully smelling every mouthful of food
before eating it. One idiot is described as often using his
mouth in aid of his hands while hunting for lice. They
are often filthy in their habits, and have no sense of de-
cency; and several cases have been published of their bodies
being remarkably hairy.*

Reversion. — Many of the cases to be here given, might
have been introduced under tlie last heading. When a
structure is arrested in its development, but still continues
growing, until it closely resembles a corresponding struct-
ure in some lower and adult member of the same group, it
may in one sense be considered as a case of reversion. The
lower members in a group give us some idea how the com-
mon progenitor was probably constructed; and it is hardly
credible that a complex part, arrested at an early phase of
embryonic development, should go on growing so as ulti-
mately to perform its proper function, unless it had ac-
quired such power 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, f There are other cases

* Prof. Laycock sums up the character of brute-like idiots by call-
ing them thermd ; "Journal of Mental Science," July, 1863. Dr.
Scott ("The Deaf and Dumb," 2d edit., 1870, p. 10) has often ob-
served the imbecile smelling their food. See, on this same subject,
and on the hairiness of idiots. Dr. Maudsley, "Body and Mind,"
1870, pp. 46-51. Pinel has also given a striking case of hairiness iu
an idiot.

f In my "Variation of Animals under Domestication" (vol. ii, p.
57), I attributed the not very rare cases of supernumerary mammae
in women to reversion. I was led to this as a probable conclusion,
by the additional mammae being generally placed symmetrically on
the breast; and more especially from one case, in which a single effi-
cient mammae occurred in the inguinal region of a woman, the daugh-
ter of another woman with supernumerary mammee. But I now find
(see, for instance, Prof. Preyer, " Der Kampf um das Dasein," 1869,
s. 45) that mammcB erraticm occur in other situations, as on the back,
in the armpit, and on the thigh; the mammae in this latter instance
having given so much milk that the child was thus nourished. The
probability that the additional mammae are due to reversion is thus
much weakened ; nevertheless, it still seems to me probable, because
two pairs are often found symmetrically on the breast ; and of this I
myself have received information in several cases. It is well known

42 THE DESCENT OF MAN,

which come more strictly under our present head of rever-
sion. 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 normally present in the
human embryo, they become abnormally developed, al-
though in a manner which is normal in the lower members
of the group. These remarks will be rendered clearer by
the following illustrations.

tliat some Lemurs normally have two pairs of mammae on the breast.
Five cases have been recorded of the presence of more than a pair of
mammae (of course rudimentary) in the male sex of mankind ; see
*' Journal of Anat arW Physiology," 1873, p. 56, for a case given by
Dr. Handyside, in which two brothers exhibited this peculiarity ; see
also a paper by Dr. Bartels, in " Reichert's and du Bois-Reymond's
Archiv.," 1872, p. 304. In one of the cases alluded toby Dr. Bartels,
a man bore five mammae, one being medial and placed above the
navel ; Meckel von Hemsbach thinks that this latter case is illus-
trated by a medial mammae occurring in certain Cheiroptera. On the
whole, we may well doubt if additional mammae would ever have
been developed in both sexes of mankind, had not his early progeni-
tors been provided with more than a single pair. In the above work
(vol. ii, p. 12), I also attributed, though with much hesitation, the
frequent cases of poly dactyl ism in men and various animals to rever-
sion. I was partly led to this through Prof. Owen's statement, that
some of the Ichthyopterygia possess more than five digits, and there-
fore, as I supposed, had retained a primordial condition ; but Prof.
Gegenbaur (" Jenaischen Zeitschrift," B. v. Heft. 3, s. 341), disputes
Owen's conclusion. On the other hand, according to the opinion
lately advanced by Dr. Giinther, on the paddle of Ceratodus, which
is provided with articulated bony rays on both sides of a central
chain of bones, there seems no great difiiculty in admitting that six
or more digits on one side, or on both sides, might reappear through
reversion. I am informed by Dr. Zouteveen that there is a case on
record of a man having twenty-four fingers and twenty-four toes ! I
was chiefly led to the conclusion that the presence of supernumerary
digits might be due to reversion from the fact that such digits, not
only are strongly inherited, but, as I then believed, had the power of
regrowth after amputation, like the normal digits of the lower verte-
brata. But I have explained in the second edition of my Variation
under Domestication why I now place little reliance on the recorded
cases of such regrowth. Nevertheless it deserves notice, inasmuch
as arrested development and reversion are intimately related pro-
cesses ; that various structures in an embryonic or arrested condition,
such as a cleft palate, bifid uterus, etc., are frequently accompanied
by polydactylism. This has been strongly insisted on by Meckel and
Isidore Geoff roy St.-Hilaire. But at present it is the safest course to
give up altogether the idea that there is any relation between the de-
velopment of supernumerary digits and reversion to some lowly or-
ganized progonitor of man. ^

MANNER OF DEVELOPMENT. 43

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, which is in no way double
except from having a slight internal fold, as in the higher
apes and man. The rodents exhibit a perfect series of gra-
dations 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 mid-
dle portion or body exists, the cornua remain ununited. As
the development of the uterus proceeds, the two cornua be-
come 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 in ani-
mals as high up in the scale as the lower apes and 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 in-
stance 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 per-
forming the proper office of gestation. In other and rarer
cases, two distinct uterine cavities are formed, each having
its proper orifice and passage.* 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 should know
how (if such an expression may be used) to grow into two
distinct uteri, each with a well-constructed orifice and pas-
sage, 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 struct-
ure as the abnormal double uterus in woman could be the
result of mere chance. But the principal of reversion, by

* See Dr. A. Farre's well-known article in the '* Cyclopaedia of
Anatomy and Physiology," vol. v, 1859, p. 642. Owen, "Anatomy
of Vertebrates," vol. iii, 1868, p. 687. I'rof. Turner, in " Edinburgh
Medical Journal," Feb., 1865-

44 THE DESCENT OF MAN.

which a long-lost structure is called back into existence,
might serve as the guide for its full development, even after
the lapse of an enormous interval of time.

Prof. Canestrini, after discussing the foregoing and
various analogous cases, arrives at the same conclusion as
that just given. He adduces another instance, in the case
of the malar bone,* which, in some of the Quadrumana
and other mammals, normally consists of two portions.
This is its condition in the human foetus when two months
old ; and through arrested development, it sometimes
remains thus in man when adult, more especially in the
lower prognathous races. Hence Canestrini concludes that
some ancient progenitor of man must have had this bone
normally divided into two portions, which afterward be-
came 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 approach-
ing 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.

*"Annuario della Soc, dei Naturalist! in Modena," 1867, p. 83.
Prof. Canestrini gives extracts on this subject from various authori-
ties. Laurillard remarks, that as he has found a complete similarity
in the form, proportions, and connection of the two malar bones in
several human subjects and in certain apes, he cannot consider this
disposition of the parts as simply accidental. Another paper on this
same anomaly has been published by Dr. Saviotti in the " Gazzetta
delle Cliniche," Turin, 1871, where he says that traces of the division
may be detected in about two per cent, of adult skulls ; he also re-
marks that it more frequently occurs in prognathous skulls, not of
the Aryan race, than in otliers. See also G. Delorenzi on the same
subject ; " Tre nuovi casi d'anomalia dell' osso malare," Torino, 1872.
Also, E. Morselli, " Sopra una rara anomalia dell' osso malare,"
Modena, 1872. Still more recently Gruber has written a pamphlet
on the division of this bone. I give these references because a re-
viewer, without any grounds or scruples, has thrown doubts on mj
statements.

MANIiER OF DEVELOPMENT, 45

Various other anomalies in man, more or less analogous
to the foregoing, have been advanced by different authors,
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.*

In man, the canine teeth are perfectly efficient instruments
for mastication. But their true canine character, as Owenf
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 ex-
pressed 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 con-
cerned, be considered as rudimentary. In every large col-
lection of human skulls some may be found, as Hackel;];
observes, with the canine teeth projecting considerably be-
yond the others in the same manner as in the anthropomor-
phous apes, but in a less degree. In these cases, open
spaces between the teeth in the one jaw are left for the re-
ception of the canines of the opposite jaw. An interspace
of this kind in a Kaffir skull, figured by Wagner, is sur-
prisingly wide.§ Considering how few are the ancient
skulls which have been examined, compared to recent
skulls, it is an interesting fact that in at least three cases

* A whole series of cases is given by Isid. Geoffroy St.-Hilaire,
" Hist, des Anomalies," torn, iii, p. 437. A reviewer (" Journal of
Anat. and Physiology," 1871, p. 366) blames me much for not having
discussed the numerous cases, which have been recorded, of various
parts arrested in their development. He says that, according to my
theory, " every transient condition of an organ, during its develop-
ment, is not only a means to an end, but once was an end in itself."
This does not seem to me necessarily to hold good. Why should not
variation occur during an early period of development, having no
relation to reversion ; yet such variations might be preserved and ac-
cumulated, if in any way serviceable, for instance, in shortening and
simplifying the course of development ? And again, why should not
injurious abnormalities, such as atrophied or hypertrophied parts,
which have no relation to a former state of existence, occur at an
early period, as well as during maturity ?

+ "Anatomy of Vertebrates," vol. iii, 1868, p. 323.

X " Generelle Morphologie," 1866, B. ii, s. civ.

§ Carl Vogt's " Lectures on Man," En^. translat., 1864, p. 151.

46 THE DESCENT OF MAN,

the canines project largely ; and in the Naulette jaw they
are spoken of as enormous.*

Of the anthropomorphous apes the males alone have their
canines fully developed ; but in the female gorilla, and in
a less degree in the female orang, these teeth project con-
siderably beyond the others ; therefore the fact, of which I
have been assured, that women sometimes have considerably
projecting canines, is no serious objection to the belief that
their occasional great development in man is a case of re-
version 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 forefathers 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 0. Bell), \
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. Prof.
VlacovichJ; examined forty male subjects, and found a mus-
cle, called by him the ischio-pubic, in nineteen of them; in
three others there was a ligament which represented this
muscle; and in the remaining eighteen no trace of it. In
only two out of thirty female subjects was this muscle de-
veloped on both sides, 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 belief in the descent of man from some lower
form, the fact is intelligible; 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, § has mi-

*C. Carter Blake, on a jaw from La Naulette, ** Anthropolog.
Review," 1867, p. 295. Schaaffhausen, ibid., 1868, p. 426.

t " The Anatomy of Expression," 1844, pp. 110, 131.

:j: Quoted by Prof. Canestrini in the ** Annuario," etc., 1867, p. 90.

§ These papers deserve careful study by any one who desires to
learn how frequently our muscles vary, and in varying come to re-
semble those of the Quadrumana. The following references relate
to the few points touched on in my text : "Proc. Royal Soc," vol,
xiv, 1865, pp. 379-384 ; vol. xv, 1866, pp. 241, 242 ; vol. xv, 1867, p.
044 ; vol. :$vi, 1868, p. 524. 1 may ii©j:© add that Dr. Murie and Mr

MANNER OF DEVELOPMENT. 47

nufcely described a vast number of muscular variations in
man, which resemble normal structures in the lower ani-
mals. The muscles which closely resemble those regularly
present in our nearest allies^, the Quadrumana, are too
numerous to be here even specified. In a single male sub-
ject, 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 daviculce/' such as is
found in all kinds of apes, and which is said to occur in
about one out of sixty human subjects.* Again, this man
had " a special abductor of the metatarsal bone of the fifth
digit, such as Prof. Huxley and Mr. Flower have shown to
exist uniformly in the higher and lower apes.^^ I will give
only two additional cases; the acromio-hasilar muscle is
found in all mammals below man, and seems to be correl-
ated with a quadrupedal gait,f and it occurs in about one
out of sixty human subjects. In the lower extremities Mr.
Bradley J found an abductor ossis metatarsi quinti in both
feet of man; this muscle had not up to that time been re-
corded in mankind, but is always present in the anthropo-
morphous apes. The muscles of the hands and arms — parts
which are so eminently characteristic of man — are extremely
liable to vary, so as to resemble the corresponding muscles
in the lower animals. § Such resemblances are either perfect
or imperfect; yet in the latter case they are 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

St. George Mivart have shown in their Memoir on the Lemuroidea
("Transact. Zoolog. Soc," vol. vii, 1869, p. 96), how extraordinarily-
variable some of the muscles are in these animals, the lowest
members of the Primates. Gradations, also, in the muscles leading
to structures found in animals still lower in the scale, are numerous
In the Lemuroidea.

*See also Prof. Macalister in "Proc. R. Irish Academy," vol. x*
1868, p. 124.

f Mr. Champneys in "Journal of Anat. and Phys.," November.
1871, p. 178.

X " Journal of Anat. and Phys.," May, 1872, p. 421,
§Prof. Macalister (ibid., p. 121) has tabulated his observations,
and finds that muscular abnormalities are most frequent in the fore-
arms, secondly, in the face, thirdly, in the foot, etc.

48 THE DESCENT OF MAN.

variations, makes the following pregnant remark: ''Notable
departures from the ordinary type of the muscular struct-
ures 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 an-
atomy."*

That this unknown factor is reversion to a former state
of existence may be admitted as in the highest degree
probable, f It is quite incredible that a man should through
mere accident abnormally resemble certain apes in no less
than seven of his muscles, if there had been no genetic con-
nection between them. On the other hand, if man is de-
scended from some ape-like creature, no valid reason can
be assigned why certain muscles should not suddenly reap-
pear after an interval of many thousand generations, in the
same manner as with horses, asses, and mules, dark col-
ored stripes suddenly reappear on the legs, and shoulders,
after an interval of hundreds, or more probably of thous-
ands 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 either
there or here. Thus a human uterus furnished with cornua

*Tbe Rev. Dr, HauglitoD, after giving (" Proc. R. Irisli Academy,"
June 27, 1864, p. 715) a remarkable case of variation in tlie human
flexor pollicis longus, adds: "This remarkable example shows that
man may sometimes possess the arrangement of tendons of thumb
and fingers characteristic of the macaque ; but whether such a case
should be regarded as a macaque passing upward into a man, or a
man passing downward into a macaque, or as a congenital freak of
nature, I cannot undertake to say." It is satisfactory to hear so
capable an anatomist, and so embittered an opponent of evolutionism,
admitting even the possibility of either of his first propositions.
Prof, Macalister has also described ("Proc. R. Irish Acad.," vol, x,
1864, p. 138) variations in the flexor pollicis longus, remarkable from
their relations to the same muscle in the Quadrumana.

f Since the first edition of this book appeared, Mr. Wood has pub-
lished another memoir in the "Phil. Transactions," 1870, p. 83, on
the varieties of the muscles of the human neck, shoulder, and chest.
He here shows how extremely variable these muscles are, and how
often and how closely the variations resemble the normal muscles of
the lower animals. He sums up by remarking: " It will be enough
for my purpose if I have succeeded in showing the more important
forms which, when occurring as varieties in the human subject, tend
to exhibit in a sufficiently marked manner what may be considered as
proofs and examples of the Darwinian principle of reversion, or law
of inheritance, in tiiis department of anatomical science."

MANNER OF DEVELOPMENT. 49

may be said to represent, in a rudimentary condition, the
same organ in its normal state in certain mammals. Some
parts which are rudimentary in man, as the os coccyx in
both sexes, and the mammae in the male sex, are always
present; while others, such as the supra-condyloid foramen,
only occasionally appear, and therefore might have been in-
troduced under the head of reversion. These several rever-
sionary structures, as well as the strictly rudimentary ones,
reveal the descent of man from some lower form in an
unmistakable manner.

Correlated Variation. — In man, as in the lower ani-
mals, 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 gov-
erned by some earlier developed part. Various monstrosi-
ties, as I. Geoffrey 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 color
of the skin and of the hair, color and constitution, are
more or less correlated.* Prof. Schaaffhausen first drew
attention to the relation apparently existing between a mus-
cular frame and the 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 to our ignorance, they appear to arise
without any exciting cause. It can, however, be shown
that such variations, whether consisting of slight individ-
ual differences, or of strongly marked and abrupt devi-
ations of structure, depend much more on the constitu-
tion of the organism than on the nature of the conditions
to which it has been subjected, f

*The authorities for these several statements are given in my
"Variation of Animals under Domestication," vol, ii, pp. 320-335.

f This whole subject has been discussed in chap, xxiii, vol. ii, of
my " Variation of Animals and Plants under Domestication."

50 THE! DESCENT OF MAN.

Rate of hicrease. — Civilized populations have been
known under favorable conditions, as in the United States,
to double their numbers in twenty-five years ; and, accord-
ing to a calculation, by Euler, this might occur in a little
over twelve years.* At the former rate, the present popu-
lation of the United States (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 sur-
face. 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 civilized nations
this 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, from
various diseases, of the inhabitants of crowded and miser-
able houses at all ages. The efl'ects of severe epidemics
and wars are soon counterbalanced, and more than counter-
balanced in nations placed under favorable conditions.
Emigration also comes in aid as a temporary check, but
with the extremely poor classes, not to any great extent.

There is reason to suspect, as Malthus has remarked, that
the reproductive power is actually less in barbarous,
than in civilized races. We knoAV 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 during a long time ; but it
is highly probable that savages, who often suffer much
hardship, and who do not obtain so much nutritious food
as civilized men, would be actually less prolific. I have
shown in a former work,f that all our domesticated quad-
rupeds and birds, and all our cultivated plants, are more

fertile than the corresponding species m a state of nature.

» — ■ ' —

* See tlie ever memorable "Essay on the Principle of Population,'*
by the Rev. T. Malthus, vol. i, 1826, pp. 6, 517.

f " Variation of Animals and Plants under DomcBtication," vol. ii,
pp. 111-113, 163.

MANNER OF DEVELOPMENT. 51

It is no valid objection to this conclusion that animals sud-
denly supplied with an excess of food, or when grown very
fat, and that most plants on sudden removal from very
poor to very rich soil, are rendered more or less sterile. We
might, therefore, expect that civilized men, who in one
sense are highly domesticated, would be more prolific than
wild men. It is also probable that the increased fertility of
civilized 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.*
Notwithstanding that savages appear to be less prolific
than civilized 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, as shown by Mr.
Hunter, f they have increased 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 civilized 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 pro-
truding stomachs and emaciated limbs after and during
famines. They are then, also, compelled to wander much,
and, as I was assured in Australia, their infants 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. Sav-
ages, when hard pressed, encroach on each other^s- terri-
tories, and war is the result ; but they are indeed almost

*Mr. Sedgwick, "British and Foreign Medico-CMrurg. Review,"
July, 1863, p. 170.
f "The Annals of Rural Bengal," by W. W. Hunter, 1868, p. 259.

5^ THE DESCENT OF MAN.

always at war with their neighbors. They are liable to
many accidents on land and water in their search for food ;
and in some countries they suffer much from the largei
beasts of prey. Even in India^ districts have been depop-
ulated by the ravages of tigers.

Malthus has discussed these several checks, but he does
not lay stress enough on what is probably the most import-
ant 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. McLennan* has shown,
on a still more extensive scale. These practices appear to
have originated in savages recognizing the difficulty, or
rather the impossibility of supporting all the infants that
are born. Licentiousness may also be added to the forego-
ing 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
the lowest savages at the present time. Our early semi-
human progenitors would not have practiced infanticide or
polyandry; for the instincts of the lower animals are never
so perverted f as to lead them regularly to destroy their own
offspring, or to be quite devoid of jealousy. 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;

* "Primitive Marriage," 1865.

f A writer in the " Spectator" (March 12, 1871, p. 320) comments
as follows on this passage: "Mr. Darwin finds himself compelled to
reintroduce a new doctrine of the fall of man. He shows that the
instincts of the higher animals are far nobler than the habits of sav-
age races of men, and he finds himself, therefore, compelled to re-
introduce— in a form of the substantial orthodoxy of which he
appears to be quite unconscious — and to introduce as a scientific
hypothesis the doctrine that man's gain of knowledge was the cause
of a temporary but long-enduring moral deterioration, as indicated by
the many foul customs, especially as to marriage, of savage tribes.
What does the Jewish tradition of the moral degeneration of man
through his snatching at a knowledge forbidden him by his highest
instinct assert beyond this ? "

MANNER OF DEVELOPMENT. 53

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 were we cannot say, any more than with most other
animals. We know that horses and cattle, which are not
extremely prolific animals, when first turned loose in South
America, increased at an enormous rate. The elephant,
the slowest breeder of all known animals, 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 repro-
duction in the wild horses and cattle of America, was at
first in any sensible degree increased; or that, as each dis-
trict became fully stocked, this same power was diminished.
No doubt in this case, and in all others, many checks con-
cur, and different checks under different circumstances;
periodical dearths, depending on unfavorable 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 vari-
able 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,* 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, f
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

*See some good remarks to this effect by W. Stanley Jevons, "A
Peduction from Darwin's Theory," " Nature," 1869, p. 231,
. f Lathftm, "Man and his Migrations," 1851, p. 135.

54 THE DESCENT OF MAN.

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,* to incessant variability.
If then the progenitors of man inhabiting any district, es-
pecially 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 move-
ment for gaining subsistence, or for defending themselves,
would on an average survive in greater numbers, and pro-
create 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 this earth.
He has spread more widely than any other highly organized
form: and all others have yielded before him. He mani-
festly owes this immense superiority to his intellectual fac-
ulties, to 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. As Mr.
Ohauncey Wright remarks:f '^a psychological analysis of
the faculty of language shows, that even the smallest pro-
ficiency in it might require more brain power than the
greatest proficiency in any other direction.^'' He has in-
vented and is able to use various weapons, tools, traps, etc.,
with which he defends himself, kills or catches prey, and
otherwise obtains food. He has made rafts or canoes for
fishing or crossing over to neighboring 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 discovery of fire, probably the
greatest ever made by man, excepting language, dates from
before the dawn of history. These several inventions, by

* Messrs. Murie and Mivart in their ' * Anatomy of the Lemuroidea "
("Transact. Zoolog. Soc," vol. vii, 1869, pp.* 96-98) say, "some
muscles are so irregular in their distribution that they cannot be well
classed in any of the above groups." These muscles differ even on
the opposite sides of the same individual.

f Limits of Natural Selection, "North American Beview/' Oct-
1870, p. 295.

MANNER OF DEVELOPMENT. 55

which man in the rudest state has become so pre-eminent,
are the direct results of the development of his powers of
observation, memory, curiosity, imagination, and reason. I
cannot, therefore, understand how it is that Mr. Wallace*
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 un-
derrate 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 facul-
ties being discussed in a later 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 a Fuegian in defend-
ing himself, or in killing birds, requires the most consum-
mate perfection in the correlated action of the muscles of
the hand, arm, and shoulder, and, further, 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 co-adaptation of numerous muscles.
To chip a fiint 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, f re-
marks, the shaping fragments of stone into knives, lances,
or arrow-heads, shows '^'extraordinary ability and long

* "Quarterly Review," April, 1869, p. 392. This subject is more
fully discussed in Mr. Wallace's " Contributions to the Theory of
Natural Selection," 1870, in which all the essays referred to in this
work are republished. The "Essay on Man," has been ably criti-
cized by Prof. Claparede, one of the most distinguished zoologists in
Europe, in an article published in the " Bibliotheque Universelle,"
June, 1870. The remark quoted in my text will surprise every one
who has read Mr. Wallace's celebrated paper on " The Origin of
Human Races deduced from the Theory of Natural Selection," orig-
inally published in the " Anthropological Review," May, 1864, p.
clviii. I cannot here resist quoting a most just remarli by Sir J.
Lubbock ("Prehistoric Times," 1865, p. 479) in reference to this
paper, namely, .that Mr. Wallace, "with characteristic unselfishness,
ascribes it (i. e. the idea of natural selection) unreservedly to Mr.
Darwin, although, as is well known, he struck out the idea inde-
pendently, and published it, though not with the same elaboration,
at the same time."

f Quoted by Mr. Lawson Tait in his " Law of Natural Selection,"
"Dublin Quarterly Journal of Medical Science," Feb., 1869. Dr.
Keller is likewise quoted to the same effect.

56 TEE DESCENT OF MAN

practice/' This is to a great extent proved by the fact that
primeval men practiced a division of labor ; 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. Archaeologists are convinced that an enormous
interval of time elapsed before our ancestors thought of
grinding chipped flints into smooth tools. One can hardly
doubt, that a man-like animal who possessed a hand and
arm sufliciently perfect to throw a stone with precision, or
to form a flint into a rude tool, could, with sufficient prac-
tice, as far as mechanical skill alone is concerned, make
almost any thing which a civilized 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 genus, musical
cadences; but in man the 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 men, and therefore
to the best representatives of our early progenitors, we find
that the hands of the Quadrumana are constructed on the
same general pattern as our own, but are far less perfectly
adapted for diversified uses. Their hands do not serve for
locomotion so well as the feet of a dog; as may be seen in
such monkeys as the chimpanzee and orang, which walk on
the outer margins of the palms, or on the knuckles.*
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,
in the same manner as we do. They can thus also lift
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. In a wild state they break
open hard fruits with stones. Other monkeys open mussel-
ehells with the two thumbs. With their fingers they pull

*Owen, *' Anatomy of Vertebrates," vol. iii, p. 71.

MANNER OF DEVELOPMENT, 57

out thorns and burrs, and hunt for each other's parasites.
They roll down stones, or throw them at their enemies:
nevertheless, they are clumsy in these various actions, and,
as I have myself seen, are quite unable to throw a stone
with precision.

It seems to me far from true that because ^' objects are
grasped clumsily "by monkeys, "a much less specialized
organ of prehension " would have served them* equally well
with their present hands. On the contrary, I see no reason
to doubt that more perfectly constructed hands would have
been an advantage to them, provided that they were not
thus rendered less fitted for climbing trees. We may sus-
pect that a hand as perfect as that of man would have been
disadvantageous for climbing; for the most arboreal mon-
keys in the world, namely, Ateles, in America, Oolobus, in
Africa, and Hylobates, in Asia, are either thumbless, or
their toes partially cohere, so that their limbs are converted
into mere grasping hooks, f

As soon as some ancient member in the great series of the
Primates came to be less arboreal, owing to a change in its
manner of procuring subsistence, or fo some change in the
surrounding conditions, its habitual manner of progression
would have been modified; and thus it would have been
rendered more strictly quadrupedal or bipedal. Baboons
frequent hilly and rocky districts, and only from necessity
climb high trees ; | 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 atti-
tude, which forms one of his most conspicuous characters.
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. Sir 0.
Bell§ insists that ^Hhe hand supplies all instruments, and

*" Quarterly Review," April, 1869, p. 892.

f In Hylobates syndactylus, as tlie name expresses, two of the toes
regularly cohere ; and this, as Mr. Blyth informs me, is occasionally
the case with the toes of H. agilis, lar, and leuciscus. Colobus is
strictly arboreal and extraordinarily active (Brehm, " Thierleben,"
B. i, s. 50), but whether a better climber than the species of the
allied ijenera, I do not know. It deserves notice that the feet of the
sloths, the most arboreal animals in the world, are wonderfully
hook-like.

t Brehm, " Thierleben," B. i, s. 80.

§ " The Hand," etc. *' Bridgewater Treatise," 1833, p. 38.

58 THE DESCENT OF MAN.

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 before remarked, so
long as they were especially fitted 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 become a biped,; but for many actions it is indispensable
that the arms and 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 has been peculiarly modified, though this
has entailed the almost complete loss of its power of pre-
hension. It accords with the principle of the division of
physiological labor, prevailing throughout the animal
kingdom, that as the hands became perfected for prehen-
sion, the feet should have became perfected for support
and locomotion. AVith some savages, however, the foot
has not altogether lost its prehensile power, as shown by
their manner of climbing trees and of using them in other
ways. *

If it be an advantage to man to stand firmly on his feet
and to have his hands and arms free, of which, from his
pre-eminent success in the battle of life, there can be no
doubt, 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 defend themselves with stones or clubs, to
attack their prey, or otherwise to obtain food. The best
built 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

* Hackel has an excellent discussion on tlie steps by whicli man
became a biped: "Natiirliclie Scliopfungsgeschiclite," 1868, s. 507.
Dr. Bilchner (" Conferences sur la Tbeorie Darwinienne," 1869, p.
135) has given good cases of the use of the foot as a prehensile organ
by man ; and has also written on the manner of progression of the
higher apes, to which I allude in the following paragraph ; see also
Owen (•' Anatomy of Vertebrates," vol. iii, p. 71) on this latter
subject.

MANNER OF DEVELOPMENT. 59

animal could not have been gradually converted from a
quadruped into a biped, as all the individuals in an inter-
mediate condition would have been miserably ill-fitted for
progression. But we know (and this is well worthy of re-
flection) that the anthropomorphous apes are now actually
in an 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
piove awkwardly and much less securely than man. We
$ee, in short, in existing monkeys a manner of progression
intermediate between that of a quadruped and a biped;
but, as an unprejudiced judge* insists, the anthropo-
morphous apes approach in structure more nearly to the
Mpedal than to the quadrupedal type.

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
trie same time transformed for firm support and progres-
6'ion, endless other changes of structure would have be-
come necessary. The pelvis would have to be broadened,
tJhe spine peculiarly curved, and the head fixed m an
a/tered position, all of which changes have been attained
by man. Prof. Schaafihausenf maintains that ^' the pow-
erful mastoia processes of the human skull are the result
of his erect position;" and these processes are absent in
the orang, chimpanzee, etc., and are smaller in the go-
rilla than in man. Various other structures, which appear
connected with man's erect position, might here have been
added. It is very difficult to decide how far these corre-
lated modifications are the result of natural selection, and
how far of the inherited effects of the increased use of cer-
tain parts or of the action of one part on another.

* Prof. Broca, La Constitution des Vertebres caudales ; ** La Revue
d' f^nthropologie," 1872, p. 36 (separate copy).

f " On the Primitive Form of the Skull," translated in "Anthrop-
ological Review," Oct 1868, p. 428. Owen ("Anatomy of Verte-
brates," vol. ii, 1866, p. 551) on the mastoid processes ia the higher
apes-

60 THE DESCENT OF MAN.

No doubt these means of change often co-operate; thiv»
when certain muscles, and the crests of bone to which
they are attached, become enlarged by habitual use, this
shows that certain actions are habitually performed and
must be serviceable. Hence the individuals which per-
formed 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 forefathers 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 or rivals they would use their jaws and teeth less
and less. In this case the jaws, together with the teeth,
•would become reduced in size, as we may feel almost 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 to their habits of
fighting with their incisor teeth and hoofs.

In the adult male anthropomorphous apes, as Rliti-
meyer* and others have insisted, it is the effect on the
skull of the great development of the jaw-muscles that causes
it to differ so greatly in many respects from that of man,
and has given to these animals ''a truly frightful physi-
ognomy.^^ Therefore, as the jaws and teeth in man^s pro-
genitors gradually become reduced in size, the adult skull
would have come to resemble more and more that of exist-
ing man. As we shall hereafter see, a great reduction of
the canine teeth in the males would almost certainly affect
the teeth of the females through inheritance.

As the various mental faculties gradually developed
themselves the brain would almost certainly become larger.
No one, I presume, doubts that the large proportion which
the size of man's brain bears to his body, compared to the
same proportion in the gorilla or orang, is closely connected
with his higher mental powers. We meet with closely
analogous facts with insects, for in ants the cerebral gan-
glia are of extraordinary dimensions, and in all the Hyme-

*"Die Grenzen der Thierwelt, eijie Betrachtung zu Darwin's
I^elire," 1868, s. 6J.

MANNER OF DEVELOPMENT, 61

noptera these ganglia are many times larger than in the
less intelligent orders, such as beetles.* On the other
hand, no one supposes that the intellect of any two ani-
mals 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 wonder-
fully diversified instincts, mental powers and affections of
ants are notorious, yet their cerebral ganglia are not so
large as the quarter of a small pin's head. Under this
point of view the brain of an ant is one of the most mar-
velous atoms of matter in the world, perhaps more so than
the brain of a 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 civilized races, of ancient and modern
people, and by the analogy of the whole vertebrate series.
Dr. J. Barnard Davis has proved,! ^J niany careful meas-
urements, 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 cubic inches.
Professor Broca J found that the nineteenth century
skulls from graves in Paris were larger than those from
vaults of the tAvelfth century, in the proportion of 1484 to
1426; and that the increased size, as ascertained by meas-
urements, was exclusively in the frontal part of the skull —
the seat of the intellectual faculties. Prichard is per-
suaded that the present inhabitants of Britain have
*' much more capacious brain-cases '^ than the ancient in-
habitants. 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

*Dujardin, ** Annales des Sc. Nat.," 3d series Zoolog. torn, xiv,
1850, p. 203. See also Mr. Lowne, "Anatomy and Phys. of the
Musca vomitoria," 1870, p. 14. My son, Mr. F. Darwin, dissected
for me the cerebral ganglia of tlie Formica rufa.

t " PMlosopliical Transactions," 1869, p. 513.

X " Les Selections," M. P. Broca, " Revue d' Anthropologies," 1873 ;
see also, as quoted in C. Vogt's "Lectures on Man," Eng. translat.,
1864, pp. 88, 90. Prichard, "Phys. Hist, of Mankind," vol. i, 1838,
p. 305.

§ In the interesting article just referred to. Prof. Broca has well
remarked, that in civilized nations, the average capacity of the skull

62 THE DESCENT OF MAN.

respect to the lower animals, M. E. Lartet,* 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 are
more complex in the more recent forms. On the other
hand, I have shown f 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 genera-
tions, so that they have exerted their intellect, instincts,
senses and voluntary movements but little.

The gradually increasing weight of the brain and skull
in man must have influenced the development of the sup-
porting spinal column, more especially while he was becom-
ing erect. As this change of position was being brought
about, the internal pressure of the brain will also have in-
fluenced the form of the skull; for many facts show 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 se-
vere burn, have permanently modified the facial bones. In
young persons whose heads have become fixed either side-
ways or backward, owing to disease, one of the two eyes
has changed its position, and the shape of the skull has
been altered apparently by the pressure of the brain in a
new direction. J I have shown that with long-eared rabbits

must be lowered by the preservation of a considerable nnmber of in-
dividuals, weak in mind and body, wlio would have been promptly
eliminated in the savage state. On the other hand, with savages, the
average includes only the more capable individuals, who have been
able to survive under extremely hard conditions of life. Broca thus
explains the otherwise inexplicable fact, that the mean capacity of
the skull of the ancient Troglodytes of Lozere is greater than that of
modern Frenchmen.

* " Comptes-rendus des Sciences," etc., June 1, 1868.

The Variation of Animals and Plants under Domestication,"
pp. 124-129.

X SchaafEhausen gives from Blumenbach and Busch, the cases of
the spasms and cicatrix, in " Anthropolog. Review," Oct. 1868, p.
420. Dr. Jarrold (" Anthropologia," 1808, pp. 115, 116) adduces from
Camper and from his own observations, cases of the modification of
the skull from the head being fixed in an unnatural position. He
believes that in certain trades, such as that of a shoemaker, where
the head is habitually held forward, the forehead becomes more
rounded and prominent.

A. 1,

MANNER OF DEVELOPMENT, 63

even so trifling a cause as the lopping forward of one ear
drags forward almost every bone of the skull on that side;
so that the bones on the opposite side 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 cer-
tainly be altered. I infer this from my observations on
domestic rabbits, some kinds of which have become very
much larger than the wild animal, while others have re-
tained 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 on 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 3.15 and the latter 4.3 inches in
length.* One of the most marked distinctions in different
races of men is that the skull in some is elongated and in
others .rounded; and here the explanation suggested by the
case of the rabbits may hold good; for Welcker finds that
short " men incline more to brachycephaly, and tall men
to dolichocephaly;^''f 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 understand, to a certain
extent, the means by which the great size and more or less
rounded form of the skull have been acquired by man; and
these are characters eminently distinctive of him in com-
parison with the lower animals.

Another most conspicuous difference between man and
the lower animals is the nakedness of his skin. Whales
and porpoises (Cetacea), dugongs (Sirenia) and the hippo-
potamus 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 in-
habit the colder regions are protected by a thick layer of
blubber, serving the same purpose as the fur of seals and

*" Variation of Animals," etc., vol. i, p. 117, on tlie elongation of
the skull ; p. 119, on the effect of the lopping of one ear.

f Quoted by SchaafEhausen, in **Anthropolog. Review," Oct., 1868,
p. 419.

64 THE DESCENT OF MAN.

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 hairy *
than those on the lowlands. May we then infer that man
became divested of hair from having aboriginally inhabited
some tropical land? That the hair is 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, favors this
inference — on the assumption 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 is thickly clothed with hair. The
fact, however, 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, f is opposed to the supposi-
tion that man became naked through the action of the sun.
Mr. Belt believes X that within the tropics it is an advant-
age to man to be destitute of hair, as he is thus enabled to
free himself of the multitude of ticks (acari) and other
parasites, with which he is often infested, and which some-
times cause ulceration. But whether this evil is of suffi-
cient magnitude -to have led to the denudation of his body
through natural selection, may be doubted, since none of
the many quadrupeds inhabiting the tropics have, as far as

*Owen, "Anatomy of Vertebrates," vol. iii, p. 619.

f Isidore Geoffroj St.-Hilaire remarks ("Hist. Nat, Generale," tom.
ii, 1859, pp. 215-2i7) on tke head of man being covered witb long
hair ; also on the upper surfaces of monkeys and of other mammals
being more thickly clothed than the lower surfaces. This has like-
wise been observed by various authors. Prof. P. Gervais (" Hist.
Nat. des Mammiferes," tom. i, 1854, p. 28), however, states that in
the gorilla the hair is thinner on the back where it is partly rubbed
off, than on the lower surface.

X The " Naturalist in Nicaragua," 1874, p. 209. As some confirma-
tion of Mr. Belt's view, I may quote the following passage from Sir
W. Denison ("Varieties of Vice-Regal Life," vol. i, 1870, p. 440):
" It is said to be a practice with the Australians, when the vermin
get troublesome, to singe themselves."

MANNER OF DEVELOPMENT, 65

I know, acquired any specialized means of relief. The
view which seems to me the most probable is that man, or
rather primarily woman, became divested of hair for orna-
mental purposes, as we shall see under Sexual Selection;
and, according to this belief, it is not surprising that man
should differ so greatly in hairiness from all other Primates,
for characters, gained through sexual selection, often differ
to an extraordinary degree in closely related forms.

According to a popular impression, the absence of a tail
is eminently distinctive of man ; but as those apes which
come nearest to him are destitute of this organ its disap-
pearance does not relate exclusively to man. The tail
often differs remarkably in length within the same genus :
thus in some species of Macacus it is longer than the whole
body, and is formed of twenty-four vertebrae; in others
it consists of a scarcely visible stump, containing only three
or four vertebrae. In some kinds of baboons there are
twenty-five, while in the mandrill there are ten very small
stunted caudal vertebrae, or, according to Cuvier,* some-
times only five. The tail, whether it be long or short,
almost always tapers toward the end ; and this, I presume,
results from the atrophy of the terminal muscles, together
with their arteries and nerves, through disuse, leading to
the atrophy of the terminal bones. But no explanation
can at present be given of the great diversity which often
occurs in its length. Here, however, we are more specially
concerned with the complete external disappearance of the
tail. Prof. Broca has recently shownf that the tail in all
quadrupeds consists of tAVO portions, generally separated
abruptly from each other ; the basal portion consists of
vertebrae, more or less perfectly channeled and furnished
with apophyses like ordinary vertebrae; whereas those of
the terminal portion are not channeled, are almost smooth,
and scarcely resemble true vertebrae. A tail, though not
externally visible, is really present in man and the anthro-
pomorphous apes, and is constructed on exactly the same
pattern in both. In the terminal portion of the vertebrae,

*Mr. St. George Mivart, " Proc. Zoolog. Soc," 1865, pp. 563, 583.
Dr. J. E. Gray, "Cat. Brit. Mus.: Skeletons." Owen, "Anatomy
of Vertebrates," vol. ii, p. 517. Isidore Geoffroy "Hist. Nat. Gen."
toiu. ii, p. 244.

f " Revue d'Anthropologie," 1872 ; " La Constitution des Vertebres
cau dales,**

66 THE DESCENT OF MAN,

constituting the os coccyx, are quite rudimentary, being
much reduced in size and number. In the basal portion,
the vertebras are likewise few, are united firmly together,
and are arrested in development ; but they have been ren-
dered much broader and flatter than the corresponding
vertebrae in the tails of other animals ; they constitute
what Broca calls the accessory sacral vertebrae. These are
of functional importance by supporting certain internal
parts and in other ways ; and their modification is directly
connected with the erect or semi-erect attitude of man and
the anthropomorphous apes. This conclusion is the more
trustworthy, as Broca formerly held a different view, which
he has now abandoned. The modification, therefore, of
the basal caudal vertebrae in man and the higher apes. may
have been affected, directly or indirectly, through natural
selection.

But what are we to say about the rudimentary and
variable vertebrae of the terminal portion of the tail, form^
ing the os coccyx 9 A notion which has often been, and will
no doubt again be, ridiculed, namely, that friction has had
something to do with the disappearance of the external
portion of the tail, is not so ridiculous as it at first appears.
Dr. Anderson* states that the extremely short tail of Maca-
cus brunneus is formed of eleven vertebrae, including the
imbedded basal ones. The extremity is tendinous and
contains no vertebrae; this is succeeded by five rudimentary
ones, so minute that together they are only one line and a
half in length, and these are permanently bent to one side
in the shape of a 'hook. The free part of the tail, only a
little above an inch in length, includes only four more
small vertebrae. This short tail is carried erect; but about
a quarter of its total length is doubled on to itself to the
left; and this terminal part, which includes the hook-like
portion, serves '^ to fill up the interspace between the upper
divergent portion of the calosities;^^ so that the animal sits
on it and thus renders it rough and callous. Dr. Anderson
thus sums up his observations : " These facts seem to me
to have only one explanation; this tail, from its short size,
is in the monkey^s way when it sits down, and frequently
becomes placed under the animal while it is in this atti-
tude; and from the circumstance that it does not extend

*"Proc. Zoolog.^Soc." 1873, p. 210.

MANNER OF DEVELOPMENT. 67

beyond the extremity of the ischial tuberosities, it seems as
if the tail originally had been bent round by the will of the
animal, into the interspace between the callosities, to es-
cape being pressed between them and the ground, and that
in time the curvature became permanent, fitting in of itself
when the organ happens to be sat upon/^ Under these
circumstances it is not surprising that the surface of the
tail should have been roughened and rendered callous, and
J)r. Murie,* who carefully observed this species in the
Zoological Gardens, as well as three other closely allied
forms with slightly longer tails, says that when the animal
Bits down the tail ^^ is necessarily thrust to one side of the
buttocks; and whether long or short its root is consequently
liable to be rubbed or chafed." As we now have evidence
that mutilations occasionally produce an inherited effect, f
it is not very improbable that in short-tailed monkeys the
projecting part of the tail, being functionally useless,
should after many generations have become rudimentary
and distorted, from being continually rubbed and chafed.
We see the projecting part in this condition in the Maca-
cus brunneus, and absolutely aborted in the M. ecaudatus
and in several of the higher apes. Finally, then, as far as
we can judge, the tail has disappeared in man and the
anthropomorphous apes, owing to the terminal portion
having been injured by friction during a long lapse of time;
the basal and embedded portion having been reduced and
modified so as to become suitable to the erect or semi-erect
position.

I have now endeavored to show that some of the most
ftistinctive 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 do not
serve to adapt an organism to its habits of life, to the food

**'Proc. Zoolog. Soc.," 1872, p. 786.

f I allude to Dr. Brown-Sequard's observations on the transmitted
effect of an operation causing epilepsy in guinea-pigs, and likewise
more recently on tlie analogous effects of cutting the sympathetic
nerve in the neck. I ghall hereafter have occasion to refer to Mr.
Salvin's interesting case of the apparently inherited effects of mot-
mots biting off the barbs of their own tail-feathers. See also on the
general subject ** Variation of Animals and Plants under Pomesti-
cation/' vol. ii, pp. ^%-^

68 TEE DESCENT OF MAN.

which it consumes, or passively to the surrounding con-
ditions, 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 new kinds of food. Nor must we forget the
principle of correlation, by which, as Isidore Geoffrey has
shown in the case of man, many strange deviations o±
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
color in the plumage of parrots when fed on certain fishes,
or inoculated with the poison of toads; * for we can thus
see that the fluids of the system, if altered for some
special purpose, might induce other 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 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 Nageli on plants,
and the remarks by various authors with respect to ani-
mals, more especially those recently made by Prof. Broca,
that in the earlier editions of my ^'^ Origin of Species'' I
perhaps attributed too much to the action of natural selec-
tion 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; but I am convinced, from
the light gained during even the last few, years, that very
many structures which now appear to us useless, will here-
after be proved to be useful, and will therefore come within
the range of natural selection. Nevertheless, I did not
formerly consider sufficiently the existence of structures,
which, as far as we can at present judge, are neither bene-
ficial nor injurious; and this I beliere to be one of the
greatest oversights as yet detected in my work. I may be

*"The Variation of Animals and Plants under Domestication,"
vol. ii, pp. 380, 283.

MANNER OF DEVELOPMENT. 69

permitted to say, as some excuse, that I had two distinct
objects in view; firstly, to show that species had not been
separately created, and secondly, that natural selection had
been the chief agent of change, though largely aided by
the inlierited effects of habit, and slightly by the direct
action of the surrounding conditions. I was not, however,
able to annul the influence of my former belief, then
almost universal, that each species had been purposely
created; and this led to my tacit assumption that every de-
tail of structure, excepting rudiments, was of some special,
though unrecognized, service. Any one with this assump-
tion in his mind would naturally extend too far the action
of natural selection, either during past or present times.
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 very far from admitting, or in having exagger-
ated 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.

It is, as I can now see, probable that all organic
beings, including man, possess peculiarities of structure,
which neither are now, nor were formerly of any service to
them, and which, therefore, are of no physiological im-
portance. We know not what produces the numberless
slight differences between the individuals of each species,
for reversion only carries the problem a few steps back-
ward, but each peculiarity must have had its efficient
cause. If these causes, whatever they may be, were to act
more uniformly and energetically during a lengthened
period (and against this no reason can be assigned), the re-
sult would probably be not a mere slight individual differ-
ence, but a well-marked and constant modification, though
one of no physiological importance. Changed structures,
which are in no way beneficial, cannot be kept uniform
through natural selection, though the injurious will be
thus eliminated. Uniformity of character would, however,
naturally follow from the assumed uniformity of the excit-
ing causes, and likewise from the free intercrossing of
many individuals. During successive periods, the same
organism might in this manner acquire successive modifi-
cations, which would be transmitted in a nearly uniform

70 THE DESCENT OF MAN.

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 spon-
taneous 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, liiie every other animal, to mul-
tiform individual differences or slight variations, so no
doubt were the early progenitors of man; the variations
being formerly induced by the same general causes, and
governed by the same general and complex laws as at
present. As all animals tend to multiply beyond their
means of subsistence, so it must have been with the pro-
genitors of man; and this would inevitably lead to a strug-
gle for existence and to natural selection. The latter pro-
cess would be greatly aided by the inherited effects of the
increased use of parts, and these two processes would in-
cessantly react on each other. It appears, also, as we shall
hereafter see, that various unimportant characters have
been acquired by man through sexual selection. An unex-
plained residuum of change must be left to the assumed
uniform action of those unknown agencies, which occasion-
ally induce strongly marked and abrupt deviations of struc-
ture in our domestic productions.

Judging from the habits of savages and of the greater
number of the Quadrumana, primeval men, and even
their ape-like progenitors, probably lived in society.
With strictly social animals, natural selection sometimes
acts on the individual, through the preservation of vari-
ations which are beneficial to the community. A com-
munity which includes a large number of well-endowed
individuals increases in number, and is victorious over
other less favored ones ; even although each separate
member gains no advantage over the others of the same
community. Associated insects have thus acquired many
remarkable structures, which are of little or no service
to the individual, such as the pollen-collecting appa-
ratus, or the sting of the worker-bee, or the great jaws of
soldier-ants. 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

MANNER OF DEVELOPMENT. U

service to it. For instance, the horns of ruminants and
the great canine teeth of baboons appear to have been ac-
quired by the males as weapons for sexual strife, but they
are used in defense of the herd or troop. In regard to cer-
tain mental powers the case, as we shall see in the fifth
chapter, is wholly different; for these faculties have been
chiefly, or even exclusively, gained for the benefit of the
'ommunity, and the individuals thereof have at the same
time gained an advantage indirectly.

It has often been objected to such views as the forego-
ing, that man is one of the most helpless and defenseless
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, insists* 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 ascrible to mere natural
selection.'^ He adduces the naked and unprotected state
of the body, the absence of great teeth or claws for de-
fense, the small strength and speed of man, and his slight
power of discovering food or of avoiding danger by smell.
To these deficiencies there might be added one still more
serious, namely, that he cannot climb quickly and so
escape from enemies. The loss of hair would not have
been a great injury to the inhabitants of a warm country.
For we know that the unclothed Fuegians can exist under
a wretched climate. When we compare the defenseless
state of man with that of apes we must remember that the
great canine teeth with which the latter are provided are
possessed in their full development by the males alone, and
are chiefly used by them for fighting with their rivals;
yet the females, which are not thus provided, manage to
survive.

In regard to bodily size or strength, we do not know
whether man is descended from some 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 than his ances-
tors, We should, however, bear in mind that an animal

' » "Primeval Man/' 1869, p. 66.

72 TE^ DESCENT OF MAN'.

possessing great size, strength, and ferocity, and which,
like the gorilla, could defend itself from all enemies, would
not perhaps have become social: and this would most effect-
ually have checked the acquirement of the higher mental
qualities, such as sympathy and the love of his fellows.
Hence it might have been an immense advantage to man to
have sprung from some comparatively weak creature.

The small strength and speed of man, his want of nat-
ural weapons, etc., are more than counterbalanced, firstly,
by his intellectual powers, through which he has formed
for himself weapons, tools, etc., though still remaining in
a barbarous state, and secondly, by his social qualities which
lead him to give and receive aid from his fellow-men. No
country in the world abounds in a greater degree with dan-
gerous beasts than Southern Africa; no country presents
more fearful physical hardships than the Arctic regions;
yet one of the puniest of races, that of the Bushmen, main-
tains itself in Southern Africa, as do the dwarfed Esqui-
maux in the Arctic regions. The ancestors of man were,
no doubt, inferior in intellect, and probably in social dis-
position to the lowest existing savages; but it is quite con-
ceivable that they might have existed, or even flourished,
if they had advanced in intellect, while gradually losing
their brute-like powers, such as that of climbing trees, etc.
But these ancestors would not have been exposed to any
special danger, even if far more helpless and defenseless
than any existing savages, had they inhabited some warm
continent or large island, such as Australia, New Guinea,
or Borneo, which is now the home of the orang. And
natural selection arising from the competition of tribe with
tribe in some such large area as one of these, together with
the inherited effects of habit, would, under favorable con-
ditions, have sufficed to raise man to his present high
position in the organic scale.

MENTAL POWBHS. 73

CHAPTER III.

COMPARISON OF THE MEl^TAL POWERS OF MAN AND THE
LOWER ANIMALS.

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

We have seen in the last two chapters that man bears
in his bodily structure clear traces of his descent from
some lower form; but it maybe 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
hardly any abstract terms for common objects or for the
affections,* with that of the most highly organized ape.
The difference would, no doubt, still remain immense, even
if one of the higher apes had been improved or civilized as
much as a dog has been in comparison with its parent-form,
the wolf or jackal. The Fuegians rank among, 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

* See the evidence on those points, as given by Lubbock, " Prehis-
toric Times," p. 354, etc.

74 THE DESCENT OF MAN. •

it cau be shown 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 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 navi-
gator Byron, who dashed his child on the rocks for drop-
ping a basket of sea-urchins, and a Howard or Clarkson;
and in intellect, between a savage who uses hardly any ab-
stract terms, and a Newton or Shakespeare. Differences
of this kind between the highest men of the highest races
and the lowest savages are connected by the finest grada-
tions. Therefore it is possible that they might pass and be
developed into each other.

My object in this chapter is to show that there is no fun-
damental 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 struck me most, with the
hope that they may produce some effect on the reader.

With respect to animals very low in the scale, I shall give
some additional facts under Sexual Selection, showing that
their mental powers are much higher than might have been
expected. The variability of the faculties in the individ-
uals 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 inquiry 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 organ-
isms, is as hopeless an inquiry as how life itself first origi-
nated. These are problems for the distant future if they are
ever to be solved by man.

As man possesses the same senses as the lower animals,
his fundamental intuitions must be the same. Man has
jUso some few instincts in common, as that of self-preserva'

MENTAL POWERS. %

tiou, sexual love, the love of the mother for her new-born
offspring, the desire possessed by the latter to suck, 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 afterward 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 in-
stincts 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 de-
veloped from their instincts. But Pouchet, in an interest-
ing essay,* has shown that no such inverse ratio really
exists. Those insects which possess the most wonderful
instincts are certainly the most intelligent. In the ver-
tebrate series, the least intelligent members, namely fishes
and amphibians, do not possess complex instincts ; and
among 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 work, f

Although the first dawnings of intelligence, according to
Mr. Herbert Spencer, J have been developed through the
multiplication and co-ordination of reflex actions, and
although many of the simpler instincts graduate into reflex

* " L'Instinct chez les Insectes," "Revue des Deux Mondes." Feb.
1870, p. 690.

f '* The American Beaver and His Works," 1868.

% " The Principles of Psychology," 2d edit., 1870, pp. 418-443.

% THE DESCENT OF MAN.

actions, 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 intelli-
gence. I am, however, very far from wishing to deny that
instinctive actions may lose their fixed and untaught char-
acter and be replaced by others performed by the aid of the
free will. On the other hand, some intelligent actions,
after being performed during several generations, become
converted into instincts and are inherited, as when birds
on oceanic islands learn to avoid man. These actions 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 organization, which
induce slight variations or individul 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 marvelous instincts of sterile worker-ants and bees,
which leave no offspring to inherit the effects of experience
and of modified habits.

Although, as we learn from the above-mentioned insects
and the beaver, a high degree of intelligence is certainly
compatible with complex instincts, and although actions,
at first learned voluntarily, can soon through habit be
performed with the quickness and certainty of a reflex
action, yet it is not improbable that there is a certain
amount of interference between the development of free
intelligence and of instinct, which latter implies some in-
herited modification of the brain. 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 very intricate
channels of the freest intercommunication; and as a conse-
quence each separate part would perhaps tend to be less
well fitted to answer to particular sensations or associations
in a definite and inherited — that is instinctive — manner.
There seems even to exist some relation between a low de-
gree of intelligence and a strong tendency to the formation

MENTAL POWERS. 77

of fixed, though not inherited habits; for as a sagacious
physician remarked to me, persons who are slightly imbecile
tend to act in everything by routine or habit; and they are
rendered much happier if this is encouraged.

I have thought this digression worth giving, because we
may easily underrate the mental powers of the higher ani-
mals, 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 has 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,* 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, and a spider its wonderful web,
quite as well,t the first time it tries as when old and
experienced.

To return to our immediate subjects 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, etc., when
playing together, like our own children. Even insects
play together, as has been described by that excellent
observer, P. Huber,| 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

* "Contributions to tlie Theory of Natural Selection," 1870, p 212.

f For the evidence on this head, see Mr^ J. Traherne Moggridge's
most interesting work, "Harvesting Ants and Trap-door SpiderSj^"
1873, pp. 126, 128.

X " Recherches sur les Moeurs des Fourmis," 1810, p. 173.

78 THE DESCENT OF MAN,

sphincters to be relaxed, and the hair to stand on end.
Suspicion, the offspring of fear, is eminently characteristic
of most wild animals. It is, I think, impossible to read the
account given by Sir E. Tennent, of the behavior of the
female elephants, used as decoys, without admitting that
they intentionally practice deceit, and well know what they
are about. 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, and probably true, anecdotes have been
published on the long-delayed and artful revenge of various
animals. The accurate Rengger and Brehm* state that
the American and African monkeys which they kept tame
certainly revenged themselves. Sir Andrew Smith, a zoolo-
gist whose scrupulous accuracy was known to many persons,
told me the following story of which he was himself an eye-
witness: At the Cape of Good Hope an officer had often
plagued a certain baboon, and the animal, seeing him ap-
proaching one Sunday for parade, poured water into a hole
and hastily made some thick mud, which he skillfully
dashed over the officer as he passed by, to the amusement
of many bystanders. For long afterward the baboon re-
joiced and triumphed whenever he saw his victim.

The love of a dog for his master is notorious ; as an old
writer quaintly says: f '^A dog is the only thing on this
earth that luvs you -more than he luvs himself.''^

In the agony of death a dog 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 the operation was fully justified by an increase of our
knowledge, or unless he had a heart of stone, must have
felt remorse to the last hour of his life.

As Whewell X has well asked : '* Who that reads the

* All the following statements, given on the authority of these two
naturalists, are taken from Kengger's "Naturgesch. der Saugethiere
von Paraguay," 1830, s. 41-57, and from Brehm's " Thierleben," B.
i, s. 10-87.

•f- Quoted by Dr. Lauder Lindsay, in his "Physiology of Mind in
the Lower Animals;" "Journal of Mental Science," April, 1871, p.

'\ " Bridgewater Treatise," p. 363.

MENTAL POWERS. 79

touching instances of maternal affection, related so often
of the women of all nations and of the females of all ani-
mals, 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, Eengger observed an Ameri-
can 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 in-
tense is the grief of female monkeys for the loss of their
young that it invariably caused the death of cert§,in 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 this affec-
tionate baboon, who certainly had a fine intellect, for she was
much astonished at being scratched, and immediately exam-
ined the kit ten^s feet, and without more ado bit off the claws.*
In the Zoological Gardens I heard from the keeper that an
old baboon ( G. cliacma) had adopted a Ehesus 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 Ehesus,
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 subjects of sympathy and fidel-
ity, to which I shall recur. Some of Brehm^s monkeys

*A critic, witliout any grounds (" Quarterly Review," July, 1871,
p. 73), disputes the possibility of this act as described by Brehm, for
the sake of discrediting my work. Therefore I tried, and found that
I could readily seize with my own teeth the sharp little claws of a
kitten nearly five weeks old.

80 THE DESCENT OF MAN.

took muoh delight in teasing a certain old dog whom they
disliked, as well as other animals, in various ingenious ways.

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 shows that animals not only love, but have
a desire to be loved. Animals manifestly feel emulation.
They love approbation or praise; and a dog carrying a bas-
ket for his master exhibits in a high degree self-complac-
ency 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 th-ey sometimes in-
vent imaginary offenses. 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. Dogs show what may
be fairly called a sense of humor as distinct from mere play;
if a bit of stick or other such object be thrown to one, he
will often carry it away for a short distance ; and then
squatting down with it on the ground close before him, will
wait until his master comes quite close to take it away.
The dog will then seize it and rush away in triumph, re-
peating the same maneuver, aiid evidently enjoying the
practical joke.

We will now turn to the more intellectual emotions and
faculties, which aire very important, as forming the basis
for the developfiient of the higher mental powers. Animals
manifestly enjoy excitement, and suff'er from ennui, as may
be seen with dogs, and, according to Rengger, with mon-
keys. All animals feel Wondei- and many exhibit Curiosity,
They sometimes suffer from this latter quality, as when
the hunter plays antics and thus attracts them; I have wit-
nessed this with deer, and so it is with the wary chamois,
and with some kinds of wild-ducks. Brelim gives a curious
account of the instinctive dread, which his monkeys exhib-
ited, for snakes; but their curiosity was so great that they
could not desist from occasionally satiating their horror
m a most human fashion by lifting up the lid of the box

MENTAL POWERS, 81

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 spec-
tacles 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 ohl
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 col-
lected round it in a large circle, and, staring intently, pre-
sented a most kidicrous appearance. They became ex-
tremely nervous; so that when a wooden ball, with which
they were familiar as a plaything, was accidentally moved
in the straw, under which it was partly hidden, they all in-
stantly started away. These monke3^s behaved very dif-
ferently when a dead fish, a mouse,* a living turtle, and
other new objects were placed in their cages; for though at
first frightened, they soon approached, handled and ex-
amined them. I then placed a live snake in a paper bag,
with the mouth loosely closed, in one of the larger com-
partments. 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 a momentary peep into
the upright bag, at the dreadful object lying quietly at the
bottom. It would almost appear as if monkeys had some
notion of zoological affinities, for those kept by Brehm ex-
hibited 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, f
The principle of Imitation is strong in man, and espe-
cially, as I have myself observed, with savages. In certain
morbid states of the brain this tendency is exaggerated to an
extraordinary degree; some hemiplegic patients and others,
at the commencement of inflammatory softening of the brain,
unconsciously imitate every word which is uttered, whether

*I have given a short account of their behavior on this occasion in
my *' Expression of the Emotions," p. 43.

f W. C. L. Martin, " Nat. HLst. of Mammalia," 1841, p, 405.

82 THE DESCENT OF MAN".

in their own or in a foreign language, and every gesture oi
action which is performed near them.* Desorf has re-
marked that no animal voluntarily imitates an action per-
formed by man, until in the ascending scale we come to
monkeys, which are well known to be ridiculous mockers.
Animals, however, sometimes imitate each other's actions ;
thus two species of wolves, which had been reared by dogs,'
learned to bark, as does sometimes the jackal, J; but whethex
this can be called voluntary imitation is another question.
Birds imitate the songs of their parents, and sometimes of
other birds; and parrots are notorious imitators of any sound
which they often hear. Dureau de la Malle gives an account§
of a dog reared by a cat, who learned to imitate the well-
known action of a cat licking her paws, and thus washing
her ears and face; this was also witnessed by the celebrated
naturalist Audouin. I have received several confirmatory
accounts; in one of these, a dog had not been suckled by a
cat, but had been brought up with one, together with
kittens, and had thus acquired the above habit, which ha
ever afterward practiced during his life of thirteen years.
Dureau de la Malleus dog likewise learned from the kittens
to play with a ball by rolling it about with his fore paws
and springing on it. A correspondent assures me that a
cat in his house used to put her paws into jugs of milk
having too narrow a mouth for her head. A kitten of this
cat soon learned the same trick, and practiced it ever
afterward whenever there was aix opportunity.

The parents of many animals, trusting to the principle
of imitation in their young, and more especially to their
instinctive or inherited tendencies, may be said to educate
them. We see this when a cat brings a live mouse to her
kittens; and Dureau de la Malle has given a curious ac-
count (in the paper above quoted) of his observations on
hawks which taught their young dexterity, as well as judg-
ment of distances, by first dropping through the air dead
mice and - sparrows, which the young generally failed to

*Drc Bateman "On Aphasia," 1870, p. 110.

f Quoted hj Vogt, " Memoire sur les Microcephales," 1867, p. 168.

* " The Variation of Animals and Plants under Domestication," vol.
1, p. 27.

§ •' Annales des Sc. Nat.",Clst series), tom. xxii, p. 397.

MENTAL POWERS. 83

catch, and then bringing them live birds and letting them
loose.

Hardly any faculty is more important for the intellectual
progress of man ihMi Attentio7i. 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 ap-
proached. Mr. Bartlett has given me a curious proof how
variable this faculty is in monkeys. A man who trains
monkeys to act in plays used to purchase common kinds
from the Zoological Society at the price of five pounds for
each; but he oftered 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 learn so soon
whether a particular monkey would turn out a good actor,
he answered that it all depended on their power of atten-
tion. 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 excel-
lent me?nories for persons and places. A baboon at the
Cape of Good Hope, as I have been informed by Sir An-
drew Smith, recognized 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
absense 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. Huber* has clearly shown, recog-
nized 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 former images and ideas,

* "Les Moeurs des Fourmis/' 1810, p. 150.

84 THE DESCENT OF MAN.

independently of the will, and thus creates brilliant and
novel results. A poet, as Jean Paul Richter remarks,*
" 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 \ have vivid dreams, and this is shown by their
movements and the sounds uttered, we must admit that
they possess some power of imagination. There must be
something special which causes dogs to howl in the night,
and especially during moonlight, in that remarkable and
melancholy manner called baying. All dogs do not do so;
and, according to Houzeau,^: they do not then look at the
moon, but at some fixed point near the horizon. Houzeau
thinks that their imaginations are disturbed by the vague
outlines of the surrounding objects, and conjure up before
them fantastic images ; if this be so, their feelings may
almost be called superstitious.

Of all the faculties of the human mind, it will, I pre-
sume, be admitted that Reason stands at the summit. Only
a few persons now 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
unlearned instincts. § In future chapters we shall see that
some animals extremely low in the scale apparently display

* Quoted in Dr. Maudsley's ** Physiology and Pathology of Mind,"
1868, pp. 19, 220.

•f-Dr. Jerdon, "Birds of India," vol, i, 1862, p. 21. Houzeau says
that his paroquets and canary birds dreamed; " Facultis Mentales,"
torn, ii, p. 136.

X "Facultes Mentales des Animaux," 1872, torn, ii, p. 181.

§Mr. L. U. Morgan's work on "The American Beaver," 1866,
offers a good illustration of this remark. I cannot help thinking,
however, that he goes too far in underrating the power of instinct.

MENTAL POWERS. 85

a certain amount of reason. No doubt it is often difficult
to distinguish between the power of reason and that of in-
stinct. For instance. 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 which the travelers 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 inher-
ited habit, that is, from instinct? This instinct may pos-
sibly 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 Esquimau dog,
may have acquired an instinct impelling them not to attack
their prey in a close pack, when on thin ice.

We can only judge by the circumstances under which
actions are performed, whether they are due to instinct, or
to reason, or to the mere association of ideas; this latter
principle, however, is intimately connected with reason. A
curious case has been given by Prof. Mobius,* of a pike,
separated by a plate of glass from an adjoining aquarium
stocked with fish, and who often dashed himself with such
violence against the glass in trying to catch the other fishes,
that he was sometimes completely stunned. The pike went
on thus for three months, but at last learned caution, and
ceased to do so. The plate of glass was then removed, but
the pike would not attack these particular fishes, though he
would devour others which were afterward introduced ; so
strongly was the idea of a violent shock associated in his
feeble mind with the attempt on his former neighbors. If
a savage, who had never seen a large plate-glass window,
were to dash himself even once against it, he would for a
long time afterward associate a shock wdtli a window-frame;
but, very differently from the pike, he would probably
reflect on the nature of the impediment, and be cautious
under analogous circumstances. Now with monkeys, as we
shall presently see, a painful or merely a disagreeable
impression, from an action once performed, is sometimes
sufficient to prevent the animal from repeating it. If we

* "Pie Bewegungen der Tliiere," etc., 1873, p. U.

86 THE DESCENT OF MAN.

attribute this difference between the monkey and the pike
solely to the association of ideas being so much stronger
and more persistent in the one than the other, though the
pike often received much the more severe injury, can we
maintain in the case of man that a similar diiference
implies the possession of a fundamentally different mind?

Houzeau relates * that, while crossing a wide and arid
■ )lain in Texas, his two dogs suffered greatly from thirst,
and that between thirty and forty times they rushed down
the hollows to search for water. These hollows were not
valleys, and there were no trees in them, or any other differ-
ence in the vegetation, and, as they were absolutely dry,
there could have been no smell of damp earth. The dogs
behaved as if they knew that a dip in the ground offered
them the best chance of finding water, and Houzeau has
oftened witnessed the same behavior in other animals.

I have seen, as I dare say have Others, that when a small
object is thrown on the ground beyond the reach of one of
the elephants in the Zoological Gardens, he blows through
his trunk on the ground beyond the object, so that the cur-
rent reflected on all sides may drive the object within his
reach. Again, a well-known ethnologist, Mr. Westropp,
informs me that he observed in Vienna a bear deliberately
making with his paw a current in some water, which was
close to the bars of his cage, so as to draw a piece of float-
ing bread within his reach. These actions of the elephant
and bear can hardly be attributed to instinct or inherited
' habit, as they would be of little use to an animal in a state
of nature. Now, what is the difference between such
actions, when performed by an uncultivated man, and by
one of the higher animals?

The savage and the dog have often found water at a low
level, and the coincidence under such circumstances has
become associated in their minds. A cultivated man
would perhaps make some general proposition on the sub-
ject; bat from all that we know of savages it is extremely
doubtful whether they would do so, and a dog certainly
would not. But a savage, as well as a dog, would search
In the same way, though frequently disappointed, and in
both it seems to be equally an act of reason, whether or not
any general proposition on the subject is consciously placed

* Facult^s Mentales des Animaux," 167^, torn. ii. p. 265k

MENTAL POWERS, 87

before the mind. * The same would apply to the elephant
and the bear making currents in the air or water. The
savage would certainly neither know nor care by what law
the desired movements were effected; yet his act would be
guided by a rude process of reasoning, as surely as would a
philosopher in his longest chain of deductions. . There
vvould no doubt be this difference between him and one of
the higher animals, that he would take notice of much
slighter circumstances and conditions, and would observe
any connection between them after much less experience,
and this would be of paramount importance. I kept a
daily record of the actions of one of my infants, and when
he was about eleven months old, and before he could speak
a single word, I was continually struck with the greater
quickness with which all sorts of objects and sounds were
associated together in his mind, compared with that of the
most intelligent dogs I ever knew. But the higher ani-
mals differ in exactly the same way in this power of associ-
ation from those low in the scale, such as the pike, as well
as in that of drawing inferences and of observation.

The promptings of reason, after very short experience,
are well shown by the following actions of American mon-
keys, which stand low in their order. Eengger, a most
careful observer, states that when he first gave eggs to his
monkeys in Paraguay they smashed them and thus lost
much of their contents; afterward 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 caution. Lumps of
sugar were often given them wrapped up in paper ; and
Eengger sometimes put a live wasp in the paper, so that in
hastily unfolding it they got stung; after this had once hap-
pened they always first held the packet to their ears to de-
tect any movement within, f

* Prof. Huxley has analyzed with admirable clearness the mental
steps by which a man, as well as a dog, arrives at a conclusion in a
case analogous to that given in my text. See his article, "Mr. Dar-
win's Critics," in the "Contemporary Review," Nov, 1871, p. 462,
and in his *' Critiques and Essays/' 1873, p. 279.

f Mr. Belt, in his most interesting work, "The Naturalist in Nic-
aragua," 1874 (p. 119), likewise describes various actions of a tamed
Cebus, which, I think, clearly show that this animal possessed somv
i'easouing power.

88 THE DESCENT OF MAK.

The following cases relate to dogs. Mr. Colquhonn*
winged two wild-ducks, which fell on the farther 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 otlier, and returned for the dead bird. Col.
Hutchinson relates that two partridges were shot at once,
one being killed, the other w^ounded; the latter ran away
and was caught by the retriever, who on her return came
across the dead bird; ^^she stopped, evidently greatly puz-
zled, 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 giv-
ing it a severe crunch, and afterward 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 peWect, 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. I give the
above cases as resting on the evidence of two independent
witnesses, and because in both instances the retrievers, after
deliberation, broke through a habit which is inherited by
them (that of not killing the game retrieved), and because
they show how strong their reasoning faculty must have
been to overcome a fixed habit.

I will conclude by quoting a remark by the illustrious
Humboldt, t ^^ The muleteers in South America say, *I
will not give you the mule whose step is easiest, but la mas
racional — the one that reasons best ;' " and, as he adds,
^' this popular expression, dictated by long experience, com-
bats the system of animated machines better perhaps than
all the arguments of speculative philosophy." Neverthe-
less some writers even yet deny that the higher animals pos-
sess a trace of reason; and they endeavor to explain away,
by what appears to be mere verbiage, J all such facts as those
above given.

* " Tlie Moor and the Locli," p. 45. Col. Hutchinson on "Dog
Breaking," 1850, p. 46.

f '• Personal Narrative," Eng. translat., vol. iii, p. 106.

X I am glad to find that so acute a reasoner as Mr. Leslie Stephen
("Darwinism and Divinity, Essays on Free-thinking," 1873, p. 80),
in speaking of the supposed impassable barrier between the minds of
man and the lower animals, says- " The distinctions, indeed, whiclj

MENTAL POWERS. 89

It has, I think, now been shown that man and the higher
animals, especially the Primates, have some few instincts in
common. All have the same senses, intuitions and sensa-
tions— similar passions, affections and emotions, even the
more complex ones, such as jealousy, suspicion, emulation,
gratitude and magnanimity; they practice deceit and are
revengeful; they are sometimes susceptible to ridicule, and
even have a sense of humor; they feel wonder and curiosity;
they possess the same faculties of imitation, attention, de-
liberation, choice, memory, imagination, the association of
ideas and reason, though in very different degrees. The
individuals of the same species graduate in intellect from
absolute imbecility to high excellence. They are also liable
to insanity, though far less often than in the case of man.*
Nevertheless, many authors have insisted that man is
divided by an insuperable barrier from all the lower animals
in his mental faculties. I formerly made a collection of
above a score of such aphorisms, but they are almost worth-
less, as their wide difference and number prove the diffi-
culty, if not the impossibility, of the attempt. It has been
asserted that man alone is capable of progressive improve-
ment; that he alone makes use of tools or fire, domesticates
other animals, or possesses property; that no anim.al has the
power of abstraction or of forming general concepts, is self-
conscious and comprehends itself; that no animal employs
language; that man alone has a sense of beauty, is liable to
caprice, has the feeling of gratitude, mystery, etc. ; believes
in God, or is endowed with a conscience. I will hazard a
f CAV remarks on the more important and interesting of these
points.

Archbishop Sumner formerly maintainedf that man
alone is capable of progressive improvement. That he is
capable of incomparably greater and more rapid improve-

have been drawn, seem to us to rest upon no better foundation than
a great many other metaphysical distinctions ; that is, the assumption
that because you can give two things different names, they must
therefore have different natures. It is ditficult to understand how
anybody who has ever kept a dog, or seen an elephant, can have any
doubts as to an animal's power of performing the essential processes
of reasoning."

*See "Madness in Animals," by Dr. W. Lauder Lindsay, iu
"Journal of Mental Science," July, 1871.

fQuoted by Sir a Lyell, " Antiquity of Man," p. 497.

90 THE DESCENT OF MAN.

ment than is any other animal, admits of no dispute; and
this is mainly due to his power of speaking and handing
down his acquired knowledge. 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 a trap. They must learn cau-
tion by seeing their brethren caught or poisoned. In North
America, where the fur-bearing animals have long been pur-
sued, 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 possibly have come into play. I
have received several accounts that when telegraphs are first
set up in any district many birds kill themselves by flying
against the wires, but that in the course of a few years they
learn to avoid this danger by seeing, as it would appear,
their comiades killed.*

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; f
and this caution is certainly in chief part an inherited
habit or instinct, but in part the result of individual expe-
rience. A good observer, Leroy,J; states that in districts
where foxes are much hunted the young, on first leaving
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, §
and though they may not have gained in cunning, and may

*For additional evidence, with details, see M. Houzeau, "Les
Facultes Mentales," torn, ii, 1872, p. 147.

fSee, with respect to birds on oceanic islands, my. ''Journal of
Researches during the voyage of the ' Beagle,' " 1845, p. 398. " Ori-
gin of Species," 5th edition, p. 260.

:}:*'Lettres Phil, sur I'lntelligence des Animaux,*' nouvelle edit,,
1892, p. 86.

§See the evidence on this head in chap, i, vol. i, '* On the Vatia-
tion of Animals and Plants under Domestication."

MENTAL POWERS, 91

have lost in wariness and suspicion, yet they have pro-
gressed 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,* who describes these
two latter cases, attributes the victory of the common rat
over the large Mus cotmiga to its superior cunning; and
this latter quality may probably be attributed to the habit-
ual 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 continuously destroyed by him.
It is, however, possible that the success of the common rat
may be due to its having possessed greater cunning than its
fellow-species before it became associated with man. 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 evo-
lution of species. We have seen 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, f Eengger J easily
taught an American monkey thus to break open hard palm-
nuts; and afterward 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
flavor. Another monkey was taught to open the lid of a
large box with a stick, and afterward 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. The
tamed elephants in India are well known to break off
branches of trees and use them to drive away the flies; and
this same act has been observed in an elephant in a state of

* ''Proc. Zoolog. Soc," 1864, p. 186.

f Savage and Wyman in ** Boston Journal of Nat. Hist.,** vol. iv,
1843-44, p. 383.

X ■" Saugetliiere von Paraguay," 1830, 8. 51-56.

92 THE DESCENT OF MAN,

nature.* I have seen a young orang, when she thought
she was going to be whipped, cover and protect herself
Avith a blanket or straw. In these several cases stones and
sticks were employed as implements; but they are likewise
used as weapons. . Brehmf states^ on the authority of the
well-known traveler Schimper, that in Abyssinia when the
baboons belonging to one species ( G. gelada) descend in troops
from the mountains to plunder the fields they sometimes
encounter troops of another species (C. liamadryas), 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 firearms 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 closed for a time against the
caravan. It deserves notice that these baboons thus acted
in concert. Mr. Wallace J; 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."
As I have repeatedly seen, a chimpanzee will throw any
object at hand at a person who offends him; and the before-
mentioned baboon at the Cape of Good Hope prepared mud
for the purpose.

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 after using the stone he 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 Argyll§ 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. This is no doubt a very

* The " Indian Field," March 4, 1871.

t " Thierleben," B. i, s. 79, 82.

X "The Malay Archipelago," vol. i, 1869, p. 87.

§ " Primeyai Mau," 1869. pp. 145. 147.

MENTAL POWERS. 93

important distinction; but there appears to me much truth
in Sir J. Lubbock's suggestion^* that when primeval man
first used flint-stones for any purpose, he would have acci-
dentally splintered them, and would then have used the
sharp fragments. From this step it would be a small one
to break the flints on purpose, and not a very wide step to
fashion them rudely. This latter advance, hov/ever, may
have taken long ages, if we may judge by the immense in-
terval 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 anthropomor-
phous apes, guided probably by instinct, build for them-
selves temporary platforms; but as many instincts are largely
controlled by reason, the simpler ones, such as this of build-
ing 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 sev-
eral habits, we probably see the fi^st steps toward some of
the simpler arts, such as rude architecture and dress, as
they arose among the early progenitors of man.

Abstraction, General Conceptions, Self -consciousness,
Mental Individuality. — It would be very difficult for any
one with even much more knowledge than I possess to de-
termine how far animals exhibit any traces of these high
mental powers. This difficulty arises from the impossibility
of judging what passes through the mind of an animal;
and again, the fact that writers difl;er to a great extent in
the meaning which they attribute to the above terms,
causes a further " difficulty. If one may judge from
various articles which have been published lately, the great-
est stress seems to be laid on the supposed entire absence
in animals of the power of abstraction, or of forming general
concepts. But when a dog sees another dog at a distance,

* " Prehistoric Times/' 1865, p. 473, etc.

94 THE DESCENT OF MAN.

it is often clear that he perceives that it is a dog in the
abstract; for when he gets nearer his whole manner sud-
denly changes, if the other dog be a friend. A recent
writer remarks, that in all such cases it is a pure assump-
tion to assert that the mental act is not essentially of the
same nature in the animal as in man. If either refers what
he perceives with his senses to a mental concept, then so do
both.* When I say to my terrier, in an eager voice (and I
have made the trial many times), "Hi, hi, where is it?" she
at once takes it as a sign that something is to be hunted,
and generally first looks quickly all around, and then
rushes into the nearest thicket, to scent for any game, but
finding nothing, she looks up into any neighboring tree for
a squirrel. Now do not these actions clearly show that she
had in her mind a general idea or concept that some ani-
mal is to be discovered and hunted?

It may be freely admitted that no animal is self-conscious,
if by this term it is implied, that he reflects on such points,
as whence he comes or whither he will go, or what is-life
and death, and so forth. But how can we feel sure that
an old dog with an excellent memory and some power of
imagination, as shown by his dreams, never reflects on his
past pleasures or pains in the chase? And this would be a
form of self-consciousness. On the other hand, as Biichnerf
has remarked, how little can the hard-worked wife of a de-
graded Australian savage, who uses very few abstract words,
and cannot count above four, exert her self -consciousness,
or reflect on the nature of her own existence. It is gener-
ally admitted that the higher animals possess memory, at-
tention, association, and even some imagination and reason.
If these powers, which differ much in different animals, are
capable of improvement, there seems no great improbability
in more complex faculties, such as the higher forms of ab-
straction, and self-consciousness, etc., having been evolved
through the development and combination of the simpler
ones. It has been urged against the views here maintained
that it is impossible to say at what point in the ascending
scale animals become capable of abstraction, etc. ; but who
can say at what age this occurs in our young children?

*Mr. Hookham, in a letter to Prof. Max Miiller, in the "Birm-
ingham News," May 1873.

f " Conferences sur la Theorie Darwinienne," French translat.,
1869, p. 132.

MENTAL POWERS. 95

We see at least that such powers are developed in children
by imperceptible degrees.

That animals retain their mental individuality is unques-
tionable. When my voice awakened a train of old associa-
tions in the mind of the before-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." *

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 AVhately 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 ex-
pressed by another, "f In Paraguay the Cehu^ azarce when
excited utters at least six distinct sounds, which excite in
other monkeys similar emotions. X 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 learned to bark§ in at least four or five
distinct tones. Although barking is a new art, no doubt
the wild parent-species 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,
as well as growling; the yelp or howl of despair, as when
shut up; the baying at night; the bark of joy, as when
starting on a walk with his master; and the very distinct

* The Rev. Dr. J. M'Cann, "Anti-Darwinism," 1869, p. 13.
f Quoted in " Anthropological Review," 1864, p. 158.
X Rengger, ibid, s. 45.

§ See my " Variation of Animals and Plants under Domestication,"
vol. i, p. 27.

96 THE DESCENT OF MAN.

one of demand or supplication, as when wishing for a door
or window to be opened. According to Houzeau, who paid
particular attention to the subject, the domestic fowl utters
at least a dozen significant sounds.*

The habitual use of 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. \
This specially 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, to-
gether with their appropriate actions, and the murmur of a
mother to her beloved child, are more expressive than any
words. That which distinguishes man from the lower ani-
mals is not the understanding of articulate sounds, for, as
every one knows, dogs understand many words and sen-
tences. In this respect they are at the same stage of devel-
opment as infants, between the ages of ten and twelve
months, who understand many words and short sentences,
but cannot yet utter a single word. It is not the mere ar-
ticulation which is our distinguishing character, for parrots
and other birds possess this power. Nor is it the mere
capacity of connecting definite sounds with definite ideas;
for it is certain that some parrots, which have been taught
to speak, connect unerringly words with things and per-
sons with events. J; The lower animals differ from man

* "Facultes Mentales des Animaux," torn, ii, 1872, pp. 346-349,
f See a discussion on this subject in Mr. E. B. Tylor's very inter-
esting work, " Researches into the Early History of Mankind/' 1865,
chaps, ii to iv.

X I have received several detailed accounts to this effect. Admiral
Sir B. J. Sulivan, whom I know to be a careful observer, assures me
that an African parrot, long kept in his father's house, invariably
called certain persons of the household, as well as visitors, by their
names. He said "good morning" to every one at breakfast, and
"good night" to each as they left the room at night, and never re-
versed these salutations. To Sir B. J. Sulivan's father, he used to
add to the "good morning" a short sentence, which was never once
repeated after his father's death. He scolded violently a strange
dog which came into the room through the open window; and he
scolded another parrot (saying "you naughty poUy ") which had got
out of its cage, and was eating apples on the kitchen table. See
also, to the same effect, Houzeau on parrots, " Facultes Mentales,"
torn, ii, p. 309. Dr. A. Moschkau informs me that he knew a star-
ling which never made a mistake in saying in German ' ' good morn-
ing " to persons arriving, and "good-by, old fellow," to those da-
parting. I could add several other such cases.

MENTAL POWERS. 97

solely in his almost infinitely larger power of associating
together the most diversified sounds and ideas, and this
obviously depends on the high development of his mental
powers.

As Home 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 better simile. It
certainly is not a true instinct, for every language has to be
learned. It diifers, however, widely from all ordinary arts,
for man has an instinctive tendency to speak, as we see in
the babble of our young children; while no child has an
instinctive tendency to brew, bake, or write. Moreover, no
philologist now supposes that any language has been delib-
erately invented; it has been slowly and unconsciously de-
veloped 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 in-
stinctive cries expressive of their emotions; and all the
kinds which sing exert their power instinctively; but the
actual song, and even the call-notes, are learned from their
parents or foster-parents. These sounds, as Daines Bar-
ringtonf has proved, '^ are no more innate than language
is in man.^^ The first attempts to sing ^'^may be compared
to the imperfect endeavor in a child to babble.^' The
young males continue practicing, 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 learned 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
dift'erent districts may be appositely compared, as Barring-

* See some good remarks on this head \>j Prof. Whitney, in his
'' Oriental and Linguistic Studies," 1873, p. 354. He observes that
the desire of communication between man is the living force, which,
in the development of language, "works both consciously and un-
consciously; consciously as regards the immediate end to be attained;
unconsciously as regards the further consequences of the act."

fllon. Daines Barrington in "Philosoph. Transactions," 1773, p.
263. See also Dureau de la Malle, in ''Ann. des. Sc. Nat.," 3d
series, Zoolog. torn, x, p. 119.

98 THE DESCENT OF MAN,

ton 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 fore-
going details to show that an instinctive tendency to
acquire an art is not peculiar 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,* and the celebrated lectures of Prof. Max Miil-
ler on the other side, I cannot doubt that language owes its
origin to the imitation and modification of various natural
sounds, the voices of other animals and man's own instinctive
cries, aided by signs and gestures. When we treat of sexual
selection we shall see that primeval man, or rather some
early progenitor of man, probably first used his voice in
producing true musical cadences, that is in singing, as do
some of the gibbon-apes at the present day; and we may
conclude from a widely-spread analogy, that this power
would have been especially exerted during the courtship of
the sexes — would have expressed various emotions, such as
love, jealousy, triumph — and would have served as a chal-
lenge to rivals. It is, therefore, probable that the imita-
tion of musical cries by articulate sounds may have given
rise to words expressive of various complex emotions. The
strong tendency in our nearest allies, the monkeys, in
microcephalous idiots, f and in the barbarous races of man-
kind, to imitate whatever they hear deserves notice, as
bearing on the subject of imitation. Since monkeys cer-
tainly understand much that is said to them by man, and
when wild utter signal-cries of danger to their fellows; \
and since fowls give distinct warnings for danger ou the
ground, or in the sky from hawks (both, as well as a third

* " On the Origin of Language," by H. Wedgwood, 1866. " Chap-
ters on Language," bj- the Rev. F. W, Farrar, 1865. These works
are most interesting. See also "De la Phys. et de Parole," par
Albert Lemoine, 1865, p. 190. The work on this subject, by the late
Prof. Aug. Schleicher has been translated by Dr. Bikkers into En-
glish, under the title of "Darwinism tested by the Science of Lan-
guage," 1869.

fVogt, "Memoire sur les Microcephales," 1867, p. 169. With
respect to savages, I have given some facts in my "Journal of Re-
searches," etc., 1845, p. 206.

X See clear evidence on this head in the two works so often quoted,
by Brehm and Rengger.

MENTAL POWERS. 99

cry, intelligible to dogs*), may not some unusually wise
ape-like animal have imitated the growl of a beast of prey,
and thus told his fellow-monkeys the nature of the expected
danger? This would have been a first step in the forma-
tion 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 wouldf
have reacted on the power of speech. But the relation be-
tween 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 itself, by enabling and encouraging it
to carry on long trains of thought. A 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 an ordinary train of thought almost requires, or
is greatly facilitated by some form of language, for the
dumb, deaf, and blind girl, Laura Bridgman, was observed
to use her fingers while dreaming, f 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 movements of dogs during their
dreams. We have, also, seen that animals are able to
reason to a certain extent, manifestly 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 shown by those curious cases of brain-disease in which
speech is specially affected, as when the power to remem-
ber substantives is lost, while other words can be correctly
used, or where substantives of a certain class, or all
except the initial letters of substantives and proper

* Houzeau ^ives a very curious account of his observations on this
subject in bis " Facultes Mentales des Animaux," torn, ii, p. 348.

f See remarks on this bead by Dr. Maudsley, **Tlie Physiology
and Pathology of Mind,'-' 2d edit.. 186^1 d. 199.

100 TEE DESCENT OF MAN,

names are forgotten. * There is no more improbability m
continued use of the mental and vocal organs leading to
inherited changes in their structure and functions, than in
the case of handwriting, which depends partly on the form
of the hand and partly on the disposition of the mind; and
handwriting is certainly inherited, f

Several writers, more especially Prof. Max Miiller,]; havo
lately insisted that the use of language implies the power of
forming general concepts; and that as no animals are sup-
posed to possess this power, an impassable barrier is formed
between them and man.§ With respect 'to animals, I have
already endeavored to show that they have this power, at
least in a rude and incipient degree. As far as concerns
infants of from ten to eleven months old, and deaf-mutes,
it seems to me incredible that they should be able to con-
nect certain sounds with certain general ideas as quickly as
they do, unless such ideas were already formed in their
minds. The same remark may be extended to the more
intelligent animals; as Mr. Leslie Stephen observes,] '^A

* Many curious cases have been recorded. See, for instance, Dr.
Bateman, "On Aphasia," 1870, pp. 27, 31, 53, 100, etc. Also, "In-
quiries Concerning the Intellectual Powers," by Dr. Abercrombie,
1838, p. 150.

f '• The Variation of Animals and Plants under Domestication,"
vol. ii, p. 6.

X Lectures on "Mr. Darwin's Philosophy of Language,*' 1873.

§The judgment of a distinguished philologist, such as Prof. Whit-
ney, will have far more weight on this point than anything that I
can say. He remarks (" Oriental and Linguistic Studies," 1873, p.
297), in speaking of Bleek's views: "Because on the grand scale
language is the necessary auxiliary of thought, indispensable to the
development of the power of thinking, to the distinctness and variety
and complexity of cognitions to the full mastery of consciousness;
therefore he would fain make thought absolutely impossible without
speech, identifying the faculty with its instrument. He might just
as reasonably assert that the human hand cannot act without a tool.
With such a doctrine to start from, he cannot stop short of Miiller's
worst paradoxes, that an infant {in fans, not speaking) is not a
human being, and that deaf-mutes do not become possessed of reason
until they learn to twist their fingers into imitation of spoken
words." Max Miiller gives in italics (" Lectures on Mr. Darwin's
Philosophy of Language," 1873, third lecture) the following aphor-
ism: " There is no thought without words, as little as there are
words without thought." What a strange definition must here be
given to the word thought.
, \ " Essays on Free-thinking," etc., 1873, p. 83.

MENTAL POWERS. 101

dog frames a general concept of cats or sheep, and knows
the corresponding words as well as a philosopher. And the
capacity to understand is as good a proof of vocal intelli-
gence, though in an inferior degree, as the capacity to
speak."

Why the organs now used for speech should have been
originally perfected for i\n.z purpose, rather than any other
organs, it is not difficult to see. Ants have considerable
powers of intercommunication, by means of their antennae,
as shown by Huber, who devotes a whole chapter to their
language. AVe might have used our fingers as efficient in-
struments, 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 while thus employed would have
been a serious inconvenience. As all the higher mammals
possess vocal organs, constructed on the same general plan as
ours, and used as a means of communication, it was ob-
viously probable that these same organs would be still further
developed if the power of communication hadto be improved;
and this has been effected by the aid of adjoining and well
adapted parts, namely, the tongue and lips.* The fact of
the higher apes not using their vocal organs for speech, no
doubt depends on their intelligence not having been suffi-
ciently 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 only for croak-
ing, t If it be asked why apes have not had their intellects
developed to the same degree as that of man, general causes
only can be assigned in answer, and it is unreasonable to
expect anything more definite, considering our ignorance

* See some good remarks to this effect by Dr. Maudsley, '• The
Physiology and Pathology of Mind," 1868, p. 199.

f Macgillivray, "Hist, of British Birds," vol. ii, 1839, p. 29. An
excellent observer, Mr. Black wall, remarks that the magpie learns to
pronounce single words, and even short sentences, more readily than
almost any other British bird: yet, as he adds, after long and closely
investigating its habits, he has never known it, in a state of nature,
display any unusual capacity for imitation. ** Researches in Zool»
ogy," 1834, p. 158.

102 THE DESGEm Ot" MAN,

with respect to the successive stages of development through
which each creature has passed.

The formation- of different languages and of distinct
species, and the proofs that both have been developed
through a gradual process, are curiously parallel. * But we
can trace the formation of many words further back than
that of species, for we can perceive how they actually arose
from the imitation of various sounds. We find in distinct
languages striking homologies due to community of de-
scent, 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 eUects of
long-continued use, and so forth. The frequent preeence
of rudiments, both in languages and in species, is still more
remarkable. The letter m in the word am, means /; so
that in the expression / am, a superfluous and useless rudi-
ment has been retained. In the spelling also of words, let-
ters often remain as the rudiments of ancient forms of pro-
nunciation. Languages, like organic beings, can be classed
in groups under groups; and they can be classed either nat-
urally according to descent, or artificially by other charac-
ters. Dominant languages and dialects spread widely, and
lead to the gradual extinction of other tongues. A lan-
guage like a species, when once extinct, never, as Sir 0. Lyell
remarks, reappears. The same language never has two
birth-places. Distinct languages may be crossed or blended
together.! 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 lan-
guages, gradually become extinct. As Max MiillerJ has
well remarked: '^ A struggle for life is constantly going on
among 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

* See the very interesting parallelism between the development of
species and languages, given by Sir C. Lyell in " The Geolog. Evi-
dences of the Antiquity of Man," 1863, chap, xxiii.

f See remarks to this effect by the Rev. F. W . Farrar, in an inter-
esting article, entitled "Philology and Darwinism," in " Nature^^
March 24, 1870, p. 528.

X " Nature," Jan. 6, 1870, p. 257.

MBmAL POWEMS. 103

the survival of certain words mere novelty and fashion may
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 favored words in the struggle for existence is
natural selection.

The perfectly regular and wonderfully complex con-
struction 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 civiliza-
tion 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.^^* 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. Philol-
ogists now admit that conjugations, declensions, etc.,
originally existed as distinct words, since joined together ;
p,nd as such words express the most obvious relations be-
t>veen 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 show hoAV easily we may err; a Crinoid
sometimes consists of no less than 150,000 pieces of shell, f
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 parts alike, excepting on the
opposite sides of the body. He justly considers the differ-
entiation and specialization of organs as the test of perfec-
tion. So with languages; the most symmetrical and com-
plex ought not to be ranked above irregular, abbreviated,
and bastardized languages, which have borrowed expressive
words and useful forms of construction from various con-
quering, 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

* Quoted by C. S Wake, *• Chapters on Man," 1868, p, 101
f Buckland; ** Bridgewater Treatise/' p. 411.

104 TBE DESCENT OF MAN.

to a special act of creation.* Nor, as we have seen, does
the faculty of articulate speech in itself offer any insuper-
able objection to the belief that man has been developed
from some lower form.

8e7ise of Beauty. — This sense has been declared to be
peculiar to man. I refer here only to the pleasure given by
certain colors, forms and sounds, and which may fairly be
called a sense of the beautiful; with cultivated men such
sensations are, however, intimately associated with complex
ideas and trains of thought. When we behold a male bird
elaborately displaying his graceful plumes or splendid colors
before the female, while other birds, not thus decorated,
make no such display, it is impossible to doubt that she
admires the beauty of her male partner. As women every-
wher-e deck themselves with these plumes, the beauty of
such ornaments cannot be disputed. As we shall see later,
the nests of humming-birds, and the playing passages of
bower-birds are tastefully ornamented with gayly-colored ob-
jects; and this shows that they must receive some kind of pleas-
ure from the sight of such things. With the great majority
of animals, however, the taste for the beautiful is confined,
as far as we can judge, to the attractions of the opposite
sex. The sweet strains poured forth by many male birds
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 beauti-
ful colors, the ornaments and voices of their male partners,
all the labor and anxiety exhibited by the latter in display-
ing their charms before the females would have been thrown
away; and this it is impossible to admit. Why certain
bright colors should excite pleasure cannot, I presume, be
explained any more than why certain flavors and scents are
agreeable; but habit has something to do with the result,
for that which is at first unpleasant to our senses ultimately
becomes pleasant, and habits are inherited. With respect
to sounds, Helmholtz has explained to a certain extent on
physiological principles why harmonies and certain cadences
are agreeable. But besides this, sounds frequently recur-
ring at irregular intervals are highly disagreeable, as every

* See some good remarks on tlie simplification of languages, by
Sir J. Lubbock, " Origin of Civilization," 1870, p. 278.

MENTAL P0WEM8, 105

one will admit who has listened at night to the irregular
flapping of a rope on board ship. The same principle seems
to come into play with vision, as the eye prefers symmetry
or figures with some regular recurrence. Patterns of this
kind are employed by even the lowest savages as ornaments;
and they have been developed through sexual selection for
the adornment of some male animals. Whether we can or
not give any reason for the pleasure thus derived from vision
and hearing, yet man and many of the lower animals are
alike pleased by the same colors, graceful shading and
forms, and the same sounds.

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,
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 aesthetic faculty was not so highly de-
veloped as in certain animals, for instance, as 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 are acquired through
culture, and depend on complex associations; they 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 hardly fail to lead to capricious
changes of customs and fashions. I have alluded to this
point because a recent writer* has oddly fixed on Caprice
'' as one of the most remarkable and typical differences be-
tween savages and brutes." But not only can we partially
understand how it is that man is from various conflicting
influences rendered capricious, but that the lower animals
are, as we shall hereafter see, likewise capricious in their
affections, aversions, and sense of beauty. There is also
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 Spectator," Dec. 4, 1869, p. 1430.

lOG THE DESCENT OF MAN.

the existence of an Omnipotent God. On the contrary
there is ample evidence, derived not from hasty travelers,
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.* The question is of
course wholly distinct from that higher one, whether there
exists a Creator and Euler of the universe; and this has
been answered in the affirmative by some of the highest
intellects that have ever existed.

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 universal with the less
civilized races. Nor is it difficult to comprehend how it
arose. As soon as the important faculties of the imagina-
tion, wonder, and curiosity, together with some power of
reasoning, had become partially developed, man would
naturally crave to understand what was passing around him,
and would have vaguely speculated on his own existence.
As Mr. McLennan \ 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 hypothe-
sis, 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 also probable, as Mr. Tylor has
shown, 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." J But

* See an excellent article on tliis subject by tlie Rev. F. W. Farrar,
in the "Anthropological Review," Aug., 1864, p. 217. For fur-
ther facts see Sir J. Lubbock, "Prehistoric Times," 2d edit., 1869, p.
564; and especially the chapters on Religion in his " Origin of Civil- .
ization," 1870.

f " The Worship of Animals and Plants," in the " Fortnightly Re-
view," Oct. 1, 1869, p. 422.

J Tylor, "Early History of Mankind," 1865, p. 6. See also the
three striking chapters on the Development of Religion, in Lub-
]t?0Ck'8 " Origin of Civilization," 1870. In a like manner Mr. Herbert

MENTAL POWERS, 107

until the faculties of imagination, curiosity, reason, etc.,
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 dis-
tance 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 par-
asol 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 that 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
tsame love of vengeance or simplest form of justice, and the
same affections which they themselves feel. 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 retribu-
tive 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

Spencer, in liis ingenious essay in the " Fortnightly Review " (May
t, 1870, p. 535), accounts for tlie earliest forms of religious belief
tlirougliout the world, by man being led through dreams, shadows,
and other causes, to look at himself as a double essence, corporeal
and spiritual. As the spiritual being is supposed to exist after death
and to be powerful, it is propitiated by various gifts and ceremonies,
and its aid invoked. He then further shows that names or nick-
nan\es given from some animal or other object, to the early progeni-
tors or founders of a tribe, are supposed after a long interval to rep-
resent the real progenitor of the tribe; and such animal or object is
then naturally believed still to exist as a spirit, is held sacred, and
worshiped as a god. Nevertheless I cannot but suspect that there is
a still earlier and ruder stage, when anything which manifests
power or movement is thought to be endowed with some form gf
life, and with mental faculties analogous to our own.

108 THE DESCENT OF MAN.

discover that the Fuegians believed in what we should call a
God or practiced 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 remark-
able, as with savages the belief in bad spirits is far more
common than that in good ones.

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,*
fear, reverence, gratitude, hope for the future, and per-
haps other elements. No being could experience so com-
plex an emotion until advanced in his intellectual and
moral faculties to at least a moderately high level. K"ever-
theless, 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 behavior 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 toward their fellows.
In the latter case the transports of joy appear to be some-
what less, and the sense of equality is shown in every
action. Prof. Braubach goes so far as to maintain that a
dog looks on his master as on a god.f

The same high mental faculties which first led man to
believe in unseen spiritual agencies, then in fetichism,
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 inno-
cent persons by the ordeal of poison or fire, witchcraft,
etc. — ^yet it is well occasionally to reflect on these supersti-
tions, for they show us what an infinite debt of gratitude
we owe to the improvement of our reason, to science, and
to our accumulated knowledge. As Sir J. LubbockJ has

* See an able article on the "Physical Elements of Religion," by
Mr. L. Owen Pike, in " Anthropolog. Review," April, 1870, p. 63.

f" Religion, Moral, etc., der Darwin'schen Art-Lehre," 1869, s.
53. It is said (Dr. W. Lauder Lindsay, "Journal of Mental
Science," 1871, p. 43), that Bacon long ago, and the poet Burns, held
the same notion.

:}:" Prehistoric Times," 2d edit., p. 571. In this work (p. 571)
there will be found an excellent account of the many strange an4
capricious customs of savages.

MENTAL POWERS. 109

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 com-
pared with the incidental and occasional mistakes of the
instincts of the lower animals.

1 1 0 THE BE8GENT OF MAN.

CHAPTER IV.

COMPARISON OF THE MENTAL POWERS OF MAK AND THE

LOWER ANIMALS. — Continued,

The moral sense — Fundamental proposition — The qualities of social
animals— Origin of sociability — Struggle between opposed in-
stincts— Man a social animal — The more enduring social instincts
conquer other less persistent instincts — The social virtues alona re-
garded 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 tlie judgment of those writers* 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 Mackintosh f remarks,
" has a rightful supremacy oyer every other principle of
human action;"' it is summed up in that short but imperi-
ous 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 1 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?" J

* See, for instance, on this subject, Quatrefages, ** Unit6 de TEs-
p^ce Humaine," 1861, p. 21, etc.

f ''Dissertation on Ethical Philosophy," 1837, p. 231, etc.

X •' Metaphysics of Ethics," translated by J. W. Semple, Edin-
burgh, 1836, p. 136.

MORAL SENSE. Ill

This great question has been discussed by many writers *
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 iiistory. The investigation possesses,
also, some independent interest, as an attempt to see how
far the study of the lower animals throws light on one of
the highest psychical facuicies of man.

The following proposition seems to me in a high degree
probable — namely, that any animal whatever, endowed with
well-marked social instincts,! the parental and filial affec-
tions being here included, would inevitably acquire a
moral sense or conscience, as soon as its intellectual powers
had become as well, or nearly as well developed, as in man.
For, firstly f 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

*Mr, Bain gives a list('' Mental and Moral Science," 1868, pp. 543-
725) of twenty-six British autliors who have written on this subject,
and whose names are familiar to every reader; to these, Mr. Bain's
own name, and those of Mr. Lecky, Mr, Shadworth Hodgson, Sir J.
Lubbock and others, might be added.

f Sir B. Brodie, after observing that man is a social animal (•' Psy-
chological Enquiries," 1854, p. 192), asks the pregnant question,
'* ought dot this to settle the disputed questioja as to the existence of
a moral sense?" Similar ideas have probably occurred to many per-
sons, as they did long ago to Marcus Aurelius. Mr. J. S. Mill
speaks, in his celebrated work, ** Utilitarianism," (1864, pp. 45, 46),
of the social feelings as a '* powerful natural sentiment," and as *' the
natural basis of sentiment for utilitarian morality." Again he says,
*' Like the other acquired capacities above referred to, the moral
faculty, if not a part of our nature, is a natural outgrowth from it,
capable, like them, in a certain small degree of springing up sponta-
neously." But in opposition to all this, he also remarks, " if, as is
my own belief, the moral feelings are not innate, but acquired, they
are not for that reason less natural." It is with hesitation that I
venture to differ at all from so profound a thinker, but it can hardly
be disputed that the social feelings are instinctive or innate in the
lower animals; and why should they not be so in man? Mr. Bain
(see, for instance, "The Emotions and the Will/' 1865, p 481) and
others believe that the moral sense is acquired by each individual
during his lifetime. On the general theory of evolution this is at
least extremely improbable. The ignoring of all transmitted mental
qualities will, as it seems to me, be hereafter judged as a irost serious
blemish i» th« wmr^- of Mr. M U-

112 THE DESCENT OF MAN.

and readiness, as with most of the higher social animals, to
aid their fellows in certain general ways. But these feel-
ings and services are by no means extended to all the indi-
viduals of the same species, only to those of the same asso-
ciation. 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, or even
misery, 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 commu-
nity could be expressed, the common opinion how each
member ought to act for the public good, would naturally
become in a paramount degree the guide to action. But it
should be borne in mind that however great weight we may
attribute to public opinion, our regard for the approbation
and disapprobation of our fellows depends on sympathy,
which, as we shall see, forms an essential part of the social
instinct, and is indeed its foundation-stone. Lastly, habit
in the individual would ultimately play a very important
part in guiding tlie*conduct of each member; for the social
instinct, together with sympathy, is, like any other instinct,
greatly strengthened by habit, and so consequently would
be 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

MORAL SENSE, 113

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. * Niver-
theless, the bee, or any other social animal, would gain in
our supposed case, as it appears to me, some feeling of
right or wrong, or a conscience. For each individual
would have an inward sense of possessing certain strouger
or more enduring instincts, and others less strong or
enduring; so that there would often be a struggle as to
which impulse should be followed; and satisfaction, dissat-
isfaction, or even misery 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, and the other ought not; bhe one
would have been right and the other wrong; but to these
terms I shall recur.

Sociability. — Animals of many kinds are social; we find
even distinct species living together; for example, somo
American monkeys; and 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,
etc., are when separated horn, their companion:;, and what

* Mr. H. Sidgwick remarks, in an able discussion on this subject
(tlie "Academy," June 15, 1872, p, 231), * a superior bee, we may
feel sure, would aspire to a milder solution of the population ques-
tion." Judging, however, from the habits of many or most savages,
man solves the problem by female infanticide, polyandry and pro-
miscuous intercourse, therefore it may well be doubted whether it
w»uld be by a milder method. Miss Cobbe, in commenting (" Darwin-
ism in Morals," ''Theological Review," April, 1872, pp. 188-191) on
the same illustration, says, the principles of social duty would be
thus reversed; and by this, I presume, she means that the fulfill-
ment of a social duty would tend to the injury of ndivlduals; but
she overlooks the fact, which she would doubtless idmii, tha^ tho
instincts of the bee have been acquired for fcho good 3f tho commu-
nity. She goes so far as to say that if the theory 3f ethics -lidvocated
in this chapter were ever generally accepted, ' '■ I cannot but believe
that in the hour of iheir triumph would be sounded tho knell of ths
virtue of mankind." It is to be hoped that the belief m xhe perma-
nence of virtue on this earth is not held by many persons on so weak
a tenure.

114 TBE DESCENT OF MAN.

strong mutual affection the two former kinds, at least,
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 at-
tention to the higher social animals, and pass over insects,
although some of these are social, and aid one another in
many important ways. The most common mutual service
in the higher animals is to warn one another of danger by
means of the united senses of all. Every sportsman knows,
as Dr. Jaeger remarks,* 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 of them who first discovers an enemy, warns the others.
Eabbits stamp loudly on the ground with their hind feet as
a signal ; sheep and chamois do the same with their fore
feet, uttering likewise a whistle. Many birds and some
mammals, post sentinels, which in the case of seals are saidf
generally to be the females. The leader of a troop of mon-
keys acts as the sentinel, and utters cries expressive both of
danger and of safety. | Social animals perform many little
services for each other; horses nibble, and cows lick each
other, on any spot which itches; monkeys search each other
for external parasites; and Brehm states that after a troop
of the CercopWiecus 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 one
another; thus wolves and some other beasts of prey hunt in
packs, and aid one another in attacking their victims. Peli-
cans fish in concert. The Hamadryas baboons turn over
stones to find insects, etc. ; and when they come to a large
one, as many as can stand round, turn it over together and

* " Die Darwin'sche Theorie/' s. 101.

•(•Mr. R. Brown in ^'Proc. Zoolog. Soc," 1868, p. 409.

^ Brehm, '■' Thierleben," B. i, 1864, s. 52, 79. For tlie case of the
monkeys extracting thorns from each other, see s. 54. With respect
to the Hamadryas turning over stones, the fact is given (s. 76) on the
evidence of Alvarez, whose observations Brehm thinks quite trust-
worthy. For the cases of the old male baboons attacking the dogs,
see s. 79; and with respect to the eaglOi 6. 56.

MORAL SENSE. 115

share the booty. Social animals mutually defend each other.
Bull bisons in North America, when there is danger, drive
the cows and calves into the middle of the herd, while they
defend the outside. I shall also in a future chapter give an
account of two young wild bulls at Ohillingham attacking
an old one in concert, and of two stallions together trying
to drive away a third stallion from a troop of mares. In
Abyssinia, Brehm encountered a great troop of baboons
who were crossing a valley ; some had already ascended
che opposite mountain, and some were still in the valley;
the latter were attacked by the dogs, but the old males im-
mediately hurried down from the rocks, and with mouths
widely opened, roared so fearfully that the dogs quickly
drew back. 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 f or -jid, climbed on a block of rock and was sur-
rounded. jS'ow 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 Oercopithecus,
which, by clinging to a branch, was not at once carried off;
it cried loudly for assistance, upon which the other mem-
bers 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 n6ver again
attack a single monkey of a troop. *

It is certain that associated animals have a feeling of love
for each other which is not felt by non-social adult animals.
How far in most cases they actually sympathize in the pains
and pleasures of others is more doubtful, especially with
respect to pleasures. Mr, Buxton, however, who had excel-
lent means of observation, f states that his macaws, which

* Mr. Belt gives the case of a spider-monkey (Ateles) in Nicaragua,
which was heard screaming for nearly two hours in the forest, and
was found with an eagle perched close by it. The bird apparently
feared to attack as long as it remained face to face; and Mr. Belt be-
lieves, from what he has seen of the habits of these monkeys, that
they protect themselves from eagles by keeping two or three
together. " The Naturalist in Nicaragua," 1874, p. 118.

f" Annals of Mag. of Nat. Hist.," Nov., 1868, p. 383,

116 THE DESCENT OF MAIT.

lived free in Norfolk, took '' an extravagant interest" in a
pair with a nest; and whenever the female left it she was
Burrounded by a troop '^ screaming horrible acclamations in
her honor/' It is often difficult to judge whether animals
have any feeling for the sufferings of others of their kind.
Who can say what cows feel when they surround and stare
intently on a dying or dead companion; apparently, how-
ever, as Houzeau remarks, they feel no pity. 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 \«, 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 bo 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 com-
rades to perish on the plains; or the Fijiarv*?^ who, when
their parents get old, or fall ill, bury them alive.*

Many animals, however, certainly sympathize with each
other's distress or danger. This is the case even with birds.
Capt. Stansburyf found on a salt lake in Utah an old
and completely blind pelican, which was very fat, and
must have been well fed for a long time 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.]; I have myself seen a dog, who never passed
a cat who lay sick in a basket, and was a great friend of his,
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.

»Sir .J. Lubbock, ^'Prehistoric Times," 2d edit., p. 446.

\ As quoted by Mr, L. H, Morgan, ' The American Beaver," 1868,
p. 272. Capt. Stansbury also gives an interesting account of the
manner in which a very young pelican, carried away by a strong
stream, was guided and encouraged in its attemps to reach the shore
by half a dozen old birds.

X As Mr. Bain states, " effective aid to a sufferer springs from
sympathy proper." "Mental and Moral Science," 1868, p 245.

MORAL SENSE, 117

I saw a person pretending to beat a lady, who had a very
timid little dog on her lap, and the trial had never been
made before; 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^ face,
and comfort her. Brehm * 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 the case of 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 own neck, inflicted on him, while 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 in
peril, he rushed to the rescue, and by screams and bites so
distracted the baboon that the man was able to escape,
after, as the surgeon thought, running great risk of his
life.

Besides love and sympathy, animals exhibit other quali-
ties connected with the social instincts, which in us would
be called moral; and I agree with Agassiz f that dogs
possess something very like a conscience.

Dogs possess some power of self-command, and this does
not appear to be wholly the result of fear. As Braubach I
remarks, they will refrain from stealing food in the absence
of their master. They have long been accepted as the very
type of fidelity and obedience. But the elephant is like-
wise very faithful to his driver or keeper, and probably con-
siders him as the leader of the herd. Dr. Hooker informs me
that an elephant, which he was riding in India, became so
deeply bogged that he remained stuck fast until the next
day, when he was extricated by men with ropes. Under
such circumstances elephants will seize with their trunks
any object, dead or alive, to place under their knees, to

* " Thierleben," B. i, s. 85.

t " De I'Espece et de la Classe," 1869, p. 97.

^ " Die Dwrwiu'scbe An-Lehre," 1809, s, 54,

118 THE DESCENT OF MAN.

prevent their sinking deeper in the mud; and the driver
was dreadfully afraid lest the animal should have seized
Dr. Hooker and crushed him to death. But the driver
himself, as Dr. Hooker was assured, ran no risk. This for-
bearance, under an emergency so dreadful for a heavy
animal, is a wonderful proof of noble fidelity. *

All animals living in a body, which defend themselves or
attack their enemies in concert, must indeed be in some
degree faithful to one another ; and those that follow
a leader must be in some degree obedient. When the
baboons in Abyssiniaf plunder a garden, they silently follow
their leader; and if an imprudent young animal makes a
a noise, he receives a slap from the others to teach him
silence and obedience. Mr. Gal ton, who has had excellent
opportunities for observing the half -wild cattle in S. Africa,
says, J; that they cannot endure even a momentary separa-
tion from the herd. They are essentially slavish, and
accept the common determination, seeking no better lot
than to be led by any one ox who has enough self-reliance
to accept the position. The men who break in these ani-
mals for harness, watch assiduously for those who, by graz-
ing apart, show a self-reliant disposition, and these they
train as fore oxen. Mr. Gralton adds that such animals are
rare and valuable; and if many were born they would soon
be eliminated, as lions are always on the lookout for the
individuals which wander from the herd.

With respect to the impulse which leads certain animals
to associate together, and to aid one another in many ways,
we may infer that in most cases they are impelled by the
same sense of satisfaction or pleasure which they experi-
ence in performing other instinctive actions ; or by the
same sense of dissatisfaction as when other instinctive
actions are checked. 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 shep-
herd-dog delights in driving and running round a flock of
sheep, but not in worrying them ; a young fox-hound
delights in hunting a fox, while some other kinds of dogs,

*See also Hooker's "Himalayan Journals," vol. ii, 1854, p. 333.
fBrehm, * * Thierleben, " B. i, s. 76.

XSee his extremely interesting paper on " Gregariousness in Cat-
tle and in Man," * ' Macmillan's Mag.," Feb., 1871; p. 353.

MORAL SENSE, 119

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 quite miserable if stopped from migra-
ting; perhaps they enjoy starting on their long flight; but
it is hard to believe that the poor pinioned goose, described
by Audubon, which started on foot at the proper time for
its Journey of probably more than a thousand miles, could
have felt any joy in doing so. Some instints are determined
solely by painful feelings, as by fear, which leads to self-
preservation, and is in some cases directed toward special
enemies. No one, I presume, can analyze the sensations
of pleasure or pain. In many instances, 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.

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 com-
fortable while 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 tlie
parental or filial affections, since the social instinct seems
to be developed by the young remaining for a long time
with their parents; and this extension may be attributed in
part to habit, but chiefly to natural selection. 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, while those that cared

120 THE DESCENT OF MAN.

least for their comrades, and lived solitary, would perish in
greater numbers. With respect to the origin of the parental
and filial aifections, which apparently lie at the base of the
social instincts, we know not the steps by which they have
been gained; but we may infer that it has been to a large
extent through natural selection. So it has almost cer-
tainly 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
their nearest relations having been in this case of service to
the community. Parental affection, or some feeling which
rejilaces it, has been developed in certain animals extremely
low in the scale, for example, in star-fishes and spiders.
It is also occasionally present in a few members alone in a
whole group of animals, as in the genus Eorficula, or
earwigs.

The all-important emotion of sympathy is distinct from
that of love. A mother may passionately love her sleep-
ing and passive infant, but she can hardly at such times
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, ^^tlie sight of another person enduring hunger,
cold, fatigue, revives in us some recollection of the
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.* 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.

* See the first and striking chapter in Adam Smitli's " Theory of
Moral Sentiments." Also Mr. Bain's "Mental and Moral Science,"
1868, pp. 244 and 275-282. Mr. Bain states, that '* sympathy is, in-
directly, a source of pleasure to the sympathizer;" and he accounts
for this through reciprocity. He remarks that "the person bene-
fited, or others in his stead, may make up, by sympathy and good
offices returned, for all the sacrifice." But if, as appears to be the
case, sympathy is strictly an instinct, its exercise would give direct
pleasure, in the same manner as the exercise, as before remarked, of
ftlmost every other instinct.

MORAL SENSE!, 121

The mere si^lit of suffering, independently of love, would
STiffice to call up in us vivid recollections iind associations.
The explanation may lie in the fact that, with all animals,
Bympathy is directed solely toward the members of the same
community, and therefore toward known and more or less
beloved members, but not to all the individuals of the same
species This fact is not more surprising than that the
fears of many animals should be directed against special
enemies. Species which are not social, such as lions and
tigers, no doubt feel sympathy for the suffering of their own
young, but not for that of any other aniinal. AVith man-
kind selfishness, experience, and imitation, probably add,
as ^Ir. Bain has shown, 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 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 one
another, it will have been increased through natural selec-
tion; for those communities, which included the greatest
number of the most sympathetic members, would llcurish
best and rear the greatest number of oifspring.

It is, however, impossible to decide in many cases v\rhethcr
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 ten-
dency to imitation; or again, whether they arc 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 of these
faculties; it must, therefore, have been directly acquired.
On the o.ther hand, the habit followed by the males of some
social animals of defending the community, and of attack-
ing 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 pleas-
ure in their performance, and more distress in their pre-
vention, than others; or, which is probably quite as impor-
tant, they are, through inheritance, more persistently
followed, without exciting aay special feeling of pleasuio

122 THE DESCENT OF MAN.

or pain. We are ourselves conscious that somo habits are
much more dilticult to cure or change than others, llenco
a struggle may often be observed in animals between dif-
ferent 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 getting the better of 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, in which they could continue to exist,
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 self-preservation.
Nevertheless, th? migratory instinct is so powerful that
late in the autumn swallows, house-martins, and swifts fre-
quently desert their tender young, leaving them to perish
miserably in their nests.*

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 num-
bers. Whether this is the case with the migratory in com-
parison with the maternal instinct, may be doubted. The

* This fact, the Rev. L. Jenyns states (see his edition of " White's
Nat. liist. of Selborne,'" 1853, p. 204) was first recorded by the illus-
trious Jenner, in " Phil. Transact.," 1834, and has since been confirmed
by several observers, especially by Mr. Blackwall. This latter care-
ful observer examined, late in the autumn, during two years, thirty-
six nests; he found that twelve contained young dead birds, five con-
tained eggs on the pf)int of being hatclied, and three, eggs not nearly
hatched. Many birds, not yet old enough for a prolonged flight, are
likewise deserted anrl left beliind. See Blackwall, ** Researches in
Z ;o!ogy." 1831, pp. 108, 118. For some additional evidence, although
this is not wanted, see Leroy, " Lettres Phil.," 1802, p. 217. For
swifts, Gould's "Introduction to the Birds of Great Britain," 1823,
p. 5. Similar ca.ses have been observed in Canada by Mr. Adamsj
**Pop. Science Keview," July, 1873, p. 283.

MOHAL SENSE. 123

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.

Matt a Social Animal. — Every one will 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 ojnly two or three together, roam
the solitudes of some savage lands, they always, as far as I
can discover, hold friendly relations with other families
inhabiting the same district. Such families occasionally
meet in council, and unite for their common defense. 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 majority 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 con-
scious that we do possess such sympathetic feelings;* but
our consciousness does not tell us whether they are instinct-
ive, 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 almost certain that he would inherit a
tendency to be faithful to his comrades and obedient to
the leader of his tribe; for these qualities are common to
most social animals. He would consequently possess some
capacity for self-command. He Avould from an inherited

*^ Hume remarks (' An Enquiry Concerning the Principles of
Morals." eait. of 1751, p, 132), "Tbere seems a necessity for con-
fessing that the bappinesii and misery of others are not' spectacles
altogether indifferent to us, but thai the view of the former . , .
communicates a secret joy; the appearance of the latter . , .
tiiiows a melajjciioiy damp over the imagination."

124: THE DESCENT OF MAN,

tendency 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 Bcale
are guided almost exclusively, and those which stand higher
in the scale are largely guided, by special instincts in the
aid which they give to the members of the same commu-
nity; 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 fellows; for, as
Mr. Bain has clearly shown,* the love of praise and the
strong feeling of glory, and the still ttronger horror of
Bcorn and infamy, "are due to the workings of sympathy."
Consequently man would be influenced in the highest
degree 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 some of his best
actions; but his actions are in a higher degree determined
by the expressed wishes and judgment of his fellow-men,
and unfortunately very often by his own strong selfish
desires. But as love, sympathy and self-command become
strengthened by habit, and as the power of reasoning
becomes clearer, so that man can value justly the judgments
of his fellows, he will feel himself impelled, apart from
any transitory pleasure or pain, to certain lines of conduct.
He might then declare — not that any barbarian or unculti-
vated man could thus think — T 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 Endtiring Social Ins finds Conquer the Less Per-
sistent Instincts. — We have not, however, as yet considered
the main point, on which, from our present point of view.

* '• Meutal and Moral Science," 1868, p. 254.

MOHAL SENSE. 125

the whole question of the moral sense turns. "Why should
a man feel that he ought to obey one instinctive desire
rather than another? Why is he bitterly regretful, if he
has yielded to a 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 hunger?

It is evident, in the first place, that with mankind the
instinctive impulses have different degrees of strength; a
savage will risk his own life to save that of a member of
the same community, but will be wholly indiiferent about
a stranger ; a young and timid mother urged by the
maternal instinct will, without a moment's hesitation,
run the greatest danger for her own infant, but not for
a mere fellow-creature. Neverthek^ss many a civilized man,
or even boy, who never before risked his life for another,
but full of courage and sympathy, has disregarded the
instinct of self-preservation, and plunged at once into a
torrent to save a drowning man, though a stranger. In
this case man is impelled by the same instinctive motive
which made the heroic little American monkey, formerly
described, save his keeper, by attacking the great and
dreaded baboon. Such actions as the above appear to be
the simple result of the greater strength of the social or
maternal instincts than that of any other instinct or motive;
for they are performed too instantaneously for reflection,
or for pleasure or pain to be felt at the time; though, if
prevented by any cause, distress or even misery might be
felt. In a timid man, on the other hand, the instinct of
self-preservation mi^ht be so strong, that he would be
unable to force himself to run any such risk, perhaps not
even for his own child.

I am aware that some persons maintain that actions per-
formed 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 when
prompted by some exalted motive. But it appears scarcely
possible to draw any clear line of distinction of this kind.*

* I refer here to the distinction between wliat has been called
mate.rialaLr\f\ formal mnvi\\\ty. I am glacl to find that Prof. Huxley
("Critiques and Addresses'" 1878, p. 287) takes the same view on
this subject as I do. Mr. Leslie Stephen remarks ('* Essays on Free-
thinking and Plain Speaking," 1873, p. 83), "the metaphysical dis-
tinction, between material and formal morality is as irrevelant a«
Other such distinctioiis."

126 THE DESCENT OF MATT,

As far as exalted motives are concerned, many instances
have been recorded of savages, destitute of any feeling of
general benevolence toward mankind, and not guided by
any religious motive, who have deliberately sacriticed their
lives as prisoners,* 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, in rescuing their offspring or comrades
from danger; yet their actions, though aone for the good
of others, are not called moral. Moreover, anything per-
formed very often by us, will at last be done without
deliberation or hesitation, and can then hardly be distin-
guished from an instinct; yet surely no one will pretend
that such an action 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 m.iin 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 aa
moral, if 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 Newfoundland dog
drags a child out of the water, or 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 per-
formed deliberately, after a struggle with opposing motives,
or impulsively through instinct, or from the effects of
slowly gained habit.

But to return to our more immediate subject. Although
some instincts are more powerful than others, and thus lead
to corresponding actions, yet it is untenable, that in man

*I have given one such case, namely, of three Patagonian Indians
who preferred being shot, one after the other, to betraying the plans
of tlieix compamons in war (" Journal of Kesearches," 1845, p. 103>.

MORAL SENSE, 127

tho social instincts (including the love of praise and fear of
blame) possess greater strength, or have, througn ".ong
habit, acquired greater strength than the instincts ot self-
preservation, hunger, lust, vengeance, etc. Why then does
man regret, even though trying to banish 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, Eee 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
and clearly passing through his mind. 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 com-
munity, and to give aid to their fellows in accordance with
their habits; they feel at all times, Avithout the stimulus of
any special passion or desire, some degree of love and sym-
pathy for them; they are unhappy if long separated from
them, and always happy to be again in their company. So
it is with ourselves. Even when we are quite alone, how
often do we think with pleasure or pain of what others
think of us — of their imagined approbation or disapproba-
tion; and this all follows from sympathy, a fundamental
element of the social instincts, A man who possessed no
trace of such instincts 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 satisiied. Nor is it easy, perhaps hardly pos-
sible, 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. *

* Enmity or hatred seems also to be a Liglily persistent feeling-,
perliaps more so than an> ctker that cau be uaaied Envy ie defined

128 TEE PESCEWT OF MA F.

A man cannot prevent past impressions often repassing
through his mind; he wiU thus be driven to make a com-
parison between the impressions of past hunger, vengeance
satisfied, or danger shunned at other men's cost, with the
almost ever-present instinct of sympathy, and with his
early knowledge of what others consider as praiseworthy or
blameable. This knowledge cannot be banished from his
mind, and from instinctive sympathy is esteemed of great
moment. Ha will then feel as if he had been balked in
following a present instinct or habit, and this with all
animals causes dissatisfaction, or even misery.

The above case of the swallow aft'ords an illustration,
though of a reversed nature, of a temporary though for the
time strongly persistent instinct conquering another in-
stinct, 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. AVhile
the mother-bird is feeding, or brooding over her nestlings,
the maternal instinct is probably stronger than the migra-
tory; but the instinct which is the 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 has ceased to act, what an agony of remorse the
bird would feel if, from being endowed with great mental

as hatred of anctlier for some excellence or success; and Bacon in-
sists (Essay ix), *' Of all other affections envy is the most importune
and continual." Dogs are very apt to hate both strange men and
strange dogs, especially if they live near at hand, but do not belong
to the same family, tribe, or clan; this feeling would thus seem to be
innate, and is certainly a most persistent one. It seems to be the
complement and converse of the true social instinct. From what we
hear of savages, it would appear that something of the same kind
holds good with them. If this be so. it would be a small step m any
one to transfer such feelings to any member of the same tribe if he
ba 1 done him an injury and had become his enemy. Kor is it
probable that the primitive conscience would reproach a man for in-
juring his enemy; rather it would reproach him, if he had not
rev'enged himself. To do good in return for evil, to love your
enemy, is a height of morality to which it may be doubted whether
the social instincts would, by themselves, have ever led us. It is
necessary that these instincts, togethei" with sympathy, should have
been highly cultivated and extended by the aid ot reason, instruc-
tion, and tlie love or Ukxv of God, before any suck golden rule would
ever be thought of and obeved.

MORAL SENSE. 129

activity, she could not prevent the image constantly passing
through 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 ihe stronger impulse; and though tliis may occa-
sionally prompt him to the noblest deeds, it will more com-
monly lead him to gratify his own desires at the expense of
ether men. But after their gratification, when past and
weaker impressions are judged by the ever-enduring social
instinct, and by his deep regard for the good opinion of
his fellows, retribution will surely come. He vvill then
feel remorse, repentance, regret or shame; this latter feel-
ing, nowever, relates almost exclusively to the judgment of
others. He will consequently resolve more or less lirmly
to act differently for the future; and this is conscience; for
conscience looks backward and serves as a guide for the
future.

The nature and strength of the feelings which we call
regret, shame, repentance or remorse, depend apparently
not only on the strength of the violated instinct, but partly
on the strength of the temptation, and often still more on
the Judgment of our fellows. How far each m.an values
the appreciation of others depends on the strength of his
innate or acquired feeling of sympathy; and on his own
capacity for reasoning out the remote consequences of his
acts. Another element is most important, although not
necessary, the reverence or fear of the gods, or spirits
believed in by each man; and this applies especially in
cases of remorse. Several critics have objected that
tliough some slight res^ret or repentance may be explained
by the view advocated in this chapter, it is impossible thus
to account for the soul-shaking feeling of remorse. But I
can see little force in this objection. My critics do not
define what they mean by remorse, and 1 can find no defi-
nition implying more than an overwhelming sense of
repentance. Remorse seems to bear the same relation to
rep3ntance as rage does to anger, or agony to pain. It is
far from strange that an instinct so strong and so gener-
ally admired, as maternal love, should, if disobeyed: lead to
the deepest misery, as soon as the impression of the past
cause of disobedience is weakened. Even when an action
is opposed to no special instinct, merely to know that our
friends and equals despise us for it, is enough to cause great

130 JHW DESCENT OF MAN,

misery. Who can doubt that the refusal to fight a duel
through fear has caused many men an agony of shame?
Many a Hindoo, it is said, has been stirred to the bottom
of his soul by having partaken of unclean food. Here is
another case of what must, I think, be called remorse.
Dr. Landor acted as a magistrate in West Australia, and
relates,* that a native on his farm, after losing one of his
wives from disease^ came and said that ^'' he was going to
a distant tribe to spear a woman, to satisfy his sense of
duty to his wife. I told him that if he did so I would
send him to prison for life. He remained about the farm
for some months, but got exceedingly thin, and complained
that he could not rest or eat, that his wife's spirit was
haunting him, because he had not taken a life for hers. I
was inexorable, and assured him that nothing should save
him if he did.'' Nevertheless the man disappeared for
more than a year, and then returned in high condition ;
and his other wife told Dr. Landor that her husband had
taken the life of a woman belonging to a distant tribe, but
it was impossible to obtain legal evidence of the act. The
breach of a rule held sacred by the tribe will thus, as it
seems, gi\k> rise to the deepest feelings — and this quite
apart from the social instincts, excepting in so far as the
rule is grounded on the judgment of the community.
How so many strange superstitions have arisen throughout
the world we know not; nor can we tell how some real and
great crimes, such as incest, have come to be held in an
abhorrence (which is not however quite universal) by the
lowest savages. It is even doubtful whether in some tribes
incest would be looked on with greater horror than would
the marriage of a man with a woman bearing the same
name, though not a relation. *"' To violate this law is a
crime which the Australians hold in the greatest abhor-
rence, in this agreeing exactly with certain tribes of North
America. When the question is put in either district, is
it worse to kill a girl of a foreign tribe, or to marry a girl
of one's ow.i, an answer just opposite to ours would be given
without i.'3ioi;ation."f We may, therefore, reject the
belief, la!:e_y insisted on by some writers, that the abhor-

* " insani«7 ;p. J.lelation to Law," Ontario, United States, 1871,
f E. B. Tylor in *• Contemporary Keview," April, 1873, p. 707.

MORAL SEjySE, 131

reiicG of incest is due to our possessing a special God-
implanted conscience. On the whole it is intelligible, that
a man urged by so powerful a sentiment as remorse though
arising as above explained, should be led to act in a manner,
which he has been taught to believe serves as an expiation,
such as delivering himself up to justice.

Man prompted by his conscience, will through long habit
acquire such perfect self-command, that his desires and
passions will at last yield instantly and without a struggle
to his social sympathies and instincts, including his feeling
for the judgment of his fellows. The still hungry, or the
still revengeful, man will not think of stealing food, or ot
wreaking his vengeance. It is possible, or as we shall here-
after 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
impulses. The imperious word ongld seems merely to
imply the consciousness of the existence of a rule of con-
duct, however it may have originated. Formerly it must
have been often vehemently urged that an insulted
gentleman OKf/ht to fight a duel. We even say that a
pointer ouc/ht to point, and a retriever to retrieve game.
If they fail to do so, 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, when recalled to mind, as
strong as, or stronger than, the social instinct, a man will
feel no keen regret at having followed it; but he will be
conscious that if his conduct were know^n to his fellows, it
would meet with their disapprobation; and few are so desti-
tute of sympathy as not to feel discomfort when this is
realized. 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, and the judgment of others, then he is essen-
tially.p bad man;* and the sole restraining motive left;
is t'l^'j 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. /

*Dr. Prosper Despine in bis " Psycbologie Naturelle," 1868 (tora.
}, p. 243; torn, ii, p. 169), gives many curious cases of the worst
Cfimiuals, vvko apparently have been entirely destitute of conscience.

132 THE DESCENT OF MAN.

It is obvious that every one may with an easy conscience
ratify his own desires, if they do not interfere with his
Dcial 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 disap-
probation, whether reasonable or not, of his fellow-men.
Kor 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 origin and nature of the moral sense,
wnich 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 practiced, at least
generally, by rude men, so that they may associate in a body,
are those which aie still recognized as the most important.
But they are practiced 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, etc.,
were common, consequently such crimes within the limits
of the same tribe " are branded with everlasting infamy;"*
but excite no such sentiment beyond these limits. K North
American Indian is well pleased with himself, and is hon-
ored 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, f 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 gt -leraliy

*See an able article in the *' North Britisli Review," 1867, p. «.95.
See also Mr. W, Bagehot's articles on the *' Importance of Obediencw"
and " Coherence to Primitive Man," in the " Fortnightly Keview,'*
1867, p. 529, and 1868, p. 457, etc.

f Tlie fullest account which I have met with is by Dr. Gerland, in
his •' Ueber dan Anssterben der Natnr^olker " 1868; but I shall have
to recur to the subject of iufantioidtf 4M>4uture chapter.

ifOrUL SENSB, 133

consklercd as a crime,* out rather, from the courage dis-
playetl, as an honorable act, and it is still practiced by some
Bemi-civilized and savage nations without reproach, for it
does not obviously concern others of the tribe. It has
been recorded that an Indian Thug conscientiously lugret-
ted that he had not robbed and strangled as many trav-
elers as did his father before him. In a rude state of
civilization the robbery of strangers is, indeed, generally
considered as honorable.

Slavery, although in some ways beneficial during ancient
times, t is a great crime; yet it was not so regarded until
quite recently, even by the most civilized nations. And
this was especially the case, because the slaves belonged in
general to a race different from that of their masters. As
barbarians do not regard the opinions 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 well known that the women
and children of the North American Indians aided in tor-
taring their enemies. Some savages take a horrid pleas-
ure in cruelty to animals, J and humanity is an unknown
virtue. Kevertheless, besides the family affections, kind-
ness is common, especially during sickness, between the
members of the same tribe, and is sometimes extended
beyond these limits. 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
fidelily of savages toward each other, but not to strangers;
common experience justifies the maxim of the Spainard.
" 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

*See tlie very interesting discussion on Suicide in Lecky's " Hist-
ory of European Morals," vol. i, 1869, p. 223. With respect to sav-
ages, Mr. Winwood Reade informs nie that the negroes of West
Africa often commit suicide. It is well known how common it was
among the miserable Aborigines of South America after the Spanish
conquest. For New Zealand, see the voyage of the " Novara," and
for the Aleutian Islands, Miiller, as quoted by Ilouzeau, " Les
Facultes Memales," etc., tom. ii, p. 136.

t See Mr. Bagehot, "Physics and Politics," 1872, p. 72.

:}:See, for Instance, Mr. Hamilton's account of the Kaflfirs, **An>
tliropological Kevievv," 1870, p. 15.

134 TUB DESCENT OF MAN.

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
practiced by savages, even at a high cost, toward strangers;
but to lie to your enemy has rarely been thought a sin, as
the history of modern diplomacy too plainly shows. As
soon as a tribe has a recogidzed 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 civilized coun-
tries a good yet timid man may be far more useful to the
community than a brave one, we cannot help instinctively
honoring 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 mati can practice 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 su omits to the most horrid
tortures without a groan, to prove and strengthen his forti-
tude 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 so-called self-regarding virtues, which do not
obviously, though they may really, affect the welfare of the
tribe, nave never been esteemed by savages, though now
highly appreciated by civilized nations. The greatest
intemperance is no reproach with savages. Utter licen-
tiousness and unnatural crimes prevail to an astounding
extent.* As soon, however, as marriage, whether polyga-
mous or monogamous, becomes common, jealousy will lead
to the inculcation of female virtue; and this being honored,
m\\ 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 honored, from a very early period in the moral history
of civilized mar?. As a consequence of this, the senseless
practice of celibacy has been ranked from a remote penod

*Mr M'Lennan has given ( • Primitive Marriage," 1865, p. 176) a
Kood collection of facts ou this head

MORAL SENSE. 135

as a virtue.* The hatred of indecency, which appears to
lie 60 natural as to be thought innate, and which is so val-
uabie an aid to chastity, is a modern virtue, appertaining
exclusively, as Sir G. Staunton remarks,! to civilized life.
This is shown 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 obviously affect the welfare *of the tribe
— not that of the species, nor that of 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, powers of reason-
ing insufficient to recognize the bearing of many virtues,
especially of the self-regarding virtues, on the general w^el-
fare of the tribe. Savages, for instance, fail to trace the
multiplied evils consequent on a want of temperance,
chastity, etc. And, thirdly, weak power of self-command;
for this power has not been strengthened through long-con-
tinued, perhaps inherited, habit, instruction and religion.

I have entered into the above details on the immorality
of savages, J; because some authors have recently taken a
high view of their moral nature, or have attributed most of
their crimes to mistaken benevolence. § These authors
appear to rest their conclusion on savages possessing those
virtues which are serviceable, or even necessary, for the
existence of the family and of the tribe — qualities which
they undoubtedly do possess, and often in a high degree.

Concluding Remarks. — It was assumed formerly by phi-
losophers of the derivative || school of morals that the

*Lecky, ''History of European Morals," vol. i, 1869, p. 109.

f '* Embassy to Cbina." vol. ii, p. 348.

J See on this subject co])ious evidence in chap, vii, of Sir J, Lub-
bock, "Origin of Civilization," 1870

§For instance, Lecky " Hist. European Morals," vol. 1. p. 124.

J Tins term is used in an able article in the " Westminster Re-
view," Oct., 18G9, p. 498. For the "greatest happiness principle,"
see J. S. Mil], ** Utilitarianism." u 17.

136 THE DESCENT OF MAN.

foundation of morality lay in a form of Selfishness; but
more recently the '* .iiieatest happiness principle" has been
brought prominently forward. It is, however, more cor-
rect to speak of the latter principle as the standard, and
not as the motive of conduct. Nevertheless, all the authors
whose works I have consulted, with a few exceptions,*
write as if there must be a distinct motive for every action,
and that this must be associated with some pleasure or dis-
pleasure. But man seems often to act impulsively, that is
from instinct or long habit, without any consciousness of
pleasure, in the same manner as does probably a bee or ant,
when it blindly follows its instincts. Under circumstances
of extreme peril, as during afire, when a man endeavors to
save a fellow-creature without a moment's hesitation, he
can hardly feel pleasure; and still less has he time to reflect
on the dissatisfaction which he might subsequently cxperi-.
ence if he did not make the attempt. Should he afterward
reflect over his own conduct, he would feel that there lies
within him an impulsive power widely difl'erent from a
search after pleasure or happiness; and this seems to be tho
deeply })lanted social instinct.

In the case of the lower animals it seems much more
appropriate to speak of their social instincts as having
been developed for the general good rather than for tho
general h?>.ppiiiess of the species. The term, general good,
may be defined as the rearing of the greatest number of
individuals in full vigor and health, with all their faculties
perfect, under the conditions to which they are subjected.

*Mill recognizes (*' System of Logic,'' vol. ii, p 422) in the clear-
est manner, tliat actions may be performed tliroug-b habit \vitliout
the anticipation of pleasure. Mr. H. Sidgwick also, in bis essay on
Pleasure and Desire (" The Contemporary Keview." April 1872, p.
671), remarks: "To sum up, in contravention of the doctrine that
our conscious active iujpulses are always directed toward the pro-
duction of agreeable sensations in ourselves, I would maintain that
we find everywhere in consciousness extra-regarding impulse, di-
rected toward something that is not pleasure; that in many cases tho
imi)uKse is so far incom^tatible with the self regarding that the two
do not easily ci^exist in the same moment of consciousness." A dim
feeling that our impulses do not by any mean-s always arise from any
contemporaneous or anticii)ated j)leasure, has, I cannot but think,
been one chief cause of the acceptance of the intuitive theory of
morality, and of the rejection of the utilitarian or 'greatest happi-
Qpsh '* theo.-y With respect to the latter ilieory the standard and
the n^ofive M ".onduct have no doubl often beea cuufusedj but they
are realiy jn 6Qia^ 4e^rtH) blended.

MORAL SEJ^SE. 137

As the social iiistiDcts both of man and the lower animals
have no doubt been developed by nearly the same steps, it
would be advisable, if found practicable, to use the same I
Jefiintion in both cases, and to take as the standard 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-creat-
ure it seems also more correct to say that he acts for the
general good rather than for the general happiness of man-
kind. No doubt the welfare and the happiness of the
individual usually coincide; and a contented, happy tribo
will flourish better than one that is discontented and
unhappy. We have seen that even 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 j
of each member; and as all wish for happiness, the *^ great- i
est happiness principle '^ will have become a most impor- ■
tant secondary guide and object; the social instinct, how- i
ever, together with sympathy (which leads to our regarding
the approbation and disapprobation of others), having ■
served as the primary impulse and guide. Thus the re- ]
proach is removed of laying the foundation of the noblest j
part of our nature in the base principle of selfishness; j
unless, indeed, the satisfaction which every animal feels, j
when it follows Us proper instincts, and the dissatisfaction 1
felt when prevented be called selfish. j

The wishes and opinions of the memxbers of the same ^
community, expressed at first orally but later by writing
also, either form the sole guides of our conduct or greatly
re-enforce the social instincts; such opinions, however, have
sometimes a tendency directly opposed to these instincts.
This latter fact is well exemplified by the Jmw of Honor,
that is, the law of the opinion of our equals and not of all
our countrymen. The breach of this law, even when thei
breach is known to be strictly accordant with true moral-
ity, has caused many a man more agony than a real crime.
We recognize the same influence in the burning sense of
diame 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 communitj will generally be guided by some rude

138 THE DESCENT OF MAN.

experience of what is best in the long run for all the mem-
bers; but tills judgment will not rarely eir from ignorance
and weak powers of reasoning. Hence the strangest cus-
toms and superstitions, in complete opposition to the true
welfare and happiness of mankind, have become all-power-
ful throughout the world. AVe see this in the horror felt
by a Hindoo who breaks his caste, and in many other such
cases. It would be difficult to distinguish between the
remorse felt by a Hindoo who has yieldei to the tempta-
tion of eating 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 minds of men;
but it is worthy of remark that a belief constantly incul-
cated during the early years of life, while the brain is im-.
pressible, appears to acquire almost the nature of ap
instinct; and the very essence of an instinct is that it is
followed independently of reason. Neither can we say wny
certain admirable virtues, such as the love of truth, art
much more highly appreciated by some savage tribes than
by others;* nor, again, why similar differences prevail even
among higi:ly civilized nations. Knowing iiow firmly
fixed many strange customs and superstitions have become,
we need feel no surprise that the self-regarding virtues,
supported as they are by reason, should now appear to us
so natural as to be thought innate, although they were not
valued by man in his early condition.

Notwithstanding many sources of doubt, man can gener-
ally 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 im-
plying self-sacrifice hardly deserve to be called lower, relate
chiefly to self, and arise from public opinion, matured by
experience and cultivation; for they are not practiced by
rude tribes.

As man advances in civilization, and small tribes are

*Good instances are given by Mr. Wallace in " Scientific OpiHion,"
Sept. 15, 1869, and more fully in liis " Contribationsto the Theory
of Natural Selection/' 1870, p. 353.

MORAL SENSE. 139.

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 pre-
vent his sympathies extending to the men of all nations
and races. If, indeed, such men are separated from him
by great differences m appearance or habits, experience
unfortunately shows us how long it is, before we look at
them as our fellow-creatures. Sympathy beyond the con-
fines 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 toward their pets. IIow little
the old Romans knew of it is showm 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 sym-
pathies becoming more tender and more widely diffused,
until they are extended to all sentient beings. As soon as
this virtue is honored and practiced by some few men, it
spreads through instruction and example to the young, and
eventually becomes incorporated in public opinion.

The highest possible stage in moral culture i^ wdicn we
recognize 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."* Whatever makes any
bad action familiar to the mind renders its performance
by so much tbe 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, "t

Our great philosopher, Herbert Spencer, has recently
explained his views on the moral sense. He says 4 *'I
believe that the experiences of utility organized and con-
solidated through all past generations of the human race,
have been producing corresponding modifications, which,

* Tennyson's " Idylls of tbe King," p. 244.

f *' The Tbougbls of tbe Emperor M. Aurelins Antoninus," Eng.
translat., 2d edit., 1869, p. 112. Marcus Aurelius was born A. D.
121.

J Letter to Mr. Mill iu Bain s " Mental and Moral Science," 18G8.
p. 722.

140 THE DESCENT OF MAN.

by continued transmission and accumulation, have become
in us certain faculties of moral intuition — certain rit.otione
responding to right and wrong conduct, which have no
apparent Xasis in the individual experiences of utility."
There is not the least inherent improbability, as it Eeems 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 to
their offspring, I have heard of authentic 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 a rare crime
in the wealthy classes, we can hardly account by accidental
coincidence for tlie tendency occurring in two or tliree
members of the same family. If bad tendencies are trans-
mittf^d, it is probable that good ones are likewise trans-
mitted. That the state of the bodv by affecting the brain
has great influence on the moral tendencies is known
to most of those who have suffered from chronic derange-
ments of the digestion or liver. The same fact is likewise
shown by the ''perversion or destruction of the moral
sense being often one of the earliest symptoms of mental
derangement;"' * and insanity is notoriously often inherited.
Except 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.

Even the partial transmission of virtuous tendencies
would be an immense assistance to the primary impulse
derived directly and indirectly from the social instincts.
Admitting for a moment that virtuous tendencies are
inherited, it appears probable, at least in such cases as
chastity, temperance, humanity to animals, etc., that they
become first impressed on the mental organization through
habit, instruction and example, continued during seveial
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 ap
the horror of a Hindoo for unclean food, ought on the same
principle to be transmitted. I have not met with any

♦Maudsley, "Body and Mind," 18T0, p. 60.

MORAL SENSE. 141

evidence in support of tho transmission of superstitious
customs or senseless habits, although in itself it is per-
hii])s not less probable than that animals should acquire
inherited tastes for certain kinds of food or fear of certain
foes.

Finally the social instincts, which no doubt were acquired
by man as by the lower animals for the good of the com-
munity, will from the first have given to him some wish to
aid his fellows, some feeling of sympathy, and have com-
pelled him to regard their approbation and disapprobation,
hsuch impulses will have served/iiim 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
sufticieiit knowledge to reject baneful customs and su])er-
stitions; as he regarded more and more not only the wel-
fare, but the happiness of his fellow-men; as from habit,
following on beneficial experience, instruction and example,
his sympathies became more tender and widely ditfused,
extending to men of ail races, to the imbecile, 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 deriva-
tive school and by some intuitionists, that the standard of
morality has risen since an early period in the history of
man.*

As a struggle may sometimes be seen going on between
the various instincts of the lowei animals, it is not surpris-
ing that there should be a struggle in man between his
social instincts, vvith their derived virtues, and his lower,
though momentarily stronger impulses or desires. This, as
Mr. Galtonf has remarked, is all the less surprising, as man
has emerged from a state of barbarism within a compara-
tively recent period. After having yielded to some temp-
tation we feel a sense of dissatisfaction, shame, repentance,

•* A writer in the " North British Review "(July 1869. p. 531),
well capable of formino: a sound judgment, expresses himself strongly
in favor of this conclusion Mr. Lecky (*' Hist, of Morals," vol. i, p.
143) seems to a certain extent to coincide therein.

f See his remarkable work on "Hereditary Genius," 1869, p. 349.
The Duke of Argyll (" Primeval Man." 1869, p. 188) has some good
remarks on the contest iu man's uatvu'e between right and wrong.

142 THE DESCENT OF MAN,

or remorse, analogous to the feelings caused by other power*
fal instincts or desires, when left unsatisfied or balked.
We compare the weakened impression of a past temptation
witli the ever present social instincts, or with habits, gained
in early youth and strengthened during our whole lives
until they have become almost as strong as instincts. If
with the temptation still before us we do not yield, it is
becaus3 either the social instinct or some custom is at the
moment predominant, or because we have learned that it
will appear to us hereafter the stronger, when compared
with the weakened impression of the temptation, and we
realize that its violatioii would cause us suffering. 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 c^'se the struggle between our
higher and lower impulses will be less severe, and virtue
will be triumphant.

Summary of the Last Two Cliapfers. — 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
Btones 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 mathemat-
ical 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 colored 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 ei^pressing definite ideas by delinite sounds had never
crossed llieir minds. They might insist that tliey 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; bnt they would be forced to acknowledge
that disinterested love for all living creatures, the most
noble attribute of man, was quite beyond their compre-
hensiou.

SUMMARY. 143

Nevertheless the difference in mind between man and
the higher animals, groat as it is, certainly is one of degree
and not of kind. We have seen that the senses and intui-
tions, the various emotions and faculties, such as love,
memory, attention, curiosity, imitation, reason, etc., of
■which man boasts, may be found in an incipient, or even
Bometimes in a well-developed condition, in the lower
animals. They are also capable of some inherited improve-
ment, as we see in the domestic dog coro.pared with the
wolf or jackal. If it could be proved that certain high
mental powers, such as the formation of general con-
cepts, self-consciousness, etc., were absolutely peculiar to
man, which seems extremely doubtful, it is not improbable
that these qualities are merely the incidental results of
other highly-advanced intellectual faculties ; and these
again mainly the result of the continued use of a perfect
language. At what age does the new-born infant possess
the power of abstraction, or become self-conscious and
reflect on its own existence ? We cannot answer; nor can
we answer in regard to the ascending organic scale. The
half-art, half-instinct of language still bears the stamp
of its gradual evolution. The ennobling belief in God 13
not universal with man; and the belief in spiritual agencies
naturally follows from other mental powers. The moral
sense perhaps affords the best and highest distinction
between man and the lower animals; but I need say noth-
ing on this head, as I have so lately endeavored to show
that the social instincts — the prime principle of man's
moral constitution* — with the aid of active intellectual
powers and the effects of habit, naturally lead to the golden
rule, " As ye would that m3n should do to you, do ye to
them likewise;" and this lies at the foundation of morality.

In the next 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 such evolution is at least possible, ought not to be
denied, for we daily see these faculties developing in every
infant; and we may truce a pefect gradation from the mind
of an utter idiot, lower than that of an animal low in the
scale, to the mind of a IS'ewton.

Tan ITioughts of Marcus Aurelius," etc., p. 139.

144 THE DESCENT OF MAN.

CHAPTER V.

CX THE DEVELOPMENT OF THE TN'TELLECTL'AL AN^J

MOKAL FACL'LTIES DURING PRIMEVAL AND

CIVILIZED TIMES.

Advancement of the intellectual powers through natural selection —
liuj-.oriauce of imitaiiou — Social ami moral faculties — 'I'heir
development within the limits of the same tribe — Natural
selection as affecting civilized nations — Evidence that civilized
nations were once barbarous.

The subjects to be discussed in this chapter are of the
highest interest, but are treated by me in an imperfect and
fragmentary manner. Mr. Wallace, in an admirable paper
before referred to,* argues that man, after he had partially
acquired those intellectual and moral faculties which dis-
tinguish him from the lower animals, would have been but
little liable to bodily modilications through natural selec-
tion or any other means. For man is enabled through his
mental faculties " to keep with an unchanged body in har-
mony with the changing universe." lie has great power
of adapting his habits to new conditions of life. He
invents weapons, tools, and various stratagems to procure
food and to defend 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 indigesti-
ble. H3 aids his fellow-men in many ways, and anticipates
future events. Even at a remote period he practiced some
division of labor.

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
ac(piire more eifective teeth or claws, for defense against
ucw enemies; or they must be reduced in size, so as to

* "Ajithropological Review," May, 1S64, p. 153-

mTELLECTVAL FACULTIES, 145

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. "Ucdiace
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 vaviations 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 r^dvanced through
natural selection. Of the high importance of the intel-
lectual faculties there can be no doubt, for man mainly
owes to them his predominant 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 sub-
sistence, and this depends partly on the physical nature of
the country, but in a much higher degree on the arts
which are there practiced. As a tribe increases and is vic-
torious, it is often still further increased by the absorption
of other tribes.* The stature and strength of the men of a
tribe are likewise of some importance for its suci^ess, 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 race more powerful,
and, judging from their sword -handles, with laj-ger hands;}
but their success was probably still more due to their
superiority in the arts.

All that we know about savages, or may infer from theii
tiaditions and from old monuments, the liistory of which
is quite forgotten by the present inhabitants,"show that
from the remotest times successful tribes liave supplanted
other tribes. Relics of extinct or forgotten tribes have been
discovered throughout the civilized regions of the earth, on

* After a time the nieniLers or tribes wliich are absorbed into
another tribe assume, as Sir Henry Maine remarks ("Ancient Law,"
1861, p. 131), that tbey are tbe co-descendants of the same aucebtors,

iMorlot, "Soc Vaud. Sc. ^'at." laeo. d. 29^

1^6 THE DESCENT OF MAN.

the wild plains of America, and on the isolated islands in
the Facitic Ocean. At the present day civilized nations
are everywhere supplanting barbarous nations, excepting
where the climate opposes a deadly barrier; and they suc-
ceed mainly, though not exclusively, through their arts,
which are the ])roducts of the intellect. It is, therefore,
highly probable that with mankind the intellectual facul-
ties have been mainly and gradually perfected through
natural selection; and this conclusion is sufficieut for our
purpose. Undoubtedly it would be interesting to trace 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 per-
mits 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 principle of imitation and reason and experi-
ence would have increased and much modified the intel-
lectual powers in a way, of which we see only traces in the
lower animals. 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, shows that animals learn by
experience and imitate the caution of others. 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 defense,
the plainest self-interest, without the assistance of much
reasoning power, would prompt the other members to imi-
tate him; and all would thus profit. The habitual practice
of each new art must likewise in some slight degree
^rengthen the intellect. If the new invention were an
Miportant 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 greater 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 decid-
edly better. Even if they left no children, the tribe would
still include their blood-relations; and it has been a.-"cer-
tained by agriculturists* that by preserving and breeding

* I Lave given instances in my " Variation of Animals under Do-
mestication," vol. ii, p. 190.

MORAL FACULTIES. 147

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 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 dispo-
sition. 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 defense. All this im-
plies 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 (other circumstances being equal)
the one tribe included a great number of courageous, sym-
pathetic and faithful members, who were always ready to
warn each other of danger, to aid and defend each other,
this tribe would succeed better 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 advan-
tage 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
shown,* is of the highest value, for anv form of government
is better than none. Selfish and contentious people will
not cohere, and without coherence nothing cs.n be effected.
A tribe rich in the above qualities would npread and be
victorious over other tribes; but in the course of time it
would judging from all past history, be in its turn over-
come by some other tribe still more highly endowed. Thus
the social and moral qualities would tend slowly to advance
and be diffused throughout the wovld.

But it may be asked, how within the limits of the same
tribe did a large number of members first become endowed

*See a remarkable series of articles on " Plivsics and Politics," in
the "Fortnightly Keview,' ^^ov., 18G7; April' 1, 1668; July 1, 1869.
since s^-parately publislied.

148 THB DESCENT OF MAN.

with these social and moral qualities, and how was the
standard of excellence raised? It is extremely doubtful
whether the off s^, ring of the more sympathetic and benevo-
lent parents, or of those who were tlie most faithful to
their comrades, would be reared in greater numbers than
the children of selfish and treacherous parents belonging to
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 olfspring 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 numbers than other
mt-n. Therefore it hardly seems probable, that the number
of men gifted with such virtues, or that the standard of
thi'ir excellence could be increased through natural selec-
ticQ. that is. by the survival of the fittest : for we are not
here speaking of one tribe being victorious over another.

Although the circumstances, leading to an increase in
the number of those 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 rea-
soning powers and foresight of the members became im-
proved, each man would soon learn 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 sympathv which gives
the first impulse to benevolent actions. Habits, more-
over, followed during many generations probably tend to
be inherited.

But another and much more powerful stimulus to the
development of the social virtues is afforded by the praise
and the blame of our fellow-men. To the instinct of
sympathy, as we have already seen, it is primarily due that
we habitually bestow both praise and blame on others,
while we love the former and dread the latter when applied
to ourselves; and this instinct no doubt was originally
acquired, like all the other social instincts, through nat-
ural 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 blam^e of their
fellow-creatures we cannot of course say. But it appears
that even dogs appreciate encouragement, praise, and

mohal faculties. UO

blame. The rudest savages feel the sentiment of glory, as
they clearly show by preserving the trophies of their
prowess, by their habit of excessiv-e boasting, and even by
the extreme care which they take of their personal appear-
ance 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, and apparently remorse, as shown by tlie case
of the Australian who grew thin and could not rest from
having delayed to murder some other woman so as to pro-
pitiate his dead wife's spirit. Though I have not met with
any other recorded case, it is scarcely vjredible 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,* would not feel remorse in his inmost soul if he
had failed in a duty which he held sacred.

We may therefore conclude that primeval man, at a very
remote period, was 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 olf spring with a tendency to
inherit his own high character.

With increased experience and reason, man perceives the
more remote consequences cf his actions, and the self -regard-
ing virtues, such as temperance, chastity, etc., 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
fourth chapter. Ultimately our moral sense or conscience
becomes a highly complex sentiment — originating in the

*Mr. Wallace gives cases in his "Contributions to the Theory of
Natural Selection," 1870, p. 354.

150 THE DESCENT OF MAN.

social instincts, largely guided by the approbation of our
fellow-men, ruled by reason, self-interest, and in later
times by deep religious feelings, and confirmed by instruc-
tion and habit.

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 increase in the number of well-
endowed men and an advancement in the standard of
morality will certainly give an immense advantage to one
tribe over another. A tribe including many members who,
from possessing in a high degree the spirit of patriotism, fidel-
ity, obedience, courage and sympathy, were always ready to
aid one another, 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 important 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 civilization. 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 normal 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 hi^h authority. Sir Henry Maine,* *'the greatest
part of mankind has never shown a particle of desire that its
civil institutions should be improved." Progress seems to
depend on many concurrent favorable conditions, far too
complex to be followed out. But it has often been remarked,
that a cool climate, from leading to industry and to the
various arts, has been highly favorable thereto. The Esqui-
maux, 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 detri-
mental. While observing the barbarous inhabitants of

* •' Ancient Law," 1861, p. 23. For Mr. Bageliot's remarks,
*' FortttigUtly Review," April 1, 1868, p. 453.

CIVILTZED I^^TIONS. 351

T'crra del Fiiego, 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 civilization.
Such habits almost necessitate the cultivation of the ground;
and the first steps in cultivation would probably result, as
I have elsewhere shown,* from some such accident as the
^eeds of a fruit-tree falling on a heap of refuse, and pro-
lucing an unusually fine variety. The problem, however,
of the first advance of savages toward civilization is at pres-
ent much too difficult to be solved.

Natural Selection as Affecting Civilized Nations. — T have
hitherto only considered* the advancement of man from a
semi-human condition to that of the modern savage. But
some remarks on the action of natural selection on civilized
nations may be worth adding. This subject has been ably
discussed by Mr. W. R. Greg,t and previously by Mr. AVal-
lace and Mr. Gal ton. | Most of my remarks are taken from
these three authors. With savages, the "sveak in body or
mind are soon eliminated; and those that survive commonly
exhibit a vigorous state of health. We civilized men, on
ihe other hand, do our utmost to check the process of elim-
ination; we build asylums for the imbecile, the maimed,
and the sick; we inetitute 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 civilized societies propagate their kind.
No one who has attended to the breeding of domestic ani-

*"Tlie Variation of Animals and Plants under Domestication,"
^ol. i, \). 309.

f " Fraser's Magazine," Sept., 1868, p. 353. Tliis article seems to
have struck many persons, and lias given rise to two remarkable
essays and a rejoinder in the "Spectator," Oct. 3 and 17, 18G8. It
Las also been discussed in the " Q. Journal of Science," 1869, p. 152,
and by Mr. Lawson Tait in the "Dublin Q. Journal of Medical
Science," Feb., 1869, and by Mr. E. Ray Lankester in his "Com-
parative Longevity," 1870. p. 128. Similar views a])peared pre-
viously in the " Australasian," July 13, 1867. I have borrowed ideas
from several of these writers.

t For Mr. Wallace, see " Anthropolog. Review," as before cited.
Mr. Gallon in "Macmillan's Magazine." Aug., 1865, p. 318; also lii3
great work, "Hereditary Genius," 1870.

15J THE DESCENT OF MAIT,

mals will doubt that this must be highly injurious to the
race of man. It is orprising hoAv soon a want of care, or
care wrongly directed, leads to the degeneration of a domes-
tic 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 instinctSp
but subsequently rendered, in the manner joreviously indi-
cated, more tender and more widely diffused. Nor could
we check our sympathy, even at the urging of hard reason,
without deterioration in the noblest part of our nature.
The surgeon may harden himself while performing an oper-
ation, 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
an overwhelming present evil. We must therefore bear the
undoubtedly bad effects of the weak surviving and propa-
gating their kind; but there appears to be at least one check
in steady action, namely, that the weaker and inferior
members of society do not marry so freely as the sound; and
this check might be indefinitely increased by the weak in
body or mind refraining from marriage, though this is more
to be hoped for than expected.

In every country in which a large standing army is kept
up, the finest young men are taken by the conscription or
are enlisted. They are thus exposed to early death during
war, are often tempted into vice, and are prevented from
marrying during the prime of life. On the other hand, the
shorter and feebler men, with poor constitutions, are left at
home, and consequently have a much better chance of
marrying and propagating their kind.*

Man accumulates property and bequeaths it to his chil-
dren, so that the children of the rich have an advantage
over the poor in the race for success, independently of
bodily or mental superiority. On the other hand, the
children of parents who are short-lived, and are therefore
on an average deficient in health and vigor, come into their
property sooner than other children, and will be likely

*Prof. H. Pick ('* Einfluss der Natarwissenschaft auf das Reclit,"
June, 1872) has some good remarks on this head, and on other such
points.

CIVILIZED NATIONS, 153

to marry earlier, and leave a larger number of offspring to
inherit their inferior constitutions. But the inheritance of
property by itself is very far from an evil; for without the
accumulation of capital the arts could not progress; and it
is chiefly through their power that the civilized 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 moderately 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
liave not to labor for their daily bread, is important to a
degree which cannot be overestimated; as all high intel-
lectual work is carried on by them, and on such work,
material progress of all kinds mainly depends, not to men-
tion 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 elimina-
tion here occurs, for we daily see rich men, who happen to
be fools or profligates, squandering away 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 none. Most eldest sons, though they may be weak in
body or mind, marry, while 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
civilized 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 conse-
quences, such as they may be, of the continued preserva-
tion 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. Gal ton * has shown,
apt to be sterile; and thus noble families are continually

* " Ilei-editar^ Uenius/' 1870, pp. 13S-U0.

154 THE DESCENT OF MAN,

cut off in the direct line, and their wealth flows into soms
side channel ; but unfortunately this channel is not
determined by superiority of any kind.

Although civilization thus checks in many ways the action
of natural selection, it apparently favors the better develop-
mejit of the body, by means of good food and the freedom
from occasional hardships. This may be inferred from
civilized men having been found, wherever compared, to he
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 cf our aristocracy, at all ages and of both sexes, is vepy
little iaferior to that of healthy English lives in the lower
classes. \

We will now look to the intellectual faculties. If in
each grade of society the members were divided into two
equal bodies, the one including the intellectually superioi-
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 labor,
a very small one. Hence in civilized nations there will bo
some tendency to an increase both in the number and in
the standard of the intellectually able. But I do not wisli
to assert that this tendency may not be more than counter-
balanced in othei' ways, as by the multiplication of the reck-
less and improvident; but even to such as these, ability
mnet 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. Gal ton
says:I *' I regret I am unable to solve the simple question
whether, and how far. m.en and women who are prodigie?
of genius are infertile. I have, however, shown that meu
of eminence are by no means so.'' Great lawgivers, tht

* Qiiat.-efnges, '* Revue des Cours Scieutifiques," lbC7-68, p. 659.

•(■See the fifth and sixth columns, compiled from good authorities,
in the table given in Mr. E. K. Laukester's "Comparative Longev
it;," 1870. p. 115.

X " Hereditary aenius," 1870, p. 330.

CIVILIZED NATIONS, 155

founders of beneficent religions, great philosophers and dis-
coverers in science, aid the progress of raantind 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.* So it will bo
with the intellectual faculties, since the somewhat abler
men in each grade of society succeed rather better than the
less able, and consequently increase in number, if not other-
wise prevented. When in any nation the standard of intel-
lect and the number of intellectual men have increased, we
may expect from the law of the deviation from an average,
that prodigies of genius will, as shown by Mr. Galton,
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
civilized 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. The restless who will not follow
any steady occupation — and this relic of barbarism is a
great check to civilizationf — 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 of thirty for instance, is only 13.8
years; while for the rural laborers of England at the same
age it is 40.59 years. J 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 toward success. This especially holds good with
injurious characters which tend to reappear through rever-
sion, such as blackness in sheep; and with mankind some

* " Origin of Species" (fifth edition, 1869), p. 104.

I '' Hereditary Genius," 1870, p. 347.

X E. Ray Lankester, " Comparative Longevity," 1870, p. 115. The
table of the intemperate is from Neison's " Vital Statistics." In
regard to protiigacy, see Dr. Farr, " Influence of Marriage on Mor-
tality," "Nat. Assoc, for the Promotion of Social Science," 1858.

156 THE DESCENT OF MAN.

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 recognized in the common expression that such men
are the black sheep of the family.

With civilized nations, as far as an advanced standard of
morality, and an increased number of fairly good men are
concerned, natural selection apparently effects but little;
though the fundamental social instincts were originally
thus gained. But I have already said enough, while treat-
ing 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 — exam-
ple and imitation — reason — experience, and even self-inter-
est— instruction during youth, and religious feelings.

A most important obstacle in civilized countries to an
increase in the number of men of a superior class has been
strongly insisted on by Mr. Greg and Mr. Gal ton,* namely,
the fact that the very poor and reckless, who are often
degraded by vice, almost invariably marry early, while 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 shown by Dr. Dun-
can,! ^^^y 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 so-
ciety, 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,

*" Eraser's Magazine," Sept., 1868, p. 353. " Macmillan's Maga-
zine/* Aug., 1865, p. 318. The Rev. F. W. Farrar (" Fraser's Mag.,"
Aug., 1870, p. 264) takes a different view.

f " On the Laws of the Fertility of Women," in " Transact. Royal
Soc," Edinburgh, vol. xxiv. p. 287; now published separately under
the title of " Fecundity, Fertility and Sterility," 1871. See, also,
Mr. Qalton, "Hereditary Geuius," pp. 353-357, for observations to
the above effect.

CIVILIZED NATIONS. 167

self-respecting, ambitious Scot, stern in his morality,
spiritual in his faith, sagacious and disciplined in his intel-
ligence, 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 popu-
lation 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 ex-
istence ' it would be the inferior and less favored 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 ten-
dency. 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* that at all ages the death rate is higher
m towns than in rural disticts, '^ 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 twice 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,"t 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

* " Tenth Annual Report of Birtlis, Deaths," etc., in Scotland,
1867, jk. 29.

f These quotations are taken from our highest authority on such
questions, namely, Dr. Farr. in his paper " On the Influence of Mar-
riage on the Mortality of the French People," read before the Nat.
Assoc, for the Promotion of Social Science, 1858

158 TUB DESCENT OF MAN,

much larger proportion than the married ; for instance, out
of every 1,000 unmarried men, between the ages of twenty
and thirty, 11.3 annually died, while of the married only
6.5 died.* 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 1,000 unmarried men between the ages of
'twenty and thirty, 14.97 annually died, while of the mar-
ried only 7.24 died, that is less than half.f Dr. Stark
remarks on this: "Bachelorhood is more destructive
to life than the most unwholesom^e trades, or than
residence in an unwholesome house or district where there
has never been the most distant attempt at sanitary improve-
ment.'' 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 constitu-
tion, 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 sur-
vived to old age, though remaining weak, and therefore
always with a lessened chance of life or of marrying. There
is another remarkable circumstance which seems to sup-
port 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

*Dr. Farr, ibid. Tlie quotations given below are extracted from
tlie same striking paper.

f I have taken the mean of the quinquennial means, given in " The
Tenth Annual Report of Births, Deaths, etc.. in Scotland, " 1867-
The quotation from Dr. Stark is copied from an article in the " Daily
News," Oct. 17, 1868, which Dr. Farr cjnsiders very carefully
written.

CIVILIZED NATION'S. 159

tinmanied men, which seems to be a general law, *'ia
mainly due to the constant elimination of imperfect types,
and to the skillful 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 speciried 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 bettei
class of men> the nation will retrograde, as has too often
occurred in the history of the world. We must remember
that progress is no invariable rule. It is very difficult to
say why one civilized nation rises, becomes more powerful,
and spreads more widely, than another; or why the same
nation progresses more quickly 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
appears to have little influence, except so far as vigor of
body loads to vigor of mind.

It has been urged by several writers that as high intellec-
tual powers are advantageous to a nation, the old Greeks,
who stood some grades higher in intellect than any race that
has ever existed, + ought, if the power of natural feelection
were real, to have risen 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
toward continued development in mind and body. But
development of all kinds depends on many concurrent
favorable circumstances. Natural selection acts only tenta-
tively. Individuals and races may have acquired certain
indisputable advantages, and yet have perished from failing

*Dr. Duncan remarks ("Fecundity, Fertility," etc., 1871, p. 334)
on this subject: "At every age the healthy and beautiful go over
from the unmarried side to the married, leaving the unmarried
columns crowded with the sickly and aufoi-tunate."

f See the ingenious and original argument on this subject by Mr.
Gallon, " Hereditary Genius," pp. 340-343.

160 THE DESCENT OF MAN.

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 frorti extreme sensuality; for they did
not succumb until '^ they were enervated and corrupt to
the very core/' * The western nations of Europe, who now
so immeasurably surpass their former savage progenitors
and stand at the summit of civilization, owe little or none
of their superiority to direct inheritance from the old
Greeks, though they owe much to the written works of that
wonderful people.

Who can positively say why the Spanish nation, so domi-
nant 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 that early period, as
Mr. Galton 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 a Church which
demanded celibacy; f 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 is incalculable,
though- no doubt counterbalanced to a certain, perhaps to
a large, extent in other ways; nevertheless, Europe has
progressed at an unparalleled rate.

The remarkable success of the English as colonists, com-
pared to other European nations, has been ascribed to
their ^''daring and persistent energy;^' a result which is
well illustrated by comparing the progress of the Canadians
of English and French extraction; but who can say how
the English gained their energy ? There is apparently

*Mr. Greg, "Eraser's Magazine," Sept., 1868, p. 357.

f "Hereditary Genius," 1870, pp. 357-359. The Rev. F. W.
Farrar (" Eraser's Mag.," Aug. 1870, p. 257) advances arguments on
the other side. Sir C. Lyell had already (" Principles of Geology,"
vol. ii, 1868, p. 489) in a striking passage called attention to the evil
influence of the Holy Inquisition in having, through selection,
lowered the general standard of intelligence in Europe,

CIVILIZED NATIONS. 161

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; for the more
energetic, restless, and courageous men from all parts of
Europe have emigrated during the last ten or twelve
generations to that great country, and have there succeeded
best.* Looking to the distant future, I do not think that
the Rev. Mr. Zincke takes an exaggerated view when he
says : t "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 pur-
pose 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 civilization, 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
favored nations.

Natural selection follows from the struggle for existence;
and this from a rapid rate of increase. It is impossible not
to regret bitterly, 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
civilized nations to abject poverty, celibacy, and to the late
marriages of the prudent. But as man suffers from the
same physical evils as the lower animals, he has no right to
expect an immunity from the evils consequent on the strug-
gle for existence. Had he not been subjected during
primeval times to natural selection, assuredly he would
never have attained to his present rank. Since we see in
many parts of the world enormous areas of the most fertile
land capable of supporting numerous happy homes, but
peopled only by a few wandering savages, it might be
argued that the struggle for existence had not been suf-
ficiently severe to force man upward to his highest standard.
Judging from all that we know of man and the lower ani-
mals, there has always been sufficient variability in their
intellectual and moral faculties, for a steady advance

*Mr. Galton, '♦ Macmillan's Magazine," Aug., 1865, p. 325. See
also "Nature," "On Darwinism and National Life," Dec, 1869, p.
184.

f "Last Winter in the United States," 1868, p, 89,

162 THE DESCENT OF MAN.

through natural selection. Ko doubt such advance
demands many favorable concurrent circumstances; but it
may well be doubted whether the most favorable v/ould have
sufficed, had not the rate of increase been rapid, and the
consequent struggle for existence extremely severe. It even
appears from what we see, for instance, in parts of South
America, that a people which may be called civilized, such
as the Spanish settlers, is liable to become indolent and to
retrograde, when the conditions of life are very easy. AVith
highly civilized nations continued progress depends in a
subordinate degree on natural selection; for such nations
do not supplant and exterminate one another as do savage
tribes. Nevertheless the more intelligent members within
the same community will succeed better in the long run
than the inferior, and leave a more numerous progeny, and
this is a form of natural selection. The more efficient
causes of progress seem to consist of a good education
during youth while the brain is impressible, and of a high
standard of excellence, inculcated by the ablest and best
men, embodied in the laws, customs and traditions of the
nation, and enforced by public opinion. It should, however,
bo borne in mind that the enforcement of public opinion de-
pends on our appreciation of the approbation and disapproba-
tion of others; and this appreciation is founded on our sympa-
thy, which it can hardly be doubted was originally developed
through natural selection as one of the most important
elements of the social instincts.*

On the Evidence That All Civilized Nations Were Once
Barbarous. — The present subject has been treated in so full
and admirable a manner by Sir J. Lubbock, f 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 Argyll J and formerly by Arch-
bishop Whately, in favor of the belief that man came into
the woi'ld as a civilized being, and that all savages have
since undergone degradation, seem to me weak in compari-

^ I am much indebted to Mr Jobn Morley for some good criticisms
on this subject see, also, Broca, "Les Selections," ''Revue d'Au-
thropf)h)gie," 1872.

f -On the Origin of Civilization," "Proc. Ethnological Soc,"
Nov 2G. 18G7

% '• Primeval Man,"

CIVILIZED NA TIONS. 1 63

son with those advanced on the other side. Many nations,
no doubt, liave fallen av/ay in civilization, and some may
have lapsed into utter barbarism, though on this latter head
1 have met with no evidence. The ]?uegians were probably
compelled by other conquering hordes to settle in their
inhospitable country, and they may have become in conse-
quence 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 civilized nations are the descend
ants of barbarians, consists, on the one side, of clear traces
of their former low condition in still-existing customs,
beliefs, language, etc.; and on the other side, of proofs
that savages are independently able to raise themselves a
few steps in the scale of civilization^ 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 of
the art of enumeration, which, as Mr, Tylor clearly shows
by reference to the words still used in some places, origi-
nated 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,
where, after the V, which is supposed to be an abbreviated
picture of a human hand, we pass on to VI, etc., when
the other hand no doubt was used. So again, '* when we
speak of three-score and ten, we are counting by the vigesi-
riial system, each score thus ideally made standing for 20 —
for 'one man 'as a Mexican or Carib would put it."*
According to a large and increasing school of philologists,
every language bears the marks of its slow and gradual evo-
lution. So it is with the art of writing, for letters are
rudiments of pictorial representations. It is hardly possi-
ble to read Mr. M'Lennan's work \ and not admit that
almost all civilized nations still retain traces of such rude
habits as the forcible capture of wives. What ancient

*" Royal Institution of Great Britain." March 15, 1867, Also
'' llesearclies Into the Early History of Mankind," 1865.

f " Primitive Marriage," 1885. See, likewise, an excellent article,
evidently by the same author, in the " North British Review," July,
1869. Also, Mr. L. H. Morgan, 'A Conjectural Solution of the
Origin of the Class System of Relationship," in '' Proc. American
Acad, of Sciences," vol vii, I-eb., 1868. Prof. Schaafthausen
(" Anthropolog. Review," Oct.. 1869, ]>. 373)remarkson "the vestiges
of liuman gacri^ces t'ouad botk iu Homer and the Old Testameat"

164 TEE DESCENT OF MAN.

nation, as the same author asks, can be named that was
originally monogamous? The primitive idea of justice, as
shown by the law of battle and other customs of which ves-
tiges 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 shown 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 in
use among savages in various parts of the world it cannot
be doubted that these have nearly all been independent dis-
coveries, excepting perhaps the art of making fire.* The
Australian boomerang is a good instance of one such inde-
pendent 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 abroad ;t many native
plants were there cultivated and a few native animals
domesticated. We should bear in mind that, judging from
the small influence of most missionaries, a wandering crew
from some semi-civilized land, if washed to the shores of
America, would not have produced any marked effect on
the natives unless they had already become somewhat ad-
vanced. 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 tnat 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

*Sir J. Lubbock, " Prebistoric Times," 2d edit., 1869, chap, xv
and xvi, et passim. See also tbe excellent nintb chapter in Tylor's
"Early History of Mankind," 2d edit., 1870.

f Dr. F. Miiller has made some good remarks to this effect in tb<>
" Reise der Novara: Antbropolog. Tbeil," Abtheil. iii, 1868, s 137.

CIVILIZED NATIONS, 165

countries, which include nearly the whole civilized world,
were once in a barbarous condition. To believe that man
was aboriginally civilized and then suffered utter de^ada-
tion 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 retro-
gression; that man has risen, though by slow and inter-
rupted steps, from a lowly condition to the highest standard
as yet attained by him in knowledge, morals and religion.

100 THE DESCENT OF MAN.

CriAPTER VL

ON" THE AFFIXITIES ANL' GEXEALOGY OF MAN".

Position of man in ilie anima! series— Tlie natural system genea-
logical — 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 CDunecting links— Lower stages in the geneal-
ogy of man. as inferred, firstly from his affinities and secondly
from his structure — Early audrogyuou.'s condition of liie verte-
brata — ( onclusiou.

Even" if it be ffranteJ that the difference between man
and his nearest allies is as great iu 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 earlier chapters appear to declare,
m 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 varia-
tions, which are induced by the same general causes, are
governed and transmitted in accordance with the same gen-
eral laws as in the lower animals. Man has multiplied so
rapidly that he has necessarily been exposed to struggle for
existence, and consequently to natural selection. He has
given rise to many races, some of which differ so much from
each other, 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. 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 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

AFFINITIES AND GENEALOGY. 167

least to fi large extent, if man is the co-descendant with
other mammals of son\e unknown and lower form.

8ome naturalists, from being deeply impressed with the
mental and spiritual ])owers 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.*
Spiritual powers cannot be compared or classed by the nat-
uralist; but he may endeavor to show, as I have done, that
the mental faculties of man and the lower animals do not
ditfer in kind, although immensely in degree. A difference
in degree, however great, does n.ot 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 be-
long to the same class. The difference is here greater than,
though of a somewhat different kind from, that between
man and the highest mammal. The female coccus, while
young, attaches itself by its proboscis to a plant; sucks the
sap, but never moves again; is fertilized and lays eggs; and
this is its whole history. On the other hand, to describe
the habits and mental powers of worker -ants, would
require, as Pierre Euber has shown, a large volume; I may,
however, briefly specify a few points. Ants certainly com-
municate information to each other, and several unite for
the same work, or for games of play. They recognize their
fellow-ants after months of absence, and feel sympathy for
each other. They build great edifices, keep them clean,
close the doors in the evening, and post sentries. They
make roads as well as tunnels under rivers, and temporary
bridges over them, by clinging together. They collect food
for the community, and when an object, too large for
entrance, is brought to the nest, they enlarge the door, and
afterward build it up again. They store up seeds, of which
they prevent the germination, and which, if damp, are
brought up to the surface to dry. They keep aphides and
other insects as milch-cows. They go out to tattle in regu-
lar bands, and freely sacrifice their lives for the common
weal. They emigrate according to a preconcerted plan.
They capture slaves. They move the eggs of their aphides,
as well as their own eggs and cocoons, into warm parts of

* Isidore GeofTroy Si. Hilaire gives a detailed account of the posi-
tion asFigned to man by vanons naturalists in their classifications;
••aist. :sal. Gen.," torn, ii, 1859, pu. 170-189.

16S THS: DESCENT OF MAN.

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 these
insects in distinct classes, much less in distinct kingdoms.
No doubt the difference is bridged over by other insects;
and this is not the case with man and the higher apes. But
we have every reason to believe that the breaks in the series
are simply the results of many forms having become
extinct.

Prof. Owen, relying chiefly on the structure of the braiuj
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 devel-
opment 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 arti-
ficial, f Classifications ma}'', of course, be based on any
character whatever, as on size, color, or the element inhab-
ited; 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 arrange-
ment— that is, the co-descendants of the same form must be
kept together in one group, apart 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

* Some of the most interesting facts ever published on the habits
of ants are given by Mr. Belt, in his " Naturalist in Nicaragua,"
1874. See also Mr. Moggridge's admirable work, "Harvesting
Ants," etc., 1873, also " L'Instinct chez les Insectes,"by M. George
Pouchet, " Revue des Deux Mondes," Feb. 1870, p. 682.

f WestwQod, ** Modern Class of Insects," vol. ii. 1840, p. 87,

AFFINITIES AND GENEALOQt, 169

wliicli each has undergone — is expressed by such terms as
genera, families, orders and classes. As we have no record
of the lines of descent, the pedigree 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 multi-
tude of words and points of construction, they would be
universally recognized 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 adapta-
tions 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 several unimportant structures, in use-
less and rudimentary organs, or not now functionally active,
or in an embryological condition, are by far the most serv-
iceable 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 sanie part in other allied forms has 'already,
according to the theory of evolution, varied much; conse-
quently it would (as long as the organism remained exposed
to the same exciting conditions) be liable to further varia-
tions of the same kind; and these, if beneficial, would be
preserved, and thus be 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
aid the species in gaining its food, or for any other object;
but with man we can see no definite limit to the continued
development of the brain and mental faculties, as far as
advantage is concerned. Therefore in determining the
position of man in the natural or genealogical system the
extreme development of his brain ought not to out-
weigh a multitude of resemblances in other less important
or quite unimportant points.

The gre?.ter number of naturalists who have taken into

1 70 THE DESCENT OF MA K,

consideration the whole structure of man, incliKlins- his
mental faculties, have followed Blumenbach and i'avier,
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, etc. Recently many of our
best naturalists have recurred to the view tirst propounded
by Linnaeus, 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: for in the first i)lace, we must bear in mind
the comparative insignificance for classification of the great
development of the brain in man, and that the strongly-
marked differences between the skulls of man and the
Quadrumana (lately insisted upon by Bischolf, 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 sti'Licture of their limbs, far more than does man from
the higher apes; yet in most systems, from that of Cuvier
to the most recent one by Mr. Flower,* 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 struct-
ure in which man agrees with the other Primates. Our
great anatomist and philosopher, Prof. Huxley, has fully
discussed this subject,! and concludes that man in all parts
of his organization differs less from the higher apes than
these do from the lower members of the same group. Con-
sequently there "is no justification for placing man in a
distinct order.''

In an early part of this work I brought forward various
facts, showing how closely man agrees in constitution with

* " Proc. Zoolog. Soc." 1863, p. 4.

f •* Evidence as to Man's Place in Nature," 1S63, p. 70, et passim.

AFFINITIES AND GENEALOGY, 171

tlie higher mammals: and this agreement must depend on
our close similarity in minute structure and chemical com-
position. I gave, as instances, our liability to the same dis-
eases and to the attacks of allied parasites; our tastes in
common for the same stimulants, and the similar effects
produced by them, as well as by various drugs, and other
6uch facts.

As small, unimportant points of resemblance between
man and the Qaadrumana 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 our features is manifestly t.he same;
and the various emotions are displayed by nearly similar
movements of the muscles and skin, chiefly above the 03-0-
brows 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 back-
ward and the lower eye-lids wrinkled. The external ears
are curiously alike. In man the nose is much more prom-
inent than in most monkeys; but we may trace the com-
mencement of an aquiline curvature in the nose of the
Hoolock Gibbon; and this in the Senincqjitlieciis lutsica is
carried to a ridiculous extreme.

The faces of many monkeys are ornamented with beards,
whiskers, or mustaches. The hair on the head grows to
a great length in some species of Semnopithecus ; * and
in the Bonnet monkey (Macaciis radiahis) it radiates from
a point on the crown, with a parting down the middle. 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 downward abruptly, and
is succeeded by hair so short and fine that at a little dis-
tance 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 Eschrichtf states that in our chil-
dren the limit between the hairy scalp and the naked fore-
head is sometimes not well defined; so that here we seem

*Jsid. GeofTroy, " Hist. Nat. Gen.,*' toin. ii. 1859. p. 217.
f*'Uel)er die Hiclitimg der Haaie/' etc, Mailer's *'Arcliiv. fClr
Auat. und Pbys.," 1827. s. 51.

1-^2 THE DESCENT OP MAN,

to lijive 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 con-
verge 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 gorrilla, chimpanzee, orang,
some species of Hylobates, and even to some few American
monkeys. But in Hylolates agilis the hair on the forearm
is directed downwardT or toward 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 on the back
and its direction 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, who has
carefully studed the habits of the orang, remarks that the
convergence of the hair toward the elbow on the arm,s of
the orang may be explained as serving to throw off the
rain, for this animal during rainy weather sits with its
arms bent and with the hands clasped round a branch or
over its head. According to Livingstone, the gorilla also
"sits in pelting rain with his hands over his head. ■*'* If
the above explanation is correct, as seems probable, the
direction of the hair on our own 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 foetus (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 pointa
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. \

* Quoted by Reade, " The African Sketch Book," vol. i, 1873, p.
152.
I On the hair in Hylobates, see " Nat. Hist, of Mammals," by C. Ia

AFFINITIES AND GENEALOGY. 173

It must not be supposed that the resemblances between
man and certain apes in the above and in many other
points — such as in having a naked forehead, long tresses on
the head, etc. — ^are all necessarily the result oi unbroken
inheritance from a common progenitor, or of subsequent
reversion. Many of these resemblances are more probably
due to analogous variation, which follows, as I have else-
where attempted to show,* from co-descended organisms
having a similar constitution, and having been acted on by
like causes inducing similar modifications. With respect
to the similar direction of the hair on the forearms of man
and certain monkeys, as this character is common to almost
all the anthropomorphous apes, it may probably be attribu-
ted to inheritance; but this is not certain, as some very
distinct American monkeys are thus characterized.

Although, as we have now seen, man has no just right to
form a separate Order for his own reception, he may per-
haps claim a distinct sub-order or family. Prof. Huxley,
in his last work,t divides the Primates into three sub-
orders; namely, the Anthropidse with man alone, the Simi-
adas, including monkeys of all kinds, and the Lemuridas
with the diversified genera of lemurs. As far as differ-
ences 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, from 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 stock, it is quite conceivable that two of
them might after the lapse of ages be so slightly changed
as still to remain a species of the same genus, while 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

Martin, 1841, p. 415. Also, Isid. GeofEroy on tlie American monkeys
and other kinds, "Hist. Nat. Gen.," vol. ii, 1859, pp. 216, 243,
Bscliriclit, ibid, ss. 46, 55, 61. Owen, **Anat. of Vertebrates." vol.
iii, p. 619. Wallace, ** Contributions to the Theory of Natural Selec-
tion," 1870, p. 344.

*" Origin of Species," 5th edit., 1869, p. 194. "The Variation of
Animals and Plants under Domestication," vol. ii, 1868, p. 348
f " An Introduction to the Classification of Animals," 1869, p. 99.

174 THE DESCENT OF MAN,

would still retain through inheritance numerous small
points of resemblence with the other two. 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
!esemblance in numerous unimportant points, as indicating
the lines of descent or genealogy. To attach much weight
to the few but strong differences is the most obvious and
pel haps the safest course, though it appears more correct
to pay great attention to the many small resemblances, as
giving a truly natural classification.

In forming a judgment on this head with reference to
man, we must glance at the classification of the vSimiadse.
This family is divided by almost all naturalists into the
Catarrhine group, or Old World monkeys, all of which are
characterized (as their name expresses) by the peculiar
structure of their nostrils, and by having four premolars in
each jaw; and into the Platyrrhine group or Xcw World
monkeys (including two very distinct sub-groups), all of
which are characterized by differently constructed nostrils
and by having six premolars in each jaw. vSome other
small differences might be mentioned. Now man un-
questionably belongs in his dentition, in the structure
of his nostrils, and some other resi)ects, to the Catarrhine or
Old World division; nor does he resemble the Platyrrhines
more closely than the Catarrhinesin any characters, except-
ing in a few of not much importance and apparently of an
adaptive nature. It is therefore against all probability that
some New World species should have formerly varied and
produced a man-like creature, with all the distinctive char-
acters proper to the Old World division; losing at the same
time all its own distinctive characters. There can, conse-
quently, hardly be a doubt that man is an off-shoot from
the Old World .Simian stem; and that under a genealogical
point of view he must be classed with the Catarrhine
ilivision.*

*TIii.s is nearly the same classification as that provisionally
adopted by Mr St. <ieorge Mivart ("'J'ransacl. Plulosopli Soc,"
1867. p. ;300). who. alter sei)arating ibe Lemnridae, divides the
remainder of tlie Primates into the Hotninidae. the Siiniadae which
answer to the <.'atarrhines. the Cebidae, and the Hapaiid*e — these two
latter <;roiips answering to the Platyrrhines. Mr. Mivart still abides
by the same view; see ••^Jature," 1871, p. 481.

AFFINITIES AND OENEALOGY, 175

The anthropomorphous apea. namely, the gorilla, chim-
panzeo, oraiig, ami iiylobates, aiv by modt naturalists sepa-
rated from the other Old Wurul monkeys, as a distinct
sub-gronp. I am aware thai (iratiolet, relying on the
etrnetnre of the brain, does not admit tlie existence of this
snb-grou}), and no doubt it is a broken one. Thus the
orang, as Mr. St. (r. Mivart remarks,* •* is one of the most
peculiar and aberrant forms to be found in the order." The
remaining non-anthropomorphous Old \yorld monkej's are
again divided by some naturalists into two or three smaller
sub-groups; the genus Semnopitheous, 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 8emnopithecus 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 vvhich he possesses in common with
the whole Catarrhine group, but in other peculiar characters,
such as the absence of a tail and of callosities, and in gen-
eral appearance, we may infer that some ancient member of
the anthropomorphous sub-group gave birth to man. It is
not probable that, through the law of analogous variation,
a member of one of the other lower sub-groups should 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 -conse-
quence of the great development of his brain and his erect
position; nevertheless, we should bear in mind that he "is
but one of several exceptional forms of Primates." \

Every naturalist who believes in the principle of evolu-
tion will grant that the two main divisions of the Simiada?,
namely, the Catarrhine and Platyrrhine monkeys, with their
sub-groups, have all proceeded from some one extremely
ancient progenitor. The early descendants of this progen-
itor, before they had diverged to any considerable extent
from each other, would still have formed a single natural

**• Transact. Zoolog. Soc," vol. vi. 1867. p. 214.

f Mr. St. U. Mivart, "Transact. Pliil. Soc," 1867, p. 410.

176 TEE DESCENT OF MAN.

froup; but Bome of the species or incipient genera would
ave already be^un to indicate by their diverging characters
the future distinctive marks of the Catarrhine and
Platyrrhine 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 Catarrhine monkeys in one way and the Platyrrhines
in another way, but would have resembled in this respect
the allied Lemuridse, which differ greatly from each other
in the form of their muzzles,* and to an extraordinary
degree in their dentition.

The Catarrhine and Platprhine monkeys agree in a. multi-
tude of characters, as is shown by their unquestionably
belonging to one and the same order. The many charac-
ters 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 a naturalist
would undoubtedly have ranked as an ape or a monkey, an
ancient form which possessed many characters common to
the Catarrhine and Platyrrhine monkeys, other characters in
an intermediate condition, and some few, perhaps, distinct
from those now found in either gToup. And as man from
a genealogical point of view belongs to the Catarrhine or Old
World stock, we must conclude, however much the conclu-
sion may revolt our pride, that our early progenitors would
have been properly thus designated, f 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 inquire, where was the birthplace of man
at that stage of descent when our progenitors diverged from
the Catarrhine stock? The fact that they belonged to this
stock clearly shows that they inhabitated the Old World ;
but not Australia nor any oceanic island, as we may infer

* Messrs. Murie and Mivart on the Lemuroidea, ** Transact, Zoolog.
Soc," vol. vii. 1869, p. 5.

fHSckel has come to this same conclusion. See '*tJeber die
Entstehung des Menschengeschlechts," in Virchow's "Sammlung.
gemein. wissen. Vortrage, " 1868, s. 61. Also his "NatQ.rliche Schop-
fiingsgeschichte." 1868, in which he gives in detail his views on th^
genealogy of man.

AFFINITIES AND GENEALOGY. 177

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 th^ 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 two or three anthropomor-
phous apes, one the Dryopithecus * of Lartet, nearly as
large as a man, and closely allied to Hylobates, existed in
Europe during the Miocene age; and since so remote a
period the earth has certainly undergone many great revo-
lutions, and there has been ample time for migration on the
largest scale.

At the period and place, whenever and wherever it was,
when man first lost his hairy covering, he probably
inhabited a hot country; a circumstance favorable for
the 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 Catarrhine stock;
but it may have occurred at an epoch as remote as the
Eocene period; for that the higher apes had diverged from
the lower apes as early as the Upper Miocene period is
shown 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 be modified under favorable cir-
cumstances; 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
some of the co-descendants of the same species may be not
at all, some a little, and some greatly changed, all within
the same period. 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 ex-
tinct 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

*Dr. C. Forsytli Major, "Sur les Singes Fossiles trouves en
Italie: " Soc. Ital. des Sc. Nat.," torn, xv, 1873.

1 78 THE DESCENT OF MAN.

weight to those who, from general reasons, believe m the
general principle of evolution. Breaks often occur in all
parts of the series, some being wide, sharp and defined,
others less so in various degrees; as between tlfe orang and.
its nearest allies — between the Tarsius and the other
Lenmridae — between the elephant, and in a more striking
manner between the Ornithorhynchus or PJchidna, and all
other mammals. But these breaks depend merely on the
number of related forms which have become extinct. At
some future period, not very distant as measured by cent-
uries, the civilized races of man will almost certainly ex-
terminate and replace the savage races throughout the
world. At the same time the anthropomorphous apes, as
Prof. Schaaffhausen has remarked,* will no doubt be ex-
terminated. The break between man and his nearest allies
will then be wider, for it will intervene between man in a
more civilized state, as we may hope, even than the Cauca-
sian, and some ape as low as a baboon, instead of as now
between the negro or Australian and the gorilla.

AVith 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 reads Sir C Lyell's discus-
eion.f where he shows that in all the vertebrate classes the
d:?/.*overy of fossil remains has been a very slow and fortuit-
ous process. Nor should it be forgotten that those regions
which are the most likely toafTorrl remains connecting man
with -some extinct aj)e-like creature have not as yet been
searched by geologists.

Lower Stages in the nei^enlocjij nf Man. — W"e have seen
tliat jnan appears to have diverged from the Catarrhine or
Old World division of theSimiadae after these had diverged
from the New World division. We will now endeavor to
follow the remote traces of his genealogy, trusting princi-
pally to the mutual affinities between the various classes
ami orders, with some slight reference to the periods, as
far as ascertained, of their successive appearance on the
earth. 'I'he I-.emuiidi¥ stand below and near to theSimiadae,

id con.sti'ute a eery distinct family of the Primates, or,
cor l!ng to HacKel and others, a «Hstinct onler. This

*" Anthropoltjgica! l{Hvi**\v." April. 18G7. p. v;H(j.
•f " Klemt-nts of ii<?o]ojy," 1S65, pp. 583-565. "Anliquiiy of
Man," 1863, p. 145.

AFFINITIES AND OENEALOO 7. Vt%

gror.p is rlivcrsificd and broken to an extraordinary degree,
and includes many aberrant forms. It has, therefore, proba-
bly suffered much extinction. Most of the remnants sur-
vive on ishinds, such as Madagascar and the Malayan Archi-
pelago, where they have not been exposed to so severe a
competition as they would have been on well-stocked con-
tinents. This group likewise presents many gradations,
leading, as Huxley remarks,* *' 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 the least intelligent of the placental mam-
malia.'"' From these various considerations it is probable
that the Simiadae were originally developed from the pro-
genitors of the existing Lemurida^; 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
mucli more extensive than at present. Hence the Placen-
tata are generally supposed to have been derived from the
Implacentata or Marsupials ; not, however, from forms
closely resembling the existing Marsupials, but from their
early progenitors. The Monotremata are plainly allied to
the Mf^rsupials, 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, representatives of which have been pre-
served in Australia, through some favorable concurrence of
circumstances. The Monotremata are eminently interesting,
as leading in several important points of structure toward
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; but as a most
capable Judge, Mr. Parker, has remarked, we have good
reason to believe, that no true bird or reptile interienes in
the direct line of descent. He who wishes to see what
ingenuity and knowledge can effect, may consult Prof*
Hiickers works. f I vvill content myself with a few general

*" Man's Place in Nature,'* p. 105.

f Elaborate tables are ^\\e\\ in bis Genere'.le Morpliologie " (B,
ii, s. 153 and s. 425;; and with mure especial re.ereuce to man in Lis

180 THE DESCENT OF MAN,

remarks. Every eYolntionist will adi;nit that the five grea^
vertebrate classes, namely, mammals, birds, reptiles, amphib-
ians and fishes, are descended from some one prototype; for
they have much in common, especially during their embry-
onic state. As the class of fishes is the most lowly organ-
ized, and appeared before the others, we may conclude that
all the members of the vertebrate kingdom are derived
from some fish-like animal. The belief that animals so
distinct as a monkey, an elephant, a humming-bird, a
snake, a frog, and a fish, etc., 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 binding
closely 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 several of
the great vertebrate classes more or less closely. We have
seen that the Ornithorhynchus graduates toward reptiles;
and Prof. Huxley has discovered, and is confirmed by Mr.
Cope and others, that the Dinosaurians are in many impor-
tant characters intermediate between certain reptiles and
certain birds — the birds referred to being the ostrich tribe
(itself evidently a widely-diffused remnant of a larger
group) and the Archeopteryx, that strange Secondary bird,
with a long lizard-like tail. Again, according to Prof.
Owen,* the Ichthyosaurians — great sea-lizards furnished
with paddles — present many affinities with fishes, or rather
according to Huxley, with amphibians ; a class which,
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 generalized type, that is, they presented
diversified affinities with other groups of organisms. The
Lepidosi:en is also so closely allied to amphibians and
fishes, that naturalists long disputed in which of these two
classes to rank it; it, and also some few Ganoid fishes, have

** Naturliche SchSpfungsgeschi elite," 1868. Prof. Huxley, in review-
ing this latter work (" The Academy," 1869, p. 42) says, that he con-
siders the phylum or lines of descent of the vertebrata to be admir-
ably discussed by Hackel, although he differs on some points. He
expresses, also, his high estimate of the general tenor and spirit of
the whole work.
* " Palaeontology," 1860, p. 199.

AFFINITIES AND GENEALOGY. 181

been preserved from utter extinction by inhabiting rivers,
which are harbors of refuge, and are related to the great
waters of the ocean in the same way that islands are to
continents.

Lastly, one single member of the immense and diversi-
fied class of fishes, namely, the lancelet or amphioxus, is so
different from all other fishes, that Hackel 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,
etc. ; so that it was classed by the older naturalists among
the worms. Many years ago Prof. Groodsir 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
Mulluscoida of Huxley — a lower division of the great king-
dom of the Mollusca; but . they have recently been placed
by some naturalists among the Vermes or worms. Their
larvae somewhat resemble tadpoles in shape,* and have the
power of swimming freely about. M. Kovalevsky f has
lately observed that the larvae 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 ani-
mals ; and in this he has been since confirmed by
Prof. Kupffer. M. Kovalevsky writes to me from
jSTaples, that he has now carried these observations yet fur-
ther, and should his results be well established, the whole
will form a discovery of the very greatest value. Thus, if
we may rely on embryology, ever the safest guide in classi-

* At the Falkland Islands I >vad tlie satisfaction of seeing, in April,
1833, and therefore some years nefore any other naturalist, the loco-
motive larvae of a compound Ascidian, closely allied to Synoicum,
but apparently generically distinct from it. The tail was about five
times as long as the oblong head, and terminated in a very fine fila-
ment. It was, as sketched by me under a simple microscope, plainly
divided by transverse opaque partitions, which I presume represent
the great cells figured by Kovalevsky. At an early stage of develop-
ment the tail was closely coiled round the head of the larva.

f '• Memoires de I'Acad. des Sciences de St. Petersbourg," toin. :k,
No. 15, 186a.

] 82 THE DESCENT OF MAN.

lication, it seems that we have at last gained a clew to the
Eouice whence the vertebrata were derived.* AVe should
the!i be justified in believing that at an extremely remote
peiioil a group of animals existed resembling in many-
respects the larvae of our present Ascidians, which diverged
into two great branches — the one retrograding in develop-
ment and producing the present class of Ascidians, tho
other rising to the crown and summit of the animal king-
dom by giving birth to the vertebrata.

We have thus far endeavored rudely to trace the geneal-
007 of the vertebrata by the aid 01 their mutual affinities.
We will now look to man as he exists; and we shall, I think;,
be able partially to restore the structure of our early pro-
genitors, during successive periods, but not in due order of
time. This can be effected by means of the rudiments
which man still retains, by the characters which occasion-
ally 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 must have been once cov-
ered with hair, both sexes having beards; their ears were
probably pointed and capable of movement ; and their
bodies were provided with a tail, having the proper muscles.
Their limbs and bodies v/ere also acted on by many mus-
cles which now only occasionally reappear, butare normally
present i:i the Quadrnmana. At this or some earlier period
the great artery an:l nerve of tho humerus ran through a
supracondyloid foramen. The intestine gavo forth a much
larger diverticulum or ca3cum than that now existing. Tho
foot was then prehensile, judging from the condition of fbo
great toe ii^. the foevus; and our progenitors, no doubt, wore
arboreal in their habits, and frequented some warm, forest-
clad land. The males had great canine teeth, which served

* But I am bound to add chat ^ome competent judges dispute this
conclusion; for instance, M. Giard, jn a series of papers In the
*• Archives de Zooiogie tCxpenmentale.'* ^oy 1872. Nevertheless, this
naturalist remarks, p 281. ' L organ izatirjn de la larve ascidieune en
dehors de toate bypotiiese et de toute theorie, nous montre coii.ment
la nature pent pro.iuue la disposition fondamentale du tvpe veltebre
(rexistence d'une C(»r<le dor>ale) die/ un invertebre ])ar la seule con-
diiion vitale de I'adnptation, c't cette simple ])ossibilite <iu passage
supprime I'abfme eiitre les deux sous-reguus, encore bien gu'en iguora
far ou ie passage s'est fait ea realite.'*

AFFINITIES AND GENEALOQY. 183

them as formidable weapons. At a much earlier period the
uterus was double ; the excreta were voided through a
cloana; and tlie eye was protected by a third eye-lid or nic-
titating membrane. At a still earlier perioil 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 branchiae once
existed. In the lunar or weekly recurrent periods of some
of our functions we apparently still retain traces of our
primordial birth-place, a shore washed by the tides. At
about this same early period the true kidneys Avere 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 ancestors of man, thus
seen in the dim recesses of time, must have been as simply,
or even still more simply, organized than the lancelet or
amphioxus.

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, appertain-
ing 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 possessed true male
and female glands. Hence some remote progenitor of the
whole vertebrate kingdom appears to have been hermaph-
rodite or androgynous.* But here we encounter a singu-
lar difficulty. In the mammalian class the males possess
rudiments of a uterus with the adjacent passage, in their
vesiculas prostaticae; they bear also rudiments of mammae,
and some male Marsupials htive traces of a marsupial sack.f
Other analogous facts could be added. Are we, then, to
suppose that some extremely ancient mammal continued

*This is tlie conclusion of Prof. Gegenbaur, one of tlie lng.liest
authorities in comparative anatomy; see '" Grundziige der verp:leich.
Anat.," 1870 s. 876. Tlie result Las been arrived at chiefly from the
study of the Am])hibia; but it appears from the researches of Wald-
eyer (as quoted in *' Journal of Anat. and Phys.." 1869. p. 161), that
the sexual organs of even " the liigher vertebrata are in their early
condition hermaphrodite." Similar views have long been held by
some authors, though until recently without a firm basis.

f The male Thylacinus offers the best instance. Owen, " Anatomy
of Vertebrates," vol. iii, p. 771.

184 THE DESCENT OF MAN.

androgynous, after it had acquired the chief distinctions of
its class, and, therefore, after it had diverged from the
lower classes of the vertebrate kingdom? This seems very
improbable, for we have to look to fishes, the lowest of all
the classes, to find any still existent androgynous forms.*
That various accessory parts, proper to each sex, are found
in a rudimentary condition in the opposite sex, may be
explained by such organs having been gradually acquired
by the one sex, and then transmitted in a more or less
imperfect state to the other. 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 colors, acquired for battle or ornament by
male birds and inherited by the females in an imperfect or
rudimentary condition.

The possession by male mammals of functionally imper-
fect 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 proba-
ble that the progenitors of the class also had milk-secreting
glands, but no nipples. This conclusion is supported by
what is known of their manner of development; for Prof.
Turner informs me, on the authority of Kolliker and
Langer, that in the embryo the mammary glands can be
distinctly traced before the nipples are in the least visible;
and the development of successive parts in the individual
generally represents and accords with the development of
successive beings in the same line of descent. The Mar-
supials-differ from the Monotremata by possessing nipples;
so that probably these organs were first acquired by the
Marsupials, after they had diverged from, and risen above,
the Monotremata, and were then transmitted to the

* Hermapliroditism has been observed in several species of Ser-
ranus, as well as in some other fishes, where it is either normal and
symmetrical, or abnormal and unilateral. Dr. Zouteveen has given
me references on this subject, more especially to a paper by Prof.
Halbertsma, in the "Transact, of the Dutch Acad, of Sciences," vol.
xvi. Dr. Giinther doubts the fact, but it has now been recorded by
too many good observers to be any longer disputed. Dr. M. Lessona
writes to me that he has verified the observations made by Cavolini
on Serranus. Prof. Ercolani has recently shown (" Accad. delle
Scieus5e," Bologna, Dec. 28, 1871) that eels are androgynous.

AFFINITIES AND GENEALOGY. 185

placental mammals.* 'Eo one will suppose that the Mar-
supials still remained androgynous after they had approx-
imately acquired their present structure. How then are
we to account for male mammals possessing mammae? It
is possible that they were first developed in the females and
then transferred to the males, but from what follows this is
hardly probable.

It may be suggested, as another view, that long after the
progenitors of the whole mammalian class had ceased to be
androgynous, both sexes yielded milk, and thus nourished
their young; and in the case of the Marsupials, that both
sexes carried their young marsupial sacks. This will not
appear altogether improbable, if we reflect that the males
of existing syngnathous fishes receive the eggs of the
females in their abdominal pouches, hatch them, and after-
ward, as some believe, nourish the young; f 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 Avind them round their own
thighs, keeping them there until the tadpoles are born;
that certain male birds undertake the whole duty of incuba-
tion, and that male pigeons, as well as the females, feed
their nestlings with a secretion from their crops. But the
above suggestion first occurred to me from the mammary
glands of male mammals being so much more perfectly
developed than the rudiments of the other accessory repro-
ductive 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 rudiment-
ary; they are merely not fully developed and not functionally

*Prof. Gegenbaur has sliovvn (" Jenaische Zeitsclirift," Bd. vii, p.
212)tliat two distinct types of nipples prevail throughout the several
mammalian orders, but that it is quite intelligible how both could
have been derived from the nipples of the Marsupials, and the latter
from those of the Monotremata. See, also, a memoir by Dr. Max
Huss, on the mammary glands, ibid., B. viii, p. 176.

f Mr. Lockwood believes (as quoted in ' ' Quart. Journal of
Science," April, 1868, p. 269), from what he has observed of the
development of Hippocampus, that the walls of the abdominal
pouch of the male in some way afford nourishment. On male fishes
hatching the ova in their mouths, see a very interesting paper by
Prof. Wyman, in " Proc. Boston Soc. of Nat. Hist.," Sept. 15, 1857;
also Prof. Turner, in "Journal of Anat. and Phys.," Nov. 1, 1866, p.
78. Dr. Giinther has likewise described similar cases.

186 THE DESCENT OF MAN.

active. They are sympathetically affected under the influ-
ence of certain diseases, like the same organs in the female.
They often secrete a few drops of milk at birth and at
puberty; this latter fact occurred in the curious case, before
referred to, where a young man possessed two pairs of
mammae. In man and some other male mammals these
organs have been known occasionally to become so well
developed during maturity as 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 afterward from some cause (as from the production
of a smaller number of young) the males ceased to give 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 trans-
mitted to the males at the corresponding age of maturity.
But at an earlier age these organs would be left unaffected,
so that they would be almost equally well developed in
the young of both sexes.

Conclusion. — Von Baer has defined advancement or prog-
ress in the organic scale better than any one else as resting
on the amount of differentiation and specialization of the
several parts of a being — when arrived at maturity, as I
should be inclined to add. Now, as organisms have become
slowly adapted to diversified lines of life by means of nat-
ural selection, their parts will have become more and more
differentiated and specialized for various functions from
the advantage gained by the division of physiological labor.
The same part appears often to have been modified first for
one purpose, and then long afterward for some other and
quite distinct purpose; and thus all the parts are rendered
more and more complex. But each organism still retains
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 organiza-
tion 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, how-
ever, be supposed that groups of organic beings are always

* Maddle. C. Royer has suggested a similar view iu her " Origine
de rHomme," etc., 1870.

AFFINITIES AND GENEALOGY, 187

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 look-
ing at the existing members of any lowly organized 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* resem-
bling the larvae of existing Ascidians. These animals
probably gave rise to a group of fishes, as lowly organized
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

* The inliabitants of the seashore must be greatly affected by the
tides; animals living either about the mean bigh- water mark, or about
tbe mean low-water mark, pass tbrougb a complete cycle of tidal
changes in a fortnight. Consequently their food supply will undergo
marked changes week by week. The vital functions of such ani-
mals, living under these conditions for many generations, can hardly
fail to run their course in regular weekly periods. Now it is a mys-
terious fact that in the higher and now terrestrial vertebrata, as well
as in other classes, many normal and abnormal processes have one or
more whole weeks as their periods; this would be rendered intelligi-
ble if the vertebrata are descended from an animal allied to the
existing tidal Ascidians. Many instances of such periodic processes
might be given, as the gestation of mammals, the duration of fevers,
etc. The hatching of eggs affords also a good example, for, accord-
ing to Mr. Bartlett ("Land and Water," Jan. 7, 1871), the eggs of
the pigeon are hatched in two weeks; those of the fowl in three;
those of the duck in four; those of the goose in five; and those of the
ostrich in seven weeks. As far as we can judge, a recurrent period,
if approximately of the right duration for any process of function,
would not, when once gained, be liable to change; consequently it
might be thus transmitted through almost any number of genera-
tions. But if the function changed, the period would have to
change, and would be apt to change almost abruptly by a whole
week. This conclusion, if sound, is highly remarkable; for the
period of gestation in each mammal, and the hatching of each bird's
eggs, and many other vital processes, thus betray to us the primor-
dial Inrthplace of these aniuTals.

188 THE DESCENT OF MAN.

were once intimately connected together; and the Monotre-
mata now connect mammals with reptiles in a slight degree.
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 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 Lemuridae; and the
interval is not very wide from these to the Simiadae. The
Simiadae 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 pres-
ent knowledge, approximately recognize our parentage; nor
need we feel ash*amed of it. The most humble organism is
something much higher than the inorganic dust under our
feet ; and no one with an unbiased mind can study any
living creature, however humble, without being struck with
enthusiasm at its marvelous structure and properties.

THE RAGES OF MAN. 189

CHAPTER VII.

OK THE KACES OF MAN.

The nature and value of specific characters— Application to the
races of man — Arguments in favor 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 I am about to inquire what is the
value of the differences between them under a classificatory
point of view and how they have originated. In determin-
ing 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 differ-
ence 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
shown, or rendered probable, that the forms in question
have remained distinct for a long period, this becomes an
argument of much weight in favor 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 degi*ee of mutual sterility, or in the case of
animals of some mutual repugnance to pairing.

Independently of fusion from intercrossing, the complete
absence, in a well-investigated region, of varieties linking

190 THE DESCENT OF MAN.

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 vari-
able and yet not yield intermediate varieties. Geographical
distribution is often brought into play unconsciously and
sometimes consciously; so that forms living in two widely
separated areas, in which most of tlie other inhabitants are
specifically distinct, are themselves usually looked at as dis-
tinct; 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 nat-
uralist would any other animal. In regard to the amount
of difference between the races, we must make some allow-
ance for our nice powers of discrimination gained by the
long habit of observing ourselves. In India, as Elphinstone
remarks, 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 are much
more like each other in form than would at first be sup-
posed; certain negro tribes must be excepted, while others,
as Dr. Rohlf s writes to me, and as I have myself seen, have
Caucasian features. This general similarity is well shown
by the French photographs in the Collection Anthropolo-
gique du Museum de Paris of the men belonging to various
races, the greater number of which njight pass for Euro-
peans, as many persons to whom I have shown them have
remarked. Nevertheless, these men, if seen alive, would
undoubtedly appear very distinct, so that we are clearly
much influenced in our judgment by the mere color 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 propor-
tions of all parts of the body,t the capacity of the

*" History of India," 1841, vol. i, p. 323. Father Ripa makes
exactly the same remark with respect to the Chinese.

f A vast number of measurements of Whites, Blacks and Indians
are given in the " Investigations in the Military and Anthropolog.

THE MACES OF MAN. 191

lungs, the form and capacity of the skull, and even
in the convolutions of the brain.* But it would be
an endless task to specify the numerous points of dif-
ference. The races differ also in constitution, in acclima-
tization 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 com-
parison must have been struck with the contrast between
the taciturn, even morose, aborigines of South America and
the light-hearted, talkative negroes. There is a nearly sim-
ilar contrast between the Malays and the Papuans,! 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 favor of classing the races of man as distinct
species, and then the arguments on the other side. If a
naturalist, who had never before seen a Negro, Hottentot,
Australian or Mongolian, were to compare them, he would
at once perceive that they differed in a multitude of char-
acters, 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 con-
clusion 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 4,000
years ago.]; He would also hear, on the authority of an

Statistics of American Soldiers," by B. A. Gould, 1869, pp. 298-358;
"On the capacity of the lungs," p. 471. See also the numerous and
valuable tables, by Dr. Weisbach, from the observations of Dr.
Scherzerand Dr. Schwarz, in the " Reise der No vara; Anthropolog.
Theil," 1867.

* See, for instance, Mr. Marshall's account of the brain of a Bush-
woman, in "Phil. Transact.," 1864, p. 519.

fWallace, " The Malay Archipelago," vol. ii. 1869, p. 178.

X With respect to the figures in the famous Egyptian caves of
Abou-Simbel, M. Pouchet says ("The Plurality of the Human

193 THE DESCENT OF MAN.

excellent observer. Dr. Lund,* that tlie human skulls
found in the caves of Brazil, entombed with many extinct
mammals, belonged to the same type as that now prevail-
ing throughout the American Continent.

Our naturalist would then perhaps turn to geographical
distribution, and he would probably declare that those
forms must be distinct species, which differ not only in
appearance, but are fitted for hot, as well as damp or dry
countries, and for the Arctic regions. He might appeal to
the fact that no species in the group next to man — namely,
the Quadrumana, can resist a low temperature, or any con-
siderable change of climate; and that the 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, f
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 shown, by
nearly the same line which divides the great Malayan and
Australian zoological provinces. The Aborigines of America

Races," Eng. translat., 1864, p. 50), that lie was far from finding
recognizable representations of the dozen or more nations wliicli
some authors believe that they can recognize. Even some of the
most strongly-marked races cannot be identified with that degree of
unanimity which might have been expected from what has been
written on the subject. Thus Messrs. Nott and Gliddon (" Types of
Mankind," p. 148), state that Eameses II, or the Great, has features
superbly European; whereas Knox, another firm believer in the
specific distinctness of the races of man (" Races of Man," 1850, p.
201), speaking of young Memnon (the same as Rameses II, as I am
informed by Mr. Birch), insists in the strongest manner that he is
identical in character with the Jews of Antwerp. Again, when I
looked at the statue of Amunoph III, I agreed with two oflScers of
the establishment, both competent judges, that he had a strongly-
marked negro type of features; but Messrs. Nott and Gliddon (ibid,
p. 146, fig. 53), describe him as a hybrid, but not of "negro inter-
mixture."

* As quoted by Nott and Gliddon, ' * Types of Mankind, " 1854, p. 439.
They give also corroborative evidence; but C. Vogt thinks that the
subject requires further investigation.

f "Diversity of Origin of the Human Races," in the " Christcai
Examiner," July, 1850.

THE RAGES OF MAN, 193

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
amount of difference between the mammals of the several
zoological provinces does not correspond with the degree of
separation between the latter; so that it can hardly be con-
sidered 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 African and American Continents
from the mammals 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 supposed varieties of the
same kind of domestic animal sliould be ranked as such, or
as specifically distinct, that is, whether any of them are
descended from distinct wild species, every naturalist would
lay much stress on the fact 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 in-
formed 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 coun-
tries from the different races of man;* and he finds that
they differ, not only in color, but in the structure of their
claws and limbs. In every case in which many 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 Pedi-
culi were darker colored and appeared different from those
proper to the natives of Chili, 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

* "Transact. R. Soc. of Edinburgh," vol. xxii, 1861, p. 567.

194 THE DESCENT OF MAN.

Eastern and Western coasts, from the Hottentots and
Kaffirs; 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 diiferent districts. With insects slight struct-
ural differences, if constant, are generally esteemed of
specific value; and the fact of the races of man being in-
fested by parasites which appear to be specifically distinct
might fairly be urged as an argument that the races them-
selves 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 con-
sult the work* of Prof. Broca, a cautious and philosophical
observer, 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 shown 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 burned at the same time whose
remains were found by the police, f Again, it has often
been said that when mulattoes intermarry they produce
few children; on the other hand, Dr. Bachman, of Charles-
ton,]; 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 con-

*"0n the Phenomena of Hybridity in the Genus Homo," Eng.
translat., 1864.

f See the interesting letter by Mr. T. A. Murray, in the " Anthro-
polog. Review," April, 1868, p. 53. In this letter Count Strzelecki's
statement that Australian women who have borne children to a white
man are afterward sterile with their own race is disproved. M. A.
de Quatrefages has also collected (" Revue des Cours Scientifiques,"
March, 1869, p. 239) much evidence that Australians and Europeans
are not sterile when crossed.

X '* An Examination of Prof. Agassiz's Sketch of the Nat. Provinces
of. the Animal World," Charleston, 1855, p. 44,

THE RACES OF MAN, 195

elusion.* In the United States the census for the year
1854 inckided, according to Dr. Bachman, 405,751 mulat-
toes; 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 workf as a well-known phenomenon; and
this, although a different consideration from their lessened
fertility, may perhaps be advanced as a proof of the specific
distinctness of the parent races. No doubt both animal
and vegetable hybrids, when produced from extremely dis-
tinct 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 vigor, and yet so sterile, shows how little necessary
connection there is in hybrids between lessened fertility
and vitality; other analogous cases could be cited.

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 fer-
tility of converse 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 completely fer-
tile. The degrees of sterility do not coincide strictly with

* Dr. Rohlfs writes to me that lie found the mixed races in the
Great Sahara, derived from Arabs, Berbers, and Negroes of three
tribes, extraordinarily fertile. On the other hand, Mr. Winwood
Reade informs me that the Negroes on the Gold Coast, though admir-
ing white men and mulattoes, have a maxim that mulattoes should
not intermarry, as the children are few and sickly. This belief, as
Mr. Reade remarks, deserves attention, as white men have visited
and resided on the Gold Coast for four hundred years, so that the
natives have had ample time to gain knowledge through experience.

f " Military and Anthropolog. Statistics of American Soldiers," by
B. A. Gould, 1869, p. 319.

196 THE DESCENT OF MAN.

the degrees of difference between the parents in external
structure or habits of life. Man in many respects may be
compared with those animals which have long been domes-
ticated, and a large body of evidence can be advanced in
favor of the Pallasian doctrine,* 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 sev-
eral 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 characters presented by
the offspring from a cross have been thought to indicate
whether or not the parent-forms ought to be ranked as

* " The Variation of Animals and Plants under Domestication," vol.
ii, p. 109. I may here remind the reader that the sterility of species
when crossed is not a specially acquired quality, but, like the inca-
pacity of certain trees to-be grafted together, is incidental on other
acquired differences. The nature of these differences is unknown,
but they relate more especially to the reproductive system, and much
less so to external structure or to ordinary differences in constitution.
One important element in the sterility of crossed species apparently
lies in one or both having been long habituated to fixed conditions;
for we know that changed conditions have a special influence on the
reproductive system, and we have good reason to believe (as before
remarked) that the fluctuating conditions of domestication tend to
eliminate that sterility which is so general with species, in a natural
state, when crossed. It has elsewhere been shown by me (ibid., vol.
ii, p. 185, and " Origin of Species," 5th edit., p. 317), that the steril-
ity of crossed species has not been acquired through natural selection;
we can see that when two forms have already been rendered very
sterile, it is scarcely possible that their sterility should be aug-
mented by the preservation or survival of the more and more sterile
individuals; for, as the sterility increases, fewer and fewer offspring
will be produced from which to breed, and at last only single indi-
viduals will be produced at the rarest intervals. But there is even a
higher grade of sterility than this. Both Gartner and Kcilreuter
have proved that in genera of plants, including many species, a series
can be formed from species which, when crossed, yield fewer and
fewer seeds, to species which never produce a single seed, but yet
are affected by the pollen of the other species, as shown by the
swelling of the germen. It is here manifestly impossible to select
the more sterile individuals, which have already ceased to yield
seeds; so that the acme of sterility, when the germen alone is
affected, cannot have been gained through selection. This acme,
and no doubt the other grades of sterility, are the incidental results
of certain unknown differences in the constitution of the reproductive
system of the species which are crossed,

THE RAGES OF MAN. 197

species or varieties; but after carefully studying the evi-
dence, I have come to the conclusion that no general rules
of this kind can be trusted. The ordinary result of a cross
is the production of a blended or intermediate form; but in
certain cases some of the offspring take closely after one
parent-form and some after the other. This is especially
apt to occur when the parents differ in characters which
first appeared as sudden variations or monstrosities.* 1
refer to this point because Dr. Rohlfs informs me that he
has frequently seen in Africa the offspring of negroes crossed
with members of other races, either completely black or
completely white, or rarely piebald. On the other hand, it
is notorious that in America mulattoes commonly present
an intermediate appearance.

We have now seen that a naturalist might feel himself
fully justified in ranking the races of man as distinct spe-
cies; 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. Our naturalist 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, which accords with that of other undoubtedly dis-
tinct 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 nat-
uralist were to inquire whether the forms of man keep dis-
tinct like ordinary species when mingled together in large
numbers in the same country, he would immediately dis-
cover that this was by no means the case. In Brazil he
would behold an immense mongrel population of Negroes
and Portuguese; in Chili and other parts of South Amer-
ica he would behold the whole population consisting of In-
dians and Spaniards blended in various degrees, f In many

* " The Variation of Animals," etc., vol. ii, p. 92.

I'M. de Quatrefages Las given (" Anthropolog. Review," Jan.,
1869. p. 22) an interesting account of the success and energy of the
Paulistas in Brazil, who are a much crossed race of Portuguese and
Indians, with a mixture of the blood of other race^

198 TBE DESCENT OF MAN.

parts of the same continent he would meet with the most
complex crosses between Negroes, Indians, and Europeans;
and judging from the vegetable kingdom such triple
crosses afford the severest test 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 Fiji Archipelago a population of Polynesian and
Negritos crossed in all degrees. Many analogous cases
could be added; for instance, in Africa. Hence the races
of man are not sufficiently distinct to inhabit the same
country without fusion; and the absence of fusion affords
the usual and best test of specific distinctness.

Our naturalist would likewise be much disturbed as soon
as he perceived that the distinctive characters of all thp
races were highly variable. This fact strikes every one on
first beholding 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 been often asserted. Hotten-
tot 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, color and hairiness differ considerably; as
does color 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;* and so it is with
every other character. Now all naturalists have learned 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 treat-
ing the races of man as distinct species, is that they gradu-
ate 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 animal, and yet there
is the greatest possible diversity among capable judges
whether he should be classed as a single species or race, or

* For instance, with the aborigines of America and Australia. Prof.
Huxley says (" Transact. Internat. Congress of Prehist. Arch.," 1868,
p. 105) that the skulls of many South Germans and Swiss are " as
gUort and as broad as those of the Tartars," etc.

TBE RACES OF MAN, 199

as two (Virey), as three (Jacqiiinot), as four (Kant), five
(Blumenbach), six (Buffon), seven (Hunter), eight (Agas-
siz), eleven (Pickering), fifteen (Bory St. Vincent), sixteen
(Desmoulins), twenty-two (Morton), sixty (Crawfurd), or
as sixty-three, according to Burke.* This diversity of
judgment does not prove that the races, ought not to be
ranked as species, but it shows 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 under-
take tlie description of a group of highly varying organ-
isms 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 under a single species; for he will say to him-
self 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; while
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 usually be ranked as mere
varieties or races; and this course has been followed by
most naturalists with respect to the races of man. Never-
theless, it must be confessed that there are forms, at least
in the vegetable kingdom, f which we cannot avoid naming
as species, but which are connected together by numberless
gradations, independently of intercrossing.

Some naturalists have lately employed the term *■*" sub-
species " to designate forms which possess many of the char-
acteristics of true species, but which hardly deserve so high

*See a good discussion on this subject in Waitz, **Introduct. to
Anthropology," Eng. translat., 1863, pp. 198-208, 227. I have taken
some of the above statements from H. Tuttle's " Origin and Antiquity
of Physical Man," Boston, 1866, p. 35.

f Prof. Nageli has carefully described several striking cases in his
"Botanische Mittheilungen, " B. ii, 1866, ss. 294-369. Prof. Asa
Gray has made analogous remarks on some intermediate forms in the
Compositse of North Americt^*

200 THE DESCENT OF MAN,

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, it seems that the term " sub-species" might here be
used with propriety. But from long habit the term '' race "
will perhaps always be employed. The choice of terms is
only so far important in that it is desirable to use, as far as
possible, the same terms for the same degrees of difference.
Unfortunately this can rarely be done; for the larger genera
generally include closely-allied forms, which can be distin-
guished only with much difficulty, while the smaller genera
within the same family include forms that are perfectly dis-
tinct; yet all must be ranked equally as species. So again,
species within the same large genus by no means resemble
each other to the same degree; on the contrary, some of
them can generally be arranged in little groups round other
species, like satellites round planets.*

The question whether mankind consists of one or sev-
eral species has of late years been much discussed by anthro-
pologists, who are divided into the two schools of monogen-
ists and polygenists. Those who do not admit the prin-
ciple of evolution must look at species as separate creations,
or as in some manner as distinct entities; and they must
decide what forms of man they will consider as species by the
analogy of the method commonly pursued in ranking other
organic beings as species. But it is a hopeless endeavor to
decide this point, until some definition of the term
" species " is generally accepted; and the definition must
not include an indeterminate element 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, town or city. We have a practical illus-
tration of the difficulty in the never-ending doubts whether
many closely-allied mammals, birds, insects and plants, which
represent each other respectively in North America and
Europe, should be ranked as species or geographical races;
and the like holds true of 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

**• Origin of Species," 5tli edit. p. 68.

THE RAGES OW MAN. ^01

majority of rising men, will feel no doubt that all the races
of man are descended from a single primitive stock ;
whether or not they may think fit to designate the races as
distinct species, for the sake of expressing their amount of
difference.* With our domestic animals the question
whether the various races have arisen" from one or more
species is somewhat different. Although it may be admit-
ted that all the races, as well as all the natural species
within the same genus, have sprung from the same primi-
tive stock, yet it is a fit subject for discussion, whether all
the domestic races of the dog, for instance, have acquired
their present amount of difference since some one species
was first domesticated by man; or whether they owe some
of their characters to inheritance from distinct species,
which had already been differentiated in a state of nature.
With man no such question can arise, for he cannot be said
to have been domesticated at any particular period.

During an early stage in the divergence of the races of
man from a common stock, the differences between the
races and their number must have been small; consequently
as far as their distinguishing characters are concerned, they
then had less claim to rank as distinct species than the
existing so-called races. Nevertheless, so arbitrary is the
term of species, that such early races would perhaps have
been ranked by some naturalists as distinct species, if their
differences, although extremely slight, had been more con-
stant than they are at present, and had not graduated into
each other.

It is, however, possible, though far from probable, that
the early progenitors of man might formerly have diverged
much in character, until they became more unlike each
other than any now existing races; but that subsequently,
as suggested by Yogt, f they converged in character. When
man selects the offspring of two distinct species for the
same object, he sometimes induces a considerable amount
of convergence, as far as general appearance is concerned.
This is the case, as shown by Von Kathusius,]; with the

*See Prof. Huxley to tliis effect in the " Fortnightly Review,"
1865, p. 275.

f " Lectures on" Man," Eng. translat., 1864, p. 468.

j"Die Racen des Schweines," 1860, s. 46. " Vorstudien fiir
Geschichte, etc., Schweineschadel," 1864, s, 104. With respect to
cattle, see M. de Quatrefages, "Unite de I'Espece Humaine," 1861,
J). 119.

2o^ T3E DESCENT OF MAN.

improved breeds of the pig, which are descended from two
distinct species; and in a less 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 devel-
oped gibbon or semnopithecus, the chimpanzee a highly
developed macacus, and the gorilla a highly developed man-
drill. If this conclusion, which rests almost exclusively on
brain-characters, be admitted, we should have a case of con-
vergence at least in external characters, for the anthropomor-
phous 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 con-
vergence; but this term has never been applied to super-
ficial and adaptive resemblances. It would, however, be
extremely rash to attribute to convergence close similarity
of character in many points of structure among the modi-
fied descendants of widely distinct beings. The form of a
crystal is deterniined solely by the molecular forces, and it
is not surprising that dissimilar substances should some-
times assume the same form; but with organic beings we
should bear in mind that the form of each depends on an
infinity of complex relations, namely, on variations due to
causes" far too intricate to be followed — on the nature of
the variations preserved, these depending on the physical
conditions, and still more on the surrounding organisms
which compete with each — and lastly, on inheritance (in
itself a fluctuating element) from innumerable progenitors,
all of which have have had their forms determined through
equally complex relations. It appears incredible that the
modified descendants of two organisms, if these differed
from each other in a marked manner, should ever after-
ward converge so closely as to lead to a near approach to
identity throughout their whole organization. In the case
of the convergent races of pigs above referred to, evidence
of their descent from two primitive stocks is, according to
Von Nathusius, still plainly retained in certain bones of
their skulls. If the races of man had descended, as is sup-
posed by some naturalists, from two or more species which
differed from each other as much, or nearly as much, as
does the orang from the gorilla it can hardly be doubted
that marked differences in the structure of certain bones
would still be discoverable in man as he now exists,

THE RAGES OF MAN. , J^Oo

Although the existing races of man differ in many re-
spects as in color, hair, shape of skull, proportions of the
body, etc., yet if their whole structure be taken into con-
sideration they are found to resemble each other closely in
a multitude of points. Many of these are of so unimpor-
tant or of so singular a nature that it is extremely improb-
able 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 are as different from each other in mind as
any three races that can be named; yet I was incessantly
struck while living with the Fuegians on board the
'^ Beagle^' with the many little traits of character showing
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 read Mr. Tylor's and Sir J. Lubbock^s in-
teresting works* can hardly fail to be deeply impressed
with the close similarity between the men of all races in
tastes, dispositions and habits. This is shown by the pleas-
ure which they all take in dancing, rude music, painting,
tattooing and otherwise decorating themselves ; in their
mutual comprehension of gesture-language, by the same
expression in their features, and by the same inarticulate
cries, when excited by the same emotions. This similarity,
or rather identity, is striking, when contrasted with the
different expressions and cries made by 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 as Westropp and
Nilsson have remarked,! the stone arrow-heads, brought
from the most distant parts of the world, and manufactured
at the most remote periods, are almost identical; and this
fact can only be accounted for by the various races having
similar inventive or mental powers. The same observation

* Tylor's " Early History of Mankind," 1865; with respect to ges-
ture-language, see p. 54. Lubbock's •* Prehistoric Times/' 2d edit.,
1869.

f " On Analogous Forms of Implements," in "Memoirs of Anthro-
polog. Soc," by H. M. Westropp. "The Primitive Inhabitants of
Scandinavia," Eng. translat., eHjted by Sir J. Lubbock, 1868, p, 104.

204 ' TME DBSGElTT OF MAN.

has been made by archaeologists * with respect to certain
widely-prevalent ornaments^ such as zig-zags, etc.; 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 \ that there, as in
80 many other parts of the world, men have generally
chosen the summits of lofty hills to throw up piles of
stones, either as a record of some remarkable event, or for
burying their 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
they 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 had these same characters. 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
great 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 practiced 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 learned they would never
have been forgotten. | He thus shows 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 been already discovered, for it is common to all the

* Westropp, " On Cromleclis," etc., " Journal of Ethnological Soc,"
as given in " Scientific Opinion," June 2, 1869, p. 3.

f "Journal of Researclies; Voyage of the ' Beagle,* " p. 46.
I " Prehistoric Times," 1869, p. 574.

THE RAGES OF MAN. 205

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 to what it does now, 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, con-
sidering that so many races now in existence cannot get
beyond four." Nevertheless, at this early period, the intel-
lectual and social faculties of man could hardly have been
inferior in any extreme degree to those possessed at present
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 lan-
guages, 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 intel-
lect could have risen to the standard implied, by his domi-
nant position at an early period.

Whether primeval man, when he possessed but few arts,
and those of the rudest kind, and when his power of lan-
guage 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 indif-
ference whether the so-called races of man are thus desig-
nated, or are ranked as species or sub-species; but the latter
term appears the more appropriate. Finally, we may con-
clude that when the principle of evolution is generally
accepted, as it 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

206 THE DESCENT OF MAN,

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 he formed by carefully matching the varying off-
spring from a single pair, or even from a single individual
possessing some new character; 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 ones, were
habitually preferred, we may feel sure that two distinct
sub-breeds would be produced in the course of time, with-
out any one pair having been separated and bred from, in
either country. Many races have been thus formed, and
their manner of formation is closely analogous to that of
natural species. We know, also, that the horses taken to the
Falkland Islands have, during successive generations,
become smaller and weaker, while 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 rever-
sion. The new sub-breeds in such cases are not 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 or
complete extinction of many races and sub-races of man is
historically known. Humboldt saw in South America a
parrot which was the sole living creature that could speak
a word of the language of a lost tribe. Ancient monuments
and stone implements found in all parts of the world, about
which no tradition has been 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

TEE RAGES OF MAN. 207

the ancient races were all, according to Schaaffhausen,*
^* 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 Prof. Broca 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 of high char-
acteristics. This race is " entirely different from any
other, ancient or modern, that we have heard of."f It
differed, therefore, from the quaternary race of the caverns
of Belgium.

Man can long resist conditions which appear extremely
unfavorable for his existence. J; He has long lived in the
extreme regions of the north, with no wood for his canoes
or implements, and with only blubber as fuel and melted
snow as drink. 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 arid plains, where dangerous
beasts abound. Man can withstand the deadly influence
of the Terai at the foot of the Himalaya and the pestilen-
tial shores of tropical Africa.

Extinction follows chiefly from the competition of tribe
with tribe and race with race. Various checks are always
in action, serving to keep down the numbers of each
savage tribe — such as periodical famines, nomadic habits
and the consequent deaths of infants, prolonged suckling,
wars, accidents, sickess, licentiousness, the stealing of
women, infanticide, and especially lessened fertility. If
any one of these checks increases in power, even slightly,
the tribe thus affected tends to decrease ; and when of two
adjoining tribes one becomes less numerous and less power-
ful 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 becomes extinct. §

* Translation in "Anthropological Review," Oct., 1868, p. 431.

f ** Transact. Internat. Congress of Prehistoric Arch.," 1868, pp.
172-175. See also Broca (translation) in "Anthropological Review,"
Oct., 1868, p. 410.

± Dr. Gerland, " Ueber das Aussterben der Naturvolker," 1868, s, 82.

g Gerland (ibid, s. 12) gives facts in support of this statement.

208 THE DESCENT OF MAN.

When civilized nations come into contact with barba-
rians 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 civilized nations some are plain and sim-
ple, others complex and obscure. We can see that the
cultivation of the land will be fatal in many ways to sav-
ages, for they cannot, or will not, change their habits.
New diseases and vices have in some cases proved highly
destructive; and it appears that a new disease often causes
much death until those who are most susceptible to its
destructive influence are gradually weeded out;* and so it
may be with the evil effects from spirituous liquors, as well
as with the unconquerably strong taste for them shown by
so many savages. It further appears, mysterious as is the
fact, that the first meeting of distinct and separated people
generates disease. \ Mr. Sproat, who in Vancouver Island
closely attended to the subject of extinction, believed that
changed habits of life, consequent on the advent of Euro-
peans, induces much ill-health. He lays, also, great stress
on the apparently trifling cause 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. ^'I

The grade of their civilization seems to be a most impor-
tant element in the success of competing nations. A few
centuries ago Europe feared the inroads of Eastern barba-
rians; now any such fear would be ridiculous. It is a more
curious fact, as Mr. Bagehot has remarked, that savages
did not formerly waste away before the classical nations as
they now do before modern civilized 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. § The most potent of all the causes
of extinction appears in many cases to be lessened fertility

* See remarks to this effect in Sir H. Holland's " Medical Notes
and Reflections," 1839, p. 390.

fl have collected ("Journal of Researches, Voyage of the
'Beagle,' "p. 435) a good many cases bearing on this subject; see
also Gerland, ibid, s. 8. Poeppig speaks of the " breath of civiliza-
tion as poisonous to savages."

ij: Sproat, " Scenes and Studies of Savage Life," 1868, p. 284

§ Bagehot, "Physics and Politics," "Fortnightly Review," Aprl'
I, 1868, p. 405.

THE RAGES OF MAN. 209

and ill-health, especiiilly among the children, arising from
clianged conditions of life, notwithstanding that the new
conditions may not be injurious in themselves. I am much
indebted to Mr. H. H. Howorth for having called my
attention to this subject and for having given me informa-
tion respecting it. I have collected the following cases:

When Tasmania was first colonized the natives were
roughly estimated by some at 7,000, and by others at 20,000.
Their number was soon greatly reduced, chiefly by fighting
with the English and with each other. After the famous
hunt by all the colonists, when the remaining natives deliv-
ered themselves up to the government, they consisted only of
120 individuals,* who were in 1832 transported to Flinders
Island. This island, situated between Tasmania and Aus-
tralia, is forty miles long, and from twelve to eighteen miles
broad; it seems healthy, and the natives were well treated.
Nevertheless, they suffered greatly in health. In 1834 they
consisted (Bonwick, p. 250) of forty-seven adult males,
forty-eight adult females, and sixteen children, or in all of
one hundred and eleven souls. In 1835 only one hundred
were left. As they continued rapidly to decrease, and as
they themselves thought that they should not perish so
quickly elsewhere, they were removed in 1847 to Oyster
Cove in the southern part of Tasmania. They then con-
sisted (Dec. 20, 1847) of fourteen men, twenty-two women
and ten children. \ But the change of site did no good.
Disease and death still pursued them, and in 1864 one man
(who died in 18G9) and three elderly women alone survived.
The infertility of the women is even a more remarkable
fact than the liability of all to ill-health and death. At
the time when only nine women were left at Oyster Cove
they told Mr. Bonwick (p. 386) that only two had ever
borne children; and these two had together produced only
three children!

With respect to the cause of this extraordinary state of
things Dr. Story remarks that death followed the attempts
to civilize the natives. '' If left to themselves to roam as
they were wont and undisturbed they would have reared
more children and there would have been less mortality."

* All tlie statements liere given are taken from "The Last of the
Tasmanians," by J. Bonwick, 1870.

f This is the statement of the Governor of Tasmania, Sir W. Deni
Bon, " Varieties of Vice-Regal Life," 1870, vol. i, p. 67,

210 THE DESCENT OF MAN.

Another careful observer of the natives, Mr. Davis, remarks,
' ' The births have been few and the deaths numerous.
This may have been in a great measure owing to their
change of living and food; but more so to their banishment
from the mainland of Van Diemen's Land and consequent
depression of spirits " (Bonwick, pp. 388, 390).

Similar facts have been observed in two widely different
parts of Australia. The celebrated explorer, Mr. Gregory,
told Mr. Bonwick, that in Queensland ^' the want of repro-
duction was being already felt with the blacks, even in the
most recently settled parts, and that decay would set
in." Of thirteen aborigines from Shark^s Bay who visited
Murchison River, twelve died of consumption within three
months.*

The decrease of the Maories of New Zealand has been
carefully investigated by Mr. Fenton, in an admirable
report, from which all the following statements, with one
exception, are taken, f The decrease in number since 1830
is admitted by every one, including the natives themselves,
and is still steadily progressing. Although it has hitherto
been found impossible to take an actual census of the
natives, their numbers were carefully estimated by resi-
dents in many districts. The result seems trustworthy,
and shows that during the fourteen years, previous to 1858,
the decrease was 19.42 per cent. Some of the tribes, thus
carefully examined, lived above a hundred miles apart,
some on the coast, some inland; and their means of sub-
sistence and habits differed to a certain extent (p. 28).
The total number in 1858 was believed to be 53,700, and
in 1872, after a second interval of fourteen years, another
census was taken, and the number is given as only
36,359, showing a decrease of 32.29 per cent. ! |
Mr. Fenton, after showing in detail the insufficiency of
the various causes usually assigned in explanation of this
extraordinary decrease, such as new diseases, the profligacy
of the women, drunkenness, wars, etc., concludes on
weighty grounds that it depends chiefly on the unproduc-

* For these cases see Bonwick's " Daily Life of tlie Tasmanians,'*
1870, p. 90; and the " Last of the Tasmanians," 1870, p. 386.

f ' ' Observations on the Aboriginal Inhabitants of New Zealand, *'
published by the Government, 1859.

% " New Zealand," by Alex. Kennedy, 1873, p. 47.

THE UACBS OF MAN. 211

ti veil ess of the women and on the extraordinary mortality
of the young children (pp. 31, 34). In proof of this he
shows (p. 33) that in 1844 there was one non-adult for
every 2.57 adults; whereas in 1858 there was only one non-
adult for every 3.27 adults. The mortality of the adults is
also great. He adduces as a further cause of the decrease
the inequality of the sexes; for fewer females are born than
males. To this latter point, depending perhaps on a widely
distinct cause, I shall return in a future chapter. Mr.
Fenton contrasts with astonishment the decrease in New
Zealand with the increase in Ireland; countries not very
dissimilar in climate, and where the inhabitants now follow
nearly similar habits. The Maories themselves (p. 35)
*^ attribute their decadence, in some measure, to the intro-
duction of new food and clothing, and the attendant
change of habits ;^^ and it will be seen, when we consider
the influence of changed conditions on fertility, that they
are probably right. The diminution began between the
years 1830 and 1840; and Mr. Fenton shows (p. 40) that
about 1830, the art of manufacturing putrid corn (maize),
by long steeping in water, was discovered and largely prac-
ticed; and this proves that a change of habits was begin-
ning among the natives, even when New Zealand was only
thinly inhabited by Europeans. When I visited the Bay
of Islands in 1835, the dress and food of the inhabitants
had already been much modified ; they raised potatoes,
maize and other agricultural produce, and exchanged them
for English manufactured goods and tobacco.

It is evident from many statements in the life of Bishop
Patteson,* that the Melanesians of the New Hebrides and
neighboring archipelagoes, suffered to an extraordinary
degree in health, and perished in large numbers, when they
were removed to New Zealand, Norfolk Island and other
salubrious places, in order to be educated as missionaries.

The decrease of the native population of the Sandwich
Islands is as notorious as that of New Zealand. It has
been roughly estimated by those best capable of judging,
that when Cook discovered the Islands in 1779, the popula-
tion amounted to about 300,000. According to a loose
census in 1823, the numbers then were 142,050. In 1832,

* " Life of J. C. Patteson," by C. M. Younge, 1874; see more
especially vol. 1, p. 530.

212

THE DESCENT OF MAN.

and at several subsequent periods, an accurate census was
officially taken, but I have been able to obtain only the fol-
lowing returns:

Annual rate of decrease per

Native Population.

cent., assuming it to have
been uniform between the

Ybab.

(Except during 1832 and 1836,

successive censuses; these

when the few foreigrners in

censuses being taken at ir-

the islands were included.)

regular intervals.

1832

130,313

.

4.46

1836

108,579

^

2.47

1853

71,019

0.81

1860

67,084

■

2.18

1866

58,765

I

2.17

1872 .

51,531 ^

We here see that in the interval of forty years, between
1832 and 1872, the population has decreased no less than
sixty-eight per cent. ! This has been attributed by most
writers to the profligacy of the women, to former bloody
wars, and to the severe labor imposed on conquered tribes
and to newly introduced diseases, which have been on sev-
eral occasions extremely destructive. 'No doubt these and
other such causes have been highly efficient, and may
account for the extraordinary rate of decrease between the
years 1832 and 1836; but the most potent of all the causes
seems to be lessened fertility. According to Dr. Ruschen-
berger of the United States Navy, who visited tliese islands
between 1835 and 1837, in one district of Hawaii, only
twenty-five men out of 1,134, and in another district only
ten out of 637, had a family with as many as three
children. Of eighty married women, only thirty-nine had
ever borne children ; and ^' the official report gives an
average of half a child to each married couple in the
whole island." This is almost exactly the same average as
with the Tasmanians at Oyster Cove. Jarves, who pub-
lished his history in 1843, says that ^^ families who have
three children are freed from all taxes; those having more,,

THE RACES OF MAN, 213

are rewarded by gifts of land and other encouragements/*
This unparalleled enactment by the government well shows
how infertile the race had become. The Eev. A. Bishop
stated in the Hawaiian "" Spectator " in 1839, that a large
proportion of the children die at early ages, and Bishop
Staley informs me that this is still the case, just as in New
Zealand. This has been attributed to the neglect of the
children by the women, but it is probably in large part due
to innate weakness of constitution in the children, in rela-
tion to the lessened fertility of their parents. There is,
moreover, a further resemblance to the case of New Zeal-
and, in the fact that there is a large excess of male over
female births; the census of 1872 gives 31,650 males to
25,247 females of all ages, that is 125.36 males for every
100 females; whereas in all civilized countries the females
exceed the males. No doubt the profligacy of the women
may in part account for their small fertility; but their
changed habits of life is a much more probable cause, and
which will at the same time account for the increased mor-
tality, especially of the children. The islands were visited
by Cook in 1779, by Vancouver in 1794, and often subse-
quently by whalers. In 1819 missionaries arrived, and
found that idolatry had been already abolished, and other
changes effected by the king. After this period there was
a rapid change in almost all the habits of life of the natives,
and they soon became *^ the most civilized of the Pacific
Islanders." One of my informants, Mr. Coan, who was
born on the islands, remarks that the natives have under-
gone a greater change in their habits of life in the course
of fifty years than Englishmen during a thousand years.
From information received from Bishop Staley, it does
not appear that the poorer classes have ever much changed
their diet, although many new kinds of fruit have been
introduced, and the sugar-cane is in universal use. Owing
however, to their passion for imitating Europeans, they
altered their manner of dressing at an early period, and
the use of alcoholic drinks became very general. Although
these changes appear inconsiderable, I can well believe,
from what is known with respect to animals, that they
might suffice to lessen the fertility of the natives.*

* The foregoing statements are taken chiefly from the following
works: " Jarves' History of the Hawaiian Islands," 1843, pp. 400-
407. Cheever, "Life in the Sandwich Islands," 1851. p. 377.

214 THE DESCENT OF MAN,

Lastly, Mr. Macnamara states * that the low and de-
graded inhabitants of the Andaman Islands, on the eastern
side of the Gulf of Bengal, are '' eminently susceptible to
any change of climate; in fact, take them away from their
island homes, and they are almost certain to die, and that
independently of diet or extraneous influences." He further
states that the inhabitants of the Valley of Nepal, which is
extremely hot in summer, and also the various hill-tribes
of India, suifer from dysentery and fever when on the
plains; and they die if they attempt to pass the whole year
there.

We thus see that many of the wilder races of man are
apt to suffer much in health when subjected to changed
conditions or habits of life and not exclusively from being
transported to a new climate. Mere alterations in habits,
which do not appear injurious in themselves, seem to have this
same effect; and in several cases the children are particularly
liable to suffer. It has often been said, as Mr. Macnamara
remarks, that man can resist with impunity the greatest
diversities of climate and other changes; but this is true
only of the civilized races. Man in his wild condition
seems to be in this respect almost as susceptible as his near-
est allies, the anthropoid apes, which have never yet sur-
vived long, when removed from their native country.

Lessened fertility from changed conditions, as in the case
of the Tasmanians, Maories, Sandwich Islanders, and
apparently the Australians, is still more interesting than
their liability to ill-health and death; for even a slight
degree of infertility, combined with those other causes
which tend to check the increase of every population, would
sooner 0/ later lead to extinction. The diminution of fertility
may be explained in some cases by the profligacy of the
women (as until lately with the Tahitians), but Mr. Fenton
has shown that this explanation by no means sufhces with
the New Zealanders, nor does it with the Tasmanians.

Rusclienberger is quoted by Bonwick, "Last of the Tasmanians,"
1870, p. 378. Bishop is quoted by Sir E. Belcher, " Voyage Round
the World," 1848, vol. i, p. 272. I owe the census of the several
years to the kindness of Mr. Coan, at the request of Dr. Youmans, of
New York; and in most cases I have compared the Youmans figures
with those given in several of the above-named works. I have
omitted the census for 1850, as I have seen two widely different num-
bers given.
* '• The Indian Medical Gazette/' Nov. \, 1871, p. 240,

THE RAGES OF MAN, 21 5

In the paper above quoted, Mr. Macnamara gives reasons
for believing that the inhabitants of districts subject to
malaria are apt to be sterile; but this cannot apply in sev-
eral of the above cases. Some writers have suggested that
the aborigines of islands have suffered in fertility and
health from long continued inter-breeding; but in the above
cases infertility has coincided too closely with the arrival
of Europeans for us to admit this explanation. Nor have
we at present any reason to believe that man is highly sen-
sitive to the evil effects of inter-breeding, especially in
areas so large as New Zealand and the Sandwich Archi-
pelago with its diversified stations. On the contrary, it is
known that the present inhabitants of Norfolk Island are
nearly all cousins or near relations, as are the Todas in
India, and the inhabitants of some of the Western Islands
of Scotland; and yet they seem not to have suffered in
fertility. *

A much more probable view is suggested by the analogy
of the lower animals. The reproductive system can be
shown to be susceptible to an extraordinary degree (though
why we know not) to changed conditions of life; and this
susceptibility leads both to beneficial and to evil results.
A large collection of facts on this subject is given in chap-
ter xviii, of volume ii, of my ^' Variation of Animals and
Plants under Domestication." I can here give only the
briefest abstract; and every one interested in the subject
may consult the above work. Very slight changes increase
the health, vigor and fertility of most or all organic beings,
while other changes are known to render a large number of
animals sterile. One of the most familiar cases is that of
tamed elephants not breeding in India; though they often
breed in Ava, where the females are allowed to roam about
the forests to some extent, and are thus placed under more
natural conditions. The case of various American mon-
keys, both sexes of which have been kept for many years
together in their own countries, and yet have very rarely
or never bred, is a more apposite instance, because of their
relationship to man. It is remarkable how slight a change

* On the close relationship of the Norfolk Islanders, see Sir W.
Denison, "Varieties of Vice-Regal Life," vol. i, 1870, p. 410. For
the Todas, see Col. Marshall's work, 1873, p. 110. For the Western
Islands of Scotland, Dr. Mitchell, "Edinburgh Medical Journal,"
March to June, 1865,

216 THE DESCENT OF MAN,

in the conditions often induces sterility in a wild animal
when captured; and this is the more strange as all our
domesticated animals have become more fertile than they
were in a state of nature; and some of them can resist the
most unnatural conditions with undiminished fertility.*
Certain groups of animals are much more liable than others
to be affected by captivity; and generally all the species of
the same group are affected in the same manner. But
sometimes a single species in a group is rendered sterile^
while the others are not so; on the other hand, a single
species may retain its fertility while most of the others fail
to breed. The males and females of some species when
confined, or when allowed to live ahnost but not quite free,
in their native country never unite; others thus circum-
stanced frequently unite but never produce offspring;
others again produce some offspring, but fewer than in a
state of nature; and as bearing on the above cases of man
it is important to remark that the young are apt to be
weak and sickly, or malformed, and to perish at an early
age.

Seeing how general is this law of the susceptibility of the
reproductive system to changed conditions of life, and that
it holds good with our nearest allies, the Quadrumana, I
can hardly doubt that it applies to man in his primeval state.
Hence, if savages of any race are induced suddenly to change
their habits of life they become more or less sterile, and
their young offspring suffer in health in the same manner
and from the same cause as do the elephant and hunting-
leopard in India, many monkeys in America, and a host
of animals of all kinds on removal from their natural
conditions.

We can see why it is that aborigines, who have long
inhabited islands, and who must have been long exposed to
nearly uniform conditions, should be specially affected by
any change in their habits, as seems to be the case. Civil-
ized races can certainly resist changes of all kinds far
better than savages ; and in this respect they resemble
domesticated animals, for though the latter sometimes
suffer in health (for instance European dogs in India), yet
they are rarely rendered sterile, though a few such

*For tlie evidence on this head, see " Variation of Animals," etc., .
vol. ii, p. 111.

THE RAGES OF MAN. 217

instances have been recorded.* The immunity of civilized
races and domesticated animals is probably due to their
having been subjected to a greater extent, and, therefore,
having grown somewhat more accustomed, to diversified or
varying conditions, than the majority of wild animals; and
to their having formerly immigrated or been carried from
country to country, and to different families or sub-races
having inter-crossed. It appears that a cross with civilized
races at once gives to an aboriginal race an immunity from
the evil consequences of changed conditions. Thus the
crossed offspring from the Tahitians and English, when
settled in Pitcairn Island, increased so rapidly that the
island was soon overstocked; and in June, 1856, they were
removed to Norfolk Island. They then consisted of
60 married persons and 134 children, making a total of
194. Here they likewise increased so rapidly that,
although 16 of them returned to Pitcairn Island in 1859,
they numbered in January, 1868, 300 souls; the males and
females being in exactly equal numbers. What a contrast
does this case present with that of the Tasmanians; the
Norfolk Islanders increased in only twelve and a half years
from 194 to 300; whereas the Tasmanians decreased during
15 years from 120 to 46, of which latter number only 10
were children, f

So again in the interval between the census of 1866 and
1872 the natives of full blood in the Sandwich Islands
decreased by 8,081, while the half-castes, who are believed
to be healthier, increased by 847; but I do not know
whether the latter number includes the offspring from
the half-castes, or only the half-castes of the first genera-
tion.

The cases which I have here given all relate to aborigines
who have been subjected to new conditions as the result of
the immigration of civilized men. But sterility and ill-
health would probably follow if savages were compelled by
any cause, such as the inroad of a conquering tribe, to
desert their homes and to change their habits. It is an

*" Variation of Animals," etc., vol. ii, p. 16.

f These details are taken from " The Mutineers of the ' Bounty,' '*
by Lady Belcher, 1870; and from "Pitcairn Island," ordered to be
printed by the House of Commons, May 29, 1863. The following"
statements about the Sandwich Islanders are from the "Honolulu
Gazette," and from Mr. Coan.

21 8 THE DESCENT OF MAK

interesting circumstance that tlie chief check to wild ani-
mals becoming domesticated, which implies the power of
their breeding freely when first captured, and one chief
check to wild men, when brought into contact with civil-
ization, surviving to form a civilized race, is the same,
namely, sterility from changed conditions of life.

Finally, although the gradual decrease and ultimate
extinction of the races of man is a highly complex
problem, depending on many causes which differ in
different places and at different times ; it is the same
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 afterward to be
replaced, within the same districts, by countless troups of
the Spanish horse. The New Zealander seems conscious of
this parallelism, for he compares his future fate with that
of the native rat now almost exterminated by the Euro-
pean rat. Though the difficulty is great to our imagi-
nation, and really great, if we wish to ascertain the precise
causes and their manner of action, it 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 checked
in various ways; so that if any new check, even a slight
one, be superadded, the race will surely decrease in number;
and decreasing numbers will sooner or later lead to extinc-
tion; the end, in most cases, being promptly determined
by the inroads of conquering tribes.

Ofi the Formation of the Races of Man. — In some cases
the crossing of distinct races has led to the formation of a
new race. The singular fact that the Europeans and Hin-
doos, who belong to the same Aryan stock and speak 'a
language fundamentally the same, differ widely in appear-
ance, while Europeans differ but little from Jews, who
belong to the Semitic stock and speak quite another lan-
guage, has been accounted for by Broca,* through certain
Aryan branches having been largely crossed by indigenous
tribes during their wide diffusion. AVhen two races in
close contact cross the first result is a heterogeneous mix-
ture; thus Mr. Hunter, in describing the Santali or hill-

*" On Anthropology," translation " Antliropolog. Review," Jan.,
1868, p. 38.

THE RAGES OF MAN, 219

tribes of India, says that hundreds of imperceptible grada-
tions may be traced '^ from the black, squat tribes of the
mountains to the tall olive-colored Brahman, with his intel-
lectual brow, calm eyes, and high but narrow head;" so
that it is necessary in courts of justice to ask the wit-
nesses whether they are Santalis or Hindoos.* 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 evi-
dence. But as with our domesticated animals, a cross-
breed can certainly be fixed and made uniform by careful
selection f in the course of a few generations, we may infer
that the free intercrossing of a heterogeneous mixture
during a long descent would supply the place of selection
and overcome any tendency to reversion ; so that the
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 color
of the skin is the most conspicuous and one of the best
marked. It was formerly thought that differences of this
kind could be accounted for by long exposure to
different climates ; but Pallas first showed that this
is not tenable and he has since been followed
by almost all anthropologists. I This view has been
rejected chiefly because the distribution of the variousl}^
colored races, most of whom must have long inhabited their
present homes, does not coincide with corresponding dif-
ferences of climate. Some little weight may be given to
such cases as that of the Dutch families, who, as we hear on
excellent authority, § have not undergone the least change
of color after residing for three centuries in S. Africa.
An argument on the same side may likewise be drawn

* " The Annals of Rural Bengal," 1868, p. 134.

•f-"Tlie Variation of Animals and Plants under Domestication,"
vol. ii, p. 95.

X Pallas, " Act. Acad. St. Petersburg," 1780, part ii, p. 69. He
was followed by Rudolpbi, in bis " Beytrage zur Anthropologie, "
1812. An excellent summary of the evidence is given by Godron,
" De I'Espece," 1859, vol. ii, p. 246, etc.

§ Sir Andrew Smitb, as quoted by Knox, " Races of Man," 1850,
p. 473.

220 THE DESCENT OF MAN.

from the uniform appearance in various parts of the world
of gypsies and Jews, though the uniformity of the latter
has been somewhat exaggerated.* A very damp or a very
dry atmosphere has been supposed to be more influential in
modifying the color 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. \

Various facts, which I have given elsewhere, prove that
the color 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 from the
deadly influence of the miasma of their native countries,
during a long series of generations.

I afterward found that this same idea had long ago
occurred to Dr. Wells. J It has long been known that
negroes, and even mulattoes are almost completely exempt
from the yellow fever, so destructive in tropical America. §
They likewise escape to a large extent the fatal intermit-
tent fevers that prevail along at least 2,600 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. || This immunity in the negro seems to be partly
inherent, depending on some unknown peculiarity of con-
stitution and partly the result of acclimatization. Pouchet^
states that the negro regiments recruited near the Soudan

* See De Quatref ages on this head, ' ' Revue des Cours Scien-
tifiques," Oct. 17, 1868, p. 731.

f Livingstone's "Travels and Researches in S. Africa," 1857, pp.
338, 339. D'Orbigny, as quoted by Godron, " De I'Espece," vol. ii,
p. 266.

X See a paper read before tlie Royal Soc. in 1813 and published in
his Essays in 1818. I have given an account of Dr. Wells' views in
the Historical Sketch (p. 16) to my " Origin of Species." Various
cases of color correlated with constitutional peculiarities are given in
my " Variationof Animals under Domestication," vol. ii, pp. 227, 335.

§ See, for instance, Nott and Gliddon, " Types of Mankind," p. 68.

II Maj. Tulloch, in a paper read before the Statistical Society, April
20, 1840, and given in the " Athenaeum," 1840, p. 353.

Y' The Plurality of the Human Race " (translate), 1864, p 60.

THE RAGES OF MAN, 221

and borrowed from the Viceroy of Egypt for the Mexican
war escaped the yellow fever almost equally with the
negroes originally brought from various parts of Africa and
accustomed to the climate of the West Indies. That
acclimatization plays a part is shown by the many cases in
which negroes have become somewhat liable to tropical
fevers, after having resided for some time in a colder
climate.* 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 acclimatization,
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 Kev. H. B. Tristram states that there are districts
in Northern Africa w^hich the native inhabitants are com-
pelled annually to leave, though the negroes can remain
with safety.

That the immunity of the negro is in any degree corre-
lated with the color of his skin is a mere conjecture; it
may be correlated with some difference in his blood, nerv-
ous system or other tissues. Nevertheless, from the facts
above alluded to and from some connection apparently ex-
isting between complexion and a tendency to consumption,
the conjecture seemed to me not improbable. Conse-
quently I endeavored, with but little success, f to ascertain

* Quatrefages, " Unite de I'Espece Humaine," 1881, p. 205. Waitz,
*' Introduct. to Anthropology," translat., vol. i, 1863, p. 134. Liv-
ingstone gives analogous cases in his " Travels."

f In the spring of 1862 I obtained permission from the Director-
General of the Medical Department of the Army to transmit to the
surgeons of the various regiments on foreign service a blank table,
with the following appended remarks, but I have received no
returns: "As several well-marked cases have been recorded with
our domestic animals of a relation between the color of the dermal
appendages and the constitution; and it being notorious that there is
some limited degree of relation between the color of the races of man
and the climate inhabited by them; the following investigation seems
worth consideration. Namely, whether there is any relation in Euro-
peans between the color of their hair and their liability to the diseases
of tropical countries. If the surgeons of the several regiments, when
gtatioued in unhealthy tiopical districts, would be so good as first to

222 THE DESCENT OF MAN,

how far it holds 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 ex-
perienced negro chief predicted from his appearance that
this would prove the case. Dr. Nicholson, of Antigua,
after having attended to this subject, writes to me that
dark-colored Europeans escape the yellow fever more than
those that are light colored. Mr. J. M. Harris altogether
denies that Europeans with dark hair withstand a hot cli-
mate 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 go, there seems no
foundation for the hypothesis that blackness has resulted
from the darker and darker individuals having survived
better during long exposure to fever-generating miasma.
Dr. Sharpe remarks, \ that a tropical sun, which burns

count, as a standard of comparison, how many men, in the force
whence the sick are drawn, have dark and light-colored hair and
hair of intermediate or doubtful tints; and if a similar account were
kept by the same medical gentlemen of all the men who suffered
from malarious and yellow fevers, or from dysentery, it would soon
be apparent, after some thousand cases had been tabulated, whether
there exists any relation between the color of the hair and constitu-
tional liability to tropical diseases. Perhaps no such relation would
be discovered, but the investigation is well worth making. In case
any positive result were obtained it might be of some practical use
in selecting men for any particular service. Theoretically the result
would be of high interest, as indicating one means by which a race
of men inhabiting from a remote period an unhealthy tropical cli-
mate, might have become dark-colored by the better preservation of
dark-haired or dark-complexioned individuals during a long succes-
sion of generations. "

*" Anthropological Review," Jan., 1866, p. 21. Dr. Sharpe also
says, with respect to India (" Man a Special Creation," 1873, p. 118),
" that it has been noticed by some medical officers that Europeans
with light hair and florid complexions suffer less from diseases of
tropical countries than persons with dark hair and sallow complex-
ions; and, so far as I know, there appear to be good grounds for
this remark." On the other hand, Mr. Heddle, of Sierra Leone,
" who has had more clerks killed under him than any other man,"
by the climate of the West African Coast (W. Reade, "African
Sketch Book," vol. ii, p. 522), holds a directly opposite view, as does
Capt. Burton.

f ''Man a Special Creation," 1873, p. 119.

THE RACES OF MAN. 223

and blisters a white skin, does not injure a black one at all;
and, as he adds, this is not due to habit in the individual,
for children only six or eight months old are often carried
about naked, and are not affected. I have been assured by
a medical man that some years ago during each summer,
but not during the winter, his hands became marKed with
light brown patches, like, although larger than freckles,
and that these patches were never affected by sun-burning,
while the white parts of his skin have on several occasions
been much inflamed and blistered. With the lower ani-
mals there is, also, a constitutional difference in liability to
the action of the sun between those parts of the skin
clothed with white hair and other parts.* Whether the
saving of the skin from being thus burned is of sufficient
importance to account for a dark tint having been gradually
acquired by man through natural selection I am unable to
judge. If it be so, we should have to assume that the
natives of tropical America have lived there for a much
shoL-ter time than the negroes in Africa, or the Papuans in
the southern parts of the Malay Archipelago, just as the
lighter-colored Hindoos have resided in India for a shorter
time than the darker aborigines of the central and southern
parts of the peninsula.

Although with our present knowledge we cannot account
for the differences of color in the races of man, through
any advantage thus gained, or from 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, f

We have seen in the second chapter that the conditions
of life affect the development of the bodily frame in a
direct manner, and that the effects are transmitted. Thus,
as is generally admitted, the European settlers in the
United States undergo a slight but extraordinary rapid

* " Variation of Animals and Plants under Domestication," vol. ii,
pp. 336, 387.

f See, for instance, Quatrefages (" Revue des Cours Scientifiques,"
Oct. 10, 1868, p. 724) on tlie effects of residence in Abyssinia and
Arabia, and other analogous cases. Dr. Rolle (''Der Menscb, seine
Abstammung," etc., 1865, s. 99) states, on the authority of Khanikof,
that the greater number of German families settled in Georgia have
acquired in the course of two generations dark hair and eyes. Mr.
D. Forbes informs me that the Quichuas in the Andes vary greatly in
color, according to the position of the valleys inhabited by tnem.

224 THE DESCENT OF MAN.

change of appearance. Their bodies and limbs become
elongated; and I hear from Col. Bernys that during the
late war in the United States, good evidence was afforded
of this fact by the ridiculous appearance presented by the
German regiments when dressed in ready-made clothes
manufactured for the American market, and which were
much too long for the men in every way. There is, also, a
considerable body of evidence showing that in the Southern
States the house slaves of the third generation present a
markedly different appearance from the field slaves.*

If, however, we look to the races of man as distributed
over the world we must infer that their characteristic dif-
ferences 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 exclu-
sively 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 inhabit-
ants of Southern China, who live entirely on vegetable
food and are exposed almost naked to a hot, glaring cli-
mate. The unclothed Fuegians live on the marine pro-
ductions 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 Tuegians 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 ex-
posed to a nearly similar climate and follow nearly the
same habits of life.

Nor can the differences between the races of man be ac-
counted for by the inherited effects of the increased or
decreased use of parts except to a quite insignificant degree.
Men who habitually live in canoes may have their legs
somewhat stunted; those who inhabit lofty regions may
have their chests enlarged; and those who constantly use
certain sense organs may have the cavities in which they
are lodged somewhat increased in size, and their features
consequently a little modified. With civilized nations the

* Harlan, ** Medical Researches," p. 532. Quatrefages ("Unite de
I'Espece Humaine," 1861, p. 128) has collected much evidence on this
head.

THE RAGES OF MAN. 225

reduced size of the jaws from lessened nse — the habitual
play of different muscles serving to express different emo-
tions— and the increased size of the brain from greater
intellectual activity have together produced a considerable
effect on their general appearance when compared with
savages. * Increased bodily stature, without any corre-
sponding increase in the size of the brain, may (judging
from the previously adduced case of rabbits), have given
to some races an elongated skull of the dolichocephalic
type.

Lastly, the little understood principle of correlated de-
velopment has sometimes come into action, as in the case
of great muscular development and strongly projecting
supra-orbital ridges. The color of the skin and hair are
plainly correlated, as is the texture of the hair with its
color in the Mandans of North America. \ The color also
of the skin and the odor 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 ex-
cretory pores are related. J If we may judge from the
analogy of our domesticated animals, many modifications
of structure in man probably come under this principle
of correlated development.

We have now seen that the external characteristic differ-
ences 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 there-
fore led to inquire whether slight individual differences, to
which man is eminently liable, may not have been pre-
served and augmented during a long series of generations
through natural selection. But here we are at once met

*See Prof. ScTiaaffliausen, translat., in " Antliropological Review,"
Oct., 1868, p. 429.

fMr, Catlin states (" North American Indians," 3d edit., 1842, vol.
i, p. 49) tbat in the whole tribe of the Mandans, about one in ten or
twelve of the members, of all ages and both sexes, have bright sil-
very gray hair, which is hereditary. Now this hair is as coarse and
harsh as that of a horse's mane, while the hair of other colors is fine
and soft.

XOn the odor of the skin, Godron, " Sur I'Espece," tom ii, p. 217.
On the pores in the skin, Dr. Wilckens, ** Die Aufgaben der Land-
wirth. Zootechnik," 1869, s. 7.

226 THE DESCENT OF MAN,

by the objection that beneficial variations alone can be
thus preserved; and as far as we are enabled to judge,
although always liable to err on this head, none of the dif-
ferences 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. The great variability of all the external differ-
ences between the races of man, likewise indicates that
they cannot be of much importance; for if 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 such
variations being of an indifferent nature, and to their
having thus 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 Selec-
tion, which appears to have acted 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 only say, in our ignorance, 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 inter-
crossing. Such variations come under the provisional
class, alluded to in our second chapter, which for the want
of a better term are often called spontaneous. Nor do I
pretend that the effects of sexual selection can be indicated
with scientific precision ; but it can be shown that it
would be an inexplicable fact if man had not been modi-
fied by this agency, which appears to have acted power-
fully on innumerable animals. It can further be shown
that the differences between the races of man, as in color,
hairiness, form of features, etc., are of a kind which might
have been expected to come under the influence of sexual
selection. But in order to treat this subject properly, I
have found it necessary to pass the whole animal kingdom
in review. I have therefore devoted to it Part II of this
work. At the close I shall return to man, and, after

THE RACES OF MAN. 227

attempting to show how far he has been modified through
sexual selection, will give a brief summary of the chapters
in Part I.

Note on the Resemblances and Diffekences in the Structure
AND the Development op the Brain in Man and Apes.
By Prof. Huxley, F.R.S.

The controversy respecting the nature and the extent of the differ-
ences in the structure of the brain in man and the apes, which arose
some fifteen years ago, has not yet come to an end, though the sub.
ject matter of the dispute is, at present, totally different from what
it was formerly. It jvas originally asserted and reasserted, with sin-
gular pertinacity, that the brain of all the apes, even the highest,
differs from that of man, in the absence of such conspicuous struct-
ures as the posterior lobes of the cerebral hemispheres, with the pos-
terior cornu of the lateral ventricle and the hippocampus minor, con-
tained in those lobes, which are so obvious in man.

But the truth that the three structures in question are as well
developed in apes as in human brains, or even better; and that it is
characteristic of all the Primates (if we exclude the Lemurs) to have
these parts well developed, stands at present on as secure a basis as
any proposition in comparative anatomy. Moreover, it is admitted
by every one of the long series of anatomists who, of late years, have
paid special attention to the arrangement of the complicated sulci
and gyri which appear upon the surface of the cerebral hemispheres
in man and the higher apes, that they are disposed after the very
same pattern in hin; as in them. Every principal gyrus and sulcus
of a chimpanzee's brain is clearly represented in that of a man, so
that the terminology which applies to the one answers for the other.
On this point there is no difference of opinion. Some years since,
Prof. Bischoff published a memoir* on the cerebral convolutions of
man and apes; and as the purpose of my learned colleague was cer-
tainly not to diminish the value of the differences between apes and
men in this respect, I am glad to make a citation from him.

** That the apes, and especially the orang, chimpanzee and gorilla,
come very close to man in their organization, much nearer than to
any other animal, is a well-known fact, disputed by nobody. Look-
ing at the matter from the point of view of organization alone, no
one probably would ever have disputed the view of Linnseus, that
man should be placed, merely as a peculiar species, at the head of
the mammalia and of those apes. Both show, in all their organs, so
close an affinity that the most exact anatomical investigation is needed
in order to demonstrate those differences which really exist. So it is
with the brains. The brains of man, the orang, the chimpanzee, the
gorilla, in spite of all the important differences which they present,
come very close to one another " (1. c, p. 101).

There remains, then, no dispute as to the resemblance in funda-
mental characters, between the ape's brain and man's; nor any as to

*"Die Grosshirn-Windungen des Menschen;" *' AbUandlungeu der K.
BayeriscUen Akademie," Bd. x. 1868.

228 THE DESCENT OF MAN.

tlie wonderfully close similarity between tlie chimpanzee, orang and
man, in even the details of the arrangement of the gyri and sulci of
the cerebral hemispheres. Nor, turning to the differences between
the brains of the highest apes and that of man, is there any serious
question as to the nature and extent of these differences. It is ad-
mitted that the man's cerebral hemispheres are absolutely and rela-
tively larger than those of the orang and chimpanzee; that his frontal
lobes are less excavated by the upward protrusion of the roof of the
orbits; that his gyri and sulci are, as a rule, less symmetrically dis-
posed, and present a greater number of secondary plications. And it
is admitted that, as a rule, in man, the temporo-occipital or '* exter-
nal perpendicular " fissure, which is usually so strongly marked a
feature of the ape's brain is but faintly marked. But it is also clear,
that none of these differences constitutes a sharp demarcation between
the man's and the ape's brain. In respect to the external perpendic-
ular fissure of Gratiolet, in the human brain for instance, Prof. Turner
remarks : *

" In some brains it appears simply as an indentation of the margin
of the hemisphere, but in others it extends for some distance more or
less transversely outward. I saw it in the right hemisphere of a
female brain pass more than two inches outward; and on another
specimen, also the right hemisphere, it proceeded for four-tenths of
an inch outward, and then extended downward as far as the lower
margin of the outer surface of the hemisphere. The imperfect defi-
nition of this fissure in the majority of human brains, as compared
with its remarkable distinctness in the brain of most Quadrumana, is
owing to the presence in the former of certain superficial, well-
marked, secondary convolutions which bridge it over and connect the
parietal with the occipital lobe. The closer the first of these bridg-
ing gyri lies to the longitudinal fissure the shorter is the external
parieto-occipital fissure " (1. c, p. 12).

The obliteration of the external perpendicular fissure of Gratiolet,
therefore, is not a constant character of the human brain. On the
other hand, its full development is not a constant character of the
higher ape's brain. For, in the chimpanzee, the more or less exten-
sive obliteration of the external perpendicular sulcus by "bridging
convolutions," on one side or the other, has been noted over and over
again by Prof, RoUeston, Mr. Marshall, M. Broca and Prof. Turner.
At the conclusion of a special paper on this subject the latter writes:f

'* The three specimens of the brain of a chimpanzee just described,
prove that the generalization which Gratiolet has attempted to draw
of the complete absence of the first connecting convolution and the
concealment of the second, as essentially characteristic features in the
brain of this animal, is by no means universally applicable. In only
one specimen did the brain, in these particulars, follow the law
which Gratiolet has expressed. As regards the presence of the
superior bridging convolution, I am inclined to think that it has
existed in one hemisphere, at least, in a majority of the brains of this

* " Convolutions of the Human Cerebrum Topographically Considered,"
1866, p. 12.

t Notes more especially on the bridging convohitions in the brain of the
chimpanzee, " Proceedings of the Royal Society of Edinburgh," 1865-66,

THE RAGES OF MAN. 229

animal wliicli liave, up to this time, been figured or described. Tlie
superficial position of the second bridging convolution is evidently
less frequent, and has as yet, I believe, only been seen in the brain
(A) recorded in this communication. The asymmetrical arrangement
in the convolutions of the two hemispheres, which previous observ-
ers have referred to in their descriptions, is also well illustrated in
these specimens " (pp. 8, 9).

Even were the presence of the temporo-occipital, or external per-
pendicular, sulcus, a mark of distinction between the higher apes
and man, the value of such a distinctive character would be ren-
dered very doubtful by the structure of the brain in the Platyrrhine
apes. In fact, while the temporo-occipital is one of the most con-
stant of sulci in the Catarrhine, or Old World, apes, it is never very
strongly developed in the New World apes; it is absent in the smaller
Platyrrhini; rudimentary in Pithecia ;* and more or less obliterated
by bridging convolutions in Ateles.

A character which is thus variable within the limits of a single
group can have no great taxonomic value.

It is further established that the degree of asymmetry of the con-
volution of the two sides in the human brain is subject to much indi-
vidual variation; and that, in those individuals of the Bushman
race who have been examined, the gyri and sulci of the two hemis-
pheres are considerably less complicated and more symmetrical than
in the European brain, while, in some individuals of the chimpanzee,
their complexity and asymmetry become notable. This is particu-
larly the case in the brain of a young male chimpanzee figured by M.
Broca ("L'ordre des Primates," p. 165, fig. 11).

Again, as respects the question of absolute size, it is established
that the difference between the largest and the smallest healthy
human brain is greater than the difference between the smallest
healthy human brain and the largest chimpanzee's or orang's brain.

Moreover, there is one circumstance in which the orang's and the
chimpanzee's brains resemble man's, but in which they differ from the
lower apes, and that is the presence of two corpora candicantia — the
Gynomorpha having but one.

In view of these facts 1 do not hesitate in this year, 1874, to
repeat and insist upon the proposition which I enunciated in 1863 :f

" So far as cerebral structure goes, therefore, it is clear that man
differs less from the chimpanzee or the orang than these do even
from the monkeys, and that the difference between the brain of the
chimpanzee and of man is almost insignificant when compared with
that between the chimpanzee brain and that of a Lemur."

In the paper to which I have referred. Prof, Bischoff does not
deny the second part of this statement, but he first makes the irrele-
vant remark that it is not wonderful if the brains of an orang and a
Lemur are very different; and secondly, goes on to assert that, "If
we successively compare the brain of a man with that of an orang;
the brain of this with that of a chimpanzee; of this with that of a
gorilla, and so on of a Hylobates, Semriopithecus, Cynocephalus, Ger-

* Flower "On the Anatomy of Pithecia JfowocAw," " Proceedings of the
. Zoological Society," 1862.

t " Man's Place m Nature," p. 103,

230 THE DESCENT OF MAN.

copithecuH, Macacus, Cebus, GalUthrix, Lemur, Stenops, Ilapate, we
shall not meet with a greater, or even as great, a break in the degree
of development of the convolutions as we find between the brain of
a man and that of an orang or chimpanzee."

To which I reply, firstly, that whether this assertion be true or
false, it has nothing whatever to do with the proposition enunciated
in "Man's Place in Nature," which refers not to the development of
the convolutions alone, but to the structure of the whole brain. If
Prof. Bischoff had taken the trouble to refer to p. 96 of the work he
criticises, in fact, he would have found the following passage; " And
it is a remarkable circumstance that though, so far as our present
knowledge extends, there is one true structural break in the series of
forms of Simian brains, this hiatus does not lie between man and the
manlike apes, but between the lower and the lowest Simians, or in
other words, between the Old and New World apes and monkeys and
the Lemurs. Every Lemur which has yet been examined, in fact,
has its cerebellum partially visible from above; and its posterior lobe,
with the contained posterior cornu and hippocampus minor, more or
less rudimentary. Every marmoset, American monkey. Old World
monkey, baboon, or manlike ape, on the contrary, has its cerebellum
entirely hidden, posteriorly, by the cerebral lobes, and possesses a
large posterior cornu with a well-developed hippocampus minor."

This statement was a strictly accurate account of what was known
when it was made; and it does not appear to me to be more than
apparently weakened by the subsequent discovery of the relatively
small development of the posterior lobes in the Siamang and in the
Howling monkey. Notwithstanding the exceptional brevity of the
posterior lobes in these two species, no one will pretend that their
brains in the slightest degree approach those of the Lemurs. And
if, instead of putting Hapale out of its natural place, as Prof, Bischoff
most unaccountably does, we write the series of animals he has
chosen to mention as follows : Homo, Pithecus, Troglodytes, Hylo-
hates, Semnopithecus, Cynocephalus, Cercopithecus, Macacus, Cebus,
Callithrix, Hapale, Lemur, Stenops. I venture to reaffirm that the
great break in this series lies between Hapale and Lemur, and that
this break is considerably greater than that between any other two
terms of that series. Prof. Bischoff ignores the fact that long before
he wrote Gratiolet had suggested the separation of the Lemurs from
the other Primates on the very ground of the difference in their cere-
bral characters ; and that Prof. Flower had made the following
observations in the course of his description of the brain of the Javan
Loris : *

"And it is especially remarkable that, in the development of the
posterior lobes, there is no approximation to the Lemurine, short-
hemisphered brain, in those monkeys which are commonly supposed
to approach this family in other respects, viz. , the lower members of
the Platyrrhine group."

So far as the structure of the adult brain is concerned, then, the
very considerable additions to our knowledge, which have been made
by the researches of so many investigators during the past ten years
fully justify the statement which I made in 1863. But it has been

♦ *' Transaotioiw pf tbe Zoological Sooioty,"'yol. t, 1868.

ms RAGES OF MAN, ^31

said that, admitting tlie similarity between the adult brains of man
and apes, tbey are, nevertheless, in reality, widely different, because
they exhibit fundamental differences in the mode of their develop-
ment. No one would be more ready than I to admit the force of this
argument, if such fundamental differences of development really
exist. But I deny that they do exist. On the contrary, there is a
fundamental agreement in the development of the brain in men and
apes.

Gratiolet originated the statement that there is a fundamental dif-
ference in the development of the brains of apes and that of man —
•consisting in this; that in the apes the sulci which first make their
appearance are situated on the posterior region of the cerebral hem-
ispheres, while in the human foetus the sulci firpt become visible on
the frontal lobes.*

This general statement is based upon two observations, the one of
a Gibbon almost ready to be born, in which the posterior gyri were
"well developed," while those of the frontal lobes were *' hardly
indicated"! (1. c, p. 39), and the other of a human foetus at the
22d or 23d week of uterogestation, in which Gratiolet notes that the
insula was uncovered, but that nevertheless "des incisures sement
de lobe anterieur, une scissure peu profonde indique la separation du
lobe occipital, tres-reduit, d'ailleurs des cette epoque. Le reste de la
surface cerebrale est encore absolument lisse."

Three views of this brain are given in plate 2, figs. 1, 2, 3, of the
work cited, showing the upper, lateral and inferior views of the
hemispheres, but not the inner view. It is worthy of note that the
figure by no means bears out Gratiolet's description, inasmuch as the
fissure (antero -temporal) on the posterior half of the face of the hem-
isphere is more marked than any of those vaguely indicated in the
anterior half. If the figure is correct, it in no way justifies Gratio-
let's conclusion: "II y a done entre ces cerveaux [those of a Calli-
thrix and of a Gibbon] et celui du foetus humain une difference fonda-
mental. Chez celui-ci, longtemps avant que les plis temporaux
apparaissent, les plis frontaux essayent ^'e-si^Xer"

Since Gratiolet's time, however, the development of the gyri and

* " Chez tous les singes, les plis posterieurs se developpent les premiers ;
les plis anterieurs se developpent plus tard, aussi la vertebre occipitale et la
parietale sont-elles relativement tresgrandes chez le fcEtus. L'Homme pres-
ente une exception remarquable quant a I'epoque de I'apparition des plis
frontaux, qui sont les premiers indiques ; mais le developpement general du
lobe frontal, envisage seulement par rapport a son volume, suit les memes lois
que dans les singes ;" Gratiolet, " Memoire sur les plis cerebraux de I'Homme
et des Primates," p. 39, Tab. Iv, fig. 3.

t Gratiolet's words are (1. c., p. 39): "Dans le foetus dont il a'agit les plis
cerebraux posterieurs sont bien developpes, tandis que les plis du lobe frontal
sont a peine indiques." The figure, however (PI. iv, fig. 3), shows the fissure
of Rolando, and one of the frontal sulei, plainly enough, l^evertheless, M.
Alix, in his " Notice sur les travaux anthropologiques de Gratiolet " (Mem. de
la Societe d'Anthropologie de Paris," 18()8, p. 3-4), writes thus: " Gratiolet a
eu entre les mains le cerveau d'un foetus de Gibbon, singe eminemment supe-
rieur, et tellement rapproche de Porang, que des naturalistes tres-competents
I'ont range parmi les anthropoides. M. Huxley, par exemple, n'hesite pas sur
ce point. Eh bien, c'est sur le cerveau d'un foetus de Gibbon que Gratiolet a
vu " les circonvolutions du lobe temporo-sphenoidal d^a derelojrpees lorsguHl n'^eocist-
ent pas encor^; de plis mr le lobe ^frontal. II etait done bien autorise a dire que,
chez I'Homme les circonvolutions apparaissent d'a en w^ tandis que chez les
8iiiges elles se developnent ^'w «{i 0.^'^

^32 TBE DESCENT OF MAlT.

sulci of the brain has been made tlie subject of renewed investigation
by Schmidt, Bischoff, Pansch,* and more particularly by Ecker,f
whose work is not only the latest, but by far the most complete
memoir on the subject.

The final results of their inquiries may be summed up as follows:

1. In the human foetus, the sylvian fissure is formed in the course
of the third month of uterogestation. In this, and in the fourth
month, the cerebral hemispheres are smooth and rounded (with the
exception of the sylvian depression), and they project backward far
beyond the cerebellum.

2. The sulci, properly so called, begin to appear in the interval
between the end of the fourth and the beginning of the sixth month
of foetal life, but Ecker is careful to point out that, not only the
time, but the order, of their appearance is subject to considerable
individual variation. In no case, however, are either the frontal or
the temporal sulci the earliest.

The first which appears, in fact, lies on the inner face of the hem-
isphere (whence doubtless Gratiolet, who does not seem to have
examined that face in his foetus, overlooked it), and is either the
internal perpendicular (occipito- parietal), or the calcarine sulcus,
these two being close together and eventually running into one
another. As a rule the occipito-parietal is the earlier of the two.

3. At the latter part of this period, another sulcus, the " posterio-
parietal," or " Fissure of Rolando," is developed, and it is followed,
in the course of the sixth month by the other principal sulci of the
frontal, parietal, temporal and occipital lobes. There is, however,
no clear evidence that one of these constantly appears before the
other; and it is remarkable that, in the brain at the period described
and figured by Ecker (1. c, p. 212-213, Taf. II, figs. 1, 2, 3, 4), the
antero-temporal sulcus {scissure parallele) so characteristic of the ape's
brain, is as well if not better developed than the fissure of Rolando,
and is much more marked than the proper frontal sulci.

Taking the facts as they now stand, it appears to me that the
order of the appearance of the sulci and gyri in the foetal human
brain is in perfect harmony with the general doctrine of evolution,
and with the view that man has been evolved from some ape-like
form; though there can be no doubt that that form was, in many
respects, different from any member of the Primates now living.

Von Baer taught us, half a century ago, that, in the course of
their development, allied animals put on at first, the characters of
the greater groups to which they belong, and, by degrees, assume
those which restrict them within the limits of their family, genus,
and species; and he proved, at the same time, that no developmental
stage of a higher animal is precisely similar to the adult condition of
any lower animal. It is quite correct to say that a frog passes through
the condition of a fish, inasmuch as at one period of its life the tad-
pole has all the characters of a fish, and if it went no further would

♦"Ueber die typische Anordnung derFurchen und Windungen auf den
Grosshirn-Hemispbaren des Menschen und der Affen." " Archiv. f ur Anthro-
pologie," iii, 1868.

t " Zur Entwickelungs Geschichte der Furehen und Windunge i der Gross-
hirn-Hemispharen im Foetus des Menschen." " Archiv. fur Anthropologies* '

fHl£ MACB8 OP MAN. 233

have to be grouped among fishes. But it is equally true that a tad-
pole is very different from any known fish.

In like manner, the brain of a human foetus, at the fifth month,
may correctly be said to be, not only the brain of an ape, but that of
an Arctopithecine or marmoset-like ape; for its hemispheres, with
their great posterior lobster, and with no sulci but the sylvian and
the calcarine, present the characteristics found only in the group of
the Arctopithecine Primates. But it is equally true, as Gratiolot
remarks, that in its widely open sylvian fissure it differs from the
brain of any actual marmoset. No doubt it would be much more
similar to the brain of an advanced foetus of a marmoset. But we
know nothing whatever of the development of the brain in the mar-
mosets. In the Platyrrhini proper, the only observation with which
I am acquainted is due to Pansch, who found in the brain of a foetal
Cebus Apella, in addition to the sylvian fissure and the deep calcarine
fissure, only a very shallow antero-temporal fissure {scissure paralUle
of Gratiolet).

Now this fact, taken together with the circumstance that the
antero-temporal sulcus is present in such Platyrrhini as the Saimiri,
which present mere traces of sulci on the anterior half of the exterior
of the cerebral hemispheres, or none at all, undoubtedly, so far as it
goes, affords fair evidence in favor of Gratiolet's hypothesis, that the
posterior sulci appear before the anterior, in the brains of the
Platyrrhini. But it by no means follows that the rule which may
hold good for the Platyrrhini extends to the Gatarrhini. We have
no information whatever respecting the development of the brain in
the Gynomorpha; and as regards the Anthropomorpha, nothing but
the account of the brain of the Gibbon, near birth, already referred
to. At the present moment there is not a shadow of evidence to show
that the sulci of a chimpanzee's or orang's brain do not appear in the
same order as a man's.

Gratiolet opens his preface with the aphorism : "II est dangereux
dans les sciences de conclure trop vite." I fear he must have for-
gotten this sound maxim by the time he had reached the discussion
of the differences between men and apes in the body of his work. No
doubt the excellent author of one of the most remarkable contribu-
tions to the just understanding of the mammalian brain which has
ever been made, would have been the first to admit the insufficiency
of his data had he lived to profit by the advance of inquiry. The
misfortune is that his conclusions have been employed by persons
incompetent to appreciate their foundation as arguments in favor of
obscurantism.*

But it is important to remark that, whether Gratiolet was right or
wrong in his hypothesis respecting the relative order of appearance
of the temporal and frontal sulci, the fact remains, that before either
temporal or frontal sulci appear, the foetal brain of man presents
characters which are found only in the lowest group of the Primates
(leaving out the Lemurs); and that this is exactly what we should
expect to be the case if man has resulted from the gradual modifica-
tion of the same form as that from which the other Primates have
sprung.

* For example, M. I'Abbe Leconite in his terrible pamphlet* " Le Darwia-
poa^ et rorigiue de rEomme," I87<i.

234 THE DESCENT OF MAIit.

PART IL

SEXUAL SELECTION.

CHAPTER VIII.

PRINCIPLES OF SEXUAL SELECTIOI!^.

Secondary sexual cliaracters — Sexual selection — Manner of action-—
Excess of males — Polygamy — The male aione generally modified
tlirough 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 — The proportion of the sexes in
relation to natural selection.

"With animals which have their sexes separated, the
males necessarily differ from the females in their organs of
reproduction; and these are 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, the male possesses
certain organs of sense or locomotion, of which the female
is quite destitute, or has them more highly developed, in
order that he may readily find or reach her; or again the
male has special organs of prehension for holding her
securely. These latter organs, of infinitely diversified
kinds^ graduate into those which are commonly ranked as
primary, and in some cases can hardly be distinguished
from them; we see instances of* this in the complex append-
ages at the apex of the abdomen in male insects. Unless
indeed we confine the term '^ primary " to the reproductive

BEXUAL SELECTION. 235

glands, it is scarcely possible to decide 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, such as the
mammary glands of mammals and the abdominal sacks of
the marsupials. In some few cases also the male possesses
similar organs, which are wanting in the female, such as
.receptacles for the ova in certain male fishes, and those
^ temporarily developed in certain male frogs. The females
of most bees are provided with a special apparatus for col-
lecting and carrying pollen, and their ovipositor is modified
into a sting for the defense of the larvae and the community.
Many similar cases could be given, but they do not here
concern us. There are, however, other sexual differences
quite unconnected with the primary reproductive organs,
and it is with these that we are more especially concerned,
such as the greater size, strength and pugnacity of the male,
his weapons of offense or means of defense against rivals,
his gaudy coloring and various ornaments, his power of song
and other such characters.

Besides the primary and secondary sexual differences,
such as the foregoing, the males and females of some
animals differ in structures related to different habits
of life, and not at all, or only indirectly, to the repro-
ductive functions. Thus the females of certain flies
(Culicidae and Tabanida?) are blood-suckers, while the
males, living on flowers, have mouths destitute of mandi-
bles. * The males 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 the hermaph-
rodite form, and are destitute of a mouth and of prehensile
limbs. In these cases it is the male which has been modi-
fied and has lost certain important organs which the
females possess. In other cases it is the female which has
lost such parts; for instance, the female glow-worm is des-
titute" of wings, as also are many female moths, some of
which never leave their cocoons. Many female parasitic
crustaceans have lost their natatory legs. In some weevil-

*Westwood, "Modern Class of Insects," vol. ii, 1840, p. 541.
For the statement about Tanais, mentioned below, I am indebted to
Fritz Miiller.

236 THE DESCENT OF MAN.

beetles (Curculionidae) there is a great difference between
the male and the female in the length of the rostrum or
snout; * 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. In the Huia of New Zealand the difference is
wonderfully great, and we hear from Dr. Buller f that the
male uses his strong beak in chiseling the larvae of insects
out of decayed wood, while the female probes the softer
parts with her far longer, much curved and pliant beak;
and thus they mutually aid each other. In most cases
differences of structure between the sexes are more or less
directly connected with the propagation of the species; thus
a female, which has to nourish a multitude of ova, requires
more food than the male, and consequently requires special
means for procuring it. A male animal, which lives for a
very short time, might lose its organs for procuring food
through disuse, without detriment; 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 sexual selec-
tion. This depends on the advantage which certain indi-
viduals have over others of the same sex and species solely
in respect of reproduction. When, as in the cases above
mentioned, the two sexes differ in structure in relation to
different habits of life, they have no doubt been modified
through natural selection, and 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 the same influence; for those individuals which
generated or nourished their offspring best, would leave,
cceteris paribus, the greatest number to inherit their
superiority; while those which generated or nourished their
offspring badly would leave but few to inherit their weaker
powers. As the male has to find the female he requires

*Kirby and Spence, ''Introduction to Entomology," vol. iii, 1826,
p. 309.
} " Birds of New Zealand," 1872, p. 66.

SEXUAL SELECTION. 237

organs of sense and locomotion, but if tliese organs are
necessary for the other purposes of life, as is generally the
case, they will have been developed through natural selec-
tion. 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, when adult, have
their legs and antennae modified in an extraordinary
manner for the prehension of the female; hence we may
suspect that it is because these animals are washed about
by the waves of the open sea that they require these organs
in order to propagate their kind, and, if so, their develop-
ment has been the result of ordinary or natural selection.
Some animals extremely low in the scale have been modified
for this same purpose; thus the males of certain parasitic
worms, when fully grown, have the lower surface of the
terminal part of their bodies roughened like a rasp, and
with this they coil round and permanently hold the
females.*

When the two sexes follow exactly the same habits of
life, and the male has the censory or locomotive organs
more highly developed than those of the female, it may be
that the perfection of these is 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
with sufficient time the less well-endowed males w^ould suc-
ceed in pairing with the females; and judging from the
structure of the female, they would be in all other respects
equally well adapted for their ordinary habits of life. Since
in such cases the males have acquired their present struct-
ure not from being better fitted to survive in the struggle

*M. Perrier advances this case ("Revue Scientifique," Feb. 1,
1873, p. 865) as one fatal to the belief in sexual selection, inasmuch
as he supposes that I attribute all the differences between the sexes
to sexual selection. This distinguished naturalist, therefore, like so
many other E'renchmen, has not taken the trouble to understand even
the first principles of sexual selection. An English naturalist insists
that the claspers of certain male animals could not have been devel-
oped through the choice of the female ! Had I not met with this
remark I should not have thought it possible for any one to have
read this chapter and to have imagined that I ijiaintain that the
choice of the female had anything to do with th^ development of th^
prehensile organs in the male.

238 THE DESCENT OF MAK

for existence, but from having gained an advantage ovei
other males, and from having transmitted this advantage to
their male offspring alone, sexual selection must here have
come into action. 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
individuals over their rivals. But in most cases of this
kind it is impossible to distinguish between the effects of
natural and sexual selection. Whole chapters could 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 pass
them over almost entirely, 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 offense and the means of defense of the
males for fighting with and driving away their rivals — their
courage and pugnacity — their various ornaments — their
contrivances for producing vocal or instrumental music —
and their glands for emitting odors, most of these latter
structures serving only to allure or excite the female. It
is clear that these characters are the result of sexual and
not of ordinary selection, since unarmed, unornamented, or
unattractive males would succeed equally well in the battle
for life and in leaving a numerous progeny, but for the
presence of better endowed males. We may infer that this
would be the case, because 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 chap-
ters, as being in many respects interesting, but especially
as depending on the will, choice, and rivalry of the indi-
viduals of either sex. When we behold two males fighting
for the possession of the female, or several male birds dis-
playing their, gorgeous plumage and performing strange
antics before an assembled body of females, we cannot doubt
that; though led by instinct, they know what they are

SEXUAL SELECTION, 239

about, and consciously exert tlieir mental and bodily
powers.

Just as man can improve the breed of his game-cocks by
the selection of those birds which are victorious in the
cock-pit, so it appears that the strongest and most vigorous
males, or those provided with the best weapons, have pre-
vailed under nature, and have led to the improvement of
the natural breed or species. A slight degree of variability
leading to some advantage, however slight, in reiterated
deadly contests would suffice for the work of sexual selec-
tion; and it is certain that secondary sexual characters are
eminently variable. Just as man can give beauty, accord-
ing to his standard of tase, to his male poultry, or more
strictly can modify the beauty originally acquired by the
parent species, can give to the Sebright bantam a new and
elegant plumage, an erect and peculiar carriage — so it
appears that female birds in a state of nature have by a
long selection of the more attractive males added to
their beauty or other attractive qualities. Ko doubt
this implies powers of discrimination and taste on the part
of the female, which will at first appear extremely improb-
able; but by the facts to be adduced hereafter, I hope to
be able to show that the females actually have these
powers. When, however, it is said that the lower animals
have a sense of beauty, it must not be supposed that such
sense is comparable with that of a cultivated man, with his
multiform and complex associated ideas. A more just
comparison would be between the taste for the beautiful in
animals, and that in the lowest savages, who admire and
deck themselves with any brilliant, glittering, or curious
object.

From our ignorance on several points, the precise manner
in which sexual selection acts is somewhat 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 sectual selection has
played an important part in the history of the organic
world. It is certain that among 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 super-
fluous to give instances. Hence the females have the oppor-
tunity of selecting one out of several males, on the suppo-
sition that their mental capacity suffices for the exertion of

240 THE DESCENT OF MAN.

a choice. In many cases special circumstances tend to
make the struggle between the males particularly severe.
Thus the males of our migratory birds generally arrive at
their places of breeding before the females, so that many
males are ready to contend for each female. I am informed
by Mr. Jenner Weir, that the bird-catchers assert that this
is invariably the case with the nightingale and blackcap,
and with respect to the latter he can himself confirm the
statement.

Mr. Swaysland, of Brighton, has been in the habit during
the last forty years of catching our migratory birds on
their first arrival, and lie has never known the females of
any species to arrive before their males. During one
spring he shot thirty-nine males of Eay^s wagtail {Budytes
Bail) before he saw a single female. Mr. Gould has ascer-
tained by the dissection of those snipes which arrive the
first in this country that the males come before the females.
And the like holds good with most of the migratory birds
of the United States.* The majority of the male salmon
in our rivers on coming up from the sea are ready to breed
before the females. So it appears to be with frogs and
toads. Throughout the great class of insects the males
almost always are the first to emerge from the pupal state,
so that they generally abound for a time before any females
can be seen, f 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 the most eager, would leave the
largest number of offspring; and these would tend to in-
herit similar instincts and constitutions. It must be borne
in mind that it would have been impossible to change very
materially the time of sexual maturity in the females with-
out at the same time interfering with the period of the

*J. A. Allen on the "Mammals and Winter Birds of Florida,"
Bull. Comp. Zoology, Harvard College, p. 268.

f Even witli those plants in which the sexes are separate, the male
flowers are generally mature before the female. As first shown by
C. K. Sprengel, many hermaphrodite plants are dichogamous; that
is, their male and female organs are not ready at the same time, so
that they cannot be self-fertilized. Now in such flowers the pollen
is in general matured before the stigma, though there are exceptional
cases in which the female organs are beforehand.

SEXUAL SELECTION, 241

production of the young — a period which must be deter-
mined by the seasons of the year. 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 under-
standing how it is that the males which conquer other
males, or those which prove the most attrative to the
females, leave a greater number of oif spring to inherit their
superiority than their beaten and less attractive rivals.
Unless this result does follow the characters which give to
certain males an advantage over others could not be per-
fected and augmented through sexual selection. When
the sexes exist in exactly equal numbers the worst endowed
males will (except where polygamy prevails) ultimately
find females and leave as many offspring as 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 charac-
ters are well developed, the males considerably exceeded
the females in number; but this is not by any means
always true. If the males were to the females as two to
one, or 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
proportion of the sexes I do not believe that any great in-
equality 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 carefully attended to
the habits of birds during many years. There can also be
no doubt that the most vigorous, best-nourished and earliest
breeders would on an average succeed in rearing the
largest number of fine offspring.* The males, as we have

* Here is excellent evidence on tlie cliaracter of the offspring from
an experienced ornithologist. Mr. J. A. Allen, in speaking (" Mam-

U2 THE DESGBNT OF MAN,

seen, are generally ready to breed before the females; the
strongest, and with some species the best armed of the
males, drive away the weaker; and the former would then
unite with the more vigorous and better-nourished females,
because they are the first to breed.* Such vigorous pairs
would surely rear a larger number of offspring than the
retarded females, which would be compelled to unite with
the conquered and less powerful males, supposing the sexes
to be numerically equal; 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 very many cases the males which conquer their
rivals do not obtain possession of the females, independently
of the choice 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 pair-
ing with, the more ornamented males, or those which are
the best songsters, or play the best antics; but it is obviously
probable that they would at the same time prefer the more
vigorous and lively males, and this has in some cases been
confirmed by the actual observation, f 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. Both sexes, therefore, of such early
pairs would, as above explained, have an advantage over
others in rearing offspring ; and this apparently has
sufficed during a long course of generations to add not

mals and Winter Birds of E. Florida," p. 229) of the later broods
after the accidental destruction of the first, says that these " are found
to be smaller and paler-colored than those hatched earlier in the sea-
son. In cases where several broods arc reared each year, as a general
rule the birds of the earlier broods seem in all respects the most per-
fect and vigorous."

* Hermann Mtiller has come to this same conclusion with respect
to those female bees which are the first to emerge from the pupa each
year. See his remarkable essay, "Anwendung den Darwin'schen
Lehre auf Bienen," •* Verb. d. V. Jahrg.," xxix, p. 45.

f With respect to poultry, I have received information, hereafter to
be given, to this effect. Even with birds, such as pigeons, which
pair for life, the female, as I hear from Mr. Jenner Weir, will desert
her mate if he is injured or grows weak.

SEXUAL SELE6TI0K. S43

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 select-
ing 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 her in providing for the young. The same principles
would apply if each sex preferred and selected certain
individuals of the opposite sex; supposing that they selected
not only the more attractive, but likewise the more vigor-
ous individuals.

Numerical Proportion of the Two Sexes. — I have remarked
that sexual selection would be a simple aff'air if the males
were considerably more numerous than 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 supple-
mentary discussion so as not to interfere with the course of
my argument. Domesticated animals alone afford the
means 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 statistics, from which it appears that with most
of our domestic animals the sexes are nearly equal at birth.
Thus 25,560 births of race-horses have been recorded during
twenty-one years, and the male births were to the female
births as 99.7 to 100. In greyhounds the inequality is
greater than with any other animal, for out of 6,878 births
during twelve years, the male births were to the female as
110.1 to 100. It is, however, in some degree doubtful
whether it is safe to infer that the proportion would be the
same under natural conditions as under domestication; for
slight and unknown differences in the conditions affect the
proportion of the sexes. Thus with mankind, the male
births in England are as 104.5, in Kussia as 108.9, and with
the Jews of Livonia as 120 to 100 female births. But I
ehall recur to this curious point of the excess of male births

244 THE DESCENT OF MAN.

in the supplement to this chapter. At the Cape of Good
Hope, however, male children of Eiiropeon extraction have
been born during several years in the proportion of between
90 and 99 to 100 female children.

For our present purpose we are concerned with the pro-
portion of the sexes, not only at birth, but also at maturity,
and this adds another element of doubt; for it is a well-
ascertained fact that with man the number of males dying
before or during birth and during the first few years of
infancy is considerably larger than that of females. So it
almost certainly is with male lambs, and probably with
some other animals. The males of some species kill one
another by fighting; or they drive one another about until
they become greatly emaciated. They must also be often
exposed to various dangers while wandering about in eager
search for the females. In 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. The
females of some birds appear to die earlier than the males;
they are also liable to be destroyed on their nests or while
in charge of their young. With insects the female larvae
are often larger than those of the males, and would conse-
quently be more likely to be devoured. In some cases the
mature females are less active and less rapid in their move-
ments than the males and could not escape so well from
danger. Hence, with animals in a state of nature we must
rely on mere estimation in order to judge of the propor-
tions of the sexes at maturity; and this is but little trust-
worthy except when the inequality is strongly marked.
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, are considerably more numerous than the
females.

The proportion between the sexes fluctuates slightly
during successive years; thus with race-horses, for every
100 mares born the stallions varied from 107.1 in one year
to 92.6 in another year, and with greyhounds from 116.3
to 95.3. But had larger numbers been tabulated through-
out an area more extensive than England these fluctuations
would probably have disappeared; and such as they are,
would hardly suffice to lead to effective sexual selection in
a, state of nature. Nevertheless, in the cases of some few

SEXUAL SELECTION. 245

wild animals, as shown in the supplement, the proportions
seem to fluctuate either during different seasons or in dif-
ferent localities in a sufficient degree to lead to such selec-
tion. For it should be observed that any advantage gained
during certain years or in certain localities by those males
which were able to conquer their rivals, 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 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 weaker 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 cannot 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 evi-
dence of this habit. The intellectual powers of such ani-
mals are, perhaps, not sufficient to lead them to collect and
guard a harem of females. That some relation exists be-
tween 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 favorable to the action of sexual selection.
Nevertheless many animals which are strictly monogamous,
especially birds, display strongly marked secondary sexual
characters; while some few animals which are polygamous
do not have such characters.

We will first briefly run through the mammals and
then turn to birds. The gorilla seems to be polygamous,
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 car ay a presents well-marked sexual differences,
in color, beard, and vocal organs ; and the male generally
lives with two or three wives; the male of the Cehus capuci-
nus differs somewhat from the female, and appears to be

246 THE DESCENT OF MAN.

polygamous.* Little is known on this head with respect to
most other monkeys, but some species are strictly monoga-,
mous. The ruminants are eminently polygamous, and they
present sexual differences more frequently than almost any
other group of mammals; this holds good, especially in
their weapons, but also in other characters. Most deer,
cattle, and sheep are polygamous; as are most antelopes,
though some are monogamous. Sir Andrew Smith, in
speaking of the antelopes of S. 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 Pallasf states
that the male drives away all rivals and collects a herd of
about a hundred females and kids together; the female is
hornless and has softer hair, but does not otherwise differ
much from the male. The wild horse of the Falkland
Islands and of the Western States of North America is
polygamous, but, except in his greater size and the propor-
tions of his body, diff'ers but little from the mare. The
wild boar presents well-marked sexual characters, in his
great tusks and some other points. In Europe and in India
he leads a solitary life, except during the breeding-season ;
but as is believed by Sir W. Elliot, who has had many
opportunities in India of observing this animal, he consorts
at this season with several females. Whether this holds
good in Europe is doubtful, but it is supported by some
evidence. The adult male Indian elephant, like the boar,
passes much of his time in solitude; but as Dr. Campbell
states, when with others, *^ it is rare to find more than one
male with a whole herd of females ;" the larger males
expelling or killing the smaller and weaker ones. The
male differs from the female in his immense tusks, greater
size, strength and endurance; so great is the difference in
these respects, that the males when caught are valued at

*0n the Gorilla, Savage and Wyman, "Boston Journal of Nat.
Hist.," vol. v, 1845-47, p. 423. On Cynocephalus, Brebui, " Illust.
Thierleben," B.i, 1864, s. 77. On Mycetes, Rengger, " Naturgescli.:
Saugethiere von Paraguay," 1830, ss. 14, 20. Cebus, Brehm, ibid, s.
108.

f Pallas, "Spicilegia Zoolog., Fasc," xii, 1777, p. 29. Sir Andrew
Smith, " Illustrations of the Zoology of S. Africa," 1849, pi. 29, on
the Kobus. Owen, in his "Anatomy of Vertebrates" (vol. iii, 1868,
p. 633) gives a table showing incidentally which species of antelopes
are gregarious.

SEXUAL SELECTION. 247

one-fifth more than the females.* The sexes of other
pachydermatous animals differ very little or not at all, and,
as far as known, they are not polygamists. Nor have I
heard of any species in the orders of Cheiroptera, Edentata,
Insectivora and Eodents being polygamous, excepting that
among the Eodents, the common rat, according to some
rat-catchers, lives with several females. Nevertheless the
two sexes of some sloths (Edentata) differ in the character
and color of certain patches of hair on their shoulders, f
And many kinds of bats (Cheiroptera) present well-
marked sexual differences, chiefly in the males possessing
odoriferous glands and pouches, and by their being of
a lighter color. X In the great order of Eodents, as far as I
can learn, the sexes rarely differ, and when they do so it
is but slightly in the tint of the fur.

As I hear from Sir Andrew Smith, the lion in S. Africa
sometimes lives with a single female, but generally with
more, and, in one case, was found with as many as five
females; so that he is polygamous. As far as I can dis-
cover he is the only polygamist among all the terrestrial
Carnivora, and he alone presents well-marked sexual char-
acters. If, however, we turn to the marine Carnivora, as
we shall hereafter see, the case is widely different; for many
species of seals offer extraordinary sexual differences,
and they are eminently polygamous. Thus, according to
Peron, the male sea -elephant of the Southern 'Ocean
always possesses 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. It is an interesting
fact, as Dr. Gill remarks, § that in the monogamous species,
*' or those living in small communities, there is little differ-
ence in size between the males and females; in the social
species, or rather those of which the males have harems,
the males are vastly larger than the females.'^

*Dr. Campbell, in " Proc. Zoolog. Soc," 1869, p. 138. See also
an interesting paper, by Lieut. Johnstone, in ' ' Proc. Asiatic Soc. of
Bengal," May, 1868.

f Dr. Gray, in "Annals and Mag. of Nat. Hist.," 1871, p. 302.

:t:See Dr. Dobson's excellent paper in " Proc. Zoolog. Soc," 187S,
p. 241.

§ Tbe Eared Seals, " American Naturalist," vol. iv, Jan., 1871.

248 THE DESCENT OF MAN.

Among birds, many species, the sexes of which differ
greatly from each other, are certainly monogamous. In
Great Britain we see well-marked sexual differences, for
instance, in the wild duck which pairs with a single female,
the common blackbird, and the bullfinch which is said to
pair for life. I am informed by Mr. Wallace that the like
IS true of the Chatterers or Cotingidae of South America,
and of many 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 tells me he has been led to believe that hum-
ming - birds are polygamous. The male widow - bird,
remarkable for his caudal plumes, certainly seems to be a
polygamist.* I have been assured by Mr. Jenner Weir and
by others that it is somewhat common for three starlings to
frequent the same nest; but whether this is a case of
polygamy or polyandry has not been ascertained.

The Gallinacese exhibit 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 pre-
sented between the sexes of the polygamous peacock or
pheasant, and the monogamous guinea-fowl or partridge!
Many similar cases could be given, as in the gi'ouse tribe,
in which the males of the polygamous capercailzie and
black-cock differ greatly from the females; while the sexes
of the monagamous red grouse and ptarmigan differ very
little. In the Cursores, except among the bustards, few
species offer strongly-marked sexual differences, and the
great bustard ( Otis tarda) is said to be polygamous. With
the Grallatores extremely few species differ sexually, but
the ruff' (Machetes pvgnax) affords a marked exception and
this species is believed by Montagu to be a polygamist.
Hence it appears that among birds there often exists a close
relation between polygamy and the development of strongly-

* " The Ibis," vol. iii, 1861, p. 133, on the Progne Widow-bird.
See also on the Vidua axillans, ibid., vol. ii, 1860, p. 211. On the
polygamy of the Capercailzie and Great Bustard, see L. Llovd,
"Game Birds of Sweden," 1867, pp. 19, 182. Montagu and Selby
speak of the Black Grouse as polygamous and of the Red Grouse as
monogamous.

SELUAL SELECTION, 249

marked sexual differeoces. 1 asked Mr. Bartlett, of the
Zoological Gardens, who has had T?ry large oxpeiience
with birds, whether the male Gragopan (one of the Gailin-
accEP) was polygamous, and I was struck by his answering,
*' I do not know, but should think so from his splendid
colors."

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 polyga-
mous. The Rev. W. D. Fox informs me that out of some
half-tamed wild-ducks, on a large pond in his neighbor-
hood, 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 suc-
ceed best when he keeps one cock to two or three hens.
Canary-birds pair in a state of nature, but the breeders in
England successfully put one male to four or five females.
I have noticed these cases as rendering it probable that
wild monogamous species might readily become either tem-
porarily or permanently polygamous.

Too little is known of the habits of reptiles and fishes
to enable us to speak of their marriage arrangements. The
stickle-back (Gasterosteus), however, is said to be a polyg-
amist;* 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 second-
ary sexual characters. It has been shown that the largest
number of vigorous offspring will be reared from the pair-
ing of the strongest and best-armed males, victorious in
contests over other males, with the most vigorous and best-
nourished females, which are the first to breed in the spring.
If such females select the more attractive, and at the same
time vigorous males, they will rear a larger number of off'-
c«pring 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
Slime time healthy and vigorous females; and this will espe-
cially hold good if the male defends the female and aids
in providing food for the young. The advantage thus

♦i^oei Humphreys, " River Gardens," 1857.

350 THE DESCENT OF MAN,

gained by the more vio^orous pairs in rearing a larger
number of offspring lias apparently sufficed to render sex-
ual selection efficient. But a large numerical preponder-
ance of males over females will be still more efficient;
whether the preponderance is only occasional and local, or
permanent; whether it occurs at birth, or afterward from
the greater destruction of the females; or whether it in-
directly follows from the practice of polygamy.

The Male Generally More Modified than the Female. —
Throughout the animal kingdom when the sexes differ
in external appearance, it is, with rare exceptions, the male
which has been the more modified; for, generally, the
female retains a closer resemblance to the young of her own
species and to other adult 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 tight together and sedulously display
their charms before the females; and the victors transmit
their superiority to their male offspring. Why both sexes
do not thus acquire the characters of their fathers will be
considered hereafter. That the males of all mammals
eagerly pursue the females is notorious to every one. So it
is with birds; but many cock birds do not so much pursue
the hen, as display their plumage, perform strange antics,
and pour forth their song in her presence. The male in the
few fish observed seems much more eager than the female:
and the same is true of alligators, and apparently of
Batrachians. Throughout the enormous class of insects,
as Kirby remarks,* ^' the law is that the male shall seek the
female." Two good authorities, Mr. Blackwall and Mr. C.
Spence Bate, tell me that the males of spiders and crusta-
ceans are more active and more erratic in their habits than
the females. When the organs of sense or locomotion are
present in the one sex of insects and crustaceans and absent
in the other, or when, as is frequently the case, they are
more highly developed in the one than in the other, it is, as
far as I oan discover, almost invariably the male which
retains such organs, or has them most developed; and this

* Kirby and Spence, '* Introduction to Entomology," vol. ili, 1826,
p. a42.

SEXUAL SELECTION. 261

bIiows that the male is the more active member in the
courtship of the sexes.*

The female, on the other hand, with the rarest excep-
tions, is less eager than the male. As the illustrious
Hunter f long ago observed she generally " requires to be
courted;" she is coy, and may often be seen endeavoring for
a long time to escape from the male. Every observer of
the habits of animals will be able to call to mind instances
of this kind. It is shown by various facts, given hereafter,
and by the results fairly attributable to sexual selection,
that the female, though comparatively passive, generally
exerts some clioice and accepts one male in preference to
others. Or she may accept, as appearances would some-
times lead us to believe, not the male which is the most
attractive to her, but the one which is the least dis-
tasteful. The exertion of some choice on the part of the
female seems a law almost as general as the eagerness of the
male.

We are naturally led to inquire why the male, in so
many and such distinct classes, has become 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 each sex searched
for the other; but why should the male almost always be
the seeker? The ovules of plants after fertilization have
to be nourished for a time; hence the pollen is necessarily
brought to the female organs — being placed on the stigma,
by means of insects or the wind, or by the spontaneous
movements of the stamens; and in the Algae, etc., by the
locomotive power of the antherozooids. With lowly-organ-
ized aquatic animals, permanently affixed to the same spot
and having their sexes separate, the male element is invari-
ably brought to the female; and of this we can see the

* One parasitic Hymenopterous insect (Westwood, " Modern Class,
of Insects," vol. ii, p. 160) forms an exception to the rule, as the
male has rudimentary wings, and never quits the cell in M^hich it is
born, while the female has well-developed wings. Audouin helieves
that the females of this species are impregnated by the males which
are born in the same cells with them; but it is much more probable
that the females visit other cells, so that close interbreeding is thus
avoided. We shall hereafter meet in various classes, with a few
exceptional cases, in which the female, instead of the male, is the
seeker and wooer.

f "Essays and Observations," edited by Owen, vol. i, 1861. p. 194.

252 THE DESCENT OF MAN.

reason, for even if the ova were detached before fertiliza-
tion, and did not require subsequent nourishment or pro-
tection, there would yet be greater difficulty in transporting
them than the male element, because, being larger than
the latter, they are produced in far smaller numbers. So
that many of the lower animals are, in this respect, analo-
gous with plants.* The males of affixed and aquatic ani-
mals having been led to emit their fertilizing elements in
this way, it is natural that any of their descendants, which
rose in the scale and became locomotive, should retain the
same habit; and they would approach the female as closely
as possible, in order not to risk the loss of the fertilizing
element in a long passage of it through the water. With
some few of the lower animals, the females alone are fixed,
and the males of these must be the seekers. But it is dif-
ficult to understand why the males of species, of which the
progenitors were primordially free, should invariably have
acquired the habit of approaching the females, instead of
being approached by them. But in all cases, in order that
the males should seek efficiently, it would be necessary that
they should be endowed with strong passions; and the
acquirement of such passions would naturally follow from
the more eager leaving a larger number of offspring than
the less eager.

The great eagerness of the males has thus indirectly led
to their much more frequently developing secondary sexual
characters than the females. But the development of such
characters would be much aided if the males were more
liable to vary than the females — as I concluded they were —
after a long study of domesticated animals. Von Nathu-
eius, who has had very wide experience, is strongly of the
same opinion. \ Good evidence also in favor of this con-
clusion can be produced by a comparison of the two sexes
in mankind. During the Novara Expedition^: a vast

*Prof. Sachs (" Lelirbucli der Botauik," 1870, s. 633), in speaking
of the male and female reproductive cells, remarks, '• verhalt sich
die eine bei der Vereinigung activ, . . . die andere erscheint bei
der Vereinigung passiv."

t '' Vortrage iiber Viehzucht," 1872, p. 63.

X '-Reise der Novara, Anthropolog. Theil," 1867, ss. 216-269. The
results were calculated by Dr. Weisbach from measurements made
by Drs. K. Scherzer and Schwarz. On the greater variability of the
males of domesticated animals, see my *' Variation of Animals and
Plants under Dgmestication/' vol. ii, 1868, p. 75.

SEXUAL SELECTION. 253

number of measurements was made of various parts of the
body in different races, 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,* 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 grejiter
frequency of deficiency in females before described." Prof.
Macalister likewise remarksf that variations in the muscles
''are probably more common in males than females."
Certain muscles which are not normally present in man-
kind are also more frequently developed in the male than
in the female sex, although exceptions to this rule are said
to occur. Dr. Burt Wilder J 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 over-
looked that women would more frequently endeavor to con-
ceal a deformity of this kind than men. Again, Dr. L.
Meyer asserts that the ears of man are more variable in
form than those of a woman. § Lastly, the temperature is
more varia^)le in man than in woman, n

The cause of the greater general variability in the male
sex than in the female is unknown, except in so far as sec-
ondary sexual characters are extraordinarily variable and
are usually confined to the males; and, as we shall presently
see, this fact is, to a certain extent, intelligible. Through
the action of sexual and natural selection mal6 animals
have been rendered in very many instances widely different
from their females ; but independently of selection the
two sexes, from differing constitutionally, tend to vary in

* " Proceedings Royal Soc," vol. xvi, July, 1868, pp. 519, 524.

f " Proc. Royal Irish Academy," vol. x, 1868, p. 123.

X " Massachusetts Medical Soc," vol. ii, No 3, 1868, p. 9.

§ " Arcliiv fiir Path. Anat. und Phys,," 1871, p. 488.

II The conclusions recently arrived at by Dr. J. Stockton Hongh, on
the temperature of man, are given in the " Pop. Science Review,*'
Jan. 1, 1874, p. 97,

<^ THE DESCENT OF MAN.

a somewhat different manner. The female has to expend
much organic matter in the formation of her ova, whereas
the male expends much force in fierce contests with his
rivals, in wandering about in search of the female, in exert-
ing his voice, pouring out odoriferous secretions, etc. ; and
this expenditure is generally concentrated within a short
period. The great vigor of the male during the season of
love seems often to intensify his colors independently of
any marked difference from the female.* In mankind,
and even as low down in the organic scale as in the Lepi-
doptera, the temperature of the body is higher in the male
than in the female, accompanied in the case of man by a
slower pulse, f On the whole, the expenditure of matter
and force by the two sexes is probably nearly equal, though
effected in very different ways and at different rates.

From the causes just specified the two sexes can hardly
fail to differ somewhat in constitution, at least during the
breeding season; and although they may be subjected to
exactly the same conditions they will tend to vary in a
different manner. If such variations are of no service to
either sex they will not be accumulated and increased by
sexual or natural selection. Nevertheless, they may be-
come permanent if the exciting cause acts permanently;
and in accordance with a frequent form of inheritance
they may be transmitted to that sex alone in which they
first appeared. In this case the two sexes will come to
present permanent, yet unimportant, dift'erences of char-
acter. For instance, Mr. Allen shows that with a large
number of birds inhabiting the northern and southern
United States, the specimens from the south are darker-
colored than those from the north; and this seems to be
the direct result of the difference in temperature, light, etc.,
between the two regions. Now, in some few cases, the

*Prof. Mantegazza is inclined to believe (" Lettera a Carlo Dar-
win," '* Archivio per I'Anthropologia," 1871, p. 306) that tlie bright
colors, common in so many male animals, are due to the presence and
retention by them of the spermatic fluid; but this can hardly be the
case; for many male birds, for instance young pheasants, become
brightly colored in the autumn of their first year.

f For mankind, see Dr. J. Stockton Hough, whose conclusions are
given in the " Pop. Science Review," 1874, p. 97. See Girard's
observations on the Lepidoptera, as given in the "Zoological Becord,"
1869, p. 847.

SEX VAL selection: 255

two sexes of the same species appear to have been differ-
ently affected; in the Agelceus phoBmceus the males have
had their colors greatly intensified in the south; whereas
with Cardinalis virginianus it is the females which have
been thus affected; with Qniscalus major the females have
been rendered extremely variable in tint, while the males
remain nearly uniform.*

A few exceptional cases occur in various classes of ani-
mals, in which the females instead of the males have
acquired well-pronounced secondary sexual characters, such
as brighter colors, greater size, strength or pugnacity.
"With birds there has sometimes been a complete transposi-
tion 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 the more attractive females, as we may infer from
the results. Certain hen birds have thus been rendered
more highly colored or otherwise ornamented, as well as
more powerful and pugnacious than the cocks ; 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; that the males have selected
the more attractive females and the latter the more attract-
ive 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 tastes for
the beautiful differed; but this is a supposition too improba-
ble to be worth considering in the case of any animal, except-
ing man. 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 feaaales selecting the more
attractive and vigorous males, the latter rejecting all
except the more attractive females. But from what we
know of the habits of animals, this view is hardly probable,
for the male is 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

» "Mammals and Birds of E. Florida," pp. 234, 280, 295.

,•556 THE DESCENT OF MAN.

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, but 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 sax is brilliantly colored or provided with special
ornaments, and yet the members of both sexes ot of one
alone have probably acquired simple colors, such as white
or black, 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 having preferred plain black or white. Obscure
tints have often been developed through natural selection for
the sake of protection, and the acquirement through sexual
selection of conspicuous colors appears to have been some-
times checked from the danger thus incurred. But in
other cases the males during long ages may have struggled
together for the possession of the females, 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; and this, as
previously shown, depends on many 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 indi-
viduals. 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 a retarded
and less vigorous female later in the season, or, if polyga-
mous, obtains fewer females; so that they leave fewer, 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 purposes; 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. TJiis circumstance may partly account for the

SBXTTAL SELECTION 257

frequent and extraordinary amount of variability presented
by secondary sexual characters. Nevertheless, natural
selection will determine that such characters shall not be
acquired by the victorious males, if they would be highly
injurious, 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 won-
derful extreme; and in some cases 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 favored males derive from con-
quering other males in battle or courtship, and thus leaving
a numerous, progeny, are in the long run greater than those
derived from rather more perfect adaptation to their condi-
tions of life. AVe shall further see, and it could never have
been anticipated, that the power ^ to charm the female has
sometimes been more important than the power to conquer
other males in battle.

Laws of Inheritance. — In order to understand how sexual
selection has acted on many animyJs of many classes, and
in the course of ages has produced a conspicuous result, 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'"' — 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 oif spring of either
sex. 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, as, for instance,
when the common hen assumes the flowing tail-feathers,
hackles, comb, spurs, voice, and even pugnacity of the
cook. Conversely the same thing is evident more or less

258 THE DESCENT OF MAN,

plainly with castrated males. Again, independently of
old age or disease, characters are occasionally 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 develo]jed in the
female; for in every breed each detail in the structure of
the spur is transmitted through the female to her male off-
spring. Many cases will hereafter be given where the
female exhibits more or less perfectly characters proper to
the male, in whom they must have been first developed and
then transferred to the female. The converse case of the
first development of characters in the female and of trans-
ference to the male is less frequent; it will therefore be
well to give one striking instance. With bees the pollen-
collecting apparatus is used by the female alone 'for gather-
ing pollen for the larvae, yet in most of the species it is
partially developed in the males to whom it is quite useless,
and it is perfectly developed in the males of Bombus or the
humble-bee. * As not a single other Hymenopterous insect,
not even the wasp, which is closely allied to the bee, is
provided with a pollen-collecting apparatus, we have no
grounds for supposing that male bees primordially collected
pollen as well as the females; although we have some reason
to suspect that male mammals primordially suckled their
young as well as the females. Lastly, in all cases of rever-
sion characters are transmitted through two, three or many
more generations, and are then developed under certain
unknown favorable conditions. This important distinction
between transmission and development will be best kept in
mi?ui by the aid of the hypothesis of pangenesis. Accord-
ing to this hypothesis every unit or cell of the body throws
off gemmnles 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; and their
development into units or cells, like those from which they
were derived, depends 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

*H. Miiller, " Anwendung der Darwin'schen Lelire," etc. Verli.
d. n. V . Jakrg. xxix, p. 43.

SEXUAL SELECTION. 259

tendency is well-established. A new character, appearing
in a young animal, whether it lasts throughout life^ or is
only transient, will, in general, reappear in the offspring at
the same age and last for the same time. If, on the other
hand, a new character appears at maturity, or even during
old age, it tends to reappear in the oifspring 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 dwelt on this sub-
ject sufficiently in another work,* 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
down-covered chickens, the young birds in their first true
plumage, and the adults differ greatly from one another, as
well as from their common parent-form, the Gallus hanhiva;
and these characters are faithfully transmitted by each
breed to their offspring at the corresponding periods of
life. For instance, the chickens of spangled Hamburgs,
while covered with down, have a few dark spots on me
head and rump, but are not striped longitudinally, as in
many other breeds; in their first true plumage, '' they are
beautifully penciled,'^ that is, each feather is transversely
marked by numerous dark bars; but in their second plum-
age the feathers all become spangled or tipped with a dark
round spot, f Hence in this breed variations have occurred
at, and been transmitted to, three distinct periods of life.
The pigeon offers a more remarkable case, because the abo-
riginal parent-species does not undergo any change of plum-
age with advancing age, excepting at maturity the breast
becomes more iridescent ; yet there are breeds which do
not acquire their characteristic colors until they have
moulted two, three, or four times; and these modifications
of plumage are regularly transmitted.

Inheritance at Corresponding Seasons of the Tear. — With

*"The Variation of Animals and Plants under Domestication,"
vol. ii, 1868, p. 75. In tlie last chapter but one tlie provisional hypo-
thesis of pangenesis, above alluded to, is fully explained.

f These facts are given on the high authority of a great breeder,
Mr. Teebay; see Tegetmeier's " Poultry Book," 1868, p. 158. On
the characters of chickens of different breeds, and on the breeds of
the pigeon, alluded to in the following paragraph, see '* Variation of
Animals," etc., vol. i, pp. 160, 249; vol. ii, p. 77.

260 THE DESCENT OF MAN,

animals in a state of nature, innumerable instances occur
of characters appearing periodically at different seasons.
We see this in tne horns of the stag, and in the fur of the
Arctic animals, which becomes thick and white during the
winter. Many birds acquire bright colors and other deco-
rations during the breeding-season alone. Pallas states,*
that in Siberia domestic cattle and horses become lighter-
colored during the winter; and I have myself observed, and
heard of similar strongly-marked changes of color, that is,
from brownish-cream color or reddish-brown to a perfect
white, in several ponies in England. Although I do not know
that this tendency to change the color of the coat during
different seasons is transmitted, yet it probably is so, as all
shades of color are strongly inherited by the horse. Nor is
this form of inheritance as limited by the seasons, more
remarkable than its limitation by age or sex.

Inheritance as Limited ly Sex. — The equal transmission
of characters to both sexes is the commonest form of inher-
itance, at least with those animals which do not present
strongly-marked sexual differences, and indeed with many
of these. But characters are somewhat commonly trans-
ferred exclusively to that sex in which they first appear.
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.
As a rule, it is the females alone in cats which are tortoise-
shell, the corresponding color in 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 varia-
tions in certain breeds are transmitted equally to both
sexes. There are also certain sub-breeds of the fowl in
which the males can hardly be distinguished from one
another, while the females differ considerably in color.
The sexes of the pigeon in the parent-species do not differ

* •* N0V8B species Quadrupedum e Glirium ordine," 1778, p. 7. On
the transmission of color by the Lorse, see " Variation of Animals,
etc., under Domestication.'' vol. 1, p. 51. Also vol. ii, p. 71, for a
general discussion on " Inheritauce as Limited by Sex."

SEXUAL 8ELECTI0K 261

in any external character; nevertheless, in certain domesti-
cated breeds the male is colored differently from the female.*
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 slight differ-
ences between the sexes are wholly due to the form of
inheritance which has prevailed; for they have arisen, not
from, but rather in opposition to, the wish 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 dissimilar-
ity and complete similarity. Instances have already been
given with the breeds of the fowl and pigeon, and under
nature analogous cases are common. With animals under
domestication, but whether in nature I will not venture to
Bay, one sex may lose characters proper to it, and may thus
come somewhat to resemble the opposite sex; for instance,
the males of some breeds of the fowl have lost their mascu-
line tail-plumes and hackles. On the other hand, the dif-
ferences between the sexes may be increased under domesti-
cation, as with merino sheep, in which the ewes have lost
their horns. Again, characters proper to one sex may sud-
denly appear in the other sex; as in those sub-breeds of the
fowl in which the hens acquire spurs while young; or, as in
certain Polish sub-breeds, in which the females, as there is
reason to believe, originally acquired a crest, and subse-
quently transferred it to the males. All these cases are
intelligible on the hypothesis of pangenesis; for they depend
on the gemmules of certain parts, although present in both
sexes, becoming, through the influence of domestication,
either dormant or developed in either sex.

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 could through selection be
limited in its development to one sex alone. If, for
instance, a breeder observed that some of his pigeons (of

* Dr. Chapuis, " Le Pigeon Voyageur Beige," 1865, p. 87. Boitard
et Corbie, " Les Pigeons do Voliere," etc., 1824, p. 173. See, also,
on similar differences in certain breeds at Modena, " Le variazioiu d€4
Colombi doiuestici/' del Paolo Bonizzi, 187S,

2B2 THE DESCENT OF MAK.

which the 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 malJd
alone should be of this tint, while 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 the whole stock of both sexes to 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 with the two sexes of a different color, 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 to the females, it
would be easy to make a breed with the females alone thus
characterized; 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 cer-
tain sub-breeds of the pigeon black striae, though trans-
mitted through the female, should be developed in the
male alone, while every other character is equally trans-
ferred to both sexes. Why, again, with cats, the tortoise-
shell color should, with rare exceptions, be developed in
the female alone. The very same character, such as defi-
cient or supernumerary digits, color-blindness, etc., may

* Since the publication of tlie first edition of tliis work, it has been
highly satisfactory to me to find the following remarks (the " Field,"
Sept., 1872) from so experienced a breeder as Mr. Tegetraeier.
After describing some curious cases in pigeons, of the transmission ol
color by one sex alone, and the formation of a sub-breed with this
character, he says: " It is a singular circumstance that Mr. Darwin
should have suggested the possibility of modifying the sexual colors
of birds by a course of artificial selection. When he did so, he was
in ignorance of these facts that I have related ; but it is remarkable
bow very closely he suggested the right method of procedure."

SEXUAL SELECTION. J363

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
through the same sex.* Although we are thus ignorant,
the two following rules seem often to hold good — that varia-
tions which first appear in either sex at a late period of life
tend to be developed in the same sex alone; while varia-
tions which first appear early in life in either sex tend to
be developed in both sexes. I am, however, far from sup-
posing that this is the sole determining cause. As I have
not elsewhere discussed this subject, and as it has an impor-
tant 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 differs 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, such as certain
orthoptera and libellulae. In all these cases the variations,
through the accumulation of which the male acquired his
proper masculine characters, must have occurred at a some-
what late period of life; otherwise the young males would
have been similarly characterized; and conformably with
our rule, the variations 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

* References are given in my " Variation of Animals under Domes'
tlcation," voL ii, p. 73.

264 THE DESCENT OF MAN.

adult female; and in most of these cases the variations
through which the young and old acquired their pre&ent
characters, probably occurred, according to our rule, during
youth. But there is here room for doubt, for 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 while 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. AVe must not, however, overlook the possibility or
even probability of successive variations of the same nature
occurring, under exposure to similar conditions, simul-
taneously in both sexes at a rather late period of life; and
in this case the variations would be transferred to the off-
spring of both sexes at a corresponding late age; and there
would then be no real contradiction to the rule that varia-
tions occurring late in life are transferred exclusively to the
sex in which they first appeared. This latter rule seems to
hold true more generally than the second one, 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 held 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 but one the horns are
developed only in the males, though certainly transmitted
through the females and capable of abnormal development
in them. 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 are mature and have come to differ
much in constitution. In all the other species the horns
ought to appear later in life, which would lead 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

SEXUAL SELECTION. ^65

horns, I find that the horns first appear at periods varying
from nine months after birth in the roebuck to ten, twelve
or even more months in the stags of the six other and
larger species.* But with the reindeer the case is widely
different; for, as I hear from Prof. Nilsson, who kindly
made special inquiries 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
s}'/ecies of the family and likewise common to both sexes in
this one species alone.

In several kinds of antelopes only the males are provided
with horns, while in the greater number both sexes bear
horns. With respect to the period of development, Mr.
Blyth informs me that there was at one time in the Zoo-
logical Gardens a young koodoo (Ant. strepsiceros) of
v/hich the males alono are horned, and also the young of a
closely allied species, the eland {Ant. areas), in which both
sexos are horned. Now it is in strict conformity with our
rule that in the young male koodoo, although ten months
old, the horns were remarkably sm>i]l, considering the size
ultimately attained by them; whila in the young male
eland, although only three months old, the horns were
already very much larger than in the koodoo. It is also a
noticeable fact that in the prong-horned antelope f only a
few of the females, about one in five, have horns, and
these are in a rudimentary state, thongh sometimes above
four inches long; so that as far as coi'cerns the possession
of horns by the males alone, this spocies is in an inter-
mediate condition and the horns do not appear until about
five or six months after birth. Therefcre in comparison

* I am much obliged to Mr. Cupples for Laving' mode inquiries for
me in regard to tbe Roebuck and Red Deer of Scotland from Mr.
Robertson, tbe experienced bead-forester to tbe Marqui,« of Breadal-
bane. In regard to Fallow-deer, I bave to tbank Mr, Eyton and
otbers for information. For tbe Cervus alces of North Auierica. see
" Land and Water," 1868, pp. 221, 254; and for tbe C, Vv-ginianua
and strongyloceros of tbe same continent, see J. D. Caton, in '' Ottawa
Acad, of Nat. Sc," 1868, p. 13. For Cermis Eldi of Pegu, see Lieut.
Beavan, " Proc. Zoolog. Soc," 1867, p. 762.

f Antilocapra Americana. I bave to tbank Dr. Canfield for infor-
mation witb respect to tbe bonis of tbe female; see also bis paper in
" Proc. Zoolog. Soc." 1868, p. 109. Also Owen, " Anatony of Vertt-
Vrates," vol. Ui, p. 627.

266 THE DESCENT OF MAN.

with what little we know of the development of the horns
in other antelopes and from what we do know with respect
to the horns of deer, cattle, etc., those of the prong-horned
antelope appear at an intermediate period of life — that is
not very early, as in cattle and sheep, nor very late, as in
the larger deer and antelopes. The horns of sheep, goats
and cattle which are well developed in both sexes, though
not quite equal in size, can be felt, or even seen, at birth
or soon afterward.* Our rule, however, seems to fail in
some breeds of sheep, for instance merinos, in which the
rams alone are horned; for I cannot find on inquiry f 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; for a certain proportion of the
merino ewes bear small horns, and some of the rams are
hornless; and in most breeds hornless ewes are occasionally
produced.

Dr. W. Marshall has lately made a special study of the
protuberances so common on the heads of birds, J; and he
comes to the following conclusion: that with those species
in which they are confined to the males, they are developed
late in life; whereas with those species in which they are
common to the two sexes, they are developed at a very
early period. This is certainly a striking confirmation of
my two laws of inheritance.

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

* I have been assured that the horns of the sheep in North Wales
can always be felt, and are sometimes even an inch in length at
birth. Youatt says ("Cattle," 1834, p. 277), that the prominence of
the frontal bone in cattle penetrates the cutis at birth, and that the
horny matter is soon formed over it.

f I am greatly indebted to Prof. Victor Carus for having made
inquiries for me, from the highest authorities, with respect to the
merino sheep of Saxony. On the Guinea coast of Africa there is.
however, a breed of sheep in which, as with merinos, the rams alone
bear horns; and Mr. Winwood Reade inforuis me that in one case
observed by him, a young ram, born on Feb, 10th, first showed horns
on March 6th, so that in this instance, in conformity with rule, the
development of the horns occurred at a later period of life than in
Welsh sheep, in which both sexes are homed.

X " Ueber die knSchermen Schadelhocker der Vflgel " in the " Ni©-
derlandischen Archiv. fOr Zoologie," Baud I, Heft 2, 1872.

SEXUAL SELECTION. 267

life. The eared pheasant {Orossoptilon mirifum), however,
olfers a remarkable exception, for both sexes possess the
fine caudal plumes, the large ear- tufts and the crimson
velvet about the head; I find that all these characters
appear very early in life in accordance with rule. The
adult male can, however, be distinguished from the adult
female by the presence of spurs; and, conformably with
our rule, these do not begin to be developed before the age
of six months, as I am assured by Mr. Bartlett, and even
at this age the two sexes can hardly be distinguished.* The
male and female peacock differ conspicuously from each
other in almost every part of their plumage, except m the
elegant head-crest, which is common to both sexes; and this
is developed very early in life, long before the other orna-
ments which are confined to the male. The wild duck
offers an analogous case, for the beautiful g/e«xi speculum
on the wings is common to both sexes, though duller and
somewhat smaller in the female, and it is developed early
in life, while the curled tail-feathers and other ornaments
of the male are developed later, f Between such extreme
cases of close sexual resemblance and wide dissimilarity, as
those of the Orossoptilon and peacock, many intermediate

*In the common peacock (Pavo cristatus) the male alone possesses
spurs, while both sexes of the Java Peacock (P. imitictis) offer the
unusual case of being furnished with spurs. Hence I fully expected
that in the latter species they would have been developed earlier in
life than in the common peacock; but M. Hegt of Amsterdam informs
me, that with young birds of the previous year, of both species,
cotn})ared on April 23, 1869, there was no difference in the develop-
ment of the spurs. The spurs, however, were as yet represented
merely by slight knobs or elevations. I presume that I should have

pen informed if any difference in the rate of development had been

userved subsequently.

f In some other species of the Duck family the speculum differs in
a greater degree in the two sexes; but I have not been able to dis-
cover whether its full development occurs later in life in the males of
such species, than in the males of the common duck, as ought to be the
case according to our rule. With the allied Mergus ciicuUatus we
have, however, a case of this kind: the two sexes differ conspicu-
ously in general plumage, and to a considerable degree in the specu-
lum, which is pure white in the male and grayish white in the
female. Now the young males at first entirely resemble the females,
and have a grayish-white speculum, which becomes pure white at an
earlier age than that at which the adult male acquires his other and
more strongly -marked sexual differences: see Audubon, *♦ Ornitholo-
gical Biography," vol. iii, 1835, pp. 249-250.

268 THE DESCENT OF HAK,

ones could be given, in which the characters follow our two
rules in their order of development.

As most insects emerge from the pupal state in a mature
condition it is doubtful whether the period of development
can determine the transference of their characters to one or
to both sexes. But we do not know that the colored scales,
for instance, in two species of butterflies, in one of which
the sexes differ in color, while 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 devel-
oped on the wings of the same species of butterfly, in
which certain colored marks are confined to one sex, while
others 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 suc-
cession of moults, the young males of some species at first
resemble the females, and acquire their distinctive mascu-
line characters only at a later moult. Strictly analogous
cases occur at the successive moults of certain male
crustaceans.

We have as yet considered the transference of characters,
relatively to their period of development, only in species in
a natural state; we will now turn to domesticated animals,
and first touch 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 con-
genital, as is probably color-blindness — yet these peculiar-
ities, and other similar ones, are often limited in their
transmission to one sex; so that the rule that characters,
developed at an early period, tend to be transmitted to both
eexes, here wholly fails. But this rule, as before remarked,
does not appear to be nearly so general as the converse one,
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 some difference 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 safe conclusion. Gout, however,
eeei^is to fall under our rule, for it is generally caused by

SEXUAL SELECTION. 369

intemperance during manhood, 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 pecu-
liarities, in accordance with our rule, are not fully devel-
oped until a rather late period of life. The sexes of dogs
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, according to rule, will account for
his increased size being transmitted to his male offspring
alonCc On the other hand, the tortoise-shell color, which
is confined to female cats, is quite distinct at birth, and
this case violates the 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 pigeons, the full develop-
ment of the wattle and crop occurs rather late in life,
and conformably with the rule, these characters are trans-
mitted in full perfection to the males alone. The follow-
ing cases perhaps come within the class previously alluded
tOj in wliich both sexes have varied in the same manner at
a rather late period of life, and have consequently trans-
ferred their new characters to both sexes at a corresponding
late period, and if so, these cases are not opposed to our
rule; there exist sub-breeds of the pigeon, described by
J^'eumeister,* in wliich both sexes change their color during
two or three moults (as is likewise the case with 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 or both sexes seems generally determined

* " Das Ganze der Taubenzuclit," 1837, ss. 21, 24. For tlie case of
tbe streaked pigeons, see Dr. Chapuis. *' Le pigeon voyageur Beige,"
I860, p. 87,

270 THE DESCENT OF MAN.

by the period at which such characters are developed. Thus
iu all the many breeds in which the adult male differs
greatly in color from the female, as well as from the wild
parent-species, he differs also from the young male, so that
the newly-acquired characters must have appeared at a
rather late period of life. On the other hand, in most of
the breeds in which the two sexes resemble each other, the
young are colored in nearly the same manner as their
parents, and this renders it probable that their colors 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, which
leads to its transference to both sexes; for the males alone
of many natural species are either black or white, the
females being differently colored. With the so-called
Cuckoo sub-breeds of the fowl in which the feathers are
transversely penciled with dark stripes, both sexes and the
chickens are colored in nearly the same manner. The
laced plumage of the Sebright bantam is the same in both
sexes, and in the young chickens the wing-feathers are dis-
tinctly, though imperfectly, laced. Spangled Hamburgs,
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 penciled. With respect to other
characters besides color, in the wild-parent species and in
most of the domestic breeds the males alone possess a well-
developed comb; but in the young of the Spanish fowl it
is largely developed at a very early age, and, in accordance
with this early development in the male, it is of unusual
size in the adult female. 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;* and in this breed the adnlts

* For full particulars and references on all tliese points respecting
the several breeds of the fowl, see " Variation of Animals and Plants

SEXUAL SELECTION. 271

of both sexes are characterized by a great bony protuber-
ance and an immense crest.

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 char-
acters 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 bear horns, in comparison
with their much later growth in the other species in which
the male alone bears horns — we may conclude that one,
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 effective
cause of characters being inherited by both sexes, is their
development at an early age, while the sexes differ but
little in constitution. It appears, however, that some dif-
ference must exist between the sexes even during a very
early embryonic period, for characters developed at this
age not rarely become attached to one sex.

Summary and Concluding Remarks. — From the forego-
ing discussion on the various laws of inheritance we learn
that the chai'acters of the parents often, or even generally,
tend to become developed in the offspring of 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 rules, owing to unknown causes, are far from being
fixed. Hence, during the modification of a species the
successive changes may readily be transmitted in different
ways; some to one sex and some to both; some to the off-
spring at one age and some to the offspring 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 induced are preserved and accumulated
by sexual selection, which is in itself an extremely complex
affair, depending as it does on the ardor of love, the cour-
age and the rivalry of the males as well as on the powers
of perception, the taste and will of the female. Sexual
selection will also be largely dominated by natural selection

under Domestication," vol. i, pp. 250, 256. In regard to the higher
animals, the sexual differences which have arisen under domestica-
tion are described in the same work under the head of each species.

272 THE DESCENT OF MAN

tending toward the general welfare of the species. Hence
the manner in which the individuals of either or both
sexes have been 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 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 tlie species are similarly modified. In the
following chapters it will be seen that all these cases fre-
quently occur in nature.

Sexual selection can never act on any animal before the
age for reproduction arrives. 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, with organs for dis-
covering and securely holding the female andfor exciting
or 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 did
not generally occur much before the age for reproduction.
Whenever some or many of the variations occurred early in
life the young males would partake more or less of "the
characters of the adult males; and differences of this kind
between the old and young males may be observed in many
species of animals.

It is probable that young male animals have often tended
to vary in a manner which would not only have been of no
use to them at an ondy age, but would have been actually
injurious — as by acquiring bright colors which would
render them conspicuous to their enemies, or by acquiring
structures, such as great horns, which would expend much
vital force in their development. Variations of this kind
occurring in the young males would almost certainly be
eliminated through natural selection. With the adult and
experienced males, on the other hand, the advantages
derived from the acquisition of such characters would
more than counterbalance some exposure to danger and
some loss of vital force.

SEXUAL SELECTION, 273

As variations which give to the male a better chance of
conquering other males or of finding, securing or charm-
ing the opposite sex would, if they happened to arise in the
female, be of no service to her, tliey would not be pre-
served in her through sexual selection. We have also good
evidence with dom.esticated animals that variations of all
kinds are, if not carefully selected, soon lost through inter-
crossing and accidental deaths. Consequently in a state
of nature if variations of the above kind chanced to aiise
in the female line, and to be transmitted exclusively in
this line, they would be extremely liable to be lost. If,
however, the females varied and transmitted their newly
acquired characters to their offspring of both sexes the
characters which were advantageous to the males would be
preserved by them through sexual selection, {ind the two
sexes would in cousequence be modified in the same man-
ner, although such characters were of no use to the
females; but I shall hereafter have to recur to these more
intricate contingencies. Lastly, the feuiales may acquire
and apparently have often acquired by transference char-
acters from the male sex.

As variations occurring late in life and transmitted to
one sex alone have incessantly been taken advantage of and
accumulated through sexual selection in relation to the
reproduction of the species; therefore it appears, at first
sight, an unaccountable fact that similar variations have
not frequently been accumulated through natural selection,
in relation to the ordinary habits of life. If this had
occurred, the two sexes would often have been differently
modified, for the sake, for instance, of capturing ]»rey or
of escaping from danger. Differences of this kind between
the two sexes do occasionally occur, especially in the lower
classes. But this implies that the two sexes follow different
habits in their struggles for existence, which is a rare cir-
cumstance with the higher animals. Tiie case, however, is
widely different with the reproductive functions, in which
respect the sexes necessarily differ. For variations in
.structure, which are related to these functions, have often
proved of value to one sex, and from having arisen at a late
period of life, have been transmitted to one sex alone; and
such variations, thus preserved and transmitted, have given
rise to secoiulary sexual characters.

lu the following chapters I shall treat of the secondary

274 THE DESCENT OF MAN.

sexual characters in animals of all classes, and shall
endeavor 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 the aid of which the male con-
quers 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.
Tliey consist in only a few instances of actual enumeration
and the numbers are not very large. As the proportions
are known with certainty only in mankind, 1 will first give
them as a standard of comparison.

Man. — In England during ten years (from 1857 to 1866)
the average number of children born alive yearly was
707,120, in the proportion of 104.5 males to 100 females.
But in 1857 the male births throughout England wore as
105.^, and in 1865 as 104 to 100. Looking to separate
districts, in Buckinghamshire (where about 5,000 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, while in N. AVales (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 avernge only 730), in 1864 the male
births were #s 114.6, and in 1862 as only 97 to 100; but
even in this small district the average of the 7,385 births
during the whole ten years was as 104.5 to 100; that

PROPORTION OF THE SEXES. 275

18 in the same ratio as throughout England.* The propor-
tions 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, while 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, and
in Philadelphia, in the United States, as 110.5 to 100. f The
average for Europe, deduced by Bickes from about 70,000,-
000 births, is 106 males to 100 females. On the other
hand, with white children born at the Cape of Good Hope,
the proportion of males is so low as to fluctuate during suc-
cessive years between 90 and 99 mules for every 100 females.
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 coun-
tries being the same as usual, for instance, in Livonia as
104 to 100. t

Prof. Faye remarks that " 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.
During the first four or five years of life, also, 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 unfavorable." § Dr. Stock-

*" Twenty-ninth Annual Report of the Rsgistrar- General for
1866." In this report (p. 12) a special decennial table is given.

f For Norway and Russia, see abstract of Prof. Faye's researches
in "British and Foreign Medico-Cbirurg. Review," April, 1867, pp.
343,345. For France, the "Annuaire pour I'An, 1867," p. 213.
For Philadelphia, Dr. Stockton Hough. *' Social Science Assoc,"
1874. For the Cape of Good Hope, Quetelet as quoted by Dr. H. H.
Zouteveenin the Dutch translation of this work (vol. i, p. 417), where
much information is given on the proportion of the sexes.

:j: In regard to the Jews, see M. Thury, " La Loi de Production des
Sexes," 1863, p. 25.

§" British and Foreign Medico-Chirurg. Review," April, 1867, p.
343. Dr. Stark also remarks (" Tenth Annual Report of Births,

276 TEE DESCENT OF MAN.

toil Hongh accounts for these facts in part by the more
frequent defective development of males than of females.
We have before seen that the male sex is more variable in
structure thun the female ; and variations in important
organs would generally be injurious. But the size of the
body, and especially of the head, being greater in male
than female infants is another cause; for the males are thus
more liable to be injured during parturition. Consequently
the still-born males are more numerous; and as a highly
competent judge, Dr. Crichton Browne,* believes male
infants often suffer in health for some years after birth.
Owing to this excess in the death-rate of male children,
both at birth and for some time subsequently, and owing to
the exposure of grown men to various dangers and to their
tendency to emigrate, the females in all old-settled coun-
tries, where statistical records have been kept,f are found
to preponderate considerably over the males.

It seems at first sight a mysterious fact that in different
nations, nnder different conditions and climates, in Naples,
Prussia, Westphalia, Holland, France, England and the
United States, the excess of male over female births is less
when they are illegitimate than when legitimate.]; This
has been explained by different writers in many different
ways, as from the mothers being generally young, from the
large proportion of first pregnancies, etc. But we have

Deatlis, etc., in Scotland." 1867, p. 28) tliat "These examples may
suffice to show that, at almost every stage of life, the males in Scot-
land have a greater liability to death and a higher death-rate than
the females. The fact, however, of this peculiarity being most
strongly developed at that infantile period of life when the dress,
food and general treatment of both sexes are alike, seems to prove
that the higher male death-rate is an impressed, natural and consti-
tutional peculiarity due to sex alone."

* " West Riding Lunatic Asylum Reports." vol. i, 1871, p. 8. Sir
J, Simpson has proved that the head of the male infant exceeds that
of the female *>y three-eighths of an inch in circumference and by
one eighth in transverse diameter. Quetelet has shown that woman
is born smaller than man ; see Dr. Duncan, " Fecundity, Fertility,
Sterility," 1871, p. 382.

f With the savage Guaranys of Paraguay, according to the accu-
rate Azara ('• Voyages dans TAmerique merid ," tom, ii, 1809, pp. 60,
179) the women are to the men in the porportion of 14 to 13.

ifBabbage. "Edinburgh Journal of Science," 1829, vol. i, p. 88;
also p. 90, on still-born children. On illegitimate children in En-
gland, see "Report of Registrar-General for 1866," p. 15.

PROPORTION OF THE SEXES. 277

seen that male infants, from the large size of their heads,
suffer more than female infants during parturition; and as
the mothers of illegitimate children must be more liable
than other women to undergo bad labors, from various
causes, such as attempts at concealment by tight lacing,
hard work, distress of mind, etc., their male infants would
proportionately suffer. And this probably is the most effi-
cient of all the causes of the proportion of males to females
born alive being less among illegitimate children than
among the legitimate. With most animals the greater size
of the adult male than of the female is due to the stronger
males having conquered the weaker in their struggles for
the possesBion of the females, and no doubt it is owin^ to
this fact that the two sexes of at least some animals differ
in size at birth. Thus we have the curious fact that we
rnay attribute the more frequent deaths of male than
female infants, especially among the illegitimate, at least
in part to sexual selection.

It has often been supposed that the relative age of the
two parents determines the sex of the offspring; and Prof.
Leuckart * has advanced what he considers sufficient evi-
dence, with respect to man and certain domesticated
animals, that this is one important though not the sole
factor in the result. So again the period of impregnation
relatively to the state of the female has been thought by
some to be the efficient cause; but recent observations dis-
countenance this belief. According to Dr. Stockton
Hough, t the season of the year, the poverty or wealth of
the parents, residence in the country or in cities, the cross-
ing of foreign immigrants, etc., all influence the proportion
of the sexes. With mankind, polygamy has also been sup-
posed to lead to the birth of a greater proportion of female
infants; but Dr. J. Campbell J carefully attended to this
subject in the harems of Siam, and concludes that the pro-
portioji of male to female births is the same as from
monogamous unions. Hardly any animal has been rendered
so highly polygamous as the English race-horse, and we
shall immediately see that his male and female offspring

* Leuckart, in Wagner, " Handworterbuch der Pliys,," B.iv, 1853,
s. 774.
f Social Science Assoc, of Philadelphia, 1874.
j " Anthropological Review," April, 1870, p. 108,

278 THE DESCENT OF MAN.

are almost exactly equal in number. I will now give the
facts which I have collected with respect to the proportional
numbers of the sexes of various animals; and will then
briefly discuss how far selection has come into play in
determining the result.

Horses. — Mr. Tegetmeier has been so kind as to tabulate for me
from the " Racinij 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
were 25,560,* consisting of 12,763 males and 12,797 females, or in the
proportion of 99.7 males to 100 females. As these numbers are tol-
erably large, and as they are drawn from all parts of England, dur-
ing 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 propor-
tions 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.

Dogs. — During a period of twelve years, from 1857 to 1868, the
births of a large number of greyhounds throughout England were
sent to the "Field" newspaper; and I am again indebted to Mr.
Tegetmeier for carefully tabulating the results. The recorded births
were 6,878, consisting of 3,605 males and 3,273 females, that is, in
the proportion of 110.1 males to 100 females. The greatest fluctua-
tions occurred in 1864, when the proportion was as 95.3 males, and
in 1867; as 116.3 males to 100 females. The above average propor-
tion of 110.1 to 100 is probably nearly correct in the case of the grey-
hound, but whether it would hold with other domesticated breeds is
in some degree doubtful. Mr. Cupples has inquired from several
great breeders of dogs, and finds that all without exception believe
that females are produced in excess; but he suggests that this belief
may have arisen from females being less valued, and from 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

* During eleven years a record was kept of the number of mares which
proved barren or prematurely slipped their foals ; and it deserves notice, as
Bhowinj? how infertile these highly nurtured and rather closely interhred ani-
mals have become, that not far from one-third of the mares failed to produce
living foals. Thus during 1866, 8<i9 maie colts and 816 female colts were born,
and 743 mares failed to produce offspring. Dux-ing 1867, 836 males and 908
female were born» and 794 mares failed.

PROPORTION OF THE SEXES. 279

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 year
or two. Therefore the proportion of males would be somewhat larger
at birth than at the age of castration. This is a remarkable coiuci-
dence with what, as we have seen, occurs with mankind, ahd both
cases probably depend on the same cause. I have received returns
from four gentlemen in England who have bred Lowland sheep,
chiefly Leicesters, during the last ten to sixteen years; they amount
altogether to 8,965 births, consisting of 4,407 males and 4,558 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 extend 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 castra-
tion the females are certainly in excess of the males, but probably
this would not hold good at birth.*

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 tbe proportion of 94.4 males to 100 females.
The Rev. VV. 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
has inquired from several breeders of pigs, and most of them esti-
mate 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. But estima-
tions are of little value.

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 ;" f 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. Africa:):

* I am much indebted to Mr. Cupples for having procured for me the above
returns from Scotland, as well as some of the following: returns on cattle. Mr.
R. Elliot, of Laighwood, first called my attention to the premature deaths of
the males— a statement subsequently confirmed by Mr. Aitchison and others.
To this latter gentleman, and to Mr. Payan, I owe my thanks for large j^^tunis
as to sheep.

+ Bell, " History of British Quadrupeds," p. 100.

X '' lUustratiouA of the Zoology of S. Africa,'' 1849, pL 29i

ago THE DESCENT OF MATT,

{Kobus eUipsiprymnus), remarks, tliat in tlie herds of this and otheaf
species, the males are few in number compared with the females ;
the natives believe that tbey are born in tbis proportion; others
believe tbat the younger males are expelled from the herds, and Sir
A. Smith, says, tbat tlioagh he has himself never seen herds con-
sisting of young males alone, otbers affirm tbat tbis doei? occur. It
appearsprobable tbat the young when expelled from the herd would
often fall 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 1,001 chickens of a highly-bred stock of
Cocbins, 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 eitbertbat the males are produced in excess,
or that tbey live 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 are a male and a 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 bens ; 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 otbers*
are convinced tbat the males are generally the more numerous ; and
as the young males of many species resemble the females, tbe latter
would naturally appear to be the more numerous. Large numbers
of pbeasants are reared by Mr. Baker of licadenhall from eggs laid
by wild birds, and be informs Mr. Jenner Weir that four or five
males to one feirale are generally produced. An experienced
observer remarks, f that in Scandinavia the broods of the capercailzie
and black-cock contain more males than females ; and tbat with the
Dal ripa (a kind of ptarmigan) more males tban females attend the
leks or places of courtsbip ; 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 Wbite of Selborne,^
it seems clear that the males of tbe partridge must be in considerable
excess in tbe soutb of England ; and I have been assured that this is
the case in Scotland. Mr. Weir on inquiring from the dealers who
receive at certain seasons large numbers of ruffs {Machetes pugnax),
was told tbat the males are much the more numerous. This same
naturalist bas also inquired for me from the bird-catchers, who annu-
ally 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 cbaffinch 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. § The males

* Brehui (*' Illust Thierleben," B. iv. s. 990) comes to the same conclusion.

t On tbe authority of L. Lloyd, " Game Birds of Sweden,'' 1837, pp. 12, 132

t *' Nat. Hist, of Selborne," letter xxix. edit, of 1825, vol, i p 139.

§Mr. Jenner Weir received similar information, on maklnsr inquiries
durJnj? the following? year. To show the number of living chaffinches caui?b£
I may mention that in 18G9 there was a match between two experts and one
man caufrht in a day 62, and another 40, male chaliinches. The greatest num-
ber ever caught by one man in a singlrday was 7a

PROFonrroN of tub sexes. 281

of tlie V.acl^bird, lie likewise maintained, were hy far tLe more
nunieroas, wbetber caught by traps or by netting at nig-bt. These
statements may apparently be trusted, because this same man said
that the sexes are about equal with the lark, the twite [Linavia
montana), and goldfinch. On the other band, be is certain that with
the comuion linnet, the females preponderate greatly, but unequally,
during different years; during some years he has found the females
to the males as 4 to 1. It should, however, be borne in mind,
that the chief season for catching birds does not begin till September,
so that with some species ]>artial migrations may have begun, and
the flocks at this period often consist of hens ab^ne. Mr. Salvia
paid particular attention to the sexes of the humming-birds mi Cen-
tral America, and he is convinced that with most of the species the
males are in excess; thus one year he procured 204 specimens belong-
ing to ten species, and these consisted of 166 males and of only 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 tlie males of Campyloptei'us
hemileuciirus were to the females as 5 to 2. and on another occasion*
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
chaffiuch keeping apart, and "the females by Car the most numer-
ous;" while in Palestine, Mr. Tristram found "the male flocks
api)earing greatly to exceed the female in number. "| So again
with the Quiscaius major, Mr. G. Taylor^ says, that in Florida there
were "very vew females in pro])ortion to the males," while in Hon-
duras the proportion was the other way, the species there having the
character of a polygamist.

Fish. — With fish tlie 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. i^
Infertile females might readily be mistaken for liiales, as Dr. Giiii-
ther has remarked to me in regard to irout. With some species the
males are believed to die soon after fertilizing the ova. With many
species the males are of much smaller size than the females, go that
a lai'ge number of males would escape from the same net by which
the females were caught. M. Carbonnier,|| who has especially
attended to the natural history of the pike {Elsox 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 this same cause to greater danger than the females. Neverthe-
less, 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,

*" Ibis," vol. ii, p. C60, as quoted in '"Gould's Trochilidas," ISfil, p. ?2.
For the foregoing proportions. I am indebted to Mr. Salvia for a table of his
results.

t '• Ibis," 18(50. p. 1.37; and 1837, p. 369.

X " Ibis," 18C-.>. p, 187.

ILeuckart quotes Bloch (Wagner, *' Handworterbuch der Phvs.," B, iv,
1853, 8. 77.b), that with fish there uro twice as many males as Jenaalea.

J Quoted ia th© '' Farmer," Max-ca 18, 1869^ p. 869.

283 THE DESCENT OF MAN,

says tliat in 1865, out of 70 salmon first landed for tlie purpose of
obtaining the ova, upward of 60 were males. In 1867 Le 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," Afterward
female> sufficient for obtaining ova were i)rocure<l. He adds. ** from
the great proportion of the nuiles, »hey are constantly fightiv\g and
tearing each other on the spawning-beds."* This disproportion, no
donbt, can be accounted for in part, but whethbr wholly is doubtful,
by the males ascending the rivers before tlie females. Mr. F. Buck-
land remarks in regard to trout, that " it is a curious fact that the
nuiles preponderate very largely m number over the females. It
invaridbli/ happens that when the first rush of fish is made to the
TiCt theve 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 tlight." lie then adds, that by carefully searching the
banks sufficient females for obtaining ova can be found. f Mr. H.
Lee informs me that out of 212 trout taken for this purpose in Lord
Poitsmouth's park, 150 were males and 62 females.

The males of the Cyprinidse likewise seem to be in excess; but sev-
eral members of this family, viz., the carp, tench, bream and min-
now, appear reguhrly to follow the practice, rare in the animal king-
dom, of polyandry; tor the female while 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 weii known that it is always recom-
mended to stock a pond with two male tenches to one female, or at
least with three males to two females. With the minnow, an excel-
lent observer states, that on the spawning-beds the males are ten
times as numerous as the females; when a female comes among the
males, '• she is immediately pressed clo.selyljy a male on each side;
and when they have been in that situation for a time are superseded
by two other males.":}:

Insects. — Tn this great class tbe Lepidoptera almost alone afford
means for 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 'reatises,
1 cannot find that this has ever been done. The general opinion ap-
pears to be that the sexes are nearly equal, but in Italy, as I hear
from Prof. Canestrini, many breeders are convinced that the females
are produced in excess. This same naturalist, however, informs me
that in the two yearly broods of the Ailanthus silk-moth (Bombyx
cyiUhiti), the males greatly preponderate in the first, while in the
second the two sexes are nearly equal, or the females rather in
excess.

*-The Stormontfield Piscicultural Experiments,'' 1866, p. 23. The
*' Field '■ new.spaper. June 2^. 18:J7.

t •• Land and Water," 18G8, . . A\.

X YarreJl, *" Hist. British Fishes," vol. i, 1826, p. 807; on the Cyprinus carpio,
p. 331; on the 7'i/ica vulgaris, p, ;S31; on the Abramls brama, p. 33(5. See, for the
minnow iLeuciscus phoxinue), " Loudon's Mag. of Nat. Uist.," voL y, lB3Si, p. 682.

PROPORTION OF THE SEXES, 283

In regard to butterflies in a state of nature, several observers bave
been mucb struck by tbe apparently enormous preponderance of tbe
males.* Tbus Mr. Bates. f in speaking of several species, about a
hundred in number, wbicb inhabit the Upper Amazons, says that
the males are much more numerous than the females, even in the
proportion of 100 to 1. In North America, Edwards, who
had great experience, estimates in the genus Papilio the males to the
females as 4 to 1; and Mr. Walsh, w^ho informed me of this
statement, says that with P. turrius this is certainly the case. In
S. Africa, Mr. R. Trimen found the males in excess in nineteen spe-
cies; X and in one of these, which swarms in open places, he estimated
the number of males as 50 to 1 female. With another species,
in which the males are numerous in certain localities, he collected
only five females during seven years. In the Island of Bourbon, M.
Maillard states that the males of one species of Papilio are twenty
times as numerous as the females. § 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 the males in number; but three
South African species perhaps offer an exception. Mr. W'allace||
states that the females of Ornithoptera crcesus, in the Malay Archi-
pelago, 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, Guenee 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, 1[ 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 Avell known to occur
with most Lepidoptera, as well as with other insects. So that, as M.
Personnat remarks, tbe males of the domesticated Bomhyx Tamamai
are useless at the beginning of the season, and the females at the
end, from the want of mates.** I cannot, however, persuade myself
that these causes suflSce to explain the great excess of males in the
above cases of certain butterflies which are extremely common in
their native countries. Mr. Stainton, who has paid venj»-close atten-
tion 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 more numerous. Several entomologists concur

* Leuekart quotes Meinecke (Wajirner, " Handworterbuch der Phys.," B.
Iv. 1858, s. 775), that the males of butterflies are three or four times as numer-
ous as the females.

t •• The Naturalist on the Amazons." vol. ii, 1863, pp. 238, 347.

% " Four of these cases are given by Mr. Trimen in his " Rhopalocera Africaa
Australis."

§ Quoted by Trimen, '• Transact. Ent. Soc," vol. v, part Iv, 1866, p. 880.

i •• Transact. Linn. Soc.," vol. xxv, p. 37.

^ •' Proc. Entomolog. Soc," Feb. 17, 1868.

•♦Quoted by Dr. Wallace in ** Proc. Ent. Soc," 8d series, yoL y, 1867, p. 487.

284 THE DESCENT OF MATT.

in tills view. Mr. Doubleday, however, and some otters, take an
opposite view, and are conviuced tliat tliey Lave reared from tlie
e^gs and caterpillars a larger proportion of males tlian of females.

Besides the more active Labits of tlie males, their earlier emergence
from the cocoon, and in some cases their frequenting more open
stations, other causes may be assigned for an ap])arent or real differ-
ence in the proportional numbers of the sexes of Lepidoptera, when
captured in the imago state, and when reared from the egg or cater-
pillar state. I hear from Prof. C'anestrini that it is believed by many
breeders in Italy 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 piactice;
but Dr. Wallace is sure that most collectors take all the speci-
mens 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 Prof. Canestrini informs me
that in Italy some breeders believe, though on insufficient evidence,
that in the first broods 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 con-
sume more food and moisture; and thus they would be exposed
during a longer time to danger from ichneumons, birds, etc., 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 their relative 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 ElacMsta 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
in confinement. In the Isle of Wight, Mr. Trimen exposed a box in
which a female of the Lasiocampa had been confined on the previous
day, and five males soon endeavored to gain admittance. In Aus^
tralia, M. Verreaux, 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. *

Mr. Doubleday has called my attention to M. Staudinger 'sf list

* Blanchard, " Metamorphoses, Moeurs des Insectes," 186S, pp. 8^226.
t " Lepidopteren-Poublettea Ligte," Berlin, Ko. x. IS&Q.

PROPORTION OF TEB SEXES.

285

of Lepidoptera, which gives the prices of the males and females of
800 species or well-marlced varieties of butterflies (Khopalocera).
The prices for both sexes of the very common species are of course
the same; but in 114 of the rarer species they differ; the males
being in all cases, excepting one, the cheaper. On an average of the
prices of the 113 species, tiie 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 the same proportion. About
2,000 species or varieties of moths (Heterocera) are catalogued,
those with wingless females being here excluded on account
of the difference in habits between the two sexes: of these
2,000 species, 141 differ in price according to sex, the males of 130
being cheaper, and those 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
price-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 number
of the males. But I am bound to add that Dr. Staudinger informs
me that he is himself of a different opinion. He thinks that the
less active habits of the females and the earlier euiergence 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 cater[)illar
state, Dr. Staudinger believes, as previously stated, that a greater
number of females than of males die while confined 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

Males.

Females ,

The Rev. J. Hellins * of Exeter reared, during 1868, imajjos

of 73 species, which consisted of . .

Mr. Albert Jones of Eltham reared, during 1868, imaffos of

{) species, which consisted of

Durinsj 1869 he reared imagos from 4 species, consisting

of

Mr. Buckler of Emswrnth, Hants, during 1860, reared

imagos from 74 species, consisting of

Dr. Wallace of Colchester reared from one brood of Bom-

bvx cvnthia

153
159
114
180

52
221

62

137
126
112
169
48

Dr. Wallace raised, from cocoons of Bombyx Pernyi sent

from China, durinjr ]8!iO

Dr. Wallace raised, during 1808 and 1869, from two lots of

123
46

Total

031

761

♦ This natui-alist has been so kind as to send me some results from former
years, in wliich the females seemed to preponderate ; but so many of the
figures were estimates that I found it impossible to tabulate theca.

286 TEE DESCENT OF MAK

So that in these eigLt lots of cocoons and eggs males were pro-
duced 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 these various sources of evidence, all pointing
in the same direction, I infer that with most species of Lepidoptera
the mature males generally exceed the fenjales 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 {Lu-
canus 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 6 to 1. With one
of the Elateridse, the males are said to be much more numerous than
the females, and "two or three are often found united with one
female;* so that here polyandry seems to prevail." With Siagonium
(Staphylinidse), in which the males are furnished with horns, "the
females are far more numerous than the opposite sex." Mr. Jansou
stated at the Entomological Society that the females of the bark-
feeding Tomiciis villosus are so common as to be a plague, while the
males are so rare as to be hardly known.

It is hardly worth while saying anything about the proportion of
the sexes in certain species and even groups of insects, for the males
are unknown or very rare, and the females are parthenogenetic,
that is, fertile without sexual union ; examples of this are
afforded by several of the Cynipidae.f In all the gall-making
Cynipidae 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 Cecidomyiidse (Diptera). With some common species
of Saw-flies (Tenthredinae) Mr. F. Smith has reared hundreds of
specimens from larvas of all sizes, but has never reared a single
male; on the other hand, Curtis says,t that with certain species
(Athalia) bred by him, the^ males were to the females as 6 to 1 ;
while exactly the reverse occurred with the mature insects of the
same species caught in the fields. In the family of bees, Hermann
Mliller^ collected a large number of specimens of many species, and
reared others from the cocoons, and counted the sexes. He found
that the males of some species greatly exceeded the females in num-
ber; in others the reverse occurred; and in' others the two sexes were
nearly equal. But as in most cases the males emerge from the co-
coons before the females, they gire at the commencement of the breed>
ing season practically in excess. Miiller also observed that the rela-
tive number of the two sexes in some species differed much in differ-
ent localities. But as H. Miiller has himself remarked to me, these
remarks must be received with some caution, as one sex might more

* Gunther's " Record of Zoological Literature," 18';7. p. 2fi0. On the excess
of female Lueanus, ibid. p. 2.5'>. On the males of Lucmiius in England, West-
wood, " Modern Class of Insects," vol i. p. 187. On the Siagonium, ibid. p. 172.

t Walsh in "The American Entomologist." vol. i, 18U9, p. 103. F. Smi'.h.
"Record of Zoological Literature," 1807. p. 3.8.

t " Farm Insects " pp. 4V-4G.

§ " Anwendung der Darwinschen Lehre Verb. d. n. V. Jahrg.," xxiy.

PROPORTION OF THE SEXES, 287

easily escape observation tlian the otlier. Tlius Lis brother Fritz
Miiller Lai4 noticed in Brazil that tlie two sexes of tlie same species of
bee sometimes frequent diiferent kinds of flowers. With respect to
the Orthoptera, 1 know hardly anything about the relative number of
the sexes; Koite,* however, says that out of 500 locusts %vhich he
examined, the males were to the females as 5 to 6, With the
Neuroptera, Mr. Walsh states tbat in many, but by no means In all
tbe species of the Odonatous group, tbere is a great overplus of males;
in the genus Hetaerina, also, the males are generally at least four
times as numerous as tbe females. In certain species in the genus
(Jomjdius tbe males are equally in excess, while in two other species
tbe females are twice or thrice as numerous as the males. In some
European species of Psocus thousands of lemales may be collected
without a single male, while with other species of the same genus
both sexes are common. f In England, Mr. MacLachlan has captured
hundreds of the fen)ale Apatania mvUebris, but Las never seen the
male; and of Boreas hyemalu only four or five males have been seen
here.| With most of these species (excepting the Tentbredinse) there
is at present no evidence that the females are subject to partheno-
genesis; and thus we see bow ignorant we are of the causes of the
apparent discrepancy in the proportion 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 care-
fully attended to this class during many years, writes to me that the
males from their more erratic habits are more commonly seen, and
therefore api)ear more numerous. This is actually the case with a
few species; but he mentions several species m six genera, in which
the females appear to be much more numerous than the males.§ The
small size of the males in comparison with the females (a peculiarity
which is sometimes carried to an extreme degree), and their widely
different appearance, may account in some instances for their rarity
in collections. |j

Some of the lower Crustaceans are able to propagate their kind
sexually, and this will account for the extreme rarity of the males;
thus Von Siebold^ carefully examined no less than 13,000 specimens
of Apus from twenty-one localities, and among these be found only
319 males. With some other forms (as Tanais and Cypris), as Fritz
Muller informs me, there is reason to believe that the males are much
shorter-lived than the females; and this would ex])lain their scarcity,
supposing the two sexes to be at tirst equal in number. On the other
band, Miiller has invariably taken far more males than females of
the Diastylidfe and of Cypridina on the shores of Brazil; thus with a

* " Die Stricb, Zug oder Wanderheuschrecke." 1828, p. CO.

+ " Observations on North American Neuroptera," by H. Haffen and B. D.
Walsh, " Proc. Ent. Soc, Philadelphia," Oct., 18Gi, pp. U8, :C23, 239.

X " Proc. Ent. Soc, London," Feb. 17, 18C8.

§ Another great authority with respect to this class. Prof. Thorell. of Upsala
("On European Spiders," )8G -18^0, part i, p. :iOo), speaks as if female spidera
were generally commoner than the males.

II See, on this subject, Mr. O. P. Cambridge, as quoted In " Quarterly Jour-
nal of Science," 18C8. p. 429.

^"Beitrage zur Parthenogenesis," p. 174.

288 TEE DESCENT OF MAW,

species in tLe latter g:enns, 63 specimens caught tlie same day included
57 males; but lie suggests that this preponderance may be due to
some unknown differeuce in the habits of the two sexes. With one
of the higher Brazilian crabs, namely, a Gelasimus, Fritz Miiller
found the males to be more numerous than the females. According
to the large experience of Mr. C. Spence Bate, the reverse seems to
be the case with six common British crabs, the names of which lie
has given me.

7Iie Proportion of the Sexes in delation to Natural
Selection. — There is reason to suspect that in some cases
man lias by selection indirectly influenced his own sex-
producing powers. Certain women tend to produce during
their whole lives more children of one sex than of the
other; and the same holds good of many animals, for
instance, cows and horses; thus Mr. AVright, of Yeldersley
House, informs me that one of his Arab mares, though put
seven times to different horses, produced seven fillies.
Though I have very little evidence on this head, analogy
would lead to the belief that the tendency to produce
either sex would be inherited like almost every othei
peculiarity, for instance, that of producing twins; and con-
cerning the above tendency a good authority, Mr. J.
Downing, has communicated to me facts which seem to
prove that this does occur in certain families of short-horn
cattle. Col. Marshall* has recently found on careful
examination that the Todas, a hill tribe of India, consist
of 112 males and 84 females of all ages — that is in a ratio
of 133.3 males to 100 females. The Todas, who are poly-
androus in their marriages, during former times invariably
practiced female infanticide; but this practice has now
been discontinued for a considerable period. Of the chil-
dren born within late years the males are more numerous
than the females in the proportion of 124 to 100. Col.
Marshall accounts for this fact in the follovv^ing ingenious
manner: '^ Let us for the purpose of illustration take three
families as representing an average of the entire tribe; say
that one mother gives birth to six daughters and no sons;
a second mother has six sons only, while the third mother
has three sons and three daughters. The first mother, fol-
lowing the tribal custom, destroys four daughters and pre-
serves two. The second retains her six sons. The third
kills two daughters and keeps one, us also her three sons.

*"Tbe Todas," 1873, pp. 100, HI, 104, 196.

\

PnOPORTION OF THE SEXES. 289

Wo liavc then from the three families nine sons and three
daughters with which to continue the breed. But while
the 'males belong to families in which the tendency to pro-
duce sons is great the females are of those of a converse
inclination. Thus the bias strengthens with each genera-
tion until, as we find, families grow to have habitually
more sons than daughters."

That this result would follow from the above form of
infanticide seems almost certain; that is if we assume that
a sex-producing tendency is inherited. But as the above
numbers are so extremely scanty I have searched for addi-
tional evidence, but cannot decide whether what I have
found is trustworthy; nevertheless the facts are, perhaps,
worth giving. The Maories of New Zealand have long
practiced infanticide ; and Mr. Fenton* states that he
'* iias met with instances of women who have destroyed
four, six and even seven children, mostly females. How-
ever, the universal testimony of those best qualified to
judge is conclusive that this custom has for many years
been almost extinct. Probably the year 1835 may be
named as the period of its ceasing to exist." Now
among the New Zealanders, as with the Todas, male births
are considerably in excess. Mr. Fenton remarks (p. 30) :
*' One fact is certain, although the exact period of the
commencement of this singular condition of the dispropor-
tion of the sexes cannot be demonstratively fixed, it is quite
clear that this course of decrease was in full operation
during the years 1830 to 1844, when the non-adult pop-
ulation of 1844 was being produced, and has continued
with great energy up to the present time." The following
statements are taken from Mr. Fenton (p. 20), but as the
numbers are not large, and as the census was not accu-
rate, uniform results cannot be expected. It should bo
borne in mind in this and the following cases, that the
normal state of every population is an excess of women, at
least in all civilized countries, chieiiy owing to the greater
mortality of the male sex during youth, and partly to acci-
dents of all kinds later in life. In 1858, the native popula-
tion of New Zealand was estimated as consisting of 31,007
males and 24, 303 females of all ages, that is, in the ratio

*" Aborigiualluhabitautsof New Zealand: Government lieport,"
1659, p. 30.

290 THE DESCENT OF MAN.

of 130.3 males to 100 females. But during this same year
and in certain limited districts, the numbers were ascer-
tained with much care, and the males of all ages were here
753 and the females GIG; that is in the ratio of 122.2 males
to 100 females. It is more important for us that during
this same year of 1858, the non-adiilt males within the
same district were found to be 178, and the non-achiU
females 142, that is in the ratio of 125.3 to 100. It may
be added that in 1844, at which period female infanticide
had only lately ceased, the non aduU males in one district
were 281, and the nouadalt females only 194, that is in the
ratio of 144.8 males to 100 females.

. In the Sandwich Islands, the males exceed the females
in number. Infanticide was formerly practiced there to a
frightful extent, but was by no means confined to female
infants, as is shown by Mr. Ellis,* and as I have been informed
by Bishop Staley and the Rev. Mr. Coan. Nevertheless,
another apparently trustworthy Avriter, Mr. Jarves,f whose
observations apply to the whole archipelago, remarks:
*' Numbers of women are to be found who confess to the
murder of from throe to six or eight children,'" and he adds,
'* females from being considered less useful than males
were more often destroyed." From what is known to
occur in other parts of the world this statement is
probable; but must be received with much caution. The
practice of infanticide ceased about the year 1819, when
idolatry was abolished and missionaries settled in the
islands. A careful census in 1839 of the adult and taxable
men and women in the island of Kauai and in one district
of Oahu (Jarves, p. 404), gives 4,723 males and 3,776
females; that is in the ratio of 125.08 to 100. At the same
time the number of males under fourteen years in Kauai
and under eighteen in Oahu was 1,797, and of females of
the same ages 1,429; and here we have the ratio of 125.75
males to 100 females.

In a census of all the islands in 1850, J the males of all
ages amount to 36,272, and the females to 33,128, or as
1U9.49 to 100. The males under seventeen years amounted

* •' Narrative of a Tour througb Hawaii," 1826. p. 298.
f •' History of liie Sandwich Islands," 1843. p. 93.
X This is given in the Hev. H. T. CUeever's **Life ia the Sandwich
Islands," 1851; p. 277. >

rnoroRTioN of the sexes. 291

to 10,773, and the females under the same age to 9,593, or
as 112.3 to 100. From the census of 1872 tlie proportion
of males of all ages (including half-castes) to females is as
125.30 to 100. It must be borne in mind that all these
returns for the Sandwich Islands give the proportion of
living males to living females, and not of the births; and
judging from all civilized countries the proportion of males
would have been considerably higher if the numbers had
referred to births.*

From the several foregoing cases we have some reason to
believe that infanticide practiced in the maimer above
explained, tends to make a male-producing race; but I am
far from supposing that this practice in the case of man, or
some analogous process with other species, has been the sole
determining cause of an excess of males. There may be
some unknown law leading to this result in decreasing

*Dr. Coulter, in describing ("Journal R. Geograpli. Soc," vol. v,
1835, p. 67) the state of California about the year 1830, says tbat the
natives, reclaimed by the Spanish missionaries, have nearly all per-
ished, or are perishing, although well treated, not driven from their
native land, and kept from the use of spirits. He attributes this, in
great part, to the undoubted fact that the men greatly exceed the
vi^omen in number; bu* he does not know whether this is due to a
failure of female offspring, or to more females dying during early
youth. The latter alternative, according to all analogy, is very
improbable. He adds that "infanticide, properly so called, is not
common, though very frequent resource is had to abortion." H Dr.
Coulter is correct about infanticide, this case cannot be advanced in
support of Col. Marshall's view. From the rapid decrease of the
reclaimed natives, we may suspect that, as in the cases lately given,
their fertility has been diminished from changed habits of life. I
had hoped to gain some light on this subject from the breeding of
dogs; inasmuch as in most breeds, with the exception, perhaps, of
greyhounds, many more female puppies are destroyed than males,
just as with the Toda infants. Mr. Cupples assures me that this is
usual with Scotch deer-hounds. Unfortunately I know nothing of
the proportion of the sexes in any breed, excepting greyhounds, and
there the male births are to the females as 110.1 to 100. Now from
inquiries made from many breeders, it seems that the females are in
some respects more esteemed, though otherwise troublesome; and it
does not appear that the female puppies of the best- bred dogs are
systematically destroyed more than the males, though this does some-
times take place to a limited extent. Therefore I am unable to
decide whether we can, on the above principles, account for the pre-
ponderance of male births in greyhounds. On the other hand, we
have seen that with horses, cattle and sheep, which are too valuable
for the young of either sex to be destroyed, if there is any difference,
tlio females are slightly in excess.

292 THE DESCENT OF M^HT,

races which have already become eomewhat infertile.
Besides the several causes previously alluded to, the greater
facility of parturition among savages, and the less conse-
quent injury to their male infants, would tend to increase
the proportion of live-born males to females. There does
not, however, seem to be any necessary connection between
savage life and a marked excess of males; that is if we may
judge by the character of the scanty offspring of the lately
existing Tasmanians and of the crossed oflspring of the
Tahitians now inhabiting Norfolk Island.

As the males and females of many animals differ some-
what in habits, and are exposed in different degrees to
danger, it is probable that in many cases m.ore of one sex
than of the other are habitually destroyed. But as far as I
can trace out the complication of causes an indiscriminate
though large destruction of either sex would not tend to
modify the sex-producing power of the species. With
strictly social animals, such as bees or ants, which produce
a vast number of sterile and fertile females in comparison
with the males, and to whom this preponderance is of para-
mount importance, we can see that those communities
would flourish best which contained females having a
strong inherited tendency to produce more and more
females; and in such cases an unequal sex-producing ten-
dency would be ultimately gained through natural selection.
With animals living in herds or troops in which the males
come to the front and defend the herd, as with the bisons
of North America and certain baboons, it is conceivable
that a male-producing tendency might be gained by natural
selection; for the individuals of the better defended herds
would leave more numerous descendants. In the case of
mankind the advantage arising from having a preponderance
of men in the tribe is supposed to be one chief cause of
the practice of female infanticide.

In no case, as far as we can see, would an inherited ten-
dency to produce both sexes in equal numbers or to produce
one sex in excess, be a direct advantage or disadvantage to
certain individuals more than to others; for instance, an
individual with a tendency to produce more males than
females would not succeed better in the battle for life than
an individual with an opposite tendency; and therefore a
tendency of this kind could not be gained through natural
selection. Nevertheless, there are certain animals (for

PllOPORTION OF THE SEXES, 293

instance, fishes and cirripedes) in which two or more males
appear to be necessary for the fertilization of the female;
and the males accordingly largely preponderate, but it is
by no means obvious how this male-producing tendency
could have been acquired. I formerly thought that when
a tendency to produce the two sexes in equal numbers was
advantageous to the species it would follow from natural
selection, but I now see that the whole problem is so intri-
cate that it is safer to leave its solution for the futuie.

294 THE DESCENT OF MAN.

CHAPTER IX.

SECONDARY SEXUAL CHARACTERS IN THE LOWER CLASSES
OF THE AKIMAL KINGDOM.

Tliese cliaracters absent in tlie lowest classes — Brilliant colors —
Mollusca — Annelids — Crustacea, secondary sexual characters
strongly devoloped; dimorphism; color; characters not acquired
before maturity — Spiders, sexual colors of; stridulatiou by the
males — Myriapoda.

With animals belonging to the lower classes, the two
sexes are not rarely united in the same individual, and there-
fore secondary sexual characters cannot be developed. In
many cases where the sexes are sepai-ate both are perma-
nently 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 appreciate each other's beauty or
other attractions, or to feel rivalry.

Hence in these classes or sub-kingdoms, such as the Pro-
tozoa, Ccelenterata, Echinodermata, Scolecida secondary
sexual characters of the kind which we have to consider 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, desire 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 color from the females; but we have no reason to sup-
pose that such differences have been augmented through
sexual selection. Contrivances by which the male holda
the female, and which are indispensable for the propaga-
tion of the species, are independent of sexual selection, and
have been acquired through ordinary selection.

Many of the lower animals, whether hermaphrodites or
with separate sexes, are ornamented with the most brilliant
tints, or are shaded and striped in an elegant manner; for
instance, many corals and sea-auemones (Actiniae), some

SEXUAL SELECTION, 295

3ell5^-fish (Medusae, Porpita, etc.), some Planarias, many
star-fishes, Echini, Ascidians, etc.; 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 colors do not serve as a sexual attraction and
have not been acquired through sexual selection. ^ It
should be borne in mind that in no case have we sufficient
evidence that colors have been thus acquired, except where
one sex is much more brilliantly or conspicuously colored
than the other, and where there is i^o difference in habits
between the sexes sufficient to account for their different
colors. But the evidence is rendered as complete as it can
ever be only when the more ornamented individuals, almost
always the males, voluntarily display their attractions
before the other sex; for we cannot believe that such dis-
play is useless, and if it be advantageous sexual selection
will almost inevitably follow. We may, however, extend
this conculsion to both sexes when colored alike if their
colors 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 colors of many animals in the lowest classes? It
appears doubtful whether such colors often serve as a pro-
tection; but that we may easily err on this head will be
admitted by every one who reads Mr. Wallace's excellent
essay on this subject. It would not, for instance, at first
occur to any one that the transparency of the Medusae, or
jelly-fish, is of the highest service to them as a protection;
but when we are reminded by Iliickel that not only the
Medusae but many floating mollusca, crustaceans and even
small oceanic tishes partake of this same glass-like appear-
ance, often accompanied by prismatic colors, we can hardly
doubt that they thus escape the notice of pelagic birds and
other enemies. M. Giard is also convinced* that the
bright tints of certain sponges and ascidians serve as a pro-
tection. Conspicuous colors are likewise beneficial to many
animals as a warning to their would-be devourers that they
are distasteful, or that they possess some special means of
defense; but this subject will be discussed more conven-
iently hereafter.

We can in our ignorance of most of the lowest animals

♦ *' Arcliivea de Zoolog. Exr)er. " Oct., 1872, p. 503.

296 THE DESCENT OF MAN,

only say that their bright tints result either from the
cliemical nature or the minute structure of tlieir tissues
independently of any benetlt thus derived. Hardly any
color is finer than that of arterial blood; but there is no
reason to suppose that the color 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 colored; thus, as
I am informed by Mr. Hancock, the extreme beauty cf the
Eolidge (naked sea-slugs) is chiefly due to the biliary glands
being 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 colors, it
would have been a strange fact if substances similarly
colored had not often originated, independently of any
useful end thus gained, in the complex laboratory of living

The Siih Kingdom of the Mollnslca. — Throughout this
great division of the animal kingdom, as far as I can dis-
cover, secondary sexual characters, such as we are here con-
sidering, never occur. Nor could they be expected in the
three lowest classes, namely, in the Ascidians, Polyzoa and
Brachiopods (constituting the Molluscoida of some authors),
for most of these animals are permanently affixed to a sup-
port 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 univalve shells, the sexes are either united or separate.
But in the latter case the males never possess special organs
for finding, securing, or charming the females, or for fight-
ing with other males. As I am informed by Mr. Gwyn
Jeffreys, the sole external difference between the sexes con-
sists in the shell sometimes differing a little in form; for
instance, the shell of the male periwinkle {Littorina
lit tor ea) is narrower and has a more elongated spire than
that of the female. But differences of this nature, it may

MOLLUSKS. 297

be presumed, are directly connected with the act of repro-
duction, 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 pul-
moniferous gasteropods, or land-snails, the pairing is pre-
ceded by courtship; for these animals, though hermaphro-
dites, are compelled by their structure to pair together.
Agassiz remarks:* *' Quiconque a eu I'occasion d'observer
les amours des limagons, ne saurait mettre en doute la
seduction deployee dans les monvements et les allures qui
preparent et accomplissent le double embrassemeut 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-snails (Helix poniatia), 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 e::ploration, for both then started,
along the same track and disappeared over the wall.

Even in the highest class of the MoUuska, the Cephalo-
poda or cuttle-tishes, in which the sexes are separate,
secondary sexual characters of the present kind do not, as
far as 1 can discover, occur. This is a surprising circum-
stance, as these animals possess highly-developed sense-
organs and have considerable mental powers, as will be
admitted by everyone who has watched their artful endeav-
ors to escape from an enemy, f Certain Cephalopoda, how-
ever, are characterized by one extraordinary sexual charac-
ter, namely that the male element collects within one of
the arms or tentacles, which is then cast off, andclinging
by its sucking-disks to the female, lives for a time an inde-
pendent life. So completely does the cast-off arni resemble
a separate animal, that it was described by Cuvier as a para-

* " De I'Espece et de la Class," etc., 1869, p. 106.
\ See, for instance, the account wliicli 1 liave given in my '* Jouj^
nal of teearclies," X845, p. 7.

298 THE DESCENT OF MAN,

sitic worm nnder the name of Hectocotyle. But this mar-
velous structure may be classed as a primary rather than ao
a secondary sexual character.

Althou2fh with the MoUuska sexual selection does not
seem to liave come into play; yet many univalve and
bivalve shells, such as volutes, cones, scallops, etc., :ire
beautifully colored and shaped. The colors do not appear
in most cases to be of any use as a protection; they aio
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 be influential to a certain extent ; for
although, as repeatedly stated by Mr. Gv/yn Jeffreys, the
shells of some species living at a profound depth are brightly
colored, yet we generally see the lower surfaces, as well as
the parts covered by the mantle, less highly colored than
the upper and exposed surfaces.* In some cases, as with
shells living among corals or brightly tinted sea-weeds, the
bright colors may serve as a protection.! But that many
of the nudi-branch moUuska, or sea-slugs, are as beauti-
fully colored as any shells, may be seen in Messrs. Aider
and Hancock's magnificent work; and from information
kindly given me by Mr. Hancock, it seems extremely
doubtful whether these colors usually serve as a protection.
With some species this may be the case, as with one kind
which lives on the green leaves of algae, and is itself bright-
green. But many brightly-colored, white, or otherwise
conspicuous species, do not seek concealment; while again
some equally conspicuous species, as well as other dull-
colored kinds, live under stones and in dark recesses. So
that with these nudibranch mollusks, color 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,

*I liave given ("Geolog. Observations on Volcanic Islands," 1844,
p. 53) a curious instance of the intiuence of liglit on the colors of a
frondescent incrustation, deposited by the surf on the coast-rocks of
Ascension, and formed by the solution of triturated sea-shells.

f Dr. Morse has lately discussed this subject in his paper on the
Adaptive Coloration of MoUuska, "Proc. Boston Soc. of "^aX. Hisit.,.**
vol. xiv, April, 1871.

CRUSTACEANS. 299

attracted by each other's greater beauty, might unite
and leave offspring wliich would inherit their parents'
greater beauty. But with such lowly-organized creatures
this is extremely improbable. Nor is it at all obvious how
the oflspring from the more beautiful pairs of hermaphro-
dites would have any advantage over the offspring of the
less Deautiful, so as to increase in number, unless indeed
vigor and beauty generally coincided. We have not here
the case of a number of males becoming mature before
the females, with the more beautiful males selected by the
more vigorous females. If, indeed, brilliant colors were
beneficial to a hermaphrodite animal in relation to its gen-
eral habits of life, the more brightlj'-tinted individuals would
succeed best and would increase in number; but this would
be a case of natural and not of sexual selection.

Suh - kingdom of the Vermes — Annelida (or Sea-
worms). — In this class, although the sexes, when separate,
sometimes differ from each other in characters of such im-
portance 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 are often beautifully colored, but as the sexes do
not differ iu this respect we are but little concerned with
them. Even the Nemertians, though so lowly organized,
" vie in beauty and variety of coloring with any other
group in the vertebrate series;" yet Dr. Mcintosh * cannot
discover that these colors are of any service. The sedentary
annelids become duller-colored, according to M. Quatre-
fage£,t after the period of reproduction; and this I pre-
sume may be attributed to their less vigorous condition at
that time. All these worm-like animals 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 — Crustacea. — In
this great class we first meet with undoubted secondary
Bexual characters, often developed in a remarkable manner.

*See his beautiful monograph on "British Annelids," pari i, 1873,
p. 3.

fSee M. Perrier. " TOrigine de rHommed'aprds Darwin," "Revu©
Scientifique," Feb., 1873, jk bOa.

800 THE D KSCENT OF MAN.

Unfortunately the habits of crustaceans are very imper-
fectly 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 fur-
nished with perfect swimm.ing legs, atennfe 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 attennas are fur-
nished 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 thesmelling-threads has probably been
acquired through sexual selection, by the better provided
males having been the more successful in finding partners
and in producing offspring. Fritz Miiller has described a
remarkable dimorphic species of Tanais in which the male
is represented by two distinct forms which never graduate
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 chelae or
pincers which serve to hold the female. Fritz Miiller sug-
gests that these differences between the two male forms of
the same species may have originated in certain individuals
having varied in the number of the smelling-threads, while
other individuals varied in the shape and size of their
chelae; 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, have left the greatest number of progeny
to inherit their respective advantages.*

In some of the lower crustaceans the right anterior
antenna of the male differs greatly in structure from the
left, th^ latter resembling in its simple tapering joints the
antennae of the female. In the male the modified antenna
is either swollen in the middle or angularly bent or con-

?^ ".Facts and Arguments for Darwin." English translat., 1869, p.
20 See the previous discussion on the olfactory threads. Sars has
descrihed a soinewlmt analogous case (as quoted in " Nature," 1870|
p. 455) in a Norwegian crustacean, the PotUoporcia affiui^^

CRUSTACEANS,

301

verted (Sg. 4) into an elegant and sometimes wonderfully
complex prehensile organ.^ It serves, as I hear from Sir
J. Lubbock, to hold the female, 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 antennae are *' curiously zigzagged'' in the
males alone.

In the higher crustaceans the
anterior legs are developed into
chelae or pincers; and these are gen-
erally larger in the male than in the
female — so much so that the market
value of the male edible crab (Cancer
pa(junit(), according to Mr. C. Spence
Bate, is live times as great as that of
the female. In many species the
chelae are of unequal size on the
opposite side of the body, the right-
hand one being, as I am informed by
Mr. Bate, generally though not
invariably the largest. This ine-
quality is also often much greater in
the male than in the female. The
two chelse of the male often differ
in structure (figs. 5, 6 and 7), the
smaller one resembling that of the
female. AVhat advantage is gained
by their inequality in size on the
opposite sides of the body and by the
inequality being much greater in the
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. As
I hear from Mr. Bate, the chelae are
sometimes of such length and size
that they cannot possibly be used for
carrying food to the mouth. In the male? of certain fresh

Fig. 4. Labidocpra Dnrwinli
(from Lubbock;.

a. Part of rigrht anterior an-

tenna of male, forming a
preiiensile orjran.

b. Posterior pair of tboracio

lejrs of male.

c. Ditto of female.

* See Sir J. Lubbock in " Annals and INIag. of Nat. Hist.," vol. xi,
1853, pi. i and x; and vol. xii, 1853, pi. vii. See also Lulibock la
"Transact. Ent. Soc. ," vol iv, new series, 185j-1858, p. 8. Wiih
respect to the zigzagged antennse mentioned below, see Fritz Miiller,
♦ I'acts and Argameuts for Darwin," 1869, p. 40, foot note.

302

THE DESCENT OF MAN.

water prawns (Palaemon) the right leg is actually longer than
the whole body.* The great size of the one leg with its
chelse may aid the male in fighting with his rivalsj but this

rig. 5. Anterior part of body of Callianassa 'from Milne-Edwards),
saowinjr the unequal and differentia -constructed rig-^ and
left hand chelae of the male.

N. B.— The artist by mistake has reversed the drawing, and made the
left-hand chela the largest

Ilg. 6.

PIsr. 6. Second lee of male Orchestia Tucuratinga (from Fritz Muller).
"Sig.l. Ditto of female.

will not account for their inequality in the female on the
opposite sides of the body. In Gelasimus, according to a

*See a paper by Mr. C. Spence Bate, with figures in '* Proc.
Zoolo<^. Soc," 1868. p. 363; and on the nomenclature of the genus,
ibid. p. 585. I am greatly indebted to Mr. Spence Bate for nearly all
the above statements with respect to the chelae of the higher
crustaceans.

CRUSTACEANS. 803

Btatement quoted by Milne-Edwards, * the male and the
female live in the same burrow, and this shows that they
pair; the male closes the mouth of the burrow with one of
its chela3, which is enormously developed; so that here it
indirectly serves as a means of defense. Their main use,
however, is probably to seize and to secure the female, and
this in some instances, as with Gammarus, is known to be
the case. The male of the hermit or soldier crab (Pagiirufi)
for weeks together, carries about the shell inhabited by the
female, f The sexes, however, of the common shore-crab
(Carcinus mcenrnt), as Mr. Bate informs me, unite directly
after the female has moulted her hard shell, when she is so
soft that she would be injured if seized by the strong
pincers of the male; but as she is caught and carried about
by the male before moulting, she could then be seized with
impunity.

Fritz Miiller states that certain species of Melita are dis-
tinguished from all other amphipods by the females having
'* the coxal lamellai of the penultimate pair of feet pro-
duced into hook-like processes, of which the males lay hold
with the hands of the first pair." The development of
these hook-like processes has probably followed from those
females which were the most securely held during the act
of reproduction, having left the largest number of offspring.
Another Brazilian amphipod {Orchestia Darwinii, tig. 8)
presents a case of dimorphism, like that of Tanais; for
there are two male forms, which differ in the struc-
ture of their chelse.J; As either chela would certainly suf-
fice to hold the female — for both are now used for this pur-
pose— the two male forms probably originated by some
having varied in ons manner and some in another ;
both forms having derived certain special, but nearly equal
advantages, from their differently shaped organs.

It is not known that male crustaceans fight together for
the possession of the females, but it is probably the case ;
for with most animals when the male is larger than the
female, he seems to owe his greater size to his ancestors

*"Hist. Nat. des Crust.," torn, ii, 1837, p. 50.
+ Mr. C. Spence Bate, *' Brit. Assoc, Fourth Report on tlie Fauna
of S. Devon."

t Fritz Mailer, *' Facts and Arguments for Darwin," 1869, pp.
25-28.

304 THE DESCENT OF MAN.

having fought with other males during many generations.
In most of the orders, especially in the highest or the
Brachyura, the male is larger than the female ; the para-
sitic genera, however, in which the sexes follow diiferent

Fig. 8. Orcbestia Darwiryi (from Fiitz Muller\ showing the differently-
constructed chelaj of the two male forms.

habits of life, ami most of the Entomostraca must be
excepted, The chelae of many crustaceans are weapons
well adapted for fighting. Thus when a devil-crab {PoV'
tiinns puber) was seen by a sou of Mr. Bate fighting with
a Carcinus hkbikis, the latter was soon thrown on its back,
and had every limb tcra from its body. AVhen several

CUtrSTACBAKS, 305

males of a Brazilian Gelasimus, a species furnished with
immense pincers, were phiced together in a glass vessel by
Fritz Muller, they mutilated and killed one another. Mr.
Bate put a large male Carcimis mwims into a pan of
water, inhabited by a female which was paired with a
smaller male; but the latter was soon dispossessed. Mr,
Bate adds, *Mf they fought, the victory was a bloodless
one, for I saw no wounds.'' This same naturalist separated
a male sand -skipper (so common on our sea-shores). Gam-
marus viarinus, from its female, both of whom were
imprisoned in the same vessel with many individuals of the
same species. The female, when thus divorced, soou
joined the others. After a time the male was put again
into the same veseel; and he then, after swimming about
for a time, dashed into the crowd, and without any fighting
at once took away his wife. This fact shows that in the
Amphipoda, an order low in the scale, the males and
females recognize each other and are mutually attached.

The mental powers of the Crustacea are probably higher
than at first sight appears probable. Any one who tries to
catch one of the shore-crabs, so common on tropical coasts,
will perceive how wary and alert they are. There is a large
crab {Birgiis latro), found on coral islands, which makes a
thick bed of the picked fibers of the cocoanut, at the
bottom of a deep burrow. It feeds on the fallen fruit of
this tree by tearing off the husk, fiber by fiber; and it
always begins at that end where the three eye-like depres-
sions are situated. It then breaks through one of these
eyes by hammering with its heavy front pincers, and, turn-
ing round, extracts the albuminous core with its narrow
posterior pincers. But these actions are probably instinct-
ive, so that they would be performed as well by a young
animal as by an old one. The following case, however,
can hardly be so considered: a trustworthy naturalist, Mr.
Gardner,* while watching a shore-crab (Gelasimus) making
its burrow, threw some shells toward the hole. One rolled
in, and three other shells remained within a few inches of
the mouth. In about five minutes the crab brought out
the shell which had fallen in, and carried it away to a dis-

*" Travels in the Interior of Brazil," 1846, p. 111. I have given in
ray "Journal of KesearcUes," p. 463, au account of tke liabita of the
Birgus.

306 THE DESCENT OF MAK.

tance of a foot; it then saw the three other shells lying
near, and, evidently thinking that they might likewise roll
in, carried them to the spot where it had laid the first. It
would, I think, be difficult to distinguish this act from one
performed by man by the aid of reason.

Mr. Bate does not know of any well-marked case of dif-
ference of color in the two sexes of our British crustaceans,
in which respect the sexes of the higher animals so often
differ. In some cases, however, the males and fsmales differ
slightly in tint, but Mr. Bate thinks not more than may be
accounted for by their different habits of life; such as by
the male wandering more about, and being thus more
exposed to the light. Dr. Power tried to distinguish by
color the sexes of the several species which inhabit the
Mauritius but failed, except with one species of Sqnilla,
probably *S'. stylifera, the male of which is described as
being *^of a beautiful bluish-green," with some of the
appendages cherry-red, while the female is clouded with
brown and gray, '' with the red about her much less vivid
than in the male." * In this case we may suspect the
agency of sexual seleccion. From M. Bert's observation on
Daphuia, whdn placed in a vessel illuminated by a prism,
we have reason to believe that even the lowest crustaceans
can distinguish colors. With Saphirina (an oceanic genus
of Entomostraca), the males are furnished with minute
shields or cell-like bodies, which exhibit beautiful changing
colors; these are absent in the females, and in both sexes
of one species. t It would, however, be extremely rash to
conclude that these curious organs serve to attract the
females. I am informed by Fritz Miiller, that in the
female of a Brazilian species of Gelasimus the whole body
is of a nearly uniform grayish-brown. In the male the
posterior part of the cephalo-thorax is pure white, with the
anterior part of a rich green, shading into dark brown; and
it is remarkable that these colors are liable to change in the
course of a few minutes — the white becoming dirty gray or
even black, the green ^' losing much of its brilliancy." It
deserves especial notice that the males do not acquire their
bright colors until they become mature. They appear to

*Mr. Ch. Eraser, in '' Proc. Zcolog. Soc," 18G9, p, 3. 1 am
indebted to Mr. Bate for Dr. Power's btaieiiient.
f Claus, "Die freilebendeu Copepoden," 1863, s. 35.

SPIDEHS. 307

be much more nnmerons than the females; they differ also
in the larger size of their chelae. In some species of the
genns, probably in all, the sexes pair and inhabit the same
burrow. They are also, as we have seen, highly intelligent
animals. From these various considerations it seems proba-
ble that the male in this species has become gayly orna-
mented in order to attract or excite the female.

It has just been stated that the male Gelasimus does not
acquire his conspicuous colors until mature and nearly
ready to breed. This seems a general rule in the whole
class in respect to the many remarkable structural differ-
ences between the sexes. We shall hereafter find the same
law prevailing throughout the great sub-kingdom of the
vertebrata; and in all cases it is eminently distinctive of
characters which have been acquired through sexual selec-
tion. Fritz Miiller * gives some striking instances of this
law; thus the male sand-hopper (Orchestia) does not, until
nearly full grown, acquire his large claspers, which are
very differently constructed from those of the female; while
young his claspers resemble those of the female.

Arachiida (Spiders). — The sexes do not generally
differ much in color, but the males are often darker than
the females, as may be seen in Mr. Blackwnll's magnificent
work.f In some species, however, the difference is con-
ppicuous; tluis the female of Sparassus smaragdidus is
dullish green, while the ad nit male has the abdomen of a fine
yellow, with three longitudinal stripes of rich red. In
certain species of Thoniisns the sexes closely resemble each
other, in others they differ much; and nnalogous cases occur
in many other genera. It is often difficnlt'to spy which of
the two sexes departs most from the ordinnry coloration of
the sfenus to which the species belong; but Mr. Blackwall
thinks that, as a general rule, it isthe^male; and CanestriniJ
remarks that in certain genera the males can be specifically
distinguished with ease, but the females with great difficulty.

* " Facts and Arguments," etc., p, 79.

f " A History of tl.e Spiders of Great Britain," 1861-64. For tlie
following facts, see i)p. 77. 88, 102.

:J: This author lias recently published a valuable essay on tlie
*'Caratteri sessuali secondarii de^ili Arachnioi," in tbe '* Atli delia
See. Veueto-Treiitina di Sc. Mat. Padova," vol. i, Fasc. 3, 1873.

308 TEE DESUENT OF MAW,

I am informed by Mr. Blackwall that the sexes while yoinig
usually resemble each other; and both often undergo great
changes in color during their successive moults before
arriving at maturity. In other cases the male alone appears to
change color. Thus the male of the above bright-colored
Sparassus at tirst resembles the female, and acquires his pecu-
liar tints only when nearly adult. Spiders are possessed of
acute senses, and exhibit much intelligence; as is well
known, the females often show the strongest affection for
their eggs, which they carry about enveloped in a silken
web. The males search eagerly for the females, and have
been seen by Canestrini and others to fight for possession of
them. This same author says that the union of the two
sexes has been observed in about twenty species; and he
asserts positively that the female rejects some of the males
who court her, threatens them with open mandibles
and at last after long hesitation accepts the chosen one.
From these several considerations, we may admit with some
confidence that the well-marked differences in color between
the sexes of certain species are the results of sexual selection,
though we have not here the best kind of evidence — the
display by the male of his ornaments. From the extreme
variability of color in the male of some species, for instance
of Theridion Uneatum, it would appear that these sexual
characters of the males have not as yet become well fixed.
Canestrini draws the same conclusion from the fact that the
males of certain species present two forms, differing from
each other in the size and length of their jaws; and this
reminds us of the above cases of dimorphic crustaceans.

The male is generally much smaller than the female,
sometimes to an extraordinary degree,* and he is forced to
be extremely cautious in making his advances, as tho
female often carries her coyness to a dangerous pitch.
De Geer saw a male that ^^in the midst of his preparatory
caresses was seized by the object of his attentions, envel-
oped by her in a web and then devoured, a sight which, as

* Aug. Vinson (" Arantildes des lies de la Reunion," pi. vi, figs, 1
and 2) gives a good instance of the small size of the male, in Epeira
nigra, in this species, as 1 may add, the male is testaceous and the
female black with legs banded with red. Other even more striking
cases of inequality in size between the sexes have been recorded
("Quarterly Journal of Science," 1868, July, p. 429)} but I have not
seen the original accounts.

SPIDERS, 809

he adds, filled him with liorror and indignation/'* The Rev.
0. P. Cambridget accounts in the following manner for
the extreme smallness of the male in the genus Nephila:
*' M. Vinson gives a graphic account of the agile way in
whicli the diminutive male escapes from the ferocity of the
female by gliding about and playing hide and seek over
her body and along her gigantic limbs. In such a pursuit
it is evident that the chances of escape would be in favor
of the smallest males, while the larger ones would fall
early victims; thus gradually a diminutive race of males
would be selected, until at last they would dwindle to the
smallest possible size compatible with the exercise of their
generative functions — in fact, probaby to the size we now
see them, ?. e., so small as to be a sort of parasite upon the
female, and either beneath her notice or too agile and too
small for her to catch without great difficulty."

Westring has made the interesting discovery that the
males of several species of TheridionJ have the power of
making a stridulating sound, while the females are mute.
The apparatus consists of a serrated ridge at the base of
the abdomen, against which the hard hinder part of the
thorax is rubbed; and of this structure not a trace can be
detected in the females. It deserves notice that several
writers, including the well known arachnologist Walck-
enaer, have declared that spiders are attracted by
music. § From the analogy of the Orthoptera and Homop-
tera, to be described in the next chapter, we may feel
almost sure that the stridulation serves, as Westring also
believes, to call or to excite the female; and this is the first
case known to me in the ascending scale of the animal
kingdom of sounds emitted for this purpose. ||

*Kirby and Spence, "Introduction to Entomology," vol. i, 1818,
p. 280.

t " Proc. Zoolog. Soc." 1871, p. 621.

X Theridioii {Amgena, Sund.) seri^atipeft, i-punctatum et guttatum;
see Westring. in Kioyer. " Naturliist. Tidskrift," vol. iv, 1842-1843,
p. 349; and vol. ii, 1846-1849, p. 342. See, also, for other species,
" Araneae Siiecicae," p. 184.

§ Dr. H. H. van Zouteveen, in Lis Dutch translation of this work
(vol. 1, p. 444), has collected several cases.

I Hilgendorf, howeve-, has lately called attention to an analogous
structure in some of the higher crustaceans, which seems adapted to
produce sound; see "Zoological Record," 1869, p. 603,

310 TnE DESCENT OF MAN.

Mijriapoda. — In neither of the two orders in this class,
the millipedes and centipedes, can I find any well-marked
instances of such sexual differences as more particularly
concern us. In Glomeris limhata, however, and perhaps
in some few other species, the males differ slightly m color
from the females; but this Glomeris is a highly variable
species. In the males of the Diplopoda, the legs belong-
ing either to one of the anterior or of the posterior seg-
ments of the body are modified into prehensile hooks
which serve to secure the female. In some species of
Inlas the tarsi of the male are furnished with membranous
suckers for the same purpose. As we shall see when we
treat of insects, it is a much more unusual circumstance,
that it is the female in Lithobius, which is furnished with
prehensile appendages at the extremity of her body for
holding the male.*

^Walckenaer et P. Gervais, "Hist. Nat. des Insectes; Apteres,"
torn, iv, 1847, pp. 17, 19, 68.

INSECTS. 311

CHAPTER X.

SECONDARY SEXUAL CHARACTERS OF INSECTS.

Diversified structures possessed by tlie males for seizino; the females
— DillVrences between the sexes, of whicb the meaning is not
understood — Difference in size between the sexes — Tbysanura
— Diptera — Hemiptera — Homoptera, musical powers possessed
by tlie males alone — Orthoptera, musical insiruments of tbe
niales, mucb diversified in structure; pugnacity; colors — Neu-
roptera, sexual differences in color — Hymenoptera, pugnacity
and colors — Coleoptera, colors; furnisbed witb great boms,
ajiparently as an ornament; battles; stridulatiug organs gener-
ally common to botb sexes.

In the immense class of insects the sexes sometimes
differ in their locomotive-organs, and often in their sense-
organs, as in the pectinated and beautifully plumose anten-
nae of the males of many species. In Chloeon, one of tho
Ephemerae, the male has great pillared eyes, of which the
female is entirely destitute* The ocelli are absent in tho
females of certain insects, as in theMutillidae; and here the
females are likewise wingless. But we are chiefly concerned
with structures by which one male is enabled to conquer
another, either in battle or courtship, through his strength,
pugnacity, ornaments, or music. The innumerable contriv-
ances, therefore, by which the male is able to seize the
female, may be briefly passed over. Besides the complex
structures at the apex of the abdomen, which ought per-
haps to be ranked as primary organs, f ** 1 1 is ascouibina^, its

*Sir J. Lubbock, *• Transact. Liunean Soc," vol. xxv, 186G, p.
484. Witb respect to tbe Mutillidae see Westwood, "Modern Class,
of Insects," vol. ii, p. 213.

f Tbese organs in tbe male often differ in closely allied species
and afford excellent specific characters. But their importance, from
a functional point of view, as Mr. R. MacLacblan lias remarked to
me. bas probably been overrated. It bas been suggested that slight
differences in tbese organs would suffice to prevent tbe intercrossing
of well-marked varieties or incipient species, and would tbua aid in

81t

TEE DESCENT OF MATT.

Mr. B. D. Walsh* has remarked, *' how many different
organs are worked in by nature for the seemingly insignifi-
cant object of enabling the male to grasp the female
firmly." The mandibles or jaws are sometimes nsed for
this purpose; thus the male Corydalis cornutns (a neu-
ropterous insect in some degree allied to the dragon flies,

etc.) has immense curved jaws,
many times longer than those of
the female; and they are smooth
instead of being toothed, so that
he is thus enabled to seize her
without injury, f One of the
stag-beetles of North America
(Lncanvs claphtts) uses his jaws,
which are much larger than
those of the female, for the same
purpose but probably likewise
for fighting. In one of the sand-
wasps (AmmopJiila) the jaws in
the two sexes are closely alike,
but are used for widely difl'ercnt
purposes; the males, as Prof.
VVestwood observes, ^' are exceed-
ingly ardent, seizing their part-
ners round the neck with their
sickle-shaped jaws;"J while the
females use these organs for
■"feuroSSe-iowSte^'eteX" burrowing in sand-banks aud

making their nests.
The tarsi of the front legs are dilated in many male
beetles, or are furnished with broad cushions of hair; and
in many genera of water beetles they are armed with a

their development. That this can hardly be the casp, we may infer
from the many recorded cases (see, for instance. Bronn, " Geschichte
der Natnr," k ii, 1843, s. 164; and Westwood, "Transact, Ent.
Soc," vol. ill, 1842, p. 195) of distinct species having been observed
in union, Mr. MacLachlan informs me (vide "Stett. Ent. Zeitung,"
1867, s. 155) that when several species of Phryganidae, which present
strongly pronounced differences of this kind, were confined togethei
hy Dr. Aug. Mever, they coy pled, and one pair produced fertile ova.

*" The Practical Entomologist," Phila., vol. ii, May, 1867, p. 88.

t Mr. Walsh, ibid. p. 107.

i" Modern Classification of Insects," vol. ii, 1840, pp. 205.206.
Mr. Walsh, who called my attention to the double use of the jaws.
Bays that lie has repeatedly observed this fact.

INSECTS.

313

round flat sucker, so that the male may
adhere to the slippery body of the female.
It is a much more unusual circumstance
that the females of some water beetles (Dytis-
cus) have their elytra deeply grooved, and in
Acilius sulcatus thickly set with hairs as an
aid to the male. The females of some other
water beetles (Hydroporus) have their elytra
punctured for the same purpose.* In the
male of Crabro crihrarius (fig. 9) it is the
tibia which is dilated into a broad horny
plate with minute membraneous dots, giving
to it a singular appearance like that of a
riddle, f In the male of Penthe (a genus
of beetles) a few of the middle joints of the
antennae are dilated and furnished on the
inferior surface with cushions of hair, ex-
actly like those on the tarsi of the Carabidse,
*^and obviously for the same end.^' In
male dragon-flies, ''the appendages at the
tip of the tail are modified in an almost in-
finite variety of curious patterns to enable
them to embrace the neck of the female. ^^
Lastly, in the males of many insects, the
legs are furnished with peculiar spines, knobs
or spurs; or the whole leg is bowed or thick-
ened, but this is by no means invariably a
sexual character; or one pair, or all three
pairs are elongated, sometimes to an extrava-
gant length. I

The sexes of many species in all the orders
present differences, of which the meaning is
not understood. One curious case is

Fi^. 10. Tapliro-
deres distortus
(enlarged), Up-

{)er figure, male;
o wer figure,
female.

* We have here a curious and inexplicable case of dimorphism, for
some of the females of four European species of Dysticus, and of
certain species of Hydroporus, have their elytra smooth; and no
intermediate gradations between the sulcated or punctured, and the
•juite smooth elytra have been observed. See Dr. H. Schaum, as
quoted in the " Zoologist," vols, v-vi, 1847-48, p. 1896. Also Kirby
and Spence, "Introduction to Entomology," vol. iii, 1826, p. 305.

f Westwood, "Modern Class.," vol. ii, p. 193. The following
statement about Penthe, and others in inverted commas, are taken
from Mr. Walsh, "Practical Entomologist," Phila., vol. iii, p. 88.

X Kirby and Spence, ** Introduct.," »t^., vol. iii, pp. 38^336.

314 THE DESCENT OF MAN.

that of the beetle (fig. 10), the male of which has
left mandible much enlarged; so that the mouth is
greatly distorted. In another Oarabidous beetle, Euryg-
nathus,* we have the case, unique as far as known to Mr.
Wollaston, of the head of the female being much broader
and larger, though in a variable degree, than that of the
male. Any number of such cases could be given. They
abound in the Lepidoptera; one of the most extraordinary
is that certain male butterflies have their fore legs more or
less atrophied, with the tibiae and tarsi reduced to mere
rudimentary knobs. The wings, also, in the two sexes
often diifer in neuration,f and sometimes considerably in
outline,, as in the Aricoj'is epittis, which was shown to me
in the British Museum by Mr. A. Butler. The males of
certain South American butterflies have tufts of hair on
the margins of the wings and horny excrescences on the
disks of the posterior pair. I In several British butterflies,
as shown by Mr. Wonfor, the males alone are in parts
clothed with peculiar scales.

The use of the bright light of the female glow-worm has
been subject to much discussion. The male is feebly
luminous, as are the larvae and even the eggs. It has been
supposed by some authors that the light serves to frighten
away enemies, and by others to guide the male to the
female. At last Mr. Belt§ appears to have solved the
difficulty; he finds that all the Lampyridae which he has
tried are highly distasteful to insectivorous mammals and
birds. Hence it is in accordance with Mr. Bates^ view,
hereafter to be explained, that many insects mimic the
Lampyridae closely, in order to be mistaken for them, and
thus to escape destruction. He further believes that the
luminous species profit by being at once recognized as

* ** Insecta Maderensia," 1854, p, 20.

f E. Doubleday, " Annals and Mag. of Nat. Hist," vol. i, 1848, p.
379. I may add that the wings in certain Hymenoptera (see Shuck-
ard, " Fossorial Hymenop.," 1837, pp. 39-43) differ in neuration
according to sex.

:J:H. W, Bates, in "Journal of Proc. Linn. Soc," vol. vi, 1862, p.
74. Mr. Wonfor's observations are quoted in " Popular Science
Review," 1868, p. 343.

§ '* The Naturalist in Nicaragua," 1874, pp. 316-320. On the phos-
phorescence of the eggs, see "Annals and Mag. of Nat. Hist.," 1871,
Nov., p. 372.

INSECTS. 815

unpalatable. It is probable that the same explanation may
be extended to the Elaters, both sexes of which are highly
luminous. It is not known why the wings of the female
glow-worm have not been developed; but in her present
state she closely resembles a larva, and, as larvae are so
largely preyed on by many animals, we can understand why
she has been rendered so much more luminous and con-
spicuous than the male; and why the larvae themselves are
likewise luminous.

Differ e7ice in Size Bekoeen the Sexes, — With insects of
all kinds the males are commonly smaller than the females;
and this difference can often be detected, even in the larval
state. So considerable is the difference between the male
and female cocoons of the silk-moth {Bomhyx mori), that
in France they are separated by a particular mode of
weighing.* In the lower classes of the animal kingdom
the greater size of the females seems generally to depend
on their developing an enormous number of ova; and this
may to a certain extent hold good with insects. But Dr.
Wallace has suggested a much more probable explanation.
He finds, after carefully attending to the development of
the caterpillars of Bomhyx cynthia and yamamai, and espe-
cially to that of some dwarfed caterpillars reared from a
second brood on unnatural food, ^'^that in proportion as
the individual moth is finer, so is the time required for its
metamorphosis longer; and for this reason the female, which
is the larger and heavier insect, from having to carry her
numerous eggs, will be preceded by the male, which is
smaller and has less to mature, ^'f Now as most insects are
short-lived, and as they are exposed to many dangers, it
would manifestly be advantageous to the female to be im-
pregnated as soon as possible. This end would be gained
by the males being first matured in large numbers ready for
the advent of the females; and this again would naturally
follow, as Mr. A. R. Wallace has remarked, J through nat-
ural selection; for the smaller males would be first matured,
and thus would procreate a large number of offspring which
would inherit the reduced size of their male parents, while

*Robinet, "Vers a Sole," 1848, p. 207.

f " Transact, Ent. Soc," 3d series, vol. v, p. 486.

% " Journal of Proc. Ent. Soc," Feb. 4, 1867, p. 71.

316 THE DESCENT OF MAN.

the larger males^ from being matured later, would leave
fewer offspring.

There are, however, exceptions to the rule of male insects
being smaller than the females; and some of these exceptions
are intelligible. Size and strength would be an advantage
to the males, which fight for the possession of the females;
and in these cases, as with the stag-beetle (Lucanus), the
males are larger than the females. There are, however,
other beetles which are not known to fight together, of which
the males exceed the females in size; and the meaning of this
fact is not known; but in some of these cases, as with the
huge Dynastes and Megasoma, we can at least see that there
would be no necessity for the males to be smaller than the
females, in order to be matured before them, for these
beetles are not short-lived, and there would be ample time
for the pairing of the sexes. So again, male dragon-flies
(Libellulidae) are sometimes sensibly larger, and never
smaller, than the females;* and, as Mr. MacLachlan believes,
they do not generally pair with the females until a week or
fortnight has elapsed, and until they have assumed their
proper masculine colors. But the most curious case show-
ing on what complex and easily overlooked relations so
trifling a character as difference in size between the sexes
may depend, is that of the aculeate Hymenoptera; for Mr.
F. Smith informs me that throughout nearly the whole of
this large group, the males, in accordance with the general
rule, are smaller than the females, and emerge about a
week before them; but among the bees, the males of Apis
melUjica, Antliiclium 7nanicatiim, and Anthophora acervo-
rum, and among the Fossores the males of the Methoca
ichneumonides are larger than the females. The explana-
tion of this anomaly is that a marriage flight is absolutely
necessary with these species, and the male requires great
strength and size in order to carry the female through the
air. Increased size has here been acquired in opposition to
the usual relation between size and the period of develop-
ment, for the males, though larger, emerge before the
smaller females.

We will now review the several orders, selecting such
facts as more particularly concern us. The Lepidoptera

* For this and other statements on the size of the sexes, see Kirby
and Spence, ibid., vol. ill, p. 300; on the duration of life in insects,
see p. 344.

I

INSECTS, 317

(butterflies and moths) will be retained for a separate
chapter.

Thysanura. — The members of this lowly organized
order are wingless, dull-colored, minute insects, with ugly,
almost misshapen heads and bodies. Their sexes do not
dilf er, but they are interesting as showing us that the males
pay sedulous court to the females even low down in the ani-
mal scale. Sir J. Lubbock* says: '^it is very amusing to
see these little creatures (Smynthurus hiteus) coquetting
together. The male, which is much smaller than the
female, runs round her, and they butt one another, stand-
ing face to face and moving backward and forward like two
playful lambs. Then the female pretends to run away and
the male runs after her with a queer appearance of anger,
gets in front and stands facing her again; then she turns
coyly round, but he, quicker and more active, scuttles
round too, and seems to whip her with his antennae; then
for a bit they stand face to face, play with their antennaB,
and seem to be all in all to one another.''

Diptera (Flies). — The sexes differ little in color. The
greatest difference, known to Mr. F. Walker, is in the
genus Bibio, in which the males are blackish or quite
black, and the females obscure brownish-orange. The
genus Elaphomyia, discovered by Mr. Wallace \ in New
Guinea, is highly remarkable, as the males are furnished
with horns, of which the females are quite destitute. The
horns spring from beneath the eyes, and curiously resemble
those of a stag, being either branched or palmated. In one
of the species they equal the whole body in length. They
might be thought to be adapted for fighting, but as in one
species they are of a beautiful pink color, edged with black,
with a pale central stripe, and as these insects have alto-
gether a very elegant appearance it is perhaps more proba-
ble that they serve as ornaments. That the males of some
Diptera fight together is certain; Prof. WestwoodJ has
several times seen this with the Tipulae. The males of
other Diptera apparently try to win the females by their

*" Transact. Linnean Soc," vol. xxvi, 1868, p. 296.

f " The Malay Archipelago," vol. ii, 1869, p. 313.

:^" Modern Classification of Insects," vol. ii. 1840. p. 526.

318 THE DESCENT OF MAN.

music. H. Miiller* watched for some time two males of an
Eristalis courting a female; they hovered above her, and
flew from side to side making a high humming noise at the
same time. Gnats and mosquitoes (Culicidae) also seem to
attract each other by humming; and Prof. Mayer has
recently ascertained that the hairs on the antennae of the
male vibrate in unison with the notes of a tuning-fork
within the range of the sounds emitted by the female. The
longer hairs vibrate sympathetically with the graver notes,
and the shorter hairs with the higher ones. Landois also
asserts that he has repeatedly drawn down a whole swarm
of gnats by uttering a particular note. It may be added
that the mental faculties of the Diptera are probably higher
than in most other insects, in accordance with their highly
developed nervous system, f

Hemiptera (Field Bugs). — Mr. J. W. Douglas, who has
particularly attended to the British species, has kindly
given me an account of their sexual differences. The
males of some species are furnished with wings, while the
females are wingless; the sexes differ in the form of their
bodies, elytra, antennae and tarsi; but as the signification of
these differences is unknown they may be here passed over.
The females are generally larger and more robust than the
males. With British and, as far as Mr. Douglas knows,
with exotic species the sexes do not commonly differ much
in color; but in about six British species the male is con-
siderably darker than the female, and in about four other
species the female is darker than the male. Both sexes of
some species are beautifully colored; and as these insects
emit an extremely nauseous odor their conspicuous colors
may serve as a signal that they are unpalatable to insect-
ivorous animals. In some few cases their colors appear to
be directly protective ; thus Prof. Hoffmann informs me
that he could hardly distinguish a small pink and green
species from the buds on the trunks of lime-trees which
this insect frequents.

*Anwendung, etc., "Verli. d. n. V. Jalirg.," xxix, p. 80. Mayer,
in "American Naturalist," 1874, p. 236.

f See Mr. B. T. Lowne's interesting work, " On the Anatomy of the
Blow-fly, Musca vomitoria," 1870, p. 14. He remarks (p. 33) that
** the captured flies utter a peculiar plaintive note, and that this
sound causes other flies to disappear."

IN8EGT8. 310

Some species of Reduvidae make a stridulating noise; and
in the case of Pirates stridulus this is said* to be effected
by the movement of the neck within the pro-thoracic
cavity. According to Westring, Reduvhis personatus also
stridulates. But I have no reason to suppose that this is a
sexual character, excepting that with non-social insects
there seems to be no use for sound-producing organs unless
it be as a sexual call.

Homoptera. — Every one who has wandered in a tropi-
cal forest must have been astonished at the din made
by the male Cicadas. The females are mute ; as the
Grecian poet Xenarchus says: '^ Happy the Cicadas live,
since they all have voiceless wives. ^' The noise thus made
could be plainly heard on board the " Beagle/' when
anchored at a quainter of a mile from the shore of Brazil;
and Capt. Hancock says it can be heard at the distance of a
mile. The Greeks formerly kept, and the Chinese now
keep, these insects in cages for the sake of their song, so
that it must be pleasing to the ears of some men.f The
Cicadidae usually sing during the day, while the Fulgoridas
appear to be night-songsters. The sound, according to
Landois,J: is produced by the vibration of the lips of the
spiracles, which are set in motion by a current of air
emitted from the tracheae; but this view has lately been dis-
puted. Dr. Powell appears to have proved § that it is pro-
duced by the vibration of a membrane set into action by a
special muscle. In the living insect, while stridulating,
this membrane can be seen to vibrate; and in the dead
insect the proper sound is heard, if the muscle, when a little
dried and hardened, is pulled with the point of a pin. In
the female the whole complex musical apparatus is present,
bat is much less developed than in the male, and is never
used for producing sound.

With respect to the object of the music. Dr. Hartman, in
speaking of the Cicada septemdecim of the United States,

* Westwood, "Modern Class, of Insects," vol. ii, p. 473.

f These particulars are taken from Westwood's ** Modern Class, of
Insects," vol. ii, 1840, p. 422. See also, on the Fulgoridae, Kirby
and Spence, " Introduct.," vol. ii, p. 401.

X "Zeitschrift fiir wissenschaft Zoolog.," B. xvii, 1867, ss. 152-158.

§ "Transact. New Zealand Institute," vol. v, 1873, p. 286,

3^0 THE DESCENT OF MAK

says,* "the drums are now (June 6 and 7, 1851) heard in
all directions. This I believe to be the marital su<mmons
from the males. Standing in thick chestnut sprouts about
as high as my head, where hundreds were around me, I
observed the females coming around the drumming males."
He adds, ''this season (August, 1868) a dwarf pear-tree in
my garden produced about fifty larvae of Cic. pruinosa; and
I several times noticed the females to alight near a male
while he was uttering his clanging notes." Fritz Miiller
writes to me from S. Brazil that he has often listened to a
musical contest between two or three males of a species
with a particularly loud voice, seated at a considerable dis-
tance from each other; as soon as one had finished his song
another immediately began and then another. As there is
so much rivalry between the males, it is probable that the
females not only find them by their sounds, but that, like
female birds, they are excited or allured by the male with
the most attractive voice.

I have not heard of any well-marked cases of ornamental
differences between the sexes of the Homoptera. Mr.
Douglas informs me that there are three British species, in
which the male is black or marked with black bands, while
the females are pale-colored or obscure.

Orthoptera (Crickets and Grasshoppers). — The males in
the three saltatorial families in this order are remarkable
for their musical powers, namely the Achetidse or crickets,
the Locustidae, for which there is no equivalent English
name, and the Acridiidae or grasshoppers. The stridula-
tion produced by some of the Locustidas is so loud that
it can be heard during the night at the distance of a
mile;t and that made by certain species is not unmusical
even to the human ear, so that the Indians on the Amazons
keep them in wicker cage^. All observers agree that the
sounds serve either to call or excite the mute females.
With respect to the migratory locusts of Russia, Korte has
given X an interesting case of selection by the female of a

* I am indebted to Mr. Walsh for having sent me this extract from
a ** Journal of the Doings of Cicada septemdecim," by Dr. Hartman.

f L. Guilding, "Transact, Linn, Soc," vol, xv, p. 154.

X I state this on the authority of Koppen, " Ueber die Heuschrecken
in Siidrussland," 1866, p. 33, for I have in vain endeavored to pro
cure Korte's work.

mSEGTS.

321

male. The males of this, species {Pachytylus migraforius)
while coupled with the female stridulate from anger or
jealousy if approached by other males. The house-cricket
when surprised at night uses its voice to warn its fellows.*
In North America the Katydid [Platyphyllum concavum,
one of the Locustidse) is described \ as mounting on the
upper branches of a tree, and in the evening beginning
^' his noisy babble, while rival notes issue from the neigh-
the groves resound with the call of
the live-
Bates, in
European

and

Fig.

campestris

(from

boring trees,

Katy - did - she - di

long night. ^' Mr.

speaking of the

field-cricket (one of the Ache-

tidse), says '*^the male has been

observed to place himself in

the evening at the entrance

of his burrow, and stridulate

until a female approaches,

when the louder notes are

succeeded by a more subdued

tone, while the successful

musician caresses with his

antennae the mate he has

won.^t Dr. Scudder was able

to excite one of these insects

to answer him, by rubbing on

a file with a quill. § In both

sexes a remarkable auditory

apparatus has been discovered

by Von Siebold, situated in the front legs. 1|

In the three families the sounds are differently produced.
In the males of the Achetidse both wing-covers have the
same apparatus; and this in the field-cricket (Gryllus
campestris, fig, 11) consists, as described by Landois,!^ of

♦Gilbert White, "Nat. Hist, of Selborne," vol. ii, 1825, p. 263-

f Harris, " Insects of New England," 1842, p. 128.

f The Naturalist on the Amazons," vol. i, 1863, p. 252. Mr.
Bates gives a very interesting discussion on the gradations in the
musical apparatus of the three families. See also West wood, " Mod-
ern Class.," vol. ii, pp. 445, 453.

§ " Proc. Boston Soc. of Nat. Hist.," vol. xi, April, 1868.

|"Nouveau Manuel d'Anat. Comp." (French translat.), torn, i,
1850, p. 587.

t" Zeitschrift fur wissenschaft. Zoolog.," B. xvii, 1867, s. UX

11. Gryllus
Landois).
Right-hand figure, under side of part
of a wing-nervure, much magnified,
showing the teeth, st.
Left-hand figure, upper surface of
wing-cover, with the projecting,
smooth nervure, r, across which the
teeth {st) are scraped.

322 THE DESCENT OF MAN.

from 131 to 138 sharp, transverse ridges or teeth {st) on
the under side of one of the nervures of the wing-cover.
This toothed nervure is rapidly scraped across a projecting,
smooth, hard nervure (r) on the upper surface of the oppo-
site wing. First one wing is rubbed over the other, and
then the movement is reversed. Both wings are raised a
little at the same time, so as to increase the resonance. In
some species the wing-covers of the males are furnished at
the base with a talc-like plate.* I here give a drawing
(fig. 12) of the teeth on the under side of the nervure of
another species of Gryllus, viz., G. domesticus. With
respect to the formation of these teeth. Dr. Gruber has
shown f that they have been developed by the aid of
selection, from the minute scales and hairs
with which the wings and body are covered,
and I came to the same conclusion with
respect to those of the Coleoptera. But Dr.
Gruber further shows that their development
is in part directly due to the stimulus from
the friction of one wing over the other.

In the Locustidse the opposite wing-covers
differ from each other in structure (fig 13),
■^NerviirJof Gryi- ^^^ ^^^^ action Cannot, as in the last family,
1 u s domestipus be reversed. The left wing, which acts as the

(from Landois). ^^^^ |.^g ^^^^ ^j^^ ^.^1^^ ^-^^^ which SCrVCS aS

the fiddle. One of the nervures {a) on the under surface of
the former is finely serrated, and is scraped across the
prominent nervures on the upper surface of the opposite or
right wing. In our British Phasgonura viridissiina it
appeared to me that the serrated nervure is rubbed against
the rounded hind-corner of the opposite wing, the edge of
which is thickened, colored brown, and very sharp. In
the right wing, but not in the left, there is a little plate, as
transparent as talc, surrounded by nervures, and called the
speculum. In Epliippiger vitium, a member of this same
family, we have a curious subordinate modification; for the
wing-covers are greatly reduced in size, but '' the posterior
part of the pro-thorax is elevated into a kind of dome over

* Westwood, "Modern Class, of Insects," vol. i, p. 440.
f ' ' Ueber der Tonapparat der Locustiden, ein Beitrag zum Darwin-
isinus," "Zeitscli. ftir wissensch Zoolog.," B. xxii, 1873, p. 100.

INSECTS. 323

the wing-covers, and which has probably the effect of
increasing the sound/^*

We thus see that the musical apparatus is more dif-
ferentiated or specialized in the Locustidae (which
include, I believe, the most powerful performers in

Hg. 18. ChlorocoelusTanana (from Bates), a, 6. Lobes of opposite wing-covers.

the order), and in the Achetidae, in which both wing-
covers have the same structure and the same function, f
Landois, however, detected in one of the Locustidae,
namely in Decticus, a short and narrow row of small
teeth, mere rudiments, on the inferior surface of the
right wing-cover, which underlies the other and is never
used as the bow. I observed the same rudimentary
structure on the under side of the right wing-
cover in Phasgonura viridissima. Hence we may infer
with confidence that the Locustidae are descended from a
form in which, as in the existing Achetidae, both wing-

*Westwood, •♦Modern Class, of Insects," vol. i, p. 453

f Landois, " Zeitsch. f. wiss Zoolog." B. xvii, X867» ss. 131, 133.

324

THE DESCENT OF MAN.

covers had serrated nervnres on the under surface and could
be indifferently used as the bow; but that in the Locustidae
the two wing-covers gradually became differentiated and
perfected on the principle of the division of labor, the one
to act exclusively as the bow and the other as the fiddle.
Dr. Gruber takes the same view, and has shown that rudi-
mentary teeth are commonly found on the inferior surface
of the right wing. By what steps the more simple appa-
ratus in the Achetidse originated we do not know, but it is
probable that the basal portions of the wing-covers origi-
nally overlapped each other as they do at present; and that

the friction of the nervures
produced a grating sound as
is now the case with the wing-
covers of the females.* A
grating sound thus occasion-
ally and accidentally made by
the males,if it served them ever
so little as a love-call to the fe-
males, might readily have been
intensified through sexual se-
lection by variations in the
roughness of the nervures hav-
ing been con tinually preserved .
Fig. 14, Hind-leg of stenobothrus pra- ^"^ J^^e last and third family,
torum. r, the striduiating ridge ; namely, the Acridudae or
i?S'nSmagnifild%-oSl^^ grasshoppers, the stridulation

is produced in a very differ-
ent manner, and according to Dr. Scudder, is not so shrill
as in the preceding families. The inner surface of the
femur (fig. 14, r) is furnished with a longitudinal row of
minute, elegant, lancet-shaped, elastic teeth from eighty-
five to ninety-three in number;f and these are scraped
across the sharp, projecting nervures on the wing-covers
which are thus made to vibrate and resound. HarrisJ; says
that when one of the males begins to play he first *' bends
the shank of the hind-leg beneath the thigh, where it is

*Mr. Walsh also informs me tliat lie has noticed that the female
of the Platyphyllum concavuniy "when captured, makes a feeble
grating noise by shuffling her wing-covers together."

f Landois, ibid., s. 113.

I " Insects of New England," 1842, p. 133.

INSECTS.

325

lodged in a furrow designed to receive it, and then draws
the leg briskly up and down. He does not play both
fiddles together, but alternately, first upon one and then
on the other." In many species the base of the abdomen
is hollowed out into a great cavity which is believed to act
as a resounding board. In Pneumora (fig. 15), a S. Afri-

Flg. 15.

Pneumora (fTom specimens in the British Museum). Upper
figure, male; lower figure, female.

can genus belonging to the same family, we meet with a
new and remarkable modification; in the males a small
notched ridge projects obliquely from each side of the
abdomen, against which the hind femora are rubbed.* As
the male is furnished with wings (the female being wing-

* Westwood, "Modem Classification," vol. 1, p. 462,

326 THE DESCENT OF MAN.

less) it is remarkable that the thighs are not nibbed in the
usual manner against the wing-covers; but this may per-
haps be accounted for by the unusually small size of the
hind legs. I have not been able to examine the inner sur-
face of the thighs, which, judging from analogy, would be
finely serrated. The species of Pneumora have been more
profoundly modified for the sake of stridulation than any
other orthopterous insect; for in the male the Avhole body
has been converted into a musical instrument, being dis-
tended with air like a great pellucid bladder so as to
increase the resonance. Mr. Trimen informs me that at
the Cape of Good Hope these insects make a wonderful
noise during the night.

In the three foregoing families the females are almost
always destitute of an efficient musical apparatus. But there
are a few exceptions to this rule, for Dr. Gruber has shown
that both sexes of EjjJiippiger vitium are thus provided;
though the organs differ in the male and female to a cer-
tain extent. Hence we cannot suppose that they have been
transferred from the male to the female, as appears to have
been the case with the secondary sexual characters of many
other animals. They must have been independently devel-
oped in the two sexes, which no doubt mutually call to
each other during the season of love. In most other Locus-
tidae (but not according to Landois in Decticus) the females
have rudiments of the stridulatory organs proper to the
male; from whom it is probable that these have been trans-
ferred. Landois also found such rudiments on the under
surface of the wing-covers of the female Achetidas, and on
the femora of the female Acridiidae. In the Homoptera,
also, the females have the proper musical apparatus in a
functionless state; and we shall hereafter meet, in other
divisions of the animal kingdom, with many instances of
structures proper to the male being present in a rudimentary
condition in the female.

Landois has observed another important fact, namely,
that in the females of the Acridiidae, the stridulating teeth
on the femora remain throughout life in the same condition
in which they first appear during the larval state in both
sexes. In the males, on the hand, they become further
developed, and acquire their perfect structure at the last
moult, when the insect is mature and ready to breed.

Prom the facts now given we see that the meanfi by

INSECTS. 327

which the males of the Orthoptera produce their sounds are
extremely diversified, and are altogether different from
those employed by the Homoptera.* But throughout the
animal kingdom we o'ften find the same object gained by
the most diversified means; this seems due to the whole
organization having undergone multifarious changes in the
course of ages, and as part after part varied different varia-
tions v/ere taken advantage of for the same general purpose.
The diversity of means for producing sound in the three
families of the Orthoptera and in the Homoptera,
impresses the mind with the high importance of these
structures to the males, for the sake of calling or alluring
the females. We need feel no surprise at the amount of
modification which the Orthoptera have undergone in this
respect, as we new know, from Dr. Scudder's remarkable
discovery,! that there has been more than ample time.
This naturalist has lately found a fossil insect in the
Devonian formation of New Brunswick, which is furnished
with " the well-known tympanum or stridulating apparatus
of the male Locustidse." The insect, though in most
respects related to the Neuroptera, appears, as is so often
the case with very ancient forms, to connect the two related
orders of the Neuroptera and Orthoptera.

I have but little more to say on the Orthoptera. Some
of the species are very pugnacious; when two male field-
crickets (Gryllus campestris) are confined together they
fight till one kills the other; and the species of Mantis are
described as maneuvering with their sword-like front limbs,
like hussars with their sabers. The Chinese keep these
insects in little bamboo cages, and match them like game-
cocks. J AVith respect to color, some exotic locusts are
beautifully ornamented; the posterior wings being marked
with red, blue and black; but as throughout the order the
sexes rarely differ much in color, it is not probable that
they owe their bright tints to sexual selection. Conspicu-

* Landois lias recently found in certain Ortlioptera rudimentary-
structures closely similar to the sound-producing organs in the
Homoptera; and tliis is a surprising fact. See "Zeitsclir. fiir wis-
sensch. Zoolog.," B. xxii, Heft 3, 1871, p. 348.

f " Transact. Ent. Soc," 3d series, vol. ii. (" Journal of Proceed-
ings," p 117.)

X West wood, " Modern Class of Insects,'* vol. i, p. 427; for crick-
ets, p. 445.

328 THE DESCENT OF MAN,

ous colors may be of use to these insects by giving notice
that they are unpalatable. Thus it has been observed* that
a bright-colored Indian locust was inyariably rejected when
offered to birds and lizards. Some cases^ however, are
known of sexual differences in color in this order. The
male of an American cricket f is described as being as
white as ivory, while the female varies from almost white to
greenish-yellow or dusky. Mr. Walsh informs me that the
adult male of Spectrum femoratum (one of the Phasmidae)
** is of a shining brownish-yellow color; the adult female
being of a dull, opaque, cinereous brown; the young of
both sexes being green. ^' Lastly, I may mention that the
male of one curious kind of cricket J; is furnished with ^'^a
long membranous appendage, which falls over the face like
a veil;" but what its use may be is not known.

Neuroptera, — Little need here be said, except as to color.
In the Ephemeridse the sexes often differ slightly in their
obscure tints ;§ but it is not probable that the males are
thus rendered attractive to the females. The Libellulidae
or dragon-flies are ornamented with splendid green, blue,
yellow, and vermilion metallic tints; and the sexes often
differ. Thus, as Prof. Westwood remarks, || the males
of some of the Agrionidae, *' are of a rich blue with black
wings, while the females are fine green with colorless
wings." But in Agrion Ramhurii these colors are exactly
reversed in the two sexes. 1^ In the extensive North Ameri-
can genus of Hetaerina, the males alone have a beautiful
carmine spot at the base of each wing. In A^iax Junius
the basal part of the abdomen in the male is a vivid ultra-
marine blue, and in the female grass-green. In the allied
genus Gomphus, on the other hand, and in some other
genera, the sexes differ but little in color. In closely-allied

*Mr. Ch. Home, in "Proc. Ent. Soc," May 3, 1869, p. 13.

f The (Ecanthus nivalis. Harris, " Insects of New England," 1842,
p. 124. The two sexes of the CE. pellucidus of Europe differ, as I
hear from Victor Carus, in nearly the same manner.

:|: Platyblemnus; Westwood, "Modern Class.," vol. i, p. 447.

§ B. D. Walsh, the " Pseudoneuroptera of Illinois," in " Proc. Ent.
Soc. of Philadelphia," 1862, p. 361.

I " Modern Class.," vol. ii, p. 37.

Tf Walsh, ibid., p. 381. I am indebted to this naturalist for the fol-
lowing facts on Hetaerina, Anax and Gomphus.

INSECTS, 839

forms throughout the animal kingdom similar cases of the
sexes differing greatly, or very little, or not at all, are of
frequent occurrence. Although there is so wide a diifer-
ence in color between the sexes of many Libellulidse, it is
often difficult to say which is the more brilliant; and the
ordinary coloration of the two sexes is reversed, as we have
just seen, in one species of Agrion. It is not probable that
their colors in any case have been gained as a protection.
Mr. MacLachlan, who has closely attended to this family,
writes to me that dragon-flies — the tyrants of the insect-
world — are the least liable of any insect to be attacked by
birds or other enemies, and he believes that their bright
colors serve as a sexual attraction. Certain dragon-flies
apparently are attracted by particular colors; Mr. Patterson
observed* that the Agrionidae, of which the males are blue,
settled in numbers on the blue float of a fishing line; while
two other species were attracted by shining white colors.

It is an interesting fact, first noticed by Schelver, that,
in several genera belonging to two sub-families, the males
on first emergence from the pupal state, are colored exactly
like the females ; but that their bodies in a short time
assume a conspicuous milky-blue tint, owing to the exuda-
tion of a kind of oil, soluble in ether and alcohol. Mr.
MacLachlan believes that in the male of Lihellula depressa
this change of color does not occur until nearly a fortnight
after the metamorphosis, when the sexes are ready to pair.

Certain species of Neurothemis present, according to
Brauer,f a curious case of dimorphism, some of the
females having ordinary wings, while others have them
" very richly netted, as in the males of the same species.'^
Brauer '^ explains the phenomenon on Darwinian principles
by the supposition that the close netting of the veins is a
secondary sexual character in the males, which has been
abruptly transferred to some of the females, instead of, as
generally occurs, to all of them." Mr. MacLachlan
informs me of another instance of dimorphism in sev-
eral species of Agrion, in which some individuals are
of an orange color, and these are invariably females.
This is probably a case of reversion ; for in the
true Libellulae, when the sexes differ in color, the females

♦"Transact. Ent. Soc," vol. i, 1836, p. 81.

f See abstract in the •' Zoological Record " for 1867, p. 450.

330 THE DESCENT OF MAK

are orange or yellow; so that supposing Agrion to be
descended from some primordial form which resembled the
typical Libullulse in its sexual characters, it would not be
surprising that a tendency to vary in this manner should
occur in the females alone.

Although many dragon-flies are large, powerful and fierce
insects, the males have not been observed by Mr. Mac-
Lachlan to fight together, excepting, as he believes, in some
of the smaller species of Agrion. In another group in this
order, namely, the Termites or white ants, both sexes at
the time of swarming may be seen running about, ^-the
male after the female, sometimes two chasing one female,
and contending with great eagerness who shall win the
prize.^^* The Atropos pulsatoriiis is said to make a noise
with its jaws, which is answered by other individuals, f

Hymenoptera. — That inimitable observer, M. rabre,J: in
describing the habits of Cerceris, a wasp-like insect,
remarks that '^ fights frequently ensue between the males
for the possession of some particular female, who sits an
apparently unconcerned beholder of the struggle for suprem-
acy, and when the victory is decided, quietly flies away in
company with the conqueror." AVestwood § says that the
males of one of the saw-flies (Tenthredin^) *^have been
found fighting together with their mandibles locked." As
M. Fabre speaks of the males of Cerceris striving to obtain
a particular female, it may be well to bear in mind that
insects belonging to this order have the power of recogniz-
ing each other after long intervals of time, and are deeply
attached. For instance, Pierre Huber, whose accuracy no one
doubts, separated some ants, and when, after an interval of
four months, they met others which had formerly belonged
to the same community, they recognized and caressed one
another with their antennae. Had they been strangers they
would have fought together. Again, when two commu-
nities engage in a battle the ants on the same side some-

* Kirby and Spence, *' Introduct. to Entomology," vol. ii, 1818,
p. 85.

f Houzeau, " Les Facultes Mentales," etc., torn, i, p. 104.

:f See an interesting article, "The Writings of Fabre," in "Nat
Hist. Review," April, 1862. p. 122.

I "Journal of Proc. of Entomolog. Soc," Sept. 7, 1863, p. 169,

INSECTS. 331

times attack each other in the general confusion, but they
soon pepceive their mistake, and the one ant soothes the
other.*

In this order slight differences in coloi;, according to sex,
are common, but conspicuous differences are rare except in
the family of bees; yet both sexes of certain groups are so
brilliantly colored — for instance in Chrysis, in which ver-
milion and metallic greens prevail — that we are tempted to
attribute the result to sexual selection. In the Ichneu-
monidae, according to Mr. Walsh, f the males are almost
universally lighter-colored than the females. On the other
hand, in the Tenthredinidae the males are generally darker
than the females. In the Siricidae the sexes frequently
differ; thus the male of Sir ex juvencus is banded with
orange, while the female is dark purple; but it is difficult
to say which sex is the more ornamented. In Tremex
columbcB the female is much brighter colored than the
male. I am informed by Mr. F. Smith that the male
ants of several species are black, the females being
testaceous.

In the family of bees, especially in the solitary species,
as I hear from the same entomologist, the sexes often differ
in color. The males are generally the brighter, and in
Bombus as well as in Apathus, much more variable in color
than the females. In Anthophora retusa the male is of a
rich fulvous-brown, while the female is quite black; so are
the females of several species of Xylocopa, the males being
bright yellow. On the other hand the females of some
species, as of Andrmna fulva, are much brighter colored
than the males. Such differences in color can hardly oe
accounted for by the males being defenseless and thus
requiring protection, while the females are well defended
by their stings. H. Muller,J: who has particularly attended
to the habits of bees, attributes these differences in color in
chief part to sexual selection. That bees have a keen per-
ception of color is certain. He says that the males search
eagerly and fight for the possession of the females; and he

*P. Huber, " Reclierclies sur les Moeurs des Fourmis," 1810, pp,
150, 165.

f *' Proc. Entomolog. Soc. of Philadelphia," 1866, pp. 238, 239.

X " Anwendung der Darwinschen Lehre auf Bienen." Verb. d. n
(Jabrg., xxix.

33^ TBE DESCENT OP MAN,

accounts through such contests for the mandibles of the
males being in certain species larger than those- of the
females. In some cases the males are far more numerous
than the females, either early in the season, or at all times
and places, or locally; whereas the females in other cases
are apparently in excess. In some species the more beauti-
ful males appear to have been selected by the females; and
in others the more beautiful females by the males. Conse-
quently in certain genera (Miiller, p. 42) the males of the
several species differ much in appearance, while the females
are almost indistinguishable; in other genera the reverse
occurs. H. Miiller believes (p. 82) that the colors gained
by one sex through sexual selection have often been trans-
ferred in a variable degree to the other sex, just as the
pollen-collecting apparatus of the female has often been
transferred to the male, to whom it is absolutely useless.*

Mutilla Europcea makes a stridulating noise; and accord-
ing to Goureau \ both sexes have this power. He attributes
the sound to the friction of the third and preceding
abdominal segments, and I find that these surfaces are
marked with very fine concentric ridges; but so is the pro-
jecting thoracic collar into which the head articulates, and
this collar, when scratched with the point of a needle,
emits the proper sound. It is rather surprising that both
sexes should have the power of stridulating, as the male is

*M. Perrier in his article " la Selection sexuelle d'apres Darwin"
("Revue Scientifique," Feb., 1873, p. 868), without apparently having
reflected much on the subject, objects that as the males of social bees
are known to be produced from unfertilized ova, they could not trans-
mit new characters to their male offspring. This is an extraordinary
objection. A female bee fertilized by a male, which presented some
character facilitating the union of the sexes, or rendering him more
attractive to the female, would lay eggs which would produce only
females; but these young females would next year produce males ;
and will it be pretended that such males would not inherit the char-
acters of their male grandfathers ? To take a case with ordinary ani-
mals as nearly parallel as possible; if a female of any white quad-
ruped or bird were crossed by a male of a black breed, and the male
and female offspring were paired together, will it be pretended that
the grandchildren would not inherit a tendency to blackness from
their male grandfather ? The acquirement of new characters by the
sterile worker-bees is a much more difficult case, but I have endeav-
ored to show in my " Origin of Species " how these sterile beings are
subjected to the power of natural selection.

\ Quoted by Westwood, " Modern Class, of Insects/' voL ii, p. 214

INSECTS, 333

winged and the female wingless. It is notorious that bees
express certain emotions, as of anger, by the tone of their
humming; and according to H. Miiller (p. 80) the males
of some species make a peculiar singing noise while pursu-
ing the females.

Coleoptera (Beetles). — Many beetles are colored so as to
resemble the surfaces which they habitually frequent, and
they thus escape detection by their enemies. Other species,
for instance diamond-beetles, are ornamented with splendid
colors, which are often arranged in stripes, spots, crosses
and other elegant patterns. Such colors can hardly serve
directly as a protection except in the case of certain flower-
feeding species; but they may serve as a warning or means
of recognition on the same principle as the phosphorescence
of the glow-worm. As with beetles the colors of the two
sexes are generally alike, we have no evidence that they
have been gained through sexual selection; but this is at
least possible, for they may have been developed in one sex
and then transferred to the other; and this view is even in
some degree probable in those groups which possess other
well-marked secondary sexual characters. Blind beetles,
which cannot of course behold each other^s beauty, never,
as I hear from Mr. Waterhouse, Jr,, exhibit bright colors,
though they often have polished coats; but the explanation
of their obscurity may be that they generally inhabit caves
and other obscure stations.

Some Longicorns, especially certain Prionidae, oifer an
exception to the rule that the sexes of beetles do not differ
in color. Most of these insects are large and splendidly
colored. The males in the genus Pyrodes,* which I saw

* Pyrodes pulcherrimuSy in whicli the sexes differ conspicuously,
lias been described by Mr, Bates in " Transact. Ent. Soc," 1869, p.
50. I will specify the few other cases in which I have heard of a
difference in color between the sexes of beetles. Kirby and Spence
("Introduct. to Entomology," vol. iii, p. 301) mention a Cantharis,
Meloe, Rhagium, and the Leptura testacea ; the male of the latter
being testaceous, with a black thorax, and the female of a dull red
all over. These two latter beetles belong to the family of Longi-
corns. Messrs. R. Trimen and Waterhouse junior inform me of two
Lamellicorns, viz., a Peritrichia and Trichius, the male of the latter
being more obscurely colored than the female. In Tillus elongatus
the male is biack, and the female always, as it is believed, of a dark
blue color, with a red thorax. The male, also, of Orsodacna atra, as
I hear from Mr. Walsh, is black, the female (the so called 0. rvficol.
lis) having a rufous thorax.

334

THE DESCENT OF MAN.

in Mr. Bates' collection, are generally redder but rather
duller than the females, the latter being colored of a more
or less splendid golden-green. On the other hand, in one
species the male is golden-green, the female being richly
tinted with red and purple. In the genus Esmeralda the
sexes differ so greatly in color that they have been ranked
as distinct species; in one species both are of a beautiful
shining green, but the male has a red thorax. On the
whole, as far as I could judge, the females of those
Prionidae, in which the sexes differ, are colored more richly
than the males, and this does not accord with the common
rule in regard to color when acquired through sexual
selection.

A most remarkable distinction between the sexes of many
beetles is presented by the great horns which rise from the
head, thorax and clypeus of the males; and in some few
cases from the under surface of the body. These horns
in the great family of the Lamellicorns, resemble those of
various quadrupeds, such as stags, rhinoceroses, etc, and
are wonderiui both from their size and diversified shapes.
Instead of iescribing them, I have given figures of the
males and females of some of the more remarkable forms.
(Figs. 16 to 20.) The females generally exhibit rudiments

Frg. 16. Chaloosoma atlas. Upper figure, male (reducetl); lower figure, f«mal9
Caatural size>.

INSECTS,

335

PhansBus f auuus.

Fig. 19.

Dipelicus cantori;

Fig. SO. Ontliophagus rangif er, enlarged

336 THE DESCENT OF MAN.

of the horns in the form of small knobs or ridges; but some
are destitute of even the slightest rudiment. On the other
hand^ the horns are nearly as well developed in the female
as in the male of Phanceus lancifer; and only a little less
well developed in the females of some other species of this
genus and of Copris. I am informed by Mr. Bates that
the horns do not differ in any manner corresponding with
the more important characteristic differences between the
several subdivisions of the family; thus within the same
section of the genus Onthophagus, there are species which
have a single horn and others which have two.

In almost all cases the horns are remarkable from their
excessive variability; so that a graduated series can be
formed from the most highly developed males to others so
degenerate that they can barely be distinguished from the
females. Mr. Walsh* found that in Plianmus carnifex the
horns were thrice as long in some males as in others. Mr.
Bates, after examining above a hundred males of Oiitlio-
phagus rangifer (fig. 20), thought that he had at last dis-
covered a species in which the horns did not vary; but
further research proved the contrary.

The extraordinary size of the horns and their widely dif-
ferent structure in closely-allied forms indicate that they
have been formed for some purpose; but their excessive
variability in the males of the same species leads to the
inference that this purpose cannot be of a definite nature.
The horns do not show marks of friction, as if used for any
ordinary work. Some authors suppose f that as the males
wander about much more than the females, they require
horns as a defense against their enemies; but as the horns
are often blunt, they do not seem well adapted for defense.
The most obvious conjecture is that they are used by the
males for fighting together; but the males have never been
observed to fight; nor could Mr. Bates, after a careful
examination of numerous species, find any sufficient evi-
dence, in their mutilated or broken condition, of their
having been thus used. If the males had been habitual
fighters, the size of their bodies would probably have been
increased through sexual selection, so as to have exceeded
that of the females; but Mr, Bates, after comparing the

* '* Proc. Entomolog, Soc. of Pliiladelphia," 1864, p. 228.

f Kirbj^ and Spence, ' ■ Introduct. Entomology.," vol. iii, p. 300.

INSECTS..

^37

two sexes in above a hundred species of the Copridae, did
not tiud any marked difference in this respect among well-
developed individuals. In Lethrus, moreover, a beetle
belonging to the same great division of the Lamelli corns,
the males are known to fight, but are not provided with
horns, though their mandibles are much larger than those of
the female.

The conclusion that the horns have been acquired as
ornaments is that which best agrees with the fact of their
having been so immensely, yet not fixedly, developed — as
shown by their extreme variability in the same species, and
by their extreme diversity in closely-allied species. This
view will at first appear extremely improbable; but we shall

Fig. 21. Fig. 22.

Fig. 21. Onitis furcifer, male viewed from beneath.

Fig. 22. Left-hand figure, male of Onitis furcifer, viewed laterally. Right-
hand figure, female, a. Rudiment of cephalic horn. h. Trace of
thoracic horn or crest.

hereafter find with many animals standing much higher in
the scale, namely fishes, amphibians, reptiles and birds,
that various kinds of crests, knobs, horns and combs have
been developed apparently for this sole purpose.

The males of Onitis furcifer (fig. 21), and of some other
species of the genus are furnished with singular projections
on their anterior femora, and with a great fork or pair of
horns on the lower surface of the thorax. Judging from
other insects, these may aid the male in clinging to the
female. Although the males have not even a trace of a horn
on the upper surface of the body, yet the females plainly ex-
hibit a rudiment of a single horn on the head (fig. 22, a) and
of a crest {h) on the thorax. That the slight thoracic crest
in the female is a rudiment of a projection proper to the male,
though entirely absent in the male of this particular species,
is clear; for the female of Bubas bison (a genus which

838 • THE DESCENT OF MAN.

comes next to Onitis) has a similar slight crest on tlie
thorax, and the male bears a great projection in the same
situation. So, again, there can hardly be a doubt that the
little point {a) on the head of the female Onitis furcifer,
as well as on the head of the females of two or three allied
species, is a rudimentary representative of the cephalic
horn, which is common to the males of so many Lamelli-
corn beetles, as in Phanaeus (fig. 18).

The old belief that rudiments have been created to com-
plete the scheme of nature is here so far from holding
good, that we have a complete inversion of the ordinary
state of things in the family. AVe may reasonably suspect
that the males originally bore horns and transferred them
to the females in a rudimentary condition, as in so many
other Lamellicorns. Why the males subsequently lost their
horns, we know not; but this may have been caused through

4-

Fig. 23. Bledius taurus, magnified. Left-hand figure, male; right-hand figure,

female.

the principle of compensation, owing to the development of
the large horns and projections on the lower surface; and
as these are confined to the males, the rudiments of the
upper horns on the females would not have been thus
obliterated.

The cases hitherto given refer to the Lamellicorns, but
the males of some few other beetles, belonging to two
widely distinct groups, namely, the Curculionidae and
Staphylinidae, are furnished with horns — in the former on
the lower surface of the body,* in the latter on the upper
surface of the head and thorax. In the Staphylinidae, the
horns of the males are extraordinarily variable in the same
species, just as we have seen with the Lamellicorns. In
Siagonium we have a case of dimorphism, for the males
can be divided into two sects, differing greatly in the size
of their bodies and in the development of tlieir horns, with-
out intermediate gradations. In a species of Bledius (fig.
23), also belonging to the Staphylinidae, Prof. West wood

*Kirby and Spence, " Introduct. Entomolog.," vol. iii, p. 329,

INSECTS. 339

states that, '' male specimens can be found in the same
locality in Avhich the central horn of the thorax is very
large, but the horns of the head quite rudimental ; and
others, in which the thoracic horn is much shorter, while
the protuberances on the head are long."* Here we appar-
ently have a case of compensation, which throws light on
that just given, of the supposed loss of the upper horns by
the males of Onitis.

Law of Battle. — Some male beetles, which seem ill-fitted
for fighting, nevertheless engage in conflicts for the posses-
sion of the females. Mr. Wallace \ saw two males of
Leptorhyiichus angustatus, a linear beetle with a much
elongated rostrum, " fighting for a female, who stood close
by busy at her boring. They pushed at each other with
their rostra, and clawed and thumped, apparently in the
greatest rage." The smaller male, however, " soon ran
away, acknowledging himself vanquished." In some few
cases male beetles are well adapted for fighting, by possess-
ing great toothed mandibles, much larger than those of the
females. This is the case with the common stag-beetle
(Lucanus cervus), the males of which emerge from the
pupal state about a week before the other sex, so that
several may often be seen pursuing the same female. At
this season they engage in fierce conflicts. When Mr. A.
H. Davis I inclosed two males with one female in a box
the larger male severely pinched the smaller one until he
resigned his pretensions. A friend informs me that when a
boy he often put the males together to see them fight, and
he noticed that they were much bolder and fiercer than the
females, as with the higher animals. The males would
seize hold of his finger if held in front of them, but not so
the females, although they have stronger jaws. The males
of many of the Lucanidae, as well as of the above-men-

* "Modern Classification of Insects," vol. i, p. 172; Siagonium, p.
172. In tlie British Museum I noticed one male specimen of Siago-
nium in an intermediate condition, so that the dimorphism is not
strict.

t " The Malay Archipelago," vol. ii, 1869, p. 276. Riley, Sixth
"Report on Insects of Missouri," 1874, p. 115.

X " Entomological Magazine," vol. i, 1833, p. 82. See also on the
conflicts of this species, Kirby and Spence, ibid., vol. iii, p. 314; and
West wood, ibid., vol. i, p. 187.

340 THE DESCENT OF MAN.

tioned Leptorliynchus, are larger and more powerful insects
than the females. The two sexes of Lethrus cephalotes
(one of the Lamellicorns) inhabit the same burrow; and
the male has larger mandibles than the female. If, during
the breeding season, a strange male attempts to enter the
burrow he is attacked; the female does not remain passive,
but closes the mouth of the burrow, and encourages her
mate by continually pushing him on from behind; and the
battle lasts until the aggressor is killed or runs aAvay. * The
two sexes of another Lamellicorn beetle, the Ateuchtis
cicatricosus, live in pairs, and seem much attached to each
other; the male excites the females to roll the balls of dung
in which the ova are deposited; and if she is removed he
becomes much agitated. If the male is removed the
female ceases all work, and, as M. Brulerie f believes, would
remain on the same spot until she died.

The great mandibles of the male Lucanida? are extremely
variable both in size and structure, and in this respect
resemble the horns on the head and thorax of many male
Lamellicorns and Staphylinidae. A perfect series can be
formed from the best-provided to the worst-provided or
degenerate males. Although the mandibles of the common
stag-beetle, and probably of many other species, are used as
efficient weapons for fighting, it is doubtful whether their
great size can thus be accounted for. We have seen that they
are used by the Luccmus elaphus of North America for
seizing the female. As they are so conspicuous and so
elegantly branched, and as owing to their great length
they are not well adapted for pinching, the suspicion has
crossed my mind that they may in addition serve as an
ornament, like the horns on the head and thorax of the
various species above described. The male Chiasognathus
Grantii of S. Chili — a splendid beetle belonging to the
same family — has enormously developed mandibles (fig. 24) ;
he is bold and pugnacious; when threatened he faces round,
opens his great jaws, and at the same time stridulates
loudly. But the mandibles were not strong enough to pinch
my finger so as to cause actual pain.

* Quoted from Fischer, in "Diet. Class. d'Hist. Nat.," torn, x^, p.
324.

f '* Ann. Soc. Entomolog. France,'' 1866, as quoted in "Journal of
Travel," by A. Murray, 1868, p. 135.

INSECTS.

341

Sexual selection, wliicli implies the possession of con-
siderable perceptive powers and of strong passions, seems to
have been more effective with the
Lamellicorns than with any other
family of beetles. With some species
the males are provided with weapons
for fighting; some live in pairs and
show mutual aifection; many have
the power of stridulating when ex-
cited; many are furnished with the
most extraordinary horns, apparently
for the sake of ornament; and some,
which are diurnal in their habits, are
gorgeously colored. Lastly, several
of the largest beetles in the world
belong to this family, which was
placed by Linnseus and Fabricius at
the head of the order.*

Stridulating Organs, — Beetles be-
longing to many and widely distinct
families possess these organs. The
sound thus produced can sometimes
be heard at the distance of several
feet or even yards, f but it is not
comparable with that made by the
Orthoptera. The rasp generally con-
sists of a narrow, slightly raised sur-
face, crossed by very fine, parallel
ribs, sometimes so fine as to cause
iridescent colors, and having a very
elegant appearance under the micro-
scope. In some cases, as with Ty-
phoeus, minute, bristly or scale-like
prominences, with which the whole
surrounding surface is covered in
approximately parallel lines, could
be traced passing into the ribs of the
rasp. The transition takes place

Fig. 24. Chiasognathus Gran^
tii, reduced. Upper figure,
male; lower figure, female.

* Westwood; " Modern Class.," vol. i, p. 184.
fWollaston, "On Certain Musical Curculionid»,
Ms^. of Nat. Hist.," vol. vi, 1860, p> 14.

Annals and

342

THE DESCENT OF MAK

by their becoming confluent and straight, and at the
same time more prominent and smooth. A hard ridge
on an adjoining part of the body serves as the scraper
for the rasp, but this scraper in some cases has been spe-
cially modified for the purpose. It is rapidly moved across
the rasp, or conversely the rasp across the scraper.

"~^

^ —

pi^^HO ;v

0

t=^=

'^Sbl ^

^- —

-^Sm " ^

-^Ma 0

\o

*

^^^|o eO

%*

Z^fl|o

0 »

^^

— ^So *

.\

— T^^Q t)

0

.°o

^ ~.

^^H** ^ c

o«>

i-:

-^^go II

Fig. 25. Necrophorus (from Landois). r. The two rasps. Left-hand
figure, part of the rasp highly magnified.

These organs are situated in widely different positions.
In the carrion - beetles (Necrophorus) two parallel rasps
(r, fig. 25) stand on the dorsal surface of the fifth abdomi-
nal segment, each rasp* consisting of 126 to 140 fine ribs.
These ribs are scraped against the posterior margins of the
elytra, a small portion of which projects beyond the gen-
eral outline. In many Crioceridae, and in Clythra 4:-pimc-
tata (one of the Chrysomelidae), and in some Tenebrionidae,
etc.,f the rasp is seated on the dorsal apex of the abdomen,
on the pygidium or pro-pygidium, and is scraped in the
same manner by the elytra. In Heterocerus, which belongs
to another family, the rasps are placed on the sides of the
first abdominal segment and are scraped by ridges on the

* Landois, " Zeitsclirift fiir wiss. Zoolog.," B. xvii, 1867, s. 127.

f I am greatly indebted to Mr. G. R. Crotcli for having sent me
many prepared specimens of various beetles belonging to these three
families and to others, as well as for valuable information. He be-
lieves that the power of stridulation in the Clythra has not been pre-
viously observed. 1 am also much indebted to Mr. E. W. Janson,
for information and specimens. I may add that my son,, Mr. F.
Darwin, finds that D&rmestes murimus stridulates, but he searched
in vain for the apparatus. Scolytus has lately been described by Dr.
Chapman as a stridulator, in the " Entomologist's Monthly Maga-
zine," vol. vi, p. 130.

INSECTS.

343

femora.* In certain Ciirculionidae and Carabidaef the
parts are completely reversed in position, for the rasps are
seated on the interior surface of the elytra, near their
apices, or along their outer margins, and the edges of the
abdominal segments serve as the scrapers. In Pelobius
Hermanni (one of Dytiscidae or water-beetles) a strong
ridge runs parallel and near to the sutural margin of the
elytra and is crossed by ribs, coarse in the middle part, but
becoming gradually finer at both ends, especially at the
upper end; when this insect is held under water or in the
air a stridulating noise is produced by the
extreme horny margin of the abdomen being
scraped against the rasps. In a great num-
ber of long-horned beetles (Longicornia) the
organs are situated quite otherwise, the rasp
being on the meso-thorax, which is rubbed
against the pro-thorax. Landois counted 238
very fine ribs on the rasp of Cerambyx heros.
Many Lamellicorns have the power of
stridulating, and the organs differ greatly in
position. Some species stridulate very
loudly, BO that when Mr. F. Smith caught a
Trox sahulosus, a gamekeeper who stood by
thought he had caught a mouse; but I
failed to discover the proper organs in this
beetle. In Geotrupes and Typhoeus a narrow
ridge runs obliquely across {r, fig. 26) the coxa
of each hind leg (having in G. stercorarius 84
ribs), which is scraped by a specially project-
ing part of one of the abdominal segments.
In the nearly allied Oo2)ris lunaris an excessively narrow
fine rasp runs along the sutural margin of the elytra with
another short rasp near the basal outer margin; but in
some other Ooprini the rasp is seated, according to

Fig. 26. Hind leg
of Geotrupes
stercorarius.
From Landois

r. Rasp. c. Coxa.

/. Femur, t. Tibia.

tr. Tarsi.

* Scliiodte, translated in "Annals and Mag. of Nat. Hist.," vol. xx,
1867, p. 37.

f West ring has described (Kroyer, " Naturhist. Tidskrift," B. ii,
1848-1849, p. 334) the stridulating organs in these two, as well as in
other families. In the Carabidae I have examined Klaphrus uligi-
no8U8 and Blethisa muUipunctata, sent to me by Mr. Crotch. In
Blethisa the transverse ridges on the furrowed border of the abdom-
inal segment do not, as far as I could judge, come into play in scrap-
ing the rasps on the elytra.

344 THE DESCENT OF MAN.

Leconte,* on the dorsal surface of tlie abdomen. In
Oryctes it is seated on the propygidiiim; and, according
to the same entomologist, in some other Dynastini on the
nnder surface of the elytra. Lastly, Westring states that
in OmalojMa hrunnea the rasp is placed on the pro-sternum
and the scraper on the meta-sternum, the parts thus occu-
pying the under surface of the body instead of the upper
surface, as in the Longicorns.

We thus see that in the different coleopterous families
the stridulating organs are wonderfully diversified in
position, but not much in structure. Within the same
family some species are provided with these organs, and
others are destitute of them. This diversity is intelligible,
if we suppose that originally various beetles made a shuf-
fling or hissing noise by the rubbing together of any hard
and rough parts of their bodies, which happened to be in
contact; and that from the noise thus produced being in
some way useful, the rough surfaces were gradually devel-
oped into regular stridulating organs. Some beetles as they
move now produce, either intentionally or unintentionally,
a shuffling noise without possessing any proper organs for
the purpose. Mr. Wallace informs me that the Euchirus
lo7igimanits (a Lamellicorn, with the anterior legs wonder-
fully elongated in the male) ^' makes, while moving, a low
hissing sound by the protrusion and contraction of the
abdomen ; and when seized it produces a grating sound
by rubbing its hind legs against the edges of the elytra."
The hissing sound is clearly due to a narrow rasp running
along the sutural margin of each elytron; and I could like-
wise make the grating sound by rubbing the shagreened sur-
face of the femur against the granulated margin of the cor-
responding elytron; but I could not here detect any proper
rasp; nor is it likely that I could have overlooked it in so
large an insect. After examining Cychrus, and reading
what Westring has written about this beetle, it seems very
doubtful whether it possesses any true rasp, though it has
the power of emitting a sound.

From the analogy of the Orthoptera and Homoptera, I
expected to find the stridulating organs in the Colpeotera
differing according to sex; but Landois, who has carefully

* I am indebted to Mr. Walsh, of Illinois, for liaving sent me ex-
tracts from Leconte*s " Introduction to Entomology," pp. 101, 143.

INSECTS, 345

examined several species, obsen^ed no sucli difference; nor
did Westring; nor did Mr. G. R. Crotch in preparing the
many specimens which he had the kindness to send me.
Any difference in these organs, if slight, would, however,
be difficult to detect, on account of thoir great variability.
Thus, in the first pair of specimens of Necrophorus
humator and of Pelohius which I examined, the rasp
was considerably larger in the male than in the female;
but not so with succeeding specimens. In Geotrupes
stercorarius the rasp appeared to me thicker, opaquer
and more prominent in three males than in the same
number of females ; in order, therefore, to discover
whether the sexes differed in their power of stridulat-
ing, my son, Mr. F. Darwin, collected fifty-seven living
specimens, which he separated into two lots, according as
they made a greater or lesser noise, when held in the same
manner. He then examined all these specimens and found
that the males were very nearly in the same proportion
to the females in both the lots. Mr. F. Smith has kept
alive numerous specimens of Monoynchus pseudacori (Our-
culionidse), and is convinced that both sexes stridulate,
and apparently in an equal degree.

Nevertheless, the power of stridulating is certainly a
sexual character in some few Ooleoptera. Mr. Crotch dis-
covered that the males alone of two species of Heliopathes
(Tenebrionidse) possess stridulating organs. I examined
five males of ^. gMus, and in all these there was a well-
developed rasp, partially divided into two, on the dorsal
surface of the terminal abdominal segment; while in the
same number of females there was not even a rudiment of
the rasp, the membrane of this segment being transparent
and much thinner than in the male. In H. cribratostriaius
the male has a similar rasp, excepting that it is not par-
tially divided into two portions, and the female is com-
pletely destitute of this organ; the male in addition has on
the apical margins of the elytra, on each side of the suture,
three or four short longitudinal ridges, which are crossed
by extremely fine ribs, parallel to and resembling those on
the abdominal rasp; whether these ridges serve as an inde-
pendent rasp or as a scraper for the abdominal rasp, I could
not decide ; the female exhibits no trace of this latter
structure.

Again, in three species of the Lamellicom genus Oryc-

346 THE DESCENT OF MAN.

tes, we have a nearly parallel case. In the females of 0.
gryphus and nasicornis the ribs on the rasp of the pro-
pygidium are less continuous and less distinct than in the
males; but the chief difference is that the whole upper sur-
face of this segment, when held in the proper light, is seen
to be clothed with hairs, which are absent or are repre-
sented by excessively fine down in the males. It should be
noticed that in all Coleoptera the effective part of the rasp
is destitute of hairs. In 0. senegaleiisis the difference be-
tween the sexes is more strongly marked, and this is best
seen when the proper abdominal segment is cleaned and
viewed as a transparent object. In the female the whole
surface is covered with little separate crests bearing spines;
while in the male these crests, in proceeding toward the
apex, become more and more confluent, regular and naked;
so that three-fourths of the segment is covered with ex-
tremely fine parallel ribs, which are quite absent in the
female. In the females, however, of all three species of
Oryctes, a slight grating or stridulating sound is produced
when the abdomen of a softened specimen is pushed back-
ward and forward.

In the case of the Heliopathes and Oryctes there can
hardly be a doubt that the males stridulate in order to call
or to excite the females; but with most beetles the stridu-
lation apparently serves both sexes as a mutual call.
Beetles stridulate under various emotions, in the same
manner as birds use their voices for many purposes besides
singing to their mates. The great Chiasognathus stridu-
lates in anger or defiance; many species do the same from
distress or fear, if held so that they cannot escape ; by
striking the hollow stems of trees in the Canary Islands,
Messrs. Wollaston and Crotch were able to discover the
presence of beetles belonging to the genus Acalles by their
stridulation. Lastly, the male Ateuchus stridulates to en-
courage the female in her work, and from distress when she
is removed.* Some naturalists believe that beetles make
this noise to frighten away their enemies; but I cannot
think that a quadruped or bird, able to devour a large
beetle, would be frightened by so slight a sound. The
belief that the stridulation serves as a sexual call is sup-

•M. P. de la Brulerie, as quoted in " Jouraal of Travel,** A. Mi
ray, vol. I, 1868, p. 135.

INSECTS. 347

ported by the fact that death-ticks {Anohium tessellatum)
are well known to answer each other's ticking, and, as I
have myself observed, a tapping noise artificially made.
Mr. Doubleday also informs me that he has sometimes ob-
served a female ticking,* and in an hour or two afterward
has found her united with a male, and on one occasion sur-
rounded by several males. Finally, At is probable that the
two sexes of many kinds of beetles were at first enabled to
find each other by the slight shuffling noise produced by
the rubbing together of the adjoining hard parts of their
bodies; and that as those males or females which made the
greatest noise succeeded best in finding partners, rugosities
on various parts of their bodies were gradually developed
by means of sexual selection into true stridulating organs.

* According to Mr. Doubleday, "the noise is produced by the
insect raising itself on its legs as high as it can, and then striking its
thorax five or six times in rapid succession against the substance
upon which it is sitting." For references on this subject see Landois,
" Zeitschrift fiir wissen. Zoolog.," B. xvii, s. 131. Olivier says (as
quoted by Kirby and Spence, " Introduct.," vol. ii, p. 395) that the
female of Pimelia striata produces a rather loud sound by striking
her abdomen against any hard substance, " and that the mstXe, obedi-
ent to this call, soon attends her, and they pair."

348 TEE DESCENT OF MAN,

CHAPTEK XI.

INSECTS, continued. — ordee lepidoptera.

(butterflies and moths.)

Courtship of butterflies — Battles — Ticking noise — Colors common to
both sexes, or more brilliant in the males — Examples— Not due
to the direct action of the conditions of life— Colors adapted for
protection-T-Colors of moths — Display — Perceptive powers of the
Lepidoptera — Variability — Causes of the difference in color
between the males and females — Mimicry, female butterflies more
brilliantly colored than the males — Bright colors of caterpillars —
Summary and concluding remarks on the secondary sexual char-
acters of insects — Birds and insects compared.

In this great order the most interesting points for us are
the differences in color between the sexes of the same
species, and between the distinct species of the same genus.
Nearly the whole of the following chapter will be devoted
to this subject; but I will first make a few remarks on one
or two other points. Several males may often be seen pur-
suing and crowding round the same female. Their court-
Bhip appears to be a prolonged affair, for 1 have frequently
watched one or more males pirouetting round a female
until I was tired, without seeing the end of the courtship.
Mr. A. G. Butler also informs me that he has several times
"watched a male courting a female for a full quarter of an
hour; but she pertinaciously refused him, and at last set-
tled on the ground and closed her wings, so as to escape
from his addresses.

Although butterflies are weak and fragile creatures, they
are pugnacious, and an Emperor butterfly* has been capt-
ured with the tips of its wings broken from a conflict with
another male. Mr. Oollingwood, in speaking of the fre-
quent battles between the butterflies of Borneo, says: " They

* Apatura Iris: " The Entomologist's Weekly Intelligence," 18-59,
p. 139. For the Bornean Butterflies, see C. Colling wood, " Ramble;?
of a Naiuraliert," 1868, pw 183.

INSECTS. 349

whirl round each other with the greatest rapidity, and
appear to be incited by the greatest ferocity."

The Agercnia fe\ onia makes a noise like that produced
by a toothed wheel passing under a spring catch, and
which can be heard at the distance of several yards; I
noticed this sound at Rio de Janeiro, only when two of
these butterflies were chasing each other in an irregular
course, so that it is probably made during the courtship of
the sexes.*

Some moths also produce sounds; for instance, the males
of Thecopliora fovea. On two occasions Mr. F. Buchanan
White t heard a sharp quick noise made by the male of
Hylophila prasinana, and which he believes to be produced,
as in Cicada, by an elastic membrane, furnished with a
muscle. He quotes, also, Guenee, that Setina produces a
sound like the ticking of a watch, apparently by the aid of
'^ two large tympaniform vesicles, situated in the pectoral
region;" and these *^are much more developed in the male
than in the female." Hence the sound-producing organs in
the Lepidoptera appear to stand in some relation with the
sexual functions. I have not alluded to the well-known
noise made by the Death's Head Sphinx, for it is generally
heard soon after the moth has emerged from its cocoon.

Giard has always observed that the musky odor, which
is emitted by two species of Sphinx moths, is peculiar to
the males; J and in the higher classes we shall meet with
many instances of the males alone being odoriferous.

Every one must have admired the extreme beauty of
many butterflies and of some moths; and it may be asked,
are their colors and diversified patterns the result of the
direct action of the physical conditions to which these
insects have been exposed, without any benefit being thus
derived? Or have successive variations been accumulated
and determined as a protection, or for some unknown pur-
pose, or that one sex may be attractive to the other? And,

* See my "Journal of Researches," 1845, p. 33. Mr. Doubleday
lias detected ("Proc. Ent. Soc," March 3, 1845, p. 123) a peculiar
membranous sac at the base of the front win^s, which is probably
connected with the production of the sound. For the case of Theco-
phora, see " Zoological Record," 1869, p. 401. For Mr. Buchanan
White's observations, " The Scottish Naturalist," July, 1872, p. 214.

t "The Scottish Naturalist," July, 1872, p. 213.

X ** Zoological Record," 1869, p. 347.

350 'J^SE DESCENT OF MAN.

again, what is the meaning of the colors being widely dif-
ferent in the males and females of certain species, and
alike in the two sexes of other species of the same genus?
Before attempting to answer these questions a body of
facts must be given.

With our beautiful English butterflies, the admiral, pea-
cock, and painted lady (Vanessae), as well as many others,
the sexes are alike. This is also the case with the magnifi-
cent Heliconidse, and most of the Danaidae in the tropics.
But in certain other tropical groups, and in some of our
English butterflies, as the purple emperor, orange-tip, etc.
{Apatura Iris and Anthocharis cardamines), the sexes
difler either greatly or slightly in color. No language suf-
fices to describe the splendor of the males of some tropical
species. Even within the same genus we often find species
presenting extraordinary dift'erences between the sexes,
while others have their sexes closely alike. Thus in the
South American genus Epicalia, Mr. Bates, to whom I am
indebted for most of the following facts, and for looking
over this whole discussion. Informs me that he knows twelve
species, the two sexes of which haunt the same stations
(and this is not always the case with butterflies), and
which, therefore, cannot have been diiferently affected by
external conditions.* In nine of these twelve species the
males rank among the most brilliant of all butterflies, and
differ so greatly from the comparatively plain females that
they were formerly placed in distinct genera. The females
of these nine species resemble each other in their general
type of coloration; and they likewise resemble both sexes
of the species in several allied genera found in various parts
of the world. Hence we may infer that these nine species,
and probably all the others of the genus, are descended
from an ancestral form which was colored in nearly the
same manner. In the tenth species the female still retains
the same general coloring, but the male resembles her, so
that he is colored in a much less gaudy and contrasted
manner than the males of the previous species. In the
eleventh and twelfth species the females depart from the
usual type, for they are gayly decorated almost like the

* See also Mr, Bates' paper in " Proc. Ent. Soc. of Philadelphia,"
1865, p. 206. Also Mr. Wallace on the same subject, in regard to
Piadema, in 'Transact. Entomolog, Soc. of London," 1869, p. 278.

INSECTS. 351

males, but in a somewhat less degree. Hence in these two
latter species the bright colors of the males seem to have
been transferred to the females; while in the tenth species
the male has either retained or recovered the plain colors of
the female, as well as of the parent-form of the genus. The
sexes in these three cases have thus been rendered nearly
alike, though in an opposite manner. In the allied genus
Eubagis, both sexes of some of the species are plain-colored
and nearly alike; while the greater number of the males are
decorated with beautiful metallic tints in a diversified
manner, and differ much from their females. The females
throughout the genus retain the same general style of
coloring, so that they resemble one another much more
closely than they resemble their own males.

In the genus Papilio all the species of the ^neas group
are remarkable for their conspicuous and strongly con-
trasted colors, and they illustrate the frequent tendency to
gradation in the amount of difference between the sexes.
In a few species, for instance in P, ascanius, the males and
females are alike; in others the males are either a little
brighter, or very much more superb than the females. The
genus Junonia, allied to our Vanessae, offers a nearly
parallel case, for although the sexes of most of the species
resemble each other, and are destitute of rich colors, yet in
certain species, as in J. cenone, the male is rather more
bright - colored than the female, and in a few (for
instance /. andremiaja) the male is so different from the
female that he might be mistaken for an entirely distinct
species.

Another striking case was pointed out to me in the Brit-
ish Museum by Mr. A. Butler, namely, one of the tropical
American Theclse, in which both sexes are nearly alike and
wonderfully splendid; in another species the male is colored
in a similarly gorgeous manner, while the whole upper
surface of the female is of a dull uniform brown. Our
common little English blue butterflies of the genus Lycaena
illustrate the various differences in color between the sexes
almost afi well, though not in so striking a manner, as the
above exotic genera. In Lyccena agestis both sexes have
wings of a brown color, bordered with small ocellated
orange spots and are thus alike. In L. oegon the wings of
the male are of a fine blue bordered with black, while
those of the female are brown with a similar border closely

35^ THE DESCENT OF MAN.

resembling the wings of L. agestis. Lastly, in L. arion
both sexes are of a blue color and are very like, though in
the female the edges of the wings are rather duskier with
the black spots plainer; and in a bright-blue Indian species
both sexes are still more alike.

I have given the foregoing details in order to show, in
the first place, that when the sexes of butterflies differ the
male as a general rule is the more beautiful and departs
more from the usual type of coloring of the group to which
the species belongs. Hence in most groups the females of
the several species resemble each other much more closely
than do the males. In some • cases, however, to which I
shall hereafter allude, the females are colored more splen-
didly than the males. In the second place, these details
have been given to bring clearly before the mind that
within the same genus the two sexes frequently present
every gradation from no difference in color to so great a
difference that it was long before the two were placed by
entomologists in the same genus. In the third place, we
have seen that when the sexes nearly resemble each other
this appears due either to the male having transferred his
colors to the female, or to the male having retained or per-
haps recovered the primordial colors of the group. It also
deserves notice that in those groups in which the sexes
differ the females usually somewhat resemble the males,
so that when the males are beautiful to an extraordinary
degree the females almost invariably exhibit some degree
of beauty. From the many cases of gradation in the
amount of difference between the sexes, and from the prev-
alence of the same general type of coloration throughout
the whole of the same group, we may conclude that the
causes have generally been the same which have determined
the brilliant coloring of the males alone of some species,
and of both sexes of other species. ,

As so many gorgeous butterflies inhabit the tropics it
has often been supposed that they owe their colors to the
great heat and moisture of these zones; but Mr. Bates* has
shown by the comparison of various closely-allied groups of
insects from the temperate and tropical regions that this
view cannot be maintained; and the evidence becomes con-
clusive when brilliantly colored males and plain colored

* "The Naturalist on the Amazons," vol. i, 1863, p. 19.

INSECTS. 353

females of the same species inhabit the same district, feed
on the same food and follow exactly the same habits of
life. Even wheil the sexes resemble each other we can
hardly believe that their brilliant and beautifully arranged
colors are the purposeless result of the nature of the tissues
and of the action of the surrounding conditions.

With animals of all kinds, whenever color has been
modified for some special purpose, this has been, as far as
we can judge, either for direct or indirect protection, or as
an attraction between the sexes. With many species of
butterflies the upper surfaces of the wings are obscure; and
this in all probability leads' to their escaping observation
and danger. But butterflies would be particularly liable
to be attacked by their enemies when at rest; and most
kinds while resting raise their wings vertically over their
backs, so that the lower surface alone is exposed to view.
Hence it is this side which is often colored so as to imitate
the objects on which these insects commonly rest. Dr.
Eossler, I believe, first noticed the similarity of the closed
wings of certain Vanessse and other butterflies to the 6ark
of trees. Many analogous and striking facts could be given.
The most interesting one is that recorded by Mr. Wallace*
of a common Indian and Sumatran butterfly (Kallima),
which disappears like magic when it settles on a bush; for
it hides its head and antennae between its closed wings,
which, in form, color and veining, cannot be distinguished
from a withered leaf with its footstalk. In some other
cases the lower surfaces of the wings are brilliantly colored,
and yet are protective; thus in Thecla ruM the wings when
closed are of an emerald green and resemble the young
leaves of the bramble, on which in spring this butterfly
may often be seen seated. It is also remarkable that in very
many species in which the sexes differ greatly in color on
their upper surface, the lower surface is closely similar or
identical in both sexes, and serves as a protection, f

Although the obscure tints both of the upper and under
sides of many butterflies no doubt serve to conceal them, yet
we cannot extend this view to the brilliant and conspicuous
colors on the upper surface of such species as our admiral and

* See the interesting article in the "Westminster Eeview," July,
1867, p. 10. A wood-cut of the Kallima is given by Mr. WaJlace in
"Hardwicke's Science Gossip," Sept., 1867, p. 196.

tMr. a. Fraser, in "Nature," April, 1871, p. 489.

354 THE DESCENT OF MAN,

peacock Vanessae, our white cabbage-butterflies (Pieris), or
the great swallow-tail Papilio which haunts the open fens —
for these butterflies are thus rendered visible to every living
creature. In these species both sexes are alike; but in the
common brimstone butterfly ( Gonepteryx rlimnni), the male
is of an intense yellow, while the female is much paler; and
in the orange-tip {Atitliocliaris cardanmies) the males alone
have their wings tipped with bright orange. Both the
males and females in these cases are conspicuous, and it is
not credible that their difference in color should stand in
any relation to ordinary protection. Prof. Weismann
remarks * that the female of one of the Lycaense expands
her brown wings when she settles on the ground, and is
then almost invisible; the male, on the other hand, as if
aware of the danger incurred from the bright blue of the
upper surface of his wings, rests with them closed; and this
shows that the blue color cannot be in any way protective.
Nevertheless, it is probable that conspicuous colors are
indirectly beneficial to many species, as a warning that they
are unpalatable. For in certain other cases, beauty has
been gained through the imitation of other beautiful
species, which inhabit the same district and enjoy an im-
munity from attack by being in some way offensive to their
enemies; but then we have to account for the beauty of the
imitated species.

As Mr. Walsh has remarked to me, the females of our
orange-tip butterfly, above referred to, and of an American
species (Anth. genutia) probably show us the primordial
colors of the parent-species of the genus; for both sexes of
four or five widely-distributed species are colored in nearly
the same manner. As in several previous cases, we may
here infer that it is the males of Anth. cardamines and
genidia which have departed from the usual type of the
genus. In the Anth. sara from California, the orange tips
to the wings have been partially developed in the female ;
but they are paler than in the male, and slightly different
in some other respects. In an allied Indian form, the
Iphias glaucippe, the orange-tips are fully developed in
both sexes. In this Iphias, as pointed out to me by Mr. A.
Butler, the under surface of the wings marvelously resem-
bles a pale-colored leaf; and in our English orange-tip, the

♦•• JEinfluss der Isolirung auf di. Artbildun^," 1873, p. 63.

INSECTS. 355

under surface resembles the flower-head of the wild parsley,
on which the butterfly often rests at night.* The same
reason which compels us to believe that the lower surfaces
have here been colored for the sake of protection, leads us
to deny that the wings have been tipped with bright orange
for the same purpose, especially when this character is con-
fined to the males.

Most moths rest motionless during the whole or greater
part of the day with their wings depressed; and the whole
upper surface is often shaded and colored in an admirable
manner, as Mr. Wallace has remarked, for escaping detec-
tion. The front- wings of the Bombycidas and Noctuidae,f
when at rest, generally overlap and conceal the hind wings;
so that the latter might be brightly colored without much
risk; and they are in fact often thus colored. During
flight, moths would often be able to escape from their ene-
mies; nevertheless, as the hind wings are then fully exposed
to view, their bright colors must generally have been
acquired at some little risk. But the following fact shows
how cautious we ought to be in drawing conclusions on this
head. The common yellow under wings (Triphaena) often
fly about during the day or early evening, and are then
conspicuous from the color of their hind wings. It would
naturally be thought that this would be a source of danger;
but Mr. J. Jenner Weir believes that it actually serves
them as a means of escape, for birds strike at these brightly
colored and fragile surfaces, instead of at the body. For
instance, Mr. Weir turned into his aviary a vigorous speci-
men of Triphcena 'pronu'ba, which was instantly pursued by
a robin : but the bird's attention being caught by the col-
ored wings, the moth was not captured until after about
fifty attempts, and small portions of the wings were repeat-
edly broken off. He tried the same experiment in the
open air, with a swallow and T, fimbria ; but the large
size of this moth probably interfered with its capture. |
We are thus reminded of a statement made by Mr. Wal-

* See the interesting observations by Mr. T. W. Wood, ** The
Student," Sept., 1868, p. 81.

t Mr. Wallace in " Hardwicke's Science Gossip," Sept., 1867, p. 193.

X See also on this subject, Mr. Weir's paper in " Transact. Ent.
Soc." 1869, p. 23.

356 THE DESCENT OF MAK.

lace,* namely, that in the Brazilian forests and Malayan
islands, many common and highly-decorated butterflies
are weak flyers, though furnished with a broad expanse of
wing; and they '^^are often captured with pierced and
broken wings, as if they had been seized by birds, from
which they had escaped; if the wings had been much
smaller in proportion to the body, it seems probable that
the insect would more frequently have been struck or
pierced in a vital part, and thus the increased expanse of
the wings may have been indirectly beneficial."

Display. — The bright colors of many butterflies and of
some moths are specially arranged for display, so that they
may be readily seen. During the night colors are not vis-
ible, and there can be no doubt that the nocturnal moths,
taken as a body, are much less gayly decorated than butter-
flies, all of which are diurnal in their habits. But the
moths of certain families, such as the Zygaenidae, several
Sphingidae, Uraniidas, some Arctiidae and Saturniidge, fly
about during the day or early evening, and many of these
are extremely beautiful, being far brighter-colored than the
strictly nocturnal kinds. A few exceptional cases, how-
ever, of bright - colored nocturnal species have been
recorded, f

There is evidence of another kind in regard to display.
Butterflies, as before remarked, elevate their wings when
at rest, but while basking in the sunshine often alternately
raise and depress them, thus exposing both surfaces to full
view; and although the lower surface is often colored in an
obscure manner as a protection, yet in many species it is as
highly decorated as the upper surface, and sometimes in a
very different manner. In some tropical species the lower
surface is even more brilliantly colored than the upper. |
In the English fritillaries {Argynnis) the lower surface

* " Westminster Review," July, 1867, p. 16.

f For instance, Litliosia; but Prof. Westwood ("Modern Class, of
Insects," vol. ii, p. 390) seems surprised at this case. On the relative
colors of diurnal and nocturnal Lepidoptera, see ibid., pp. 333, 392;
also Harris, " Treatise on the Insects of New England," 1842, p. 315.

X Such differences between the upper and lower surfaces of the
wings of several species of Papilio may be seen in the beautiful plates
to Mr. Wallace's "Memoir on the Papilionidae of the Malayan
Region," in "Transact. Linn. Soc," vol. xxv, part i, 1865.

INSECTS. 357

alone is oruamented with shining silver. Nevertheless, as
a general rule, the upper surface, which is probably more
fully exposed, is colored more brightly and diversely than
the lower. Hence the lower surface generally affords to
entomologists the more useful character for detecting the
affinities of the various species. Fritz Miiller informs me
that three species of Castnia are found near his house in
S. Brazil; of two of them the hind wings are obscure, and
are always covered by the front wings when these butter-
flies are at rest; but the third species has black hind wings,
beautifully spotted with red and white, and these are fully
expanded and displayed whenever the butterfly rests. Other
such cases could be added.

If we now turn to the enormous group of moths which,
as I hear from Mr. Stainton, do not habitually expose the
under surface of their wings to full view, we find this side
very rarely colored with a brightness greater than, or even
equal to, that of the upper side. Some exceptions to the
rule, either real or apparent, must be noticed, as the case of
Hypopyra.* Mr. Trimen informs me that in Guenee's
great work three moths are figured, in which the under sur-
face is much the more brilliant. For instance, in the Aus-
tralian Gastrophora the upper surface of the fore wing is
pale grayish-ochreous, while the lower surface is magnifi-
cently ornamented by an ocellus of cobalt-blue, placed in
the midst of a black mark, surrounded by orange-yellow,
and this by bluish-white. But the habits of these three
moths are unknown; so that no explanation can be given
of their unusual style of coloring. Mr. Trimen also
informs me that the lower surface of the wings in certain
other Geometrsef and quadrifid Noctuae are either more
variegated or more brightly-colored than the upper surface;
but some of these species have the habit of ^^ holding their
wings quite erect over their backs, retaining them in this
position for a considerable time," and thus exposing the
under surface to view. Other species, when settled on the
ground or herbage, now and then suddenly and slightly lift

*See Mr. Wormald on this moth; " Proc. Ent. Soc," March 2,
1868.

f See also an account of the South American genus Erateina (one
of the Geometrse) in "Transact. Ent. Soc." new series, vol. v, pis
XV and xvi.

358 THE DESCENT OF MAN.

up their wings. Hence the lower surface of the wings
being brighter than the upper surface in certain moths is
not so anomalous as it at first appears. The Saturniidae
include some of the most beautiful of all moths, their wings
being decorated;, as in our British Emperor moth, with fine
ocelli; and Mr. T. W. Wood* observes that they resemble
butterflies in some of their movements; *^for instance, in
the gentle waving up and down of the wings as if for dis-
play, which is more characteristic of diurnal than of
nocturnal Lepidoptera.''

It is a singlar fact that no British moths which are
brilliantly colored, and, as far as I can discover, hardly any
foreign species, differ much in color according to sex;
though this is the case with many brilliant butterflies. The
male, however, of one American moth, the Saturnia lo, is
described as having its fore wings deep yellow, curiously
marked with purplish-red spots; while the wings of the
female are purple-brown, marked with gray lines. \ The
British moths which difter sexually in color are all brown,
or of various dull yellow tints, or nearly white. In several
species the males are much darker than the females, J and
these belong to groups which generally fly about during
the afternoon. On the other hand, in many genera, as
Mr. Stainton informs me, the males have the hind wings
whiter than those of the female — of which fact Agrotis
exclamationis offers a good instance. In the Ghost Moth
(Hepialus humuli) the difference is more strongly
marked; the males being white and the females yellow

*"Proc. Ent. Soc. of London," July 6, 1868, p. 27.

f Harris, "Treatise," etc., edited by Flint, 1862, p 395.

X For instance, I observe in my son's cabinet that the males are
darker than the females in the Ladocampa quercus, Odonestis pota-
toria, Hypogymna dispar, DasycMra pudihunda and Gycnia mendica.
In this latter species the diiference in color between the two sexes is
strongly marked ; and Mr. Wallace informs me that we here have, as
he believes, an instance of protective mimicry confined to one sex, as
will hereafter be more fully explained. The white female of the
Cycnia resembles the very common Spilosoma menthrasti, both sexes
of which are white; and Mr. Stainton observed that this latter moth
was rejected with utter disgust by a whole brood of young turkeys,
which were fond of eating other moths; so that if the Cycnia was
commonly mistaken by British birds for the Spilosoma, it would es-
cape being devoured, and its white, deceptive color would thus be
lughly beneficial.

mSEGTS. 359

with darker markings.* It is probable that in these
cases the males are thus rendered more conspicuous, and
more easily seen by the females while flying about in the
dusk.

From the several foregoing facts it is impossible to admit
that the brilliant colors of butterflies, and of some few
moths, have commonly been acquired for the sake of pro-
tection. We have seen that their colors and elegant pat-
terns are arranged and exhibited as if for display. Hence
I am led to believe that the females prefer or are most
excited by the more brilliant males; for on any other sup-
position the males would, as far as we can see, be orna-
mented to no purpose. We know that ants and certain
Lamellicorn beetles are capable of feeling an attachment
for each other, and that ants recognize their fellows after
an interval of several months. Hence there is no abstract
improbability in the Lepidoptera, which probably stand
nearly or quite as high in the scale as these insects, having
sufficient mental capacity to admire bright colors. They
certainly discover flowers by color. The humming-bird
sphinx may often be seen to swoop down from a distance
on a bunch of flowers in the midst of green foliage; and I
have been assured by two persons abroad that these moths
repeatedly visit flowers painted on the walls of a room and
vainly endeavor to insert their proboscis into them. Fritz
Miiller informs me that several kinds of butterflies in
S. Brazil show an unmistakable preference for certain
colors over others. He observed that they very often
visited the brilliant red flowers of five or six genera of
plants, but never the white or yellow flowering species of
the same and other genera growing in the same garden;
and I have received other accounts to the same effect. As
I hear from Mr. Doubleday, the common white butterfly
often flies down to a bit of paper on the ground, no doubt
mistaking it for one of its own species. Mr. Collingwoodf

* It is remarkable that in tlie Shetland Islands the male of this
moth, instead of differing widely from the female, frequently resem-
bles her closely in color (see Mr. MacLachlan, " Transact. Ent. Soc,"
vol. ii, 1866, p. 459). Mr. G. Fraser suggests ("Nature," April,
1871, p. 489) that at the season of the year when the ghost-moth ap-
pears in these northern islands, the whiteness of the males would
not be needed to render them visible to the females in the twilight
night.

f " Rambles of a Naturalist in the Chinese Seas," 1808, p. 183,

360 THE DESCENT OF MAK.

in speaking of the difficulty in collecting certain butter-
flies in the Malay Archipelago^ states that " a dead speci-
men pinned upon a conspicuous twig will often arrest an
insect of the same species in its headlong flight and bring
it down within easy reach of the net, especially if it be of
the opposite sex."

The courtship of butterflies is, as before remarked, a
prolonged affair. The males sometimes fight together in
rivalry; and many maybe seen pursuing or crowding round
the same female. Unless, then, the females prefer one
male to another the pairing must be left to mere chance,
and this does not appear probable. If, on the other hand,
the females habitually, or even occasionally, prefer the
more beautiful males, the colors of the latter will have been
rendered brighter by degrees, and will have been trans-
mitted to both sexes or to one sex, according to the law of
inheritance which has prevailed. The process of sexual
selection will have been much facilitated, if the conclusion
can be trusted, arrived at from various kinds of evidence
in the supplement to the ninth chapter; namely, that the
males of many Lepidoptera, at least in the imago state,
greatly exceed the females in number.

Some facts, however, are opposed to the belief that female
butterflies prefer the more beautiful males; thus, as I have
been assured by several collectors, fresh females may fre-
quently be seen paired with battered, faded, or dingy males;
but this is a circumstance which could hardly fail often to
follow from the males emerging from their cocoons earlier
than the females. With moths of the family of the Bom-
bycidge, the sexes pair immediately after assuming the
imago state; for they cannot feed, owing to the rudiment-
ary condition of their mouths. The females, as several
entomologists have remarked to me, lie in an almost torpid
state, and appear not to evince the least choice in regard to
their partners. This is the case with the common silk-moth
{B. mori), as I have been told by some continental and
English breeders. Dr. Wallace, who has had great experi-
ence in breeding Bomhyx cyntliia, is convinced that the
females evince no choice or preference. He has kept above
three hundred of these moths together, and has often found
the most vigorous females mated with stunted males. The
reverse appears to occur seldom; for, as he believes, the
jnore vigorous males pass over the weakly females, and are

INSECTS. 361

attracted by those endowed with most vitality. Never-
theless, the Bombycidse, though obscurely colored, are
often beautiful to our eyes from their elegant and mottled
shades.

I have as yet only referred to the species in which the
males are brighter colored than the females, and I have
attributed their beauty to the females for many generations
having chosen and paired with the more attractive males.
But converse cases occur, though rarely, in which the
females are more brilliant than the males; and here, as I
believe, the males have selected the more beautiful females,
and have thus slowly added to their beauty. We do not
know why in various classes of animals the males of some
few species have selected the more beautiful females instead
of having gladly accepted any female, as seems to be the
general rule in the animal kingdom; but if, contrary to
what generally occurs with the Lepidoptera, the females
were much more numerous than the males, the latter would
be likely to pick out the more beautiful females. Mr. But-
ler showed me several species of Oallidryas in the British
Museum, in some of which the females equaled, and in
others greatly surpassed, the males in beauty ; for the
females alone have the borders of their wings suffused with
crimson and orange and spotted with black. The plainer
males of these species closely resemble each other, showing
that here the females have been modified; whereas in those
cases, where the males are the more ornate, it is these which
have been modified, the females remaining closely alike.

In England we have some analogous cases, though not so
marked. The females alone of two species of Thecla have
a bright purple or orange patch on their fore wings. In
Hipparchia the sexes do not differ much ; but it is the
female of H. jmiira which has a conspicuous light brown
patch on her wings; and the females of some of the other
species are brighter colored than their males. Again,
the females of Colias echisa and hyale have "orange or
yellow spots on the black marginal border, represented in
the males only by thin streaks;" and in Pieris it is the
females which "are ornamented with black spots on the
fore wings, and these are only partially present in the
males." Now the males of many butterflies are known to
support the females during their marriage flight; but in
the species just named it is the females which support the

362

THE BBSCJSl^T OF MAN,

males; so that the part which the two sexes play is reversed,
as is tlieir relative beauty. Throughout the animal king-
dom the males commonly take the more active share in
wooing, and their beauty seems to have been increased by
the females having accepted the more attractive individuals;
but with these butterflies the females take the more active
part in the final marriage ceremony, so that we may sup-
pose that they likewise do so in the wooing; and in this case
we can understand how it is that they have been rendered
the more beautiful. Mr. Meldola, from whom the fore-
going statements have been taken, says in conclusion:
" Though I am not convinced of the action of sexual selec-
tion in producing the colors of insects, it cannot be denied
that these facts are strikingly corroborative of Mr. Darwin's
views.*

As sexual selection primarily depends on variability, a
few words must be added on this subject. In respect to
color there is no difficulty, for any number of highly variable
Lepidoptera could be named. One good instance will suffice.
Mr. Bates showed me a whole series of specimens of Papilio
sesostris and P. childrenm; in the latter the males varied
much in the extent of the beautifully enameled green patch
on the fore wings, and in the size of the white mark, and
of the splendid crimson stripe on the hind wings; so that
there was a great contrast among the males between the
most and the least gaudy. The male of Papilio sesostris
is much less beautiful than of P. childrence; and it like-
wise varies a little in the size of the green patch on the
fore wings, and in the occasional appearance of the small
crimson stripe on the hind wings, borrowed, as it would
seem, from its own female; for the females of this and of
many other species in the JEneas group possess this crimson
stripe. Hence between the brightest specimens of P. ses-
ostris and the dullest of P. childrenm there was but a small
interval; and it was evident that as far as mere variability
is concerned, there would be no difficulty in permanently
increasing the beauty of either species by means of selec-
tion. The variability is here almost confined to the male

* "Nature," April 27, 1871, p
in "Soc. Ent. de France," 1837,

while pairing. See also Mr. G. Fraser, in " Nature," April 20, 1871,
p. 489, on the sexual differences of several British butterflies,

508. Mr. Meldola quotes Donzel,
p. 77, on the flight of butterflies

INSECTS. 3G3

sex; but Mr. Wallace and Mr. Bates have shown * that the
females of some species are extremely variable, the males
being nearly constant. In a future chapter I shall have
occasion to show that the beautiful eye-like spots, or ocelli,
found on the wings of many Lepidoptera are eminently
variable. I may here add that these ocelli offer a difficulty
on the theory of sexual selection; for though appearing to
us so ornamental, they are never present in one sex and
absent in the other, nor do they ever differ much in the
two sexes. t This fact is at present inexplicable; but if it
should hereafter be found that the formation of an ocellus
is due to some change in the tissues of the wings, for
instance, occurring at a very early period of development,
we might expect, from what we know of the laws of inherit-
ance, that it would be transmitted to both sexes, though
arising and perfected in one sex alone.

On the whole, although many serious objections may be
urged, it seems probable that most of the brilliantly-colored
species of Lepidoptera owe their colors to sexual selection,
excepting in certain cases, presently to be mentioned, in
which conspicuous colors have been gained through mimicry
as a protection. From the ardor of the male throughout
the animal kingdom he is generally willing to accept any
female; and it is the female which usually exerts a choice.
Hence, if sexual selection has been efficient with the
Lepidoptera, the male, when the sexes differ, ought to be
the more brilliantly colored, and this undoubtedly is the
case. When both sexes are brilliantly colored and resemble
each other the characters acquired by the males appear to
have been transmitted to both. We are led to this conclu-
sion by cases, even within the same genus, of gradation
from an extraordinary amount of difference to identity in
color between the two sexes.

But it may be asked whether the differences in color
between the sexes may not be accounted for by other means

* Wallace on the Papilionidse of the Malayan Region, in "Trans-
act. Linn. Sec," vol. xxv, 1865, pp. 8, 36. A striking case of a rare
variety, strictly intermediate between two other well-marked female
varieties, is given by Mr. Wallace. See also Mr. Bates, in " Proc.
Entomolog. Soc," Nov. 19, 1866, p. 40.

f Mr. Bates was so kind as to lay this subject before the Entomo-
logical Society, and I have received answers to this effect from several
entomologists.

364 THE DESCENT OF MAN.

besides sexual selection. Thus the males and females of the
same species of butterfly are in several cases known* to
inhabit different stations, the former commonly basking in
the sunshine, the latter haunting gloomy forests. It is
therefore possible that different conditions of life may have
acted directly on the two sexes; but this is not probable,! as
in the adult state they are exposed to different conditions
during a very short period ; and the larvae of both are
exposed to the same conditions. Mr. Wallace believes that
the difference between the sexes is due not so much to the
males having been modified, as to the females having in all
or almost all cases acquired dull colors for the sake
of protection. It seems to me, on the contrary, far
more probable that it is the males which have been
chiefly modified through sexual selection, the females having
been comparatively little changed. We can thus under-
stand how it is that the females of allied species generally
resemble one another so much more closely than do the
males. They thus show us approximately the primordial
coloring of the parent-species of the group to which they
belong. They have, however, almost always been somewhat
modified by the transfer to them of some of the successive
variations, through the accumulation of which the males
were rendered beautiful. But I do not wish to deny that
the females alone of some species may have been specially
modified for protection. In most cases the males and
females of distinct species will have been exposed during
their prolonged larval state to different conditions, and
may have been thus affected ; though with the males any
slight change of color thus caused will generally have been
masked by the brilliant tints gained through sexual selec-
tion. When we treat of birds, I shall have to discuss the
whole question, as to how far the differences in color
between the sexes are due to the males having been modi-
fied through sexual selection for ornamental purposes, or
to the females having been modified through natural selec-
tion for the sake of protection, so that I will here say but
little on the subject.

In all the cases in which the more common form of equal

*H. W. Bates, " The Naturalist on tlie Amazons," vol. ii, 1863, p.
228. A. R. Wallace, in " Transact. Linn. Soc," vol. xxv, 1865, p. 10.

f On this whole subject see " The Variation of Animals and Plants
under Domestication," 1868, vol. ii, chap, xxiii.

INSECTS. 365

inheritance by both sexes has prevailed, the selection of
bright-colored males would tend to make the females
bright colored ; and the selection of dull-colored females
would tend to make the males dull. If both processes
were carried on simultaneously, they would tend to coun-
teract each other ; and the final result would depend on
whether a greater number of females from being well pro-
tected by obscure colors, or a greater number of males by
being brightly colored and thus finding partners, succeeded
in leaving more numerous offspring.

In order to account for the frequent transmission of char-
acters to one sex alone, Mr. Wallace expresses his belief that
the more common form of equal inheritance by both sexes
can be changed through natural selection into inheritance
by one sex alone, but in favor of this view I can discover
no evidence. We know from what occurs under domestica-
tion that new characters often appear, which from the first
are transmitted to one sex alone ; and by the selection of
such variations there would not be the slightest difficulty
in giving bright colors to the males alone, and at the same
time or subsequently, dull colors to the females alone. In
this manner the females of some butterflies and moths
have, it is probable, been rendered inconspicuous for the
sake of protection, and widely different from their males.

I am, however, unwilling without distinct evidence to
admit that two complex processes of selection, each requir-
ing the transference of new characters to one sex alone,
have been carried on with a multitude of species — that the
males have been rendered more brilliant by beating their
rivals, and the females more dull colored by having escaped
from their enemies. The male, for instance, of the common
brimstone butterfly (Gronepteryx), is of a far more intense
yellow than the female, though she is equally conspicuous;
and it does not seem probable that she specially acquired
her pale tints as a protection, though it is probable that
the male acquired his bright colors as a sexual attraction.
The female of Antliocharis cardamines does not possess
the beautiful orange wing-tips of the male ; consequently
she closely resembles the white butterflies (Pieris) so com-
mon in our gardens; but we have no evidence that this
resemblance is beneficial to her. As, on the other hand, she
resembles both sexes of several other species of the genus
inhabiting various quarters of the world, it is probable that

366 THE DESCENT OF MAN.

she has simply retained to a large extent her primordial
colors.

Finally, as we have seen, various considerations lead to the
conclusion that with the greater number of brilliantly col-
ored Lepidoptera it is the male which has been chiefly
modified through sexual selection; the amount of difference
between the sexes mostly depending on the form of inherit-
ance which has prevailed. Inheritance is governed by so
many unknown laws or conditions that it seems to us to act
in a capricious manner;* and we can thus, to a certain ex-
tent, understand how it is that with closely allied species
the sexes either differ to an astonishing degree, or are iden-
tical in color. As all the successive steps in the process of
variation are necessarily transmitted through the female, a
greater or less number of such steps might readily become
developed in her; and thus we can understand the frequent
gradations from an extreme difference to none at all between
the sexes of allied species. These cases of gradation, it
may be added, are much too common to favor the supposi-
tion that we here see females actually undergoing the
process of transition and losing their brightness for the
sake of protection; for we have every reason to conclude
that at any one time the greater number of species are in a
fixed condition.

Mimicry. — This principle was first made clear in an ad-
mirable paper by Mr. Bates, f who thus threw a flood of
light on many obscure problems. It had previously been
observed that certain butterflies in South America belong-
ing to quite distinct families resembled the Heliconidae so
closely in every stripe and shade of color that they could
not be distinguished save by an experienced entomologist.
As the Heliconidae are colored in their usual manner, while
the others depart from the usual coloring of the groups to
which they belong, it is clear that the latter are the imi-
tators, and the Heliconidae the imitated. Mr. Bates further
observed that the imitating species are comparatively rare,
while the imitated abound, and that the two sets live min-
gled together. From the fact of the Heliconidae being

* *• The Variation of Animals and Plants under Domestication," vol.
ii, chap, xii, p. 17.

f " Transact. Unn. Soc," vol. xxiii, 1863, p. 495.

INSECTS. 367

conspicuous and beautiful insects, yet so numerous in indi-
viduals and species, he concluded that they must be pro-
tected from the attacks of enemies by some secretion or
odor; and this conclusion has now been amply confirmed,*
especially by Mr. Belt. Hence Mr. Bates inferred that the
butterflies which imitate the protected species have acquired
their present marvelously deceptive appearance through
variation and natural selection, in order to be mistaken for
the protected kinds, and thus to escape being devoured.
No explanation is here attempted of the brilliant colors of
the imitated, but only of the imitating butterflies. We
must account for the colors of the former in the same gen-
eral manner as in the cases previously discussed in this
chapter. Since the publication of Mr. Bates' paper similar
and equally striking facts have been observed by Mr. Wal-
lace in the Malayan region, by Mr. Trimen in S. Africa,
and by Mr. Riley in the United States, f

As some writers have felt much difficulty in understand-
ing how the first steps in the process of mimicry could
have been effected through natural selection, it may be well
to remark that the process probably commenced long ago
between forms not widely dissimilar in color. In this case
even a slight variation would be beneficial if it rendered
the one species more like the other; and afterward the
imitated species might be modified to an extreme degree
through sexual selection or other means, and if the changes
were gradual the imitators might easily be led along the
same track, until they differed to an equally extreme degree
from their original condition; and they would thus ulti-
mately assume an appearance or coloring /wholly unlike
that of the other members of the group to which they
belonged. It should also be remembered that many species
of Lepidoptera are liable to considerable and abrupt varia-
tions in color. A few instances have been given in this
chapter; and many more may be found in the papers of
Mr. Bates and Mr. Wallace.

*"Proc. Ent. Soc," Dec. 3, 1866, p. 45.

f Wallace, "Transact. Linn. Soc," vol. xxv, 1865, p. 1; also
*' Transact. Ent. Soc," vol. iv (3d series), 1867, p. 301. Trimen,
" Linn. Transact.," vol. xxvi, 1869, p. 497. Riley, " Third Annual
Report on the Noxious Insects of Missouri," 1871, pp. 163-168. This
latter essay is valuable, as Mr. Riley here discusses all the objections
which have been raised against Mr. Bates' theory.

368 THE DESCENT OF MAN.

With several species the sexes are alike, and imitate the
two sexes of another species. But Mr. Trimen gives, in
the paper already referred to, three cases in which the sexes
of the imitated form differ from each other in color, and
the sexes of the imitating form differ in a like manner.
Several cases have also been recorded where the females
alone imitate brilliantly-colored and protected species, the
males retaining ^' the normal aspect of their immediate con-
geners.^" It is here obvious that the successive variations
by which the female has been modified have been trans-
mitted to her alone. It is, however, probable that some of
the many successive variations would have been transmitted
to, and developed in, the males had not such males been
eliminated by being thus rendered less attractive to the
females; so that only those v^ariations were preserved which
were from the first strictly limited in their transmission to
the female sex. We have a partial illustration of these
remarks in a statement by Mr. Belt; * that the males of
some of the Leptalides, which imitate protected species,
still retain in a concealed manner some of their original
characters. Thus in the males '^ the upper half of the
lower wing is of a pure white, while all the rest of the wings
is barred and spotted with black, red and yellow, like the
species they mimic. The females have not this white
patch, and the males usually conceal it by covering it with
the upper wing, so that I cannot imagine its being of any
other use to them than as an attraction in courtship, when
they exhibit it to the females, and thus gratify their deep-
seated preference for the normal color of the order to which
the Leptalides belong."'

Bright Colors of Caterpillars. — While reflecting on the
beauty of many butterflies it occurred to me that some
caterpillars were splendidly colored; and as sexual selection
could not possibly have here acted, it appeared rash to
attribute the beauty of the mature insect to this agency,
unless the bright colors of their larvae could be somehow
explained. In the first place, it may be observed that the
colors of caterpillars do not stand in any close correlation
with those of the mature insect. Secondly, their bright
colors do not serve in any ordinary manner as a protection.

* ♦* The Naturalist in Nicaragua," 1874, p. 385,

INSECTS. 369

Mr. Bates informs me, as an instance of this, that the most
conspicuous caterpillar which he ever beheld (that of a
Sphinx) lived on the large green leaves of a tree on the
open llanos of South America; it was about four inches in
length, transversely banded with black and yellow, and
with its head, legs and tail of a bright red. Hence it
caught the eye of any one who passed by, even at the
distance of many yards, and no doubt that of every passing
bird.

I then applied to Mr. Wallace, who has an innate genius
for solving difficulties. After some consideration he replied:
" Most caterpillars require protection, as may be inferred
from some kinds being furnished with spines or irritating
hairs and from many being colored green like the leaves on
which they feed, or being curiously like the twigs of the trees
on which they live.'^ Another instance of protection, fur-
nished me by Mr. J. Mansel Weale, may be added, namely,
that there is a caterpillar of a moth which lives on the
mimosas in S. Africa, and fabricates for itself a case quite
indistinguishable from the surrounding thorns. From
such considerations Mr. Wallace thought it probable that
conspicuously colored caterpillars were protected by having
a nauseous taste; but as their skin is extremely tender,
and as their intestines readily protrude from a wound, a
slight peck from the beak of a bird would be as fatal to
them as if they had been devoured. Hence, as Mr. Wal-
lace remarks, '' distastefulness alone would be insufficient
to protect a caterpillar unless some outward sign indicated
to its would-be destroyer that its prey was a disgusting
morsel." Under these circumstances it would be highly
advantageous to a caterpillar to be instantaneously and
certainly recognized as unpalatable by all birds and other
animals. Thus the most gaudy colors would be service-
able, and might have been gained by variation and the
survival of the most easily recognized individuals.

This hypothesis appears at first sight very bold, but
when it was brought before the Entomological Society* it
was supported by various statements; and Mr. J. Jenner
Weir, who keeps a large number of birds in an aviary,
informs me that he has made many trials and finds no

* " Proc. Entomolog. Soc," Dec. 3, 1866, p. 45, and March 4, 1867,

370 THE DESCENT OF MAN.

exception to the rule that all caterpillars of nocturnal and
retiring habits with smooth skins, all of a green color and
all which imitate twigs are greedily devoured by his birds.
The hairy and spinose kinds are invariably rejected, as
were four conspicuously colored species. When the birds
rejected a caterpiller they plainly showed by shaking their
heads and cleansing their beaks that they were disgusted
by the taste.* Three conspicuous kinds of caterpillars and
moths were also given to some lizards and frogs by Mr. A.
Butler and were rejected, though other kinds were eagerly
eaten. Thus the probability of Mr. Wallace's view is con-
firmed, namely, that certain caterpillars have been made
conspicuous for their own good, so as to be easily recog-
nized by their enemies, on nearly the same principle that
poisons are sold in colored bottles by druggists for the good
of man. We cannot, however, at present thus explain the
elegant diversity in the colors of many caterpillars; but
any species which had at some former period acquired a
dull, mottled or striped appearance, either in imitation of
surrounding objects or from the direct action of climate,
etc., almost certainly would not become uniform in color
when its tints were rendered intense and bright; for in
order to make a caterpillar merely conspicuous there would
be no selection in any definite direction.

Summary and Concluding Remarhs on Insects. — Looking
back to the several orders we see that the sexes often differ
in various characters, the meaning of which is not in the
least understood. The sexes, also, often differ in their
organs of sense and means of locomotion, so that the males
may quickly discover and reach the females. They dift'er
still oftener in the males possessing diversified contrivances
for retaining the females when found. We are, however,
here concerned only in a secondary degree with sexual dif-
ferences of these kinds.

In almost all the orders the males of some species, even
of weak and delicate kinds, are known to be highly pug-

* See Mr, J, Jenner Weir's paper on Insects and Insectivorous
Birds, in "Transact. Ent. Soc," 1869, p. 21; also Mr. Butler's paper,
ibid., p. 27. Mr. Riley has given analogous facts in the "Third
Annual Report on the Noxious Insects of Missouri," 1871, p. 148.
Some opposed cases are, however, given by Dr. Wallace and M. H.
d'Orville; see "Zoological Record," 1869, p. 349.

INSECTS. an

nacious; and some few are furnished with special weapons
for fighting with their rivals. But the law of battle does
not prevail nearly so widely with insects as with the higher
animals. Hence it probably arises that it is in only a
few cases that the males have been rendered larger and
stronger than the females. On the contrary, they are
usually smaller, so that they may be developed within a
shorter time, to be ready in large numbers for the emerg-
ence of the females.

In two families of the Homoptera and in three of the
Orthoptera, the males alone possess sound-producing organs
in an efficient state. These are used incessantly during the
breeding-season, not only for calling the females, but ap-
parently for charming or exciting them in rivalry with
other males. No one who admits the agency of selection
of any kind, will, after reading the above discussion, dis-
pute that these musical instruments have been acquired
through sexual selection. In four other orders the mem-
bers of one sex, or more commonly of both sexes, are pro-
vided with organs for producing various sounds, which ap-
parently serve merely as call-notes. When both sexes are
thus provided the individuals which were able to make the
loudest or most continuous noise would gain partners before
those which were less noisy, so that their organs have proba-
bly been gained through sexual selection. It is instructive
to reflect on the wonderful diversity of the means for pro-
ducing sound possessed by the males alone, or by both
sexes in no less than six orders. We thus learn how effectual
sexual selection has been in leading to modifications which
sometimes, as with the Homoptera, relate to important
parts of the organization.

From the reasons assigned in the last ch?.pter, it is proba-
ble that the great horns possessed by th^ males of many
Lamellicorn, and some other beetles, have been acquired as
ornaments. From the small size of insects we are apt to
undervalue their appearance. If we could imagine a male
Chalcosoma (see fig. 16), with its polished bronzed coat of mail
and its vast complex horns, magnified to the size of a
horse, or even of a dog, it would be one of the most impos-
ing animals in the world.

The coloring of insects is a complex and obscure subject.
When the male differs slightly from th^ female, and
neither are brilliantly colored, it is probable that the sex^s

37^ 'TSE DESCENT OF MAN,

have varied in a slightly different manner, and that the
variations have been transmitted by each sex to the same,
without any benefit or evil thus accruing. When the
male is brilliantly colored and differs conspicuously from
the female, as with some dragon-flies and many butterflies,
it is probable that he owes his colors to sexual selection ,
while the female has retained a primordial or very ancient
type of coloring, slightly modified by the agencies before
explained. But in some cases the female has apparently
been made obscure by variations transmitted to her alone,
as a means of direct protection; and it is almost certain
that she has sometimes been made brilliant, so as to imitate
other protected species inhabiting the same district. When
the sexes resemble each other and both are obscurely colored
there is no doubt that they have been in a multitude of
cases so colored for the sake of protection. So it is in some
instances when both are brightly colored, for they thus imi-
tate protected species, or resemble surrounding objects such
as flowers; or they give notice to their enemies that they
are unpalatable. In other cases in which the sexes resem-
ble each other and are both brilliant, especially when the
colors are arranged for display, we may conclude that they
have been gained by the male sex as an attraction, and have
been transferred to the female. We are more especially led
to this conclusion whenever the same type of coloration pre-
vails throughout a whole group, and we find that the males
of some species differ widely in color from the females,
while others differ slightly or not at all with intermediate
gradations connecting these extreme states.

In the same manner as bright colors have often been par-
tially transferred from the males to the females, so it has
been with the extraordinary horns of many Lamellicorn
and some other beetles. So, again, the sound-producing
organs proper to the males of the Homoptera and Orthop-
tera have generally been transferred in a rudimentary, or
even in a nearly perfect condition, to the females ; yet not
sufficiently perfect to be of any use. It is also an interest-
ing fact, as bearing on sexual selection, that the stridu-
lating organs of certain male Orthoptera are not fully
developed until the last moult; and that the colors of cer-
tain male dragon-flies are not fully developed until some
little time after their emergence from the pupal state, and.
>vhen they are ready to breed.

INSECTS. 373

Sexual selection implies that the more attractive indi-
viduals are preferred by the opposite sex ; and as with
insects, when the sexes differ, it is the male which, with
some rare exceptions, is the more ornamented, and departs
more from the type to which the species belongs; and as it
is the male which searches eagerly for the female, we must
suppose that the females habitually or occasionally prefer
the more beautiful males, and that these have thus acquired
their beauty. That the females in most or all the orders
would have the power of rejecting any particular male, is
probable from the many singular contrivances possessed by
the males, such as great jaws, adhesive cushions, spines,
elongated legs, etc., for seizing the female; for these con-
trivances show that there is some difficulty in the act,
so that her concurrence would seem necessary. Judging
from what we know of the perceptive powers and affections
of various insects, there is no antecedent improbability in
sexual selection having come largely into play; but we have
as yet no direct evidence on this head, and some facts are
opposed to the belief. Nevertheless, when we see many
males pursuing the same female, we can hardly believe that
the pairing is left to blind chance — that the female exerts
no choice, and is not influenced by the gorgeous colors or
other 07'naments with which the male is decorated.

If we admit that the females of the Homoptera and
Orthoptera appreciate the musical tones of their male part-
ners, and that the various instruments have been perfected
through sexual selection, there is little improbability in the
females of other insects appreciating beauty in form or
color, and consequently in such characters having been
thus gained by the males. But from the circumstance of
color being so variable, and from its having been so often
modified for the sake of protection, it is difficult to decide
in how large a proportion of cases sexual selection has
played a part. This is more especially difficult in those
orders, such as Orthoptera, Hymenoptera, and Coleoptera,
in which the two sexes rarely differ much in color; for we
are then left to mere analogy. With the Coleoptera, how-
ever, as before remarked, it is in the great Lamellicorn
group, placed by some authors at the head of the order,
and in which we sometimes see a mutual attachment be-
tween the sexes, that we find the males of some species pos-
sessing weapons for sexual strife, others furnished with

374 THE DESCENT OF MAN.

wonderful horns, many with stridulating organs, and others
ornamented with splendid metallic tints. Hence it seems
probable that all these characters have been gained through
the same means, namely, sexual selection. With butterflies
we have the best evidence, as the males sometimes take
pains to display their beautiful colors; and we cannot be-
lieve that they would act thus, unless the display was of
use to them in their courtship.

When we treat of birds we shall see that they present in
their secondary sexual characters the closest analogy with
insects. Thus many male birds are highly pugnacious, and
some are furnished with special weapons for fighting with
their rivals. They possess organs which are used during
the breeding-season for producing vocal and instrumental
music. They are frequently ornamented with combs,
horns, wattles and plumes of the most diversified kinds,
and are decorated with beautiful colors, all evidently for
the sake of display. We shall find that, as with insects,
both sexes in certain groups are equally beautiful, and are
equally provided with ornaments which are usually confined
to the male sex. In other groups both sexes are equally
plain-colored and unornamented. Lastly, in some few
anomalous cases the females are more beautiful than the
males. We shall often find, in the same group of birds,
every gradation from no difference between the sexes to an
extreme difference. We shall see that female birds, like
female insects, often possess more or less plain traces or
rudiments of characters which properly belong to the males
and are of use only to them. The analogy, indeed, in all
these respects between birds and insects is curiously close.
Whatever explanation applies to the one class probably
applies to the other; and this explanation, as we shall here-
after attempt to show in further detail, is sexual selection.

FISHES. 375

CHAPTER XII.

SECONDAKY SEXUAL CHARACTERS OF FISHES,
AMPHIBIAi^S AKD REPTILES.

Fishes : Courtship and battles of the males — Larger size of the
females — Males, bright colors and ornamental appendages ;
other strange characters — Colors and appendages acquired by
the males during the breeding-season alone — Fishes with both
sexes brilliantly colored — Protective colors — The less conspicu-
ous colors of the female cannot be accounted for on the principle
of protection — Male fishes building nests and taking charge of
the ova and young. Amphibians: Differences in structure and
color between the sexes — Vocal organs. Reptiles : Chelonians
— Crocodiles — Snakes, colors in some cases protective — Lizards,
battles of — Ornamental appendages — Strange differences in
structure between the sexes — Colors — Sexual differences almost
as great as with birds.

We have now arrived at the great sub-kingdom of the
Vertebrata, and will commence with the lowest class, that
of fishes. The males of Plagiostomous fishes (sharks, rays)
and of Chimaeroid fishes are provided with claspers which
serve to retain the female, like the various structures
possessed by many of the lower animals. Besides the
claspers, the males of many rays have clusters of strong
sharp spines on their heads and several rows along *'the
upper outer surface of their pectoral fins.'' These are
present in the males of some species, which have other
parts of their bodies smooth. They are only temporarily
developed during the breeding-season ; and Dr. (Jiinther
suspects that they are brought into action as prehensile
organs by the doubling inward and downward of the two
sides of the body. It is a remarkable fact that the females
and not the males of some species, as of Raia clavata, have
their backs studded with large hook-formed spines.*

The males alone of the capelin (Mallotus villosus, one of

*Yarrell's "Hist, of British Fishes," vol. ii, 1836, pp. 417, 425,
436. Dr. Gtinther informs me that the spines in M clavata are
peculiar to the female.

376 THE DESCENT OF MAN,

Salmonidae) are provided with a ridge of closely-set, brush-
like scales, by the aid of which two males, one on each side,
hold the female, while she runs with great swiftness on
the sandy beach and there deposits her spawn.* The
widely distinct Mo7iacantJius scopas presents a somewhai
analogous structure. The male, as Dr. Giinther informs
me, has a cluster of stiff, straight spines, like those of a
comb, on the sides of the tail ; and these in a specimen
six inches long were nearly one and a half inches in
length; the female has in the same place a cluster of bristles,
which may be compared with those of a toothbrush. In
another species, M. peroniiy the male has a brush like that
possessed by the female of the last species, while the sides
of the tail in the female are smooth. In some other
species of the same genus the tail can be perceived to
be a little roughened in the male and perfectly smooth in
the female; and lastly in others, both sexes have smooth
sides.

The males of many fish fight for the possession of the
females. Thus the male stickleback ( Gasterosteus leiurus)
has been described as ^' mad with delight " when the female
comes out of her hiding-place and surveys the nest which
he has made for her. '^ He darts round her in every direc-
tion, then to his accumulated materials for the nest, then
back again in an instant; and as she does not advance he
endeavors to push her with his snout, and then tries to pull
her by the tail and side-spine to the nest.^'f The males are
said to be polygamists; I they are extraordinarily bold and
pugnacious, while '*^the females are quite pacific.^^ Their
battles are at times desperate; "for these puny combatants
fasten tight on each other for several seconds, tumbling
over and over again, until their strength appears completely
exhausted." With the rough-tailed stickleback (G. trachu-
rus) the males while fighting swim round and round each
other, biting and endeavoring to pierce each other with
their raised lateral spines. The same writer adds,§ ''the
bite of these little furies is very severe. They also use their

*** The American Naturalist," April, 1871, p. 119.
f See Mr. R. Warington's interesting articles in "Annals and Mag
of Nat. Hist.," Oct., 1852, and Nov., 1855.
I Noel Humphreys, " River Gardens," 1857.
§ Loudon's "Mag. of Nat. History," vol. iii, 1830, p. 331.

FISHES. 877

lateral spines with such fatal effect that I have seen ono
during a battle absolutely rip his opponent quite open, so
that he sank to the bottom and died." When a fish is con-
quered, *' his gallant bearing forsakes him; his gay colors
fade away; and he hides his disgrace among his peaceable
companions, but is for some time the constant object of hi3
conquerer's persecution."

The male salmon is as pugnacious as the little stickle-
back; and so is the male trout, as I hear from Dr. Giinther.
Mr. Shaw saw a violent contest between two male salmon
which lasted the whole day; and Mr. R. Buist, Superin-
tendent of Fisheries, informs me that he has often watched
from the bridge at Perth the males driving away their
rivals whil^ the females were spawning. The males "are
constantly fighting and tearing each other on the spawning-
beds, and many so injure each other as to cause the death
of numbers, many being seen swimming near the banks of
the river in a state of exhaustion, and apparently in a
dying state." * Mr. Buist informs me that in June, 1868,
the keeper of the Stormontfield Breeding-Ponds visited the
northern Tyne and found about 300 dead salmon, all of
which with one exception were males; and he was convinced
that they had lost their lives by fighting.

The most curious point about the male salmon is that
during the breeding-season, besides a light change in color,
''the lower jaw elongates, and a cartilaginous pro-
jection turns upwar 1 from the point, which, when the
jaws are closed, occupies a deep cavity between the inter-
maxillary bones of the upper jaw."t (I^^igs- 27 and 28.)
In our salmon this change of structure lasts only during
the breeding-season; but in the Salmo lycaodon oi North-
western America the change, as Mr. J. K. Lord J believes,
is permanent and best marked in the older males which have
previously ascended the rivers. In these old males the
jaw becomes developed into an immense hook-like projec-
tion and the teeth grow into regular fangs, often more than

*"The Field," June 29, 1867. For Mr. Sliaw's statement, see
" Edinburgli Review," 1843. Another experienced observer (Scrope's
"Days of Salmon Fishing," p. 60) remarks that like the slag, the
male would, if he could, keep all other males away.

f Yarrell, " History of British Fishes," vol. ii, 1836, p. 10.

% " The Naturalist in Vancouver's Island," vol. i, 1866, p. 64

378 THE DESGENT OF MAN,

half an inch in length. With the European salmon,
according to Mr. Lloyd,* the temporary hook-like structure

Kg. {W. Head of male common salmon (,Scdmo solar) during the breeding-
season.

[This drawing, as well as all the others in the present chapter, have been exe-
cuted by the well-known artist, Mr. G. Ford, from specimens in the British
Museum, under the kind superintendence of Dr. Gunther.]

serves to strengthen and protect the jaws, when one male
charges another with wonderful violence; hut the greatly
developed teeth of the male American salmon may be com-

• " Scandinavian Aaventures/' vol. \, 1854, pp. 100, 104

FISHES. 379

pared with the tusks of many male mammals, and they
indicate an offensive rather than a protective purpose.

The salmon is not the only fish in which the teeth differ
in the two sexes; as this is the case with many rays. In

Pig. 28. Head of female salmon.

the thornback (Raia Clavata) the adult male has sharp,
pointed teeth, directed backward, while those of the female
are broad and flat, and form a pavement; so that these
teeth differ in the two sexes of the same species more than
is usual in distinct genera of the same family. The teeth
of the male become sharp only when he is adult; while
young they are broad and flat like those of the female. A^

380 TEE DESCENT OF MAN.

BO frequently occurs with secondary sexual characters, both
sexes of some species of rays (for instance R. batis), when
adult, possess sharp, pointed teeth; and here a character,
proper to and primarily gained by the male, appears to have
been transmitted to the offspring of both sexes. The teeth
are likewise pointed in both sexes of R. maculata, but only
when quite adult; the males acquiring them at an earlier
age than the females. AVe shall hereafter meet with anal-
ogous cases in certain birds, in which the male acquires the
plumage common to both sexes when adult, at a somewhat
earlier age than does the female. With other species of
rays the males even when old never possess sharp teeth, and
consequently the adults of both sexes are provided with
broad, flat teeth like those of the young, and like those of
the mature females of the above-mentioned species.* As
the rays are bold, strong and voracic 3 fish, we may suspect
that the males require their sharp teeth for fighting with
their rivals; but as they possess many parts modified and
adapted for the jDrehension of the female, it is possible that
their teeth may be used for this purpose.

In regard to size, M. Car onnierf maintains that the
female of almost all fishes is larger than the male; and Dr.
Giinther does not know of a single instance in which the
male is actually larger than the female. With some
Cyprinodonts the male is not even half as large. As in
many kinds of fishes the males habitually fight together, it
is surprising that they have not generally become larger
and stronger than the females through the effects of sexual
selection. The males suffer from their small size, for,
according to M. Carbonnier, they are liable to be devoured
by the females of their own species when carnivorous, and
no doubt by other species. Increased size must be in some
manner of more importance to the females than strength
and size are to the males for fighting with other males;
and this perhaps is to allow of the production of a vast
number of ova.

In many species the male alone is ornamented with
bright colors; or these are much brighter in the male than
the female. The male, also, is sometimes provided with

* See Yarrell's account of the rays in his " Hist, of British Fishes/
vol. ii, 1836, p. 416, with an excellent figure, and pp. 423, 433.

f As quoted in " The Farmer," 1868, p. 369.

FI8EE8. 881

appendages which appear to be of no more use to him for
the ordinary purposes of life than are the tail feathers to
the peacock. I am indebted for most of the following
facts to the kindness of Dr. Giinther. There is reason
to suspect that many tropical fishes differ sexually in color
and structure; and there are some striking cases with our
British fishes. The male Callionymns lyra has been called
the gemmeous dragonet " from its brilliant gem-like colors/'

Fig. 29. Callionyjmis lyra Upper figure, male ; lower figure, female.
N. B.— The lower figure is more reduced than the upper.

When fresh caught from the sea the body is yellow of
various shades, striped and spotted with vivid blue on the
head; the dorsel fins are pale brown with dark longitudinal
bands; the ventral, caudal and anal fins being bluish-black.
The female, or sordid dragonet, was considered bjr Lin-
naeus and by many subsequent naturalists as a distinct
species; it is of a dingy reddish-brown with the dorsal fin
brown and the other fins white. The sexes differ also in
the proportional size of the head and mouth and in the
position of the eyes;* but the most striking difference is
the extraordinary elongattion in the male (fig. 29) of the

*I have drawn up this description from Yarrell's "British
Fishes," vol. i, 1836, pp. 261, 266.

38^ THE DESCENT OF MAN.

dorsal fin. Mr. W. Saville Kent remarks that this '^ sin-
gular appendage appears from my observations of the
species in confinement to be subservient to the same end
as the wattles, crests and other abnormal adjuncts of the
male in gallinaceous birds for the purpose of fascinating
their mates. '^* The young males resemble the adult
females in structure and color. Throughout the genus
Callionymusf the male is generally much more brightly
spotted than the female, and in several species, not only
the dorsal, but the anal fin is much elongated in the males.

The male of the Cottus scorpins, or sea-scorpion, is
slenderer and smaller than the female. There is also a
great difference in color between them. It is difficult, as
Mr. Lloyd| remarks, " for any one who has not seen this
fish during the spawning season when its hues are brighest
to conceive the admixture of brilliant colors with which it,
in other respects so ill-favored, is at that time adorned."
Both sexes of the Labrus mixtus, although very different
in color, are beautiful; the male being orange with bright
blue stripes and the female bright red with some black
spots on the back.

In the very distinct family of the Cyprinodontidae —
inhabitants of the fresh waters of foreign lands — the sexes
sometimes differ much in various characters. In the male
of the Mollienesia petenensis,% the dorsal fin is greatly de-
veloped and is marked with a row of large, round, ocellated,
bright-colored spots; while the same fin in the female is
smaller, of a different shape, and marked only with irregu-
larly curved brown spots. In the male the basal margin of
the anal fin is also a little produced and dark colored. In
the male of an allied form, the Xipliophorus Hellerii (fig.
30), the inferior margin of the caudal fin is developed into
a long filament, which, as I hear from Dr. Giinther, is
striped with bright colors. This filament does not contain
any muscles, and apparently cannot be of any direct use to
the fish. As in the case of the Callionymus, the males

*" Nature," July, 1873, p. 264.

f " Catalogue of Acanth. Fishes in the British Museum," by Dr.
Giinther, 161, pp. 138-151.

X "Game Birds of Sweden," etc., 1867, p. 466.

§ With respect to this and the following species I am indebted to
Dr. Giinther for information; see also his paper on the " Fishes of
Central America," in "Transact. Zoolog. Soc," vol. vi, 1868, p. 485.

FISHES. 883

while young resemble the adult females in color and struct-
ure. Sexual differences such as these may be strictly com-
pared with those which are so frequent with gallinaceous
birds.*

In a siluroid fish, inhabiting the fresh waters of South
America, the Plecostomiis l)ar'batus\ (fig. 31), the male has
its mouth and inter-operculum fringed with a beard of stiff
hairs, of which the female shows hardly a trace. These

Fig. 30. Xiphophonis Hellerii. Upper figure, male ; lower figure, female.

hairs are of the nature of scales. In another species of the
same genus, soft flexible tentacles project from the front
part of the head of the male, which are absent in the
female. These tentacles are prolongations of the true skin,
and therefore are not homologous with the stiff hairs of the
former species; but it can hardly be doubted that both
serve the same purpose. What this purpose may be it is
difficult to conjecture; ornament does not here seem prob-
able, but we can hardly suppose that stiff hairs and flexible

*Dr. Giintlier makes this remark; "Catalogue of Fislies in the
British Museum," vol. iii, 1861, p. 141.

f See Dr. Gtinther on this genus, in *' Proc. Zoolog. See," 1868, p.
233.

384

TEE DESCENT OF MAN.

Fig. 31. Plecostomus barbatus. Upper figure, head of male ; lower figure,
female.

FISHES. 385

filainents can be useful in any ordinary way to the males
alone. In that strange monster, the Chimcera monstrosa,
the male has a hook-shaped bone on the top of the head,
directed forward, with its end rounded and covered with
sharp spines ; in the female '^ this crown is altogether
absent," but what its use may be to the male is utterly
unknown.*

The structures as yet referred to are permanent in the
male after he has arrived at maturity; but with some Blen-
nies, and in another allied genus, f a crest is developed on
the head of the male only during the breeding season, and
the body at the same time becomes more brightly colored.
There can be little doubt that this crest serves as a tem-
porary sexual ornament, for the female does not exhibit a
trace of it. In other species of the same genus both sexes
possess a crest, and in at least one species neither sex is
thus provided. In many of the ChromidaB, for instance in
Geophagus and especially in Cichla, the males, as I hear
from Prof. Agassiz,]; have a conspicuous protuberance on
the forehead which is wholly wanting in the females and
in the young males. Prof. Agassiz adds: ^'1 have often
observed these fishes at the time of spawning when the
protuberance is largest, and at other seasons when it is
totally wanting, and the two sexes show no difference
whatever in the outline of the profile of the head. I
never could ascertain that it subserves any special func-
tion, and the Indians on the Amazon know nothing about
its use." These protuberances resemble in their periodical
appearance the fleshy carbuncles on the heads of certain
birds; but whether they serve as ornaments must remain at
present doubtful.

I hear from Prof. Agassiz and Dr. Giinther that the
males of those fishes which differ permanently in color
from the females often become more brilliant during
the breeding season. This is likewise the case with a
multitude of fishes, the sexes of which are identical in

*F. Buckland in " Land and Water," July, 1868, p. 377, with a
figure. Many other cases could be added of structures peculiar to
the male, of which the uses are not known.

f Dr. Giinther, "Catalogue of Fishes," vol. iii, pp. 221 and 240.

X Sea also •' A Journey in Brazil," by Prof, and Mrs. Agassiz, 1868,
p. 230.

386 THE DESCENT OF MAN.

color at all other seasons of the year. The tench, roach
and perch may be given as instances. The male salmon
at this season is '' marked on the cheeks with orange-
colored stripes, which give it the appearance of a Labrus,
and the body partakes of a golden-orange tinge. The
females are dark in color, and are commonTy called black-
fish.^^* An analogons and even greater change takes place
with the Salmo eriox or bull trout ; the males of the char
{S. umhla) are likewise at this season rather brighter in
color than the females, f The colors of the pike ( Esox
reticulatus) of the United States, especially of the male,
become, during the breeding-season, exceedingly intense,
brilliant, and iridescent.]; Another striking instance out
of many is afforded by the male stickleback ( Gasterosteus
leiurus), which is described by Mr. Warington,§ as being
then ^^ beautiful beyond description." The back and eyes
of the female are simply brown and the belly white. The
eyes of the male, on the other hand, are '' of the most
splendid green, having a metallic luster like the green
feathers of some humming-birds. The throat and belly are
of a bright crimson, the back of an ashy-green, and the
whole fish appears as though it were somewhat translucent
and glowed with an internal incandescence." After the
breeding-season these colors all change, the throat and
belly become of a paler red, the back more green, and the
glowing tints subside.

With respect to the courtship of fishes, other cases have
been observed since the first edition of this book appeared,
besides that already given of the stickleback. Mr. W. S.*
Kent says that the male of the Labrus mixtuSy which, as
we have seen, differs in color from the female, makes " a
deep hollow in the sand of the tank, and then endeavors in
the most persuasive manner to induce a female of the same
species to share it with him, swimming backward and for-
ward between her and the completed nest, and plainly
exhibiting the greatest anxiety for her to follow." The
males of Cantharus Uneatus become, during the breeding-

* Yarrell, "British Fishes," vol. ii, 1836, pp. 10, 12, 35.
fW. Thompson, in "Annals and Mag. of Nat. History," vol. vi,
1841, p. 440.
t " The American Agriculturist," 1868, p. 100.
§ " Annals and Mag. of Nat. Hist.," Oct., 1858.

FISHES. 387

season, of deep leaden-black; they then retire from the
shoal, and excavate a hollow as a nest. ^' Each male now
monnts vigilant guard over his respective hollow, and vig-
orously attacks and drives away any other fish of the same
sex. Toward his companions of the opposite sex his con-
duct is far different; many of the latter are now distended
with spaAvn, and these he endeavors by all the means in his
power to lure singly to his prepared hollow, and there to
deposit the myriad ova with which they are laden, which
he then protects and guards with the greatest care."*

A more striking case of courtship, as well as of display,
by the males of a Chinese Macropus has been given by M.
Carbonnier, who carefully observed these fishes under con-
finement, t The males are most beautifully colored, more
so than the females. During the breeding-season they con-
tend for the possession of the females ; and, in the act of
courtship, expand their fins, which are spotted and orna-
mented with brightly colored rays, in the same manner,
according to M. Carbonnier, as the peacock. They
then also bound about the females with much vivacity, and
appear by ^^Tetalage de leurs vives couleurs chercher a
attirer Tattention des femelles, lesquelles ne paraissaient
indifferentes a ce manege, elles nageaient avec une molle
lenteur vers les mdles et semblaient se complaire dans leur
voisinage." After the male has won his bride he makes a
little disk of froth by blowing air and mucus out of his
mouth. He then collects the fertilized ova dropped by the
female in his mouth; and this caused M. Carbonnier much
alarm, as he thought that they were going to be devoured.
But the male soon deposits them in the disk of froth, after-
ward guarding them, repairing the froth, and taking care
of the young when hatched. I mention these particulars
because, as we shall presently see, there are fishes the males
of which hatch their eggs in their mouths; and those who
do not believe in the principle of gradual evolution might
ask how could such a habit have originated; but the diffi-
culty is much diminished when we know that there are
fishes which thus collect and carry the eggs; for if delayed
by any cause in depositing them, the habit of hatching
them in their mouths might have been acquired.

* "Nature," May, 1873, p. 25.

t *' Bull, de la Soc. d'Acclimat.," Paris, July, 1869, and Jan. 1870.

388 THE DESCENT OF MAN,

To return to our more immediate subject. The case
stands thus; female fishes, as far as I can learn, never will-
ingly spawn except in the presence of the males; and the
males never fertilize the ova except in the presence of the
females. The males fight for the possession of the females.
In many species the males while young resemble the females
in color; but when adult become much more brilliant, and
retain their colors throughout life. In other species the
males become brighter than the females and otherwise more
highly ornamented, only during the season of love.' The
males sedulously court the females, and in one case, as we
have seen, take pains in displaying their beauty before
them. Can it be believed that they w^ould thus act to no
purpose during their courtship? And this would be the case
unless the females exert some choice and select those males
which please or excite them most. If the female exerts
such choice, all the above facts on the ornamentation of
the males become at once intelligible by the aid of sexual
selection.

We have next to inquire whether this view of the bright
colors of certain male fishes having been acquired through
sexual selection can, through the law of the equal trans-
mission of characters to both sexes, be extended to those
groups in which the mules and females are brilliant in the
same, or nearly tlie same, degree and manner. In such a
genus as Labrus, wliicli includes some of the most splendid
fishes in the world — for instance, the Peacock Labrus {L.
pavo), described,* with pardonable exaggeration, as formed
of polished scales of gold, incrusting lapis-lazuli, rubies,
sapphires, emeralds and amethysts — we may, with much
probability, accept this belief, for we have seen that the
sexes in at least one species of the genus differ greatly in
color. Witn some fishes, as witli many of the lowest ani-
mals, splendid colors may be the direct result of the nature
of their tissues and of the surrounding conditions, without
tlie aid of selection of any kind. The gold-fish {Cyprinus
miratus), judging from the analogy of the golden variety
of tlie common carp, is perhaps a case in point, as it may
owe its splendid colors to a single abrupt variation, due to
the conditions to which this fish has been subjected under

*Bory de Saint Vincent, in "Diet. Class. d'Hist. Nat.," torn, ix,
1826, p. 151.

FISHES, 889

confinement. It is, however, more probable that these
colors have been intensified through artificial selection, as
this species has been carefully bred in China from a remote
period.* Under natural conditions it does not seem prob-
able that beings so highly organized as fishes, and which
live under such complex relations, should become brilliantly
colored without suffering some evil or receiving some bene-
fit from so great a change, and consequently without the
intervention of natural selection.

AVhat, then, are we to conclude in regard to the many
fishes, both sexes of which are splendidly colored? Mr.
AVallace f believes that the species which frequent reefs,
where corals and other brightly-colored organisms abound,
are brightly colored in order to escape detection by their
enemies; but according to my recollection they were thus
rendered highly conspicuous. In the fresh waters of the
tropics there are no brilliantly-colored corals or other
organisms for the fishes to resemble; yet many species in
the Amazons are beautifully colored, and many of the car-
nivorous Cyprinidas in India are ornamented with " bright
longitudinal lines of various tints." X Mr. McClelland, in
describing these fishes, goes so far as to suppose that " the
peculiar brilliancy of their colors" serves as "a better
mark for king-fishers, terns, and other birds which are
destined to keep the number of these fishes in check;" but
at the present day few naturalists will admit that any
animal has been made conspicuous as an aid to its own
destruction. It is possible that certain fishes may have
been rendered conspicuous in order to warn birds and beasts
of prey that they were unpalatable, as explained when
treating of caterpillars; but it is not, I believe, known that

* Owing to some remarks on this subject made in my work " On
the Variation of Animals under Domestication," Mr. W. F. Mayers
("Chinese Notes and Queries," Aug. 1868, p. 123) has searched the
ancient Chinese encyclopedias. He finds that gold-fish were first
reared in confinement during the Sung Dynasty which commenced
A. D. 960. In the year 1129 these fishes abounded. In another
place it is said that since the year 1548 there has been " produced at
Hangchow's a variety called the fire-fish, from its intensely red color.
It is universally admired and there is not a household where it is not
cultivated, in rivalry as to its color, and as a source of profit."

y Westminster Review," July, 1867, p. 7.

t *' Indian Cyprinidse," by Mr. M'Clelland, " Asiatic Besearclies,"
vol. xix, part u, 1839, p. 230.

390 THE DESCENT OF MAN.

an J fish, at least any fresh-water fish, is rejected from
being distasteful to fish-devouring animals. On the wliolo,
the most probable view in regard to the fishes, of which
both sexes are brilliantly colored, is that their colors were
acquired by the males as a sexual ornament, and were
transferred equally, or nearly so, to the other sex.

We have now to consider whether, when the male differs
in a marked manner from the female in color or in other
ornaments, he alone has been modified, the variations being
inherited by his male offspring alone ; or whether the
female has been specially modified and rendered inconspicu-
ous for the sake of protection, such modifications being
inherited only by the females. It is impossible to doubt
that color has been gained by many fishes as a protection; no
one can examine the speckled upper surface of a flounder
and overlook its resemblance to the sandy bed of the sea on
which it lives. Certain fishes, moreover, can through the
action of the nervous system change their colors in adapta-
tion to surrounding objects, aud that within a short time.*
One of the most striking instances ever recorded of an
animal being protected by its color (as far as it can be
judged of in preserved specimens), as well as by its form,
is that given by Dr. Giintherf of a pipe-fish, which, with
its reddish streaming filaments, is hardly distinguishable
from the sea- weed to which its clings with its prehensile
tail. But the question now under consideration is whether
the females alone have been modified for this object. We
can see that one sex will not be modified through natural
selection for the sake of protection more than the other,
supposing both to vary, unless one sex is exposed for a
longer period to danger, or has less power of escaping from
such danger than the other; and it does not appear that
with fishes the sexes differ in these respects. As far as
there is any difference the males, from being generally
smaller and from wandering more about, are exposed to
greater danger than the females; and yet when the sexes
differ the males are almost always the more conspicuously
colored. The ova are fertilized immediately after being
deposited; and when this process lasts for several days, as
in the case of the salmon, J; the female during the whole

* G. Pouchet, L'Institut, Nov. 1, 1871, p. 134.

f " Proc. Zoolog. Soc," 1865, p. 327, pi. xiv and xv.

j Yarrell, ** Britisli Fishes," vol. ii, p. 11.

FI8HE8. 391

time is attended by the male. After the ova are fertilized
they are, in most cases, left unprotected by both parents,
so that the males and females, as far as oviposition is con-
cerned, are equally exposed to danger, and both are equally
important for the production of fertile ova; consequently
the more or less brightly colored individuals of either
sex would be equally liable to be destroyed or preserved,
and both would have an equal influence on the colors of
their offspring.

Certain fishes, belonging to several families, make nests,
and some of them take care of their young when hatched.
Both sexes of the bright-colored Crenilnbrus massa and
melops work together in building their nests with sea-weed,
shells, etc.* But the males of certain fishes do all the
work and afterward take exclusive charge of the young.
This is the case with the dull-colored gobies, f in which the
sexes are not known to differ in color, and likewise with
the sticklebacks (Gasterosteus), in which the males become
brilliantly colored during the spawning season. The male
of the smooth-tailed stickleback ( 0. leiurus) performs the
duties of a nurse with exemplary care and vigilance during
a long time, and is continually employed in gently leading
back the young to the nest when they stray too far. He
courageously drives away all enemies, including the females
of his own species. It would indeed be no small relief to
the male if the female after depositing her eggs were
immediately devoured by some enemy, for he is forced
incessantly to drive her from the nest. J

The males of certain other fishes inhabiting South Amer-
ica and Ceylon, belonging to two distinct orders, have the
extraordinary habit of hatching within their mouths, or
branchial cavities, the eggs laid by the females. § I am
informed by Prof. Agassiz that the males of the Amazonian

* According to the observations of M. Gerbe; see Giinther's
" Record of Zoolog. Literature," 1865, p. 194.

fCuvier, " Regne Animal," vol. ii, 1829, p. 242.

X See Mr. Warington's most interesting description of the habits of
the Gasterosteus leiurus in "Annals and Mag. of Nat. Hist./' Nov.,
1855.

§Prof. Wyman, in "Proc. Boston Soc. of Nat. Hist.," Sept. 15,
1857. Also Prof. Turner, in "Journal of Anatomy and Phys.,"
Nov. 1, 1866, p. 78. Dr. Giinther has likewise described other

392 THE DESCENT OF MAN.

species wliicli follow this habit, *' not only are generally
brighter than the females, but the difference is greater at
the spawning-season than at any other time." The species
of Geophagus act in the same manner; and in this genus, a
conspicuous protuberance becomes developed on the fore-
head of the males during the breeding- season. With the
various species of Chromids, as Prof. Agassiz likewise
informs me, sexual differences in color may be observed,
*' whether they lay their eggs in the water among aquatic
plants or deposit them in holes, leaving them to come out
without further care; or build shallow nests in the river
mud, over which they sit, as our Pomotis does. It ought
also to be observed that these sitters are among the bright-
est species in their respective families; for instance, Hygro-
gonus is bright green with large black ocelli, encircled
with the most brilliant red." Whether with all the species
of Chromids it is the male alone which sits on the eggs is
not known. It is, however, manifest that the fact of the
eggs being protected or unprotected by the parents, has had
little or no influence on the differences in color between the
sexes. It is further manifest in all the cases in which the
males take exclusive charge of the nests and young, that
the destruction of the brighter-colored males would be far
more influential on the character of the race than the
destruction of the brighter-colored females; for the death
of the male during the period of incubation or nursing
would entail the death of the young, so that they could not
inherit his peculiarities; yet in many of these very cases
the males are more conspicuously colored than the females.
In most of the Lophobranchii (Pipe-fish, Hippocampi,
etc.) the males have either marsupial sacks or hemispherical
depressions on the abdomen, in which the ova laid by the
female are hatched. The males also show great attachment
to their young.* The sexes do not commonly differ much
in color; but Dr. Gunther believes that the male Hippo-
campi are rather brighter than the females. The genus
Solenostoma, however, offers a curious exceptional case,t
for the female is much more vividly colored and spotted

*Yarrell, " Hist, of British Fishes," vol. ii, 1836, pp. 829, 338.

f Dr. Gunther, since publishing an account of this species in " The
Fishes of Zanzibar," by Col. Playfair, 1866, p. 137, has re-examine4
the specimens and has given me the above inf ormatioxu

FISHES. 893

than the male, and she alone has a marsupial sack and
hatches the eggs; so that the female of Solenostoma differs
from all the other Lophobranchii in this latter respect, and
from almost all other fishes, in being more brightly colored
than the male. It is improbable that this remarkable
double inversion of character in the female should be
an accidental coincidence. As the males of several fishes,
which take exclusive charge of the eggs and young, are
more brightly colored than the females, and as here the
female Solenostoma takes the same charge and is brighter
than the male, it might be argued that the conspicuous colors
of that sex which is the more important of the two for the
welfare of the offspring, must be in some manner pro-
tective. But from the large number of fishes, of which the
males are either permanently or periodically brighter than
the females, but whose life is not at all more important for
the welfare of the species than that of the female, this
view can hardly be maintained. AYhen we treat of birds
we shall meet with analogous cases, where tliere has been a
complete inversion of the usual attributes of the two sexes,
and we shall tlien give wliat appears to be the probable
explanation, namely, that the males have selected the more
attractive females, instead of the latter having selected, in
accordance with the usual rule tliroughout the animal
kingdom, the more attractive males.

On the whole we may conclude, that with most fishes, in
which tlie sexes differ in color or in other ornamental cliar-
acters, the males originally varied, with their variations
transmitted to the same sex, and accumulated through
sexual selection by attracting or exciting the females. In
many cases, however, sucli cliaracters have been transferred,
either partially or completely, to the females. In other
cases, again, both sexes have been colored alike for the sake
of protection; but in no instance does it appear that the
female alone lias had her colors or other characters specially
modified for this latter purpose.

The last point which need be noticed is that fishes are
known to make various noises, some of which are described
as being musical. Dr. Dufosse, who has especially attended
to tliis subject, says that the sounds are voluntarily pro-
duced in several ways by different fishes; by the friction of
the pharyngeal bones — by the vibration of certain muscles
attached to tlie swim-bladder, which serves as a resoundinir

394 THE DESCENT OF MAN.

board — and by the vibration of the intrinsic muscles of the
swim-bladder. By this latter means the Trigla producoB
pure and long-drawn sounds which range over nearly an
octave. But the most interesting case for us is that of two
species of Ophidium, in which the males alone are provided
with a sound-producing apparatus, consisting of small mov-
able bones, with proper muscles, in connection with the
swim-bladder.* The drumming of the Umbrinas in the
European seas is said to be audible from a depth of twenty
fathoms; and the fisherman of Rochelle assert '^^that the
males alone make the noise during the spawning- time; and
that it is possible by imitating it to take them without
bait."f From this statement, and more especially from
the case of Ophidium, it is almost certain that in this, the
lowest class of the Vertebrata, as with so many insects and
spiders, sound-producing instruments have, at least in some
cases, been developed through sexual selection, as a means
for bringing the sexes together.

AMPHIBIANS.

Urodela. — I will begin with the tailed amphibians. The
sexes of salamanders or newts often diifer much both in
color and structure. In some species prehensile claws
are developed on the fore legs of the males during
the breeding-season ; and at this sisason in the male Triton
palmipes the hind feet are provided with a swimming-web,
which is almost completely absorbed during the winter; so
that their feet then resemble those of the female. I This
structure no doubt aids the male in his eager search and
pursuit of the female. While courting her he rapidly
vibrates the end of his tail. With our common newts
{Triton punctatus and cristatus) a deep, much indented
crest is developed along the back and tail of the male
during the breeding-season, which disappears during tlie

* "Comptes Rendus." Tom, xlvi, 1858, p. 353. Tom. xlvii, 1858,
p. 916. Tom. liv, 1863, p. 393. The noise made by the Umbrinas
{Scicena aquila), is said by some authors to be more like that of a
tiiite or organ, than drumming: Dr. Zouteveen, in the Dutch trans-
lation of this work (vol. ii, p. 36), gives some further particulars on
the sounds made by fishes.

f The Rev, C, Kingsley, in " Nature," May, 1870, p. 40.

;Bell "History of British Reptiles," 2nd edit. 1849, pp. 166-159.

AMPHIBIANS.

395

winter. Mr. St. George Mivart informs me that it is not
t'urnislied with muscles, and therefore cannot be used for
locomotion. As during the season of courtship it becomes
edged with bright colors, there can hardly be a doubt that
it is a masculine ornament. In many species the body pre-
sents strongly contrasted, though lurid tints, and these
become more vivid during the breeding-season. The male,
for instance, of our common little newt {IViton pu7ictatus)
is " brownish-gray above, passing into yellow beneath,
which in the spring becomes a rich bright orange, marked
everywhere with round dark spots. ^' The edge of the crest

Fig. 32. Triton cristatus (tialf natural size, from Bell's " British Reptiles ")•
Upper figure, male during the breeding-season; lower figure, female.

also is then tipped with bright red or violet. The female
is usually of a yellowish-brown color with scattered brown
dots, and the lower surface is often quite plain.* The
young are obscurely tinted. The ova are fertilized during
the act of deposition, and are not subsequently tended by
either parent. We may therefore conclude that the males
have acquired their strongly-marked colors and ornamental
appendages through sexual selection; these being transmit-
ted either to the male offepring alone, or to both sexes.

Anura or BatracMa. — With many frogs and toads the
colors evidently serve as a protection, such as the bright

*Bell, "History of British Reptiles," 2d edit., 1849, pp. 146, 151,

396 THE DESCENT OE MAN,

green tints of tree frogs and the obscure mottled shades of
many terrestrial species. The most conspicuously-colored
toad which I ever saw, the Phryniscns nigricans,^ had the
whole upper surface of the body as black as ink, with the
soles of the feet and parts of the abdomen spotted with the
brightest vermilion. It crawled about the bare sandy or
open grassy plains of La Plata under a scorching sun, and
could not fail to catch the eye of every passing creature.
These colors are probably beneficial by making this animal
known to all birds of prey as a nauseous mouthful.

In Nicaragua there is a little frog '' dressed in a bright
livery of red and blue^' which does not conceal itself like
most other species, but hops about during the daytime, and
Mr. Belt says f that as soon as he saw its happy sense of
security he felt sure that it was uneatable. After several
trials he succeeded in tempting a young duck to snatch up
a young one, but it was instantly rejected; and the duck
" went about jerking its head as if trying to throw off some
unpleasant taste."

With respect to sexual differences of color Dr. Giinther
does not know of any striking instance either with frogs
or toads; yet he can often distinguish the male from the
female by the tints of the former being a little more intense.
Nor does he know of any striking difference in external
structure between the sexes, excepting the prominences which
become developed during the breeding-season on the front
legs of the male, by which he is enabled to hold the female. J;
It is surprising that these animals have not acquired more
strongly- marked sexual characters; tor though cold-blooded
their passions are strong. Dr. Giinther informs me that he
has several times found an unfortunate female toad dead
and smothered from having been so closely embraced by
three or four males. Frogs have been observed by Prof.
Hoffman in Giessen fighting all day long during the breed-
ing season, and with so much violence that one had its body
ripped open.

* "Zoology of tlie Voyage of the 'Beagle,' " 1843. Bell, ibid, p.
49.

f " The Naturalist in Nicaragua," 1874, p. 321.

X The male alone of the Bufo sikimmensifi (Dr. Anderson, ** Proo.
Zoolog. Soc," 1871, p. 204) has two plate like callosities on the
thorax and certain rugosities on the fingers, which perhaps subserve
the same end as the above mentioned prominences.

REPTILES. 397

Frogs and toads offer one interesting sexual difference,
namely, in the musical powers possessed by the males; but
to speak of music, when applied to the discordant and
overwhelming sounds emitted by male bull-frogs and some
other species seems, according to our taste, a singularly
inappropriate expression. Nevertheless, certain frogs sing
in a decidedly pleasing manner. Near Eio Janeiro I used
often to sit in the evening to listen to a number of little
Hylae perched on blades of grass close to the water, which
sent forth sweet chirping notes in harmony. The various
sounds are emitted chiefly by the males during the breed-
ing-season, as in the case of the croaking of our common
frog.* In accordance with this fact the vocal organs of the
males are more highly developed than those oi the females.
In some genera the males alone are provided with sacs
which open into the larynx, f For instance, in the edible
frog {Rana esculenta) *nhe sacs are peculiar to the males,
and become, when filled with air in the act of croaking,
large globular bladders, standing out one on each side of
the head near the corners of the mouth." The croak of
the male is thus rendered exceedingly powerful; while that
of the female is only a slight groaning noise. J In the sev-
eral genera of the family the vocal organs differ considerably
in structure, and their development in all cases may be
attributed to sexual selection.

REPTILES.

Clielonia. — Tortoises and turtles do not offer well-marked
sexual differences. In some species the tail of the male is
longer than that of the female. In some the plastron or
lower surface of the shell of the male is slightly concave in
relation to the back of the female. The male of the mud-
turtle of the United States (Chrysemys picta) has claws on
its front feet twice as long as those of the female; and
these are used when the sexes unite. § With the huge
tortoise of the Galapagos Islands ( Testudo nigra) the males

*Bell, "History of Biitisli Reptiles," 1849, p. 93.

+ J. Bishop, in "Todd's Cyclop, of Anat. and Phys.," voL iv, p.
1503.

tBell, ibid, pp. 112-114.

§Mr. C. J. Maynard, "The American Naturalist," Dec.
655

398 THE DESCENT OF MAN.

are said to grow to a larger size than the females. During
the pairing season, and at no other time, the male utters a
hoarse, bellowing noise which can be heard at the distance
of more than a hundred yards; the female, on the other
hand, never uses her voice. *

With the Testudo elegans of India it is said " that the
combats of the males may be heard at some distance from
the noise they produce in butfcing against each other/^f

Crocodilia. — The sexes apparently do not differ in color;
nor do I know that the males fight together, though this
is probable, for some kinds make a prodigious display
before the females. BartramJ describes the male alligator
as striving to win the female by splashing and roaring in
the midst of a lagoon, " swollen to an extent ready to
burst, with its head and tail lifted up, he springs or twirls
round on the surface of the water like an Indian chief
rehearsing his feats of war." During the season of love a
musky odor is emitted by the submaxiliary glands of the
crocodile and pervades their haunts. §

OpMdia. — Dr. Giinther informs me that the males are
always smaller than the females, and generally have longer
and slenderer tails; but he knows of no other difference in
external structure. In regard to color, he can almost
always distinguish the male from the female by his more
strongly pronounced tints; thus the black zigzag band on
the back of the male English viper is more distinctly
defined than in the female. The difference is much plainer
in the rattlesnakes of North America, the male of which,
as the keeper in the Zoological Gardens showed me, can at
once be distinguished from the female by having more
lurid yellow about its whole body. In S. Africa the
Bucephalus capensis presents an analogous difference, for
the female " is never so fully variegated with yellow on the
sides as the male. || The male of the Indian Dipsas cynodon,

* See my " Journal of Researches during the Voyage of the
'Beagle,'" 1845, p. 384.
f Dr. Giinther, " Reptiles of British India," 1864, p. 7.
X " Travels through Carolina," etc., 1791, p. 128.
^Owen, " Anatomy of Vertebrates," vol. i, 1866, p. 615.
I Sir Andrew Smith, " Zoolog. of S. Africa: Reptilia," 1849, pi. x.

REPTILES. 399

on the other hand, is blackish-brown, with the belly partly
black, while the female is reddish or yellowish-olive, with
the belly either uniform yellowish or marbled with black.
In the Tragops dispar of the same country the male is
bright green and the female bronze colored.* No doubt
the colors of some snakes are protective, as shown by the
green tints of tree-snakes and the various mottled shades
of the species which live in sandy places; but it is doubtful
whether the colors of many kinds, for instance of the
common English snake and viper, serve to conceal them;
and this is still more doubtful with the many foreign
species which are colored with extreme elegance. The
colors of certain species are very diiferent in the adult and
young states. \

During the breeding-season the anal scent-glands of
snakes are in active function; J and so it is with the same
glands in lizards, and as we have seen with the submaxillary
glands of crocodiles. As the males of most animals search
for the females, these odoriferous glands probably serve to
excite or charm the female, rather than to guide her to the
spot where the male may be found. Male snakes, though
appearing so sluggish, are amorous; for many have been
observed crowding round the same female, and even round
her dead body. They are not known to fight together from
rivalry. Their intellectual powers are higher than might
have been anticipated. In the Zoological Gardens they
soon learn not to strike at the iron bar with which their
cages are cleaned; and Dr. Keen, of Philadelphia, informs
me that some snakes which he kept learned after four or
five times to avoid a noose, with which they were at first
easily caught. An excellent observer in Ceylon, Mr. E.
Layard,§ saw a cobra thrust its head through a narrow hole
and swallow a toad. '^^With this incumbrance he could
not withdraw himself; finding this, he reluctantly dis-
gorged the precious morsel, which began to move off; this

*Dr. A. Giintlier, ** Reptiles of British India," Ray Soc, 1864, pp.
304, 308.

f Dr. Stoliczka, ** Journal of Asiatic Soc. of Bengal," voL xxxix,
1870, pp. 205, 211.

X Owen, " Anatomy of Vertebrates,*' vol. 1, 1866, p. 615.

§ '• Rambles in Ceylon," in "Annals and Mag. of Nat. Hist./* 2(i
series, vol. ix, 1852, p. 333.

400 THE DESCENT OF MAN,

was too much for snake philosophy to bear, and the toad
was again seized, and again was the snake, after violent
efforts to escape, compelled to part with its prey. This
time, however, a lesson had been learned, and the toad was
seized by one leg, withdrawn, and then swallowed in
triumph/'

The keeper in the Zoological Gardens is positive that
certain snakes, for instance Crotalus and Python, distin-
guish him from all other persons. Cobras kept together in
the same cage apparently feel some attachment toward each
other.*

It does not, however, follow because snakes have some
reasoning power, strong passions and mutual affection,
that they should likewise be endowed with sufficient taste
to admire brilliant colors in their partners, so as to lead to
the adornment of the species through sexual selection.
Nevertheless, it is difficult to account in any other manner
for the extreme beauty of certain species; for instance, of
the coral-snakes of South America, which are of a rich red
with black and yellow transverse bands. I well remember
how much surprise I felt at the beauty of the first coral-
snake which I saw gliding across a path in Brazil. Snakes
colored in this peculiar manner, as Mr. Wallace states on
the authority of Dr. Gunther,f are found nowhere else in
the world except in South America, and here no less than
four genera occur. One of these, Elaps, is venomous; a
second and widely-distinct genus is doubtfully venomous,
and the two otliers are quite harmless. The species belong-
ing to these distinct genera inhabit the same districts, and
are so like each other that no one '^but a naturalist would
distinguish the harmless from the poisonous kinds.'^ Hence,
as Mr. Wallace believes, the innocuous kinds have proba-
bly acquired their colors as a protection, on the principle of
imitation; for they would naturally be thought dangerous
by their enemies. The cause, however, of the bright
colors of the venomous Elaps remains to be explained, and
this may perhaps be sexual selection.

Snakes produce other sounds besides hissing. The
deadly Echis carinata has on its sides some oblique rows of
scales of a peculiar structure with serrated edges ; and

*Dr. Glintber. " Reptiles of British India," 1864, p. 340.
\ " Westminster Review," July 1, 1867, p. 33.

REPTILES. 401

when this snake is excited these scales are rubbed against
each other, which produces "a curious prolonged, almost
hissing sound/^ * AVith respect to the rattling of the
rattlesnake, we have at last some definite information; for
Prof essor Aughey states,! that on two occassons, being him-
self unseen, he watched from a little distance a rattlesnake
coiled up with head erect, which continued to rattle at
short intervals for half an hour; and at last he saw another
snake approach, and when they met they paired. Hence
he is satisfied that one of the uses of the rattle is to bring
the sexes together. Unfortunately he did not ascertain
whether it was the male or the female which remained
stationary and called for the other. But it by no means
follows from the above fact that the rattle may not be of
use to these snakes in other ways, as a warning to animals
which would otherwise attack them. Nor can I quite dis-
believe the several accounts which have appeared of their
thus paralyzing their prey with fear. Some other snakes
also make a distinct noise by rapidly vibrating their tails
against the surrounding stalks of plants ; and I have
myself heard this in the case of a Trigonocephalus in South
America.

Lacertilia. — The males of some, probably of many kinds
of lizards, fight together from rivalry. Thus the arboreal
Anolis crista felhis of South America is extremely pugna-
cious: '^During the spring and early part of the summer,
two adult males rarely meet without a contest. On first
seeing one another, they nod their heads up and down
three or four times, and at the same time expanding the
frill or pouch beneath the throat; their eyes glisten with
rage, and after waving their tails from side to side for a
few seconds, as if to gather energy, they dart at each other
furiously, rolling over and over, and holding firmly with
their teeth. The conflict generally ends in one of the com-
batants losing his tail, which is often devoured by the
victor.'^ The male of this species is considerably larger
than the female;^ and this, as far as Dr. Giinther has been

*Dr. Anderson, "Proc. Zoolog. Soc," 1871, p. 196.
f " Tlie American Naturalist," 1873, p. 85.

X Mr. N. L. Austen kept these animals alive for a considerable
time; see *' Land and Water," July, 1867, p. 0.

402

THE DESCENT OF MAN.

able to ascertain, is the general rule with lizards of all kinds.
The male alone of the Uyrtodadylus rubidus of the Anda-
man Islands possesses pre-anal pores; and these pores, judg-
ing from analogy, probably serve to emit an odor.*

The sexes often differ greatly in various external charac-
ters. The male of the above-mentioned Anolis is furnished
with a crest which runs along the back and tail, and
can be erected at pleasure ; but of this crest the
female does not exhibit a trace. In the Indian
Cophotis ceylanica the female has a dorsal crest, though
much less developed than in the male; and so it is, as Dr.

Giinther informs me, with the
females of many Iguanas,
Chameleons and other lizards.
In some species, however,
the crest is equally developed
in both sexes, as in the Iguana
tuberculata. In the genus
Sitana, the males alone are
furnished with a large throat-
pouch (fig. 33), which can be
folded up like a fan, and is
Fiff. 33. Sitana minor. Male with colored blue, black and red;

but these splendid colors are
exhibited only during the pair-
ing-season. The female does not possess even a rudi-
ment of this appendage. In the Anolis cristatellus accord-
ing to Mr. Austen, the throat pouch, which is bright red
marbled with yellow, is present in the female, though in a
rudimental condition. Again, in certain other lizards,
both sexes are equally well provided with throat pouches.
Here we see with species belonging to the same group, as
in so many previous cases, the same character either con-
fined to the males or more largely developed in them than
in the females, or again equally developed in both sexes.
The little lizards of the genus Draco, which glide through
the air on their rib-supported parachutes, and which in the
beauty of their colors baffle description, are furnished with
skinny appendages to the throat *' like the wattles of gall-
inaceous birds. ^' These become erected when the animal

the gular pouch expanded (from
Qunther's '' Reptiles of India".)

* Stoliczka, "Journal of Asiatic Soc. of Bengal,'
p. 106.

vol. xxxiv, 1870,

REPTILES. 403

is excited. They occur in both sexes, but are best devel-
oped when the male arrives at maturity, at which age the
middle appendage is sometimes twice as long as the head.
Most of the species likewise have a low crest running along
the neck; and this is much more developed in the full-grown
males than in the females or young males.*

A Chinese species is said to live in pairs during the
spring; '•^and if one is caught the other falls from the tree
to the ground, and allows itself to be captured with im-
punity, I presume from despair, f

There are other and much more
remarkable differences between
the sexes of certain lizards. The
male of Ceratophora aspera bears
on the extremity of his snout an
appendage half as long as the head.
It is cylindrical, covered with
scales, flexible and apparently
capable of erection; in the female
it is quite rudimental. In a second
species of the same genus a ter-
minal scale forms a minute horn
on the summit of the flexible

appendage; and in a third species . , , ,, ..

d Stoddartii (fig. 34), the whole %?'er°1l|i?l;''m1ae;*iSwer
appendage is converted into a horn, figure, female,
which is usually of a white color,

but assumes a purplish tint when the animal is excited. In
the adult male of this latter species the horn is half an inch
in length, but it is of quite minute size in the female and in
the young. These appendages, as Dr. Giinther has
remarked to me, may be compared with the combs of gall-
inaceous birds, and apparently serve as ornaments.

In the genus Chameleon we come to the acme of differ-
ence between the sexes. The upper part of the skull of the
male C. hifurcus (fig. 35), an inhabitant of Madagascar, is
produced into two great, solid, bony projections, covered

* All the foregoing statements and quotations in regard to Copho-
tis, Sitana and Draco, as well as the following facts in regard to
Ceratophora and ChamaBleon, are from Dr. Giinther himself, or from
his magnificent work on the "Reptiles of British India," Ray See,
1864, pp. 122, 130, 135.

f Mr. Swinhoe, "Proc. Zoolog. Soc," 1870, p. 240.

404

THE DESCENT OF MAIT.

with scales like tne rest of the head; and of this wonderful
modification of structure the female exhibits only a rudi-
ment. Again, in Chamceleo Oiuenii (fig. 36), from the
vesi coast of Africa, the male bears on his snout and fore-

ITg. 85. Chamaeleo bifurcus. Upper figure, male ; lower figure, female.

head three curious horns, of which the female has not a
trace. These horns consist of an excrescence of bone
covered with a smooth sheath, forming part of the general
integuments of the body, so that tliey are identical in
structure with those of a bull, goat, or other sheath-horned
ruminant. Although the three horns differ so much in
appearance from the two great prolongations of the skull

REPTILES,

405

in 0. Mfurcus, we can hardly doubt that they serve the
same general purpose in the economy of these two animals.
The first conjecture, which will occur to every one, is that
they are used by the males for fighting together; and as
these animals are very quarrelsome,* this is probably a cor-
rect view. Mr. T. W. Wood also informs me that ne once
watched two individuals of C. pumilus fighting violently
on the branch of a tree; they flung their heads about and
tried to bite each other; they then rested for a time and
afterward continued their battle.

Fig. 88. ChamsBleo Owenll. Upper figure, male; lower figure, female.

^ With many lizards the sexes differ slightly in color, the
tints and stripes of the males being brighter and more dis-
tinctly defined than in the females. This, for instance, is
the case with the above Cophotis and with the AcantJio-
dactylus capensis of S. Africa. In a Cordylus of the latter
country, the male is either much redder or greener than
the female. In the Indian Calotes nigrilahris there is a
still greater difference; the lips also of the male are black,
while those of the female are green. In our common little
viviparous lizard {Zootoca vivipara) '* the under side of the
body and base of the tail in the male are bright orange,

*Dr. Bucholz, " Monatsbericht K. Preuss. Akad.," Jan., 1874. p
78. . > f

406 THE DESCENT OF MAN,

spotted with black; in the female these parts are pale gray-
ish green without spots/^ * We have seen tliat the mafes
alone of Sitana possess a throat-pouch; and this is splen-
didly tinted with blue, black and red. In the Proctotretus
tenuis of Chili the male alone is marked with spots of blue,
green and coppery red. \ In many cases the males retain
the same colors throughout the year, but in others they
become much brighter during the breeding-season; I may
give as an additional instance the Calotes onaria, which at
this season has a bright red head, the rest of the body being
green. I

Both sexes of many species are beautifully colored exactly
alike; and there is no reason to suppose that such colors are
protective. No doubt with the briglit-green kinds which
live in the midst of vegetation, this color serves to conceal
them; and in N". Patagonia I saw a lizard {Proctotretus
multimacAilatus) which, when frightened, flattened its body,
closed its eyes, and then from its mottled tints was hardly
distinguishable from the surrounding sand. But the bright
colors with which so many lizards are ornamented, as well
as their various curious appendages, were probably acquired
by the males as an attraction, and then transmitted either
to their male offspring alone, or to both sexes. Sexual
selection, indeed, seems to have played almost as important
a part with reptiles as with birds; and the less conspicuous
colors of the females in comparison with the males cannot
be accounted for, as Mr. Wallace believes to be the case
with birds, by the greater exposure of the females to danger
during incubation.

*Bell, "History of British Reptiles," 2d edit., 1849, p. 40.

f For Proctotretus see " Zoology of the Voyage of the ' Beagle ; '
Reptiles," by Mr. Bell, p. 8, For the lizards of S. Africa, see
" Zoology of S. Africa: Reptiles," by Sir Andrew Smith, pi. 25 and
39. For the Indian Calotes, see " Reptiles of British India," by Dr.
Giinther, p. 143.

tGiintherin "Proc. Zoolog. Soc," 1870, p. 778, with a colored
figure.

BIRDS. 407

CHAPTER XIII.

SECONDARY SEXUAL CHARACTERS OF BIRDS.

Sexual differences — Law of battle — Special weapons — Vocal organs
— Instrumental music — Love-antics and dances — Decorations
permanent and seasonal — Double and single annual moults —
Display of ornaments by tbe males.

Secondary sexual characters are more diversified and
conspicuous in birds, though not perhaps entailing more
important changes of structure, than in any other class of
animals. I shall, therefore, treat the subject at consider-
able length. Male birds sometimes, though rarely, possess
special weapons for fighting with each other. They charm the
female by vocal or instrumental music of the most varied
kinds. They are ornamented by all sorts of combs, wattles,
protuberances, horns, air-distended sacks, top-knots, naked
shafts, plumes and lengthened feathers gracefully spring-
ing from all parts of the body. The beak and naked skin
about the head and the feathers are often gorgeously col-
ored. The males sometimes pay their court by dancing or
by fantastic antics performed either on the ground or in
the air. In one instance, at least, the male emits a musky
odor, which we may suppose serves to charm or excite the
female; for that excellent observer, Mr. Ramsay,* says of
the Australian musk duck {Biziura lohata) that *^the
smell which the male emits during the summer months is
confined to that sex, and in some individuals is retained
throughout the year. I have never, even in the breeding-
season, shot a female which had any smell of musk." So
powerful is this odor during the pairing-season that it can
be detected long before the bird can be seen.f On the
whole, birds appear to be the most aesthetic of all animals,
excepting of course man, and they have nearly the same

* "Ibis," vol. ill (new series), 1867, p. 414.

•I Gould, "Hand book to the Birds of Australia," 1865, Yol. ii, p.
383. ■ *^

408 TEE DESCENT OF MATT.

taste for the beautiful as we have. This is shown by onr
enjoyment of the singing of birds, and by our women,, both
civilized and savage, decking their heads with borrowed
plumes and using gems which are hardly more brilliantly
colored than the naked skin and wattles of certain birds.
In man, however, when cultivated the sense of beauty is
manifestly a far more complex feeling and is associated
with various intellectual ideas.

Before treating of the sexual characters with which we
are here more particularly concerned, I may just allude to
certain differences between the sexes which apparently
depend on differences in their habits of life; for such
cases, though common in the lower, are rare in the higher
classes. Two humming - birds belonging to the genus
Eustephanus, which inhabit the Island of Juan Fernandez,
were long thought to be specifically distinct, but are
now known, as Mr. Gould informs me, to be the male
and female of the same species, and they differ slightly
in the form of the beak. In another genus of hum-
ming-birds ( Grypus) the beak of the male is serrated along
the margin and hooked at the extremity, thus differing
much from that of the female. In the Neomorpha of New
Zealand, there is, as we have seen, a still wider difference
in the form of the beak in relation to the manner of feed-
ing of the two sexes. Something of the same kind has
been observed with the goldfinch (Carcluelis elegans), for I
am assured by Mr. Jenner Weir that the bird-catchers
can distinguish the males by their slightly longer beaks.
The flocks of males are often found feeding on the seeds of
the teazle (Dipsacus), which they can reach with their
elongated beaks, while the females more commonly feed on
the seeds of the betou}' or Scrophularia. AVith a slight
difference of this kind as a foundation we can see how the
beaks of the two sexes might be made to differ greatly
through natural selection. In some of the above cases,
however, it is possible that the beaks of the males may
have been first modified in relation to their contests with
other males; and that this afterward led to slightly changed
habits of life.

Lmo of Battle. — Almost all male birds are extremely
pugnacious, using their beaks, wings, and legs for fighting
together. We see this every spring with our robins and

BIRDS, 409

span*ows. ^\}ie smallest of all birds, namely., the humming-
bird, is one of the most quarrelsome. Mr. Gosse* describes
a battle in which a pair seized hold of each other's beaks,
and whirled round and round till they almost fell to the
ground; and M. Montes de Oca, in speaking of another
genus of humming-bird, says that two males rarely meet
without a fierce aerial encounter; when kept in cages " their
fighting has mostly ended in the splitting of the tongue of
one of the two, which then surely dies from being unable
to f eed. '' t With Waders, the males of the common water-
lien (GaUinula chloroptis) '^when pairing, fight violently
for the females; they stand nearly upright in the water and
Hiirike with their feet." Two were seen to be thus engaged
for half an hour, until one got hold of the head of the
other, which would have been killed had not the observer
interfered; the female all the time looking on as a quiet
spectator, j Mr. Blyth informs me that the males of an
allied bird ( f-raUicrex cristatus) are a third larger than the
females, and are so pugnacious during the breeding-season
that they are kept by the natives of Eastern Bengal for the
sake of fighting. Various other birds are kept in India for
the fjame purpose, for instance, the bulbuls (Pucnonotus
hcemorrhons) which '' fight with great spirit." §

The polygamous ruif, Maclietes pugnax (fig. 37), is
notorious for his extreme pugnacity; and in the spring, the
males, which are considerably larger than the females, con-
gregate day after day at a particular spot, where the females
propose to lay their eggs. The fowlers discover these spots
by the turf being trampled somewhat ba.re. Here they fight
very much like game-cocks, seizing each other with their
beaks and striking with their wings. The great ruff of
feathers round the neck is then erected, and according to
Col. Montagu " sweeps the ground as a shield to defend
the more tender parts;" and this is the only instance known
to me in the case of birds of any structure serving as a
shield. The ruif of feathers, however, from its varied and

* Quoted by Mr. Gould, "Introduction to the Trocliilidae," 1861,
p. 29.

t Gould, ibid, p. 53.

:tW. Thompson, " Na* Hist, of Ireland; Birds," vol. il, 1850, p.
337.

g Jsrdon, "Birds of India," 18C3. vol. ii, p. 96.

^0

THE DESCENT OF MAIT,

rich colors probably serves in chief part as an ornament.
Like most pugnacious birds, they seem always ready to

fight, and when closely confined often kill each other; but
Mcntagu observed that their pugnacity becomes greater
dining the spring, when the long feathers on their necks
are fully developed; and at this period the least movement

BIRDS, 411

by any one bird provokes a general battle.* Of the pug-
nacity of web-footed birds, two instances will suffice : m
Guiana " bloody fights occur during the breeding-season
between the males of the wild musk-duck (Cairina mo-
schata); and where these fights have occurred the " river is
covered for some distance with feathers." f Birds which
seem ill-adapted for fighting engage in fierce conflicts; thus
the stronger males of the pelican drive away the weaker
ones, snapping with their huge beaks and giving heavy
blows with their wings. Male snipe fight together, ** tug-
ging and pushing each other with their bills in the most
curious manner imaginable." Some few birds are believed
never to fight; this is the case, according to Audubon, with
one of the woodpeckers of the United States (Picu sau-
ratus), although "''the hens are followed by even half a
dozen of their gay suitors." X

The males of many birds are larger than the females,
and this no doubt is the result of the advantage gained by
the larger and stronger males over their rivals during many
generations. The difference in size between the two sexes
is carried to an extreme point in several Australian species;
thus the male musk-duck (Biziura) and the male Cinclor-
amphus cmralis (allied to our pipits) are by measure-
ment actually twice as large as their respective females. §
With many other birds the females are larger than the
males; and, as formerly remarked, the explanation often
given, namely, that the females have most of the work in
feeding their young, will not suffice. In some few cases,
as we shall hereafter see, the females apparently have
acquired their greater size and strength for the sake of con-
quering other females and obtaining possession of the
males.

The males of many gallinaceous birds, especially of the
polygamous kinds, are furnished with special weapons foi
fighting with their rivals, namely spurs, which can be used

* Macgillivray, *'Hist. Brit. Birds," vol. iv, 1852. pp. 177-181.

f Sir R. Sclioniburgk, in " Journal of R. Geograph. Soc," vol. xili,
1843. p. 31.

I "Ornithological Biography," vol. i, p. 191. For pelicans and
snipes, see vol. iii. pp 138, 477.

§ Gould, "Hand-book of Birds of Australia," vol. i, p. 395; voL ii,
p. 38a

412 THE DESCENT OF MAK.

with fearful effect. It has been recorded by a trustworthy
writer* that in Derbyshire a kite struck at a game-hen
accompanied by her chickens, when the cock rushed to the
rescue, and drove his spur right through the eye and skull
of the aggressor. The spur was with difficulty drawn from
the skull, and as the kite, though dead, retained his grasp,
the two birds were firmly locked together ; but the cock
when disentangled was very little injured. The invincible
courage of the game-cock is notorious ; a gentleman who
long ago witnessed the brutal scene, told me that a bird
had both its legs broken by some accident in the cock-pit,
and tha owner laid a wager that if the legs could be spliced
BO that the bird could stand upright, he would continue
fighting. This was effected on the spot, and the bird
fought with undaunted courage until he received his death-
stroke. In Ceylon a closely allied, wild species, the Gnllus
Staiileyi, is known to fight desperately " in defense of his
seraglio," so that one of the combatants is frequently found
dead.f An Indian partridge {Ortygornis gularis), the
male of which is furnished Avith strong and sharp spurs, is
so quarrelsome ' ' that the scars of former fights disfigure
the breast of almost every bird you kill. "J

The males of almost all gallinaceous birds, even those
which are not furnished with spurs, engage during the
breeding-season in fierce conflicts. The Capercailzie and
Black-cock {Tetrao urog alius and T. tetrix) which are
both polygamists, have regular appointed places, where
during many weeks they congregate in numbers to fight
together and to display their charms before the females.
Dr. W. Kovalevsky informs me that in Russia he has seen
the snow all bloody on the arenas where the capercailzie
have fought; and the black-cocks *^ make the feathers fly
in every direction," when several ^' engage in a battle
royal." The elder Brehm gives a curious account of the
Balz, as the love-dances and love-songs of the black-cock
are called in Germany. The bird utters almost contin-
uously the strangest noises: **he holds his tail up and
spreads \i out like a fan, he lifts up his head and neck with
all the feathers erect, and stretches his wings from the

*Mt. Hewitt in the "Poultry Book by Tegetmeier," 1866, p. 137.
f Layard, "Annals and Mag. of Nat. Hist.," vol. xiv, 1854, p. 63
J Jerdon, " Birds of India," vol. iii, p. 574

BIBDS, 418

body. Then he takes a few jumps in different direc-
tions, sometimes in a circle, and presses the under part
of his beak so hard against the ground that the
chin feathers are rubbed oft*. During these move-
ments he beats his wings and turns round and
round. The more ardent he grows the more lively he
becomes, until at last the bird appears like a frantic creat-
ure.^' At such times the black-cocks are so absorbed that
they become almost blind and deaf, but less so than the
capercailzie; hence bird after bird may be shot on the same
spot, or even caught by the hand. After performing these
antics the males begin to light; and the same black-cock,
in order to prove his strength over several antagonists, will
visit in the course of one morning several Balz-places, which
remain the same during successive years.*

The peacock with his long train appears more like a
dandy than a warrior, but he sometimes engages in fierce
contests; the Rev. \V. Darwin Fox informs me that at some
little distance from Chester two peacocks became so excited
while fighting that they flew over the whole city, still
engaged, until they al'ghted on the top of St. John's tower.

The spur, in those gallinaceous birds which are thus pro-
vided, is generally single; but Polyplectron (see fig. 51)
has two or more on each leg; and one of the blood-pheas-
ants {Ithaginis cruentus) has been seen with five spurs.
The spurs are generally confined to the male, being repre-
sented by mere knobs or rudiments in the female; but the
females of the Java peacock (Pavo muticus) and, as I am
informed by Mr. Blyth, of the small fire-backed pheasant
{Euplocawus erythroptJialmus) possess spurs. In Galloper-
dix it is usual for the males to have two spurs, and for the
females to have only one on each leg.f Hence spurs may
be considered as a masculine structure, which has been
occasionally more or less transferred to the females. Like
most other secondary sexual characters, the spurs are highly
variable, both in number and development, in -the same
species.

Various birds have spurs on their wings. But the Egyp-

*Brelira, " lllutt. TMerleben," 1867, B. iv, s. 351. Some of the
foregoing statements are taken from L. Lloyd, " The Game Birds of
Sweden," etc., 1867, p. 79.

f Jerdon, " Birds of India/' on Ithaginis, vol, iii; p. 523; on Gallo-
perdix, p. 541.

414 THE DESCEirr OF MAN,

tmiii goose {CJienalopex waj/ptincus) has only "bare obtuse
knobs/' and these probably show us the first steps by which
true spurs have been developed in other species. In the
spur-winged goose (Pleciropfenis gamhensis) the males
have mucli larger spurs than the females; and they use
them, as I am informed by Mr. Bartlett, in fighting to-
gether, so that, in this case, the wing-spurs serve as sexual
weapons ; but according to Livingstone, they are chiefly
used in the defense of the young. The Palamcdea (fig. 38)
is armed with a pair of spurs on each wing; and these are
sucIj formidable weapons that a single blow lias been known
to drive a dog howling away. But it does not appear that
the spurs in this case, or in that of some of the spur-
winged rails, are larger in the male than in the female.*
In certain plovers, however, the wing-spurs must be con-
sidered as a sexual character. Thus in the male of our
common peewit ( Vanellus cridcUus) the tubercle on tlie
shoulder of the wing becomes more prominent during the
breeding-season, and the males fight together. In some
species of Lobivanellus a similar tubercle becomes developed
during the breeding-season *' into a short, horny spur." In
the Australian L. lohatiis both sexes have spurs, but these
are much larger in the males than in the females. In an
allied bird, the .HopIopte7'^is armatus, the spurs do not in-
crease in size during the breeding-season; but these birds
have been seen in Egypt to fight together, in tiie same man-
ner as our peewits, by turning suddenly in the air and
striking sideways at each other, sometimes with fatal results.
Thus also they drive away other enemies. f

The season of love is that of battle; but the males of
some birds, as of the game-fowl and ruff, and even the
young males of the wild turkey and grouse J; are ready to

*For the Egyptian goose, see Macgillivray, "British Birds," vol
iv, p. 639. For Plectropterus, "Livingstone's Travels," p. 254.
For Palamedea, Brehm's " Tliierleben," B. iv, s. 740. See also on
tliis bird Azara, *' Voyages dans I'Amerique merid.," torn, iv, 1809,
pp. 179, 253.

f See. on our peewit, Mr. R. Carr in "Land and Water," Aug, 8,
1858, p, 46. In regard to Lol)ivanellus, see Jerdon's "Birds of
India," vol. iii. p. 647, and Gould's " Hand-book of Birds of Austra-
lia," vol. ii, p. 220, For ibe Holcpterus, see Mr. Allen in tlie
" Ibis,-' vol. V, 1863. p. 156.

:{: Audubon, "Ornitli. Biography," vol. ii, p. 492; vol. i, pp. 4-13.

BIRDS. 415

fight wheneTer they meet. The presence of the female ip

Fig. 38. PalameJea oornuta (from Bvelmii. bhowinf: the double wirg-apurs and
the filament on the head.

the ieterrima belli causa. The Bengali bahoos make the
pretty little males of the amadavat {Estrelda amandava)

416 TEE DESCENT OF MAN,

fight together by placing three small cages in a row with a
female in the middle: after a little time the two males are
tamed loose and immediately a desperate battle ensiieSc*
When many males congregate at the same appointed spot
and fight together, as in the ease of grouse and various
other birds, they are generally attended by the females, f
which afterward pair with the victorious combatants. But
in some cases the pairing precedes instead of succeeding
the combat; thus according to Audubon^ several males of
the Virginian goat -sucker {Caprimulgus virginiamis)
*' court in a highly entertaining manner the female, and
no sooner has she made her choice than her approved gives
chase to all intruders, and drives them beyond his
dominions/^ Generally the males try to drive away or kill
their rivals before they pair. It does not, however, appear
that the females invariably prefer the victorious males. 1
have indeed been assured by Dr. W. Kovalevsky that the
female capercailzie sometimes steals away with a young
male who has not dared to enter tlie arena with the older
cocks, in the same manner as occasionally happens with the
does of the red-deer in Scotland. When two males contend
in presence of a single female, the victor, no doubt^ com-
monly gains his desire; but some of these battles are caused
by wandering males trying to distract the peace of an
already mated pair.§

Even with the most pugnacious species it is probable that
the pairing does not depend exclusively on the mere
strength and courage of the male: for sucli males are
generally decorated with various ornaments, which often
become more brilliant during the breeding - season, and
which are sedulously displayed before the females. The

*Mr. Blyth, " Land and Water." 1867, p. 212-

f Hicliardson on Tetrao umhelhis " Faana Bor. Amer.: Birds,"-
1831. p. 348. L. Lloyd, " Game Birds of Sweden," 1867, pp. 22, 79,
on the capercailzie* and black-cock Brehm, liovvever, asserts
('• Tliierleben," etc.. B. iv, s, 352) tliat in Germany the gray-bens do
not generally attend tbe Balzen of tbe black-cocks, but this is
an exception to the common rule; possibly the hens may lie hidden
in the sarrounding bushes, as is known to be the case with the gray-
hens :n Scandinavia, and with other species in North America.

t • Ornilhologica! Biography," vol li. p, 275.

ji Brehm. " Thierleben " etc.. B iv, l^Ql, p. 090. Audubcs,
** Orulth. Biography," vol. ii, p. 492.

BIRDS, 417

males also endeavor to charm or excite their mates by love-
notes, songs and antics ; and the courtship is, in many
instances, a prolonged affair. Hence, it is not probable
that the females are indifferent to the charms of the oppo-
site sex, or that they are invariably compelled to yield to
the victorious males. It is more probable that the females
are excited, either before or after the conflict, by certain
males, and thus unconsciously prefer them. In the case of
Tetran uinbellus, a good observer* goes so far as to believe
that the battles of the males '^are all a sham, performed to
show themselves to the greatest advantage before the
admiring females ^rho assemble around; for I have never
been able to find a maimed hero, and seldom more than a
broken feather." I shall have to recur to this subject, but
I may here add that with the Tetrao ciipido of the United
States, about a score of males assemble at a particular spot,
and, strutting about, make the whole air resound with
their extraordinary noises. At the first answer from a
female the males begin to fight furiously, and .the weaker
give way; but then, according to Audubon, both the victors
and vanquished search for the female, so that the females
must either then exert a choice, or the battle must be
renewed. So, again, with one of the field-starlings of the
United States {SifLrneUa ludoviciana) the males engage in
fierce conflicts, " but at the sight of a female they all fly
after her as if mad.'*' f

Vocal and Tiistrnmental Music. — AVith birds the voice
serves to express various emotions, such as distress, fear,
anger, triumph, or mere happiness. It is apparently
sometimos used to excite terror, as in the case of the
hissing noise made by some nestlings-birds. Audubon |
relates that a night-heron {Ardea niicticorax, Linn.) which
he kept tame, used to hide itself when a cat approached,
and then " suddenly start up uttering one of the most
frightful cries, apparently enjoying the cat's alarm and
flight." The common domestic cock clucks to the hen,
and the hen to her chickens, when a dainty morsel is

* "Land and Water." July 25, 1868. p. 14.

f Audubon's " Ornitbolog. Biography;" on Tetrao ciipiclo, vol. ii,
p. 492; on the Sturnus, vol, ii, p. 219.
J " Ornithological Biograph.," vol. v, p. COX.

418 THE DESCENT OF MAN.

found. The hen, when she has laid an egg^ " repeats the
same note very often, and concludes with the sixth above,
which she holds for a longer time;"* and thus she expresses
her joy. Some social birds apparently call to each other
for aid; and as th(.'y flit from tree to tree the flock is kept
together by chirp answering chirp. During the nocturnal
migrations of geese and other water-fowl sonorous clangs
from the van may be heard in tlie darkness overhead,
answered by clangs in the rear. Certain cries serve as
danger signals, which, as the sportsman knows to his cost,
are understood by the same species and by others. The
domestic cock crows, and the humming-bird chirps in
triumph over a defeated rival. The true song, liowever, of
most birds and various strange cries are chiefly uttered
during the breeding-season, and serve as a charm, or merely
as a call-note to the other sex.

Naturalists are much divided with respect to the object
of the singing of birds. Few more careful observers ever
lived than. Montagu, and he maintained that tiie "males
of song-birds and of many others do not in general ' search
for the female, but on the contrary, their business in the
spring is to perch on some conspicuous spot, breathing out
their full and amorous notes, which, by instinct, the female
knows, and repairs to the spot to choose her mate.^f Mr.
Jenner Weir informs me that this is certainly the case with
the nightingale. Bechstein, who kept birds during his
whole life, asserts ''that the female canary always chooses
the best singer, and that in a state of nature the female
finch selects that male out of a hundred whose notes please
her most."X There can be no doubt that birds closely
attend to each other's song. Mr. Weir has told me of the
case of a bullfinch which had been taught to pipe a German
waltz, and who was so good a performer that he cost ten
guineas; when this bird was first introduced into a room
v/here other birds were kept and he began to sing, all the
others, consisting of about twenty linnets and canaries,

* The Hon. Daines Barrington, " Pliilosoph. Transact.," 1773, p. 252.

)• " Ornitliological Dictionary." 1833, p. 475.

:{: " Naturgeschicbte der Stubenvogel," 1840, s. 4. Mr. Harrison
Weir likewise writes to me: "1 am informed tliat the best singing
jnales generally get a mate first, wUen they are bred in the same

iTsjJUi."

BIRDS, 419

ranged themselves on the nearest side of their cages and list-
ened with the greatest interest to the new performer. Many
naturalists believe that the singing of birds is almost ex-
clusively *^the effect of rivalry and emulation/' and not
for the sake of charming their mates. This was the
opinion of Daines Barrington and White of Selborne, who
both especially attended to this subject.* Barrington,
however, admits that ''superiority in song gives to birds an
amazing ascendency over others, as is well known to bird-
catchers."

It is certain that there is an intense degree of rivalry
between the males in their singing. Bird fanciers match
their birds to see which will sing longest; and I was told
by Mr. Yarrell that a first-rate bird will sometimes sing
till he drops down almost dead, or according to Bechstein,f
quite dead from rupturing a vessel in the lungr/. What-
ever the cause may be, male birds, as I hear from Mr.
AVeir, often die suddenly during the season of song. That
the habit of singing is sometimes quite independent of love
is clear, for a sterile, hybrid canary-bird has been described^
as singing while viewing itself in a mirror and then dash-
ing at its own image ; it likewise attacked with fury
a female canary when put into the same cage. The
jealousy excited by the act of singing is constantly taken
advantage of by bird-catchers; a male, in good song, is
hidden and protected, while a stuffed bird surrounded by
limed twigs is expose to view. In this manner, as Mr.
Weir informs me, a man has in the course of a single day
caught fifty, and in one instance seventy male chaffinches.
The power and inclination to sing differ so greatly with birds
that although the price of an ordinary male chaffinch is only
sixpence, Mr. Weir saw one bird for which the bird-catcher
asked three pounds ; the test of a really good singer being
that it will continue to sing while the cage is swung round
the owners head.

That male birds should sing from emulation as well as
for charming the female is not at all incompatible; and it
might have been expected that these two habits would

*" Philosophical Transactions," 1773, p. 263. White's "Natural
History of Selborne," 1825, vol. i, p. 246.
f "Naturgesch. der Stubenvogel," 1840. s. 253.
t Mr. Bold, "Zoologist," 1843-44, p. 659.

420 THE DESGE2TT OF MAN,

have occurred, like those of display and pugnacity. Some
authors, however, argue that the song of the male cannot
serve to charm the female, because the females of some
few species, such as of the canary, robin, lark and bull-
finch, especially when in a state of widowhood, as Bech-
Btein remarks, pour forth fairly melodious strains. In
some of these cases the habit of singing may be in part
attributed to the females having been highly fed and cou-
fined,* for this disturbs all the usual functions connected
with the reproduction of the species. Many instances
have already been given of the partial transference of sec-
ondary masculine characters to the females, so that it is
not at all surprising that the females of some species should
possess the power of song. It has also been argued that
the song of the male cannot serve as a charm, because the
males of certain species, for instance of the robin, sing
during the autumn, f But nothing is more common than
for animals to take pleasure in practicing whatever instinct
they follow at other times for some real good. How often
do we see birds which fly easily gliding and sailing through
the air obviously for pleasure? The cat plays with the
captured mouse and the cormorant with the captured fish.
The weaver-bird (Ploceus), when confined in a cage,
amuses itself by neatly weaving blades of grass between the
wires of its cage. Birds which habitually fight during the
breeding-season are generally ready to fight at all times;
and the males of the capercailzie sometimes hold their
Balzen or leks at the usual place of assemblage during the
autumn. J Hence it is not at all surprising that male birds
should continue singing for their own amusement after the
season for courtship is over.

As shown in a previous chapter, singing is to a certain
extent an art, and is much improved by practice. Birds
can be taught various tunes, and even the unmelodious
sparrow has learned to sing like a linnet. They acquire
the song of their foster parents, § and sometimes that of

*D. Barrington. "Phil. Transact.," 1773, p. 262. Bechstein,
" Stubenvogel," 1840. s. 4.

f This is likewise the case with the water-ouzel; see Mr. Hepburn
in the " Zoologit^t," 1845-46. p. 1068.

X L. Lloyd, " Game Birds of Sweden," 1867, p. 25.

§ Barrington, ibid, p. 264, Bechstein, ibiJ, s. 5.

BinDS. 421

their neighbors.* Ail the common songsters belong to ihe
Order of Insessores, and their 7ocal organs are much more
complex than ihose of most other birds; yet it is a singular
fact that some of the Insessores, such as lavens, crows, and.
magpies, possess the proper apparatus,! though they never
sing, and do not naturally modulate their voices to any
great extent. Hunter asserts J; that with the true songsters
the muscles of the larynx are stronger in the males than in I
the females ; but with this slight exception there is no dif-
ference in Ghe vocal organs of the two sexes, although the
males of most species sing so much better and more con-
tinuously than the females.

It is remarkable that only small birds properly sing.
The Australian genus Menura, however, must be excepted;
for the Menura Albert i, which is about the size of a half-
grown turkey, not only mocks other birds, but *Mts own
whistle is exceedingly beautiful and varied." The males
congregate and iorm " corroboryijig places, ^Mvhere they
sing, raising and spreading their tails like peacocks, and
drooping their wings. § It is also remarkable that birds
which sing well are rarely decorated with brilliant colors
or other ornaments. Of our British birds, excepting the
bullfinch and goldfinch, the best songsters are plain-
colored. The kingfisher, bee-eater, roller, hoopoe, wood-
peckers, etc., utter harsh cries; and the brilliant birds of
the tropics are hardly ever songsters. || Hence bright
colors and the power of song seem to replace each other.
We can perceive that if the plumage did not vary in
brightness, or if bright colors were dangerous to the
species, other means would be employed to charm the
females; and melody of voice offers one such means.

In some birds the vocal organs differ greatly in the two

* Dureau de la Malle gives a curious instance (•' Annales des Sc.
Nat.," 3d series, Zoolog., torn, x, p. 118) of some wild blackbirds in
bis garden in Paris, wbicb naturally learned a republican air from a
caged bird.

] Bisbop, in "Todd's Cyclop, of Anat. and Pbys.," vol. iv, p. 1496.

:f As stated by Harrington in '* Philosopb. Transact.," 1773, p. 263.

^ Gould, "Hand-book to tbe Birds of Australia," vol. i, 1865, pp.
808-310. See also Mr. T. W. Wood m tbe " Student," April. 1870,
p. 125.

II See remarks to this effect in Gould's 'Introduciiou to tbe Tro»
cluUd®/' 1861. p. 22,

422

THE DESCENT OF MAN,

ecxes. In the Tefrao cupido (fig 39) the male has two
bare, orange-colored sacks, one on each side of the neck ;
and these are largely inflated when the male, during the
breeding-season, makes his curious hollow sound, audible
at a great distance. Audubon proved that the sound was

■'.*^ ^^

intimately conr.ected with this apparatus (which reminds
us of the air-saoKs on eacii side of the mouth of cer-
tain male frogs), for he found that the sound was
much diminished when one of tlie sacks of a tame
bird wa« pricked, and wlieu both wero pricked it

BIRDS, 423

was altogether stopped. The female has "a some-
what similar, though smaller naked space of skin
on the neck ; but this is not capable of inflation/'*
The male of another kind of grouse ( Tetrao nropliasiamis),
while courting the female, has his " bare yellow oesophagus
inflated to a prodigious size, fully half as large as the body;''
and he then utters various grating, deep, hollow tones.
With his neck-feathers erect, his wings lowered, and buzz-
ing on tlie ground, and his long pointed tail spread out
like a fan, he displays a variety of grotesque attitudes. Tiie
oesophagus of the female is not in any way remarkable, f

It seems now well made out that the great throat-pouch
of the European male bustard {Otis tarda), and of at least
four other species, does not, as was formerly supposed, serve
to hold water, but is connected with the utterance during
the breeding-season of a peculiar sound resembling " oak."|
A crow-like bird iniiabiting South America, CejjJialoptems
ornatus (fig. 40), is called the umbrella-bird from its im-
mense top-knot, formed of bai^e white quills surmounted by
dark-blue plumes, which it can elevate into a great dome
no less than five inches in diameter, covering the whole
head. This bird has on its neck a long, thin, cylindrical,
fleshy appendage, which is thickly clothed with scale-like
blue feathers. It probably serves in part as an ornament,
but likewise as a resounding apparatus; for Mr. Bates found
that it is connected '^ with an unusual development of the
trachea and vocal organs." It is dilated when the bird
utters its singularly deep, loud and Ibng-sustained fluty

* "The Sportsman and Naturalist in Canada," by Maj. W. Ross
King, 1866, pp. 144-146. Mr. T. W. Wood gives in the "Student"
;April, 1870, j). 116) an excellent account of the attitude and habits
of this bird during its courtship. He states that the efir-tufts or
neck-plumes are erected so that they meet over the crown of the
head. See his drawing, fig. 39.

f Richardson, "Fauna Bor. American: Birds," 1831, p. 359, Audu-
bon, ibid, vol. iv, p. 507.

X The following papers have been latelv written on this subject:
Prof. A. Newton in the " Ibis," 1862, p. 107; Dr. Cullen, ibid. 1865,
p. 145; Mr. Flower in "Proc. Zoo). Soc," 1865, p. 747; and Dr.
Murie in " Proc. Zool. Soc," 1868, p. 471. In this latter paper an
excellent figure is given of the male Australian bustard in full dis-
play with the sack distended. It is a singular fact that the sack is
Aot developed in all the males of the same species.

424

THE DESCENT OF MAN.

note. The head-crest and neck-appendage are rudimentary
in the female.*

The vocal organs of various web-footed and wading birds
are extraordinarily complex, and differ to a certain extent
in the two sexes. ■ In some cases the trachea is convoluted,

Fifj. 40. The Umbrella-bird or Cephalopterus ornatus, male (from Brehm).

like a French horn, and is deeply embedded in the sternum.
In the wild swan (Ci/gnus ferns) it is more deeply
embedded in the adult male than in the adult female or

* Bates, "The Naturalist on tlie Amas^ons," 1863, vol. ii, p. 284;
Wallace, in •' Proc, Zool. Soc," 1850, p. 206. A new species, with
a still iarger neck appendage (C. penduliger), lias lately been dU*
covered, see "Ibis," vol. i, p. 457.

BIRDS. 425

young male. In tho male Merganser the enlarged portion
of tlie trachea is furnished with an additional pair of mus-
cles.* In one of the ducks, however, namely, Anas
puncfafa, the bony enlargement is only a little more devel-
oped in the male than in the female. f But the meaning
of these differences in the trachea of the two sexes of the
Anatida? is not understood; for the male is not always tho
more vociferous; thus with the common duck, the*^ male
hisses, while the female utters a loud quack. J; In both
Gexes of one of the cranes {Grvs virgo) the trachea pene-
trates the sternum, but presents *' certain sexual modifica-
tions." In the male of the black stork there is also a well-
marked sexual difference in the length and curvature of the
bronchi. § Highly important structures have, therefore, in
these cases been modified according to sex.

It is often difficult to conjecture whether the many
strange cries and notes uttered by male birds during the
breeding-season serve as a charm or merely as a call to the
female. The soft cooing of the turtle-dove and of many
pigeons, it may be presumed, pleases the female. When the
female of the wild turkey utters her call in the morning, the
male answers by a note which differs from the gobbling
noise made, when with erected feathers, rustling wings and
distended wattles, he puffs and struts before her. || The
spel of the black-cock certainly serves as a call to the
female, for it has been known to bring four or five females
from a distance to a male under confinement; but as the
black-cock continues his spel for hours during successive
days, and in the case of the capercailzie 'Svith an agony
of passion," we are led to suppose that the females which
are present are thus charmed.^ The voice of the common

* Bishop, in Todd's " Cyclop, of Anat. and Pbys.," vol. iv, p. 1499.

fProf. Newton, " Proc. Zoolog. Soc," 1871. p. Col.

t The spoonbill (Platalea) has its trachea convoluted into a figure
of eight, and yet this bird (Jerdon, "Birds of India," vol, iii, p. 763)
is mute; but Mr. Blyth informs me that the convolutions are not
constantly present, so that perhaps they are now tending toward
abortion.

§ " Elements of Corap. Anat.," by R. Wagner. Eng. translat., 1845,
p. 111. With res])ect to the swan, as given above, Yarrell's "Hist,
of British Birds." 2d edit, 1845. vol. iii, p. 193.

lie. L, Bonaparte,- quoted in the "Naturalist Library; Birds," vol.
xiv, p, ]26.

T[L. Lioyd. " The Game Birds of Sweden." etc.. 1867, pp. %%, 83U

426 THE DESCENT OF MAN, .

rook is known to alter during the breeding-season, and is
therefore in some way sexual.* But what shall we say
about the harsh screams of, for instance, some kinds of
macaws; have these birds as bad taste for musical sounds
as they apparently have for color, judging by the inhar-
monious contrast of their bright yellow and blue plumage?
It is indeed possible that without any advantage being thus
gained, the loud voices of many male birds may be the
result of the inherited effects of the continued use of their
vooal organs when excited by the strong passions of love,
jealousy and rage; but to this point we shall recur when we
treat of quadrupeds.

We have as yet spoken only of the voice, but the males
of various birds practice, during their courtship, what may
be called instrumental music. Peacocks and birds of
paradise rattle their quills together. Turkey-cocks scrape
their wings against the ground, and some kinds of grouse
thus produce a buzzing sound. Another North American
grouse, the Telrao uinhellus^ when with his tail erect,
his ruffs displayed " he shows off his finery to the females
who lie hid in the neighborhood," .drums by rapidly striking
his wings together above his back, according to Mr. li.
Haymond, and not, as Audubon thought, by striking them
against his sides. The sound thus produced is compared
by some to distant thunder and by others to the quick roll
of a drum. The female never drums, **but flies directly
to the place where the male is thus engaged." The male
of the Kalij-pheasant in the Himalayas, *' often makes a sin-
gular drumming noise with his wings, not unlike the sound
produced by shaking a stiff piece of cloth." On the west
coast of Africa the little black-weavers (Ploceus?) congre-
gate in a small party on the bushes round a small open space
and sing and glide through the air with quivering wings,
" which make a rapid whirring sound like a child's rattle."
One bird after another thus performs for hours together
but only during the courting-season. At this season, and
at no other time, the males of certain night-jars (Caprimul-
gus) make a strange booming noise with their wings. The
various species of woodpeckers strike a sonorous branch
with their beaks with so rapid a vibratory movement that

*J©nner, "PliilosopU. Transactions," 1824, p. 20.

BIRDS. 427

'' the head appears to he \\\ two places at once/' The sound
thus produced is audible at a considerable distance, but
cannot be described; and I feel sure that its source would
never be conjectured by any one hearing it for the first
time. As this jarring sound is made chiefly during the
breeding-season, it has been considered as a love-so7ig; but
it is perhaps more strictly a love-call. The female, when
driven from her nest, has been observed thus to call her
mate, who answered in the same manner and scon appeared.
Lastly, the male hoopoe ( Upujja epops) combines vocal
and instrumental music; for during the breeding-season
this bird, as Mr. Swinhoe observed, first draws in air and
then taps the end of its beak perpendicularly down against
a stone or the trunk of a tree, '' when the breath being
forced down the tubular bill produces the correct sound."
If the beak is not thus struck against some object the
sound is quite different. Air is at the same time swallowed
and the oesophagus thus becomes much swollen; aifd^this
probably acts as a resonator, not only with the hoopoe but
with pigeons and other birds.*

In the foregoing cases sounds are made by the aid of
structures already present and otherwise necessary; but in
the following cases certain feathers have been specially
modified for the express purpose of producing sounds.
The drumming, bleating, neighing or thundering noise (as
expressed by different observers) made by the common
snipe {Sciilopax yalliiiago) must have surprised every one
who has ever heard it. This bird, during the pairing-
season, flies to '* perhaps a thousand feet in height," and
after zig-zagging about for a time descends to the earth in

* For the foie^oino; facts see, on birds of paradise, " Bretni,
' Thierlebtn," Band iii, s. 325. On grouse, Kicliardson, "Fauna
Bor. Americ. : Birds," pp. 848. 359; Maj. W. Boss King, "The
Sportsman in Canada," 1866, p. 156; Mr. Havmond, in Prof. Cox's
"Geol. Survey of Indiana," p. 237; Audubon. "American Ornitli-
olog. Biograpb.," vol. i, p. 216. On the Kalij pheasant, Jerdon,
"Birds of India," vol. iii. p. 533. On the weavers, "Livingstone's
Expedition to the Zambesi," 1865, p. 425. On Avoodpeckers, Mac-
eillivray. '• Hist, of British Birds." vol. iii, 1840. pp. 84, 88. 89,
95. Oi! the hoopoe, Mr. Swinhoe, in " Proc. Zoolog. Soc," June S3,
1863, 1871. p. 348. On the night-jar. Audubon, ibid, vol.
ii. p. 255, and "American Naturalist," 1873, p. 672. The English
night-jar likewise makes in the spring a curious noise during its
rapid tiigiit.

428 THE DESCENT OF MAN.

a curved line with outspread tail and quivering pinions
and surprising velocity. The sound is emitted only during
this rapid descent. No one was able to explain the cause
until M. Meves observed that on each side of the tail the
outer feathers are peculiarly formed (fig. 41), having a

rig. 41. enter tail-feather of Scolopaxgallinago (from " Proc. Zool. Soc," 1858.)

stiff saber-shaped shaft with the oblique barbs of unusual
length, the outer webs being strongly bound together. He
found that by blowing on these feathers, or by fastening
them to a long, thin stick and waving them rapidly through
the air, he could reproduce the drumming noise made by
the living bird. Both sexes are furnished with these feath-
ers, but they are generally larger in the male than in the
female and emit a deeper note. In some species, as in
S. frenata (fig. 42), four feathers, and in IS. javensis (fig.
43), no less than eight on each side of the tail are greatly

Fig. 42. Outer tall-feather of Scolopax frenata.

Fig. 43. Outer tail-feather of Scolopax javensis.

modified. Different tones are emitted by the feathers of
the different species when waved through the air; and the
Scolopax Wilsoini of the United States makes a switching
noise while descending rapidly to the earth.*

In the male of the Chamcepefps uni color (a large galli-
naceous bird of America), the first primary wing-feather is
arched toward the tip and is much more attenuated than in

*See M, Meves* interesting paper in " Prnc. Zool. Soc," 1858, p.
199. For the bal>its of the .snipe, Macgillivray, "Hist. British
Birds," vol. iv, p. 371. For the American snipe, Capt. Blakistoji,
*• ibis," vol. v, 1863, p. 131.

BIRDS. 429

the female. In an allied bird, the Penelope nigra, Mr.
Salvin observed a male, which, while it flew downward
'^with outstretched wings, gave forth a kind of crashing,
rushing noise," like the falling of a tree.* The male
alone of one of the Indian bustards {SypUeotides attriliis)
has its primary wing-feathers greatly acuminated; and the
male of an allied species is known to make a humming
noise while courting the female, f In a widely different
group of birds, namely, humming-birds, the males alone of
certain kinds have either the shafts
of their primary wing feathers
broadly dilated, or the webs ab-
ruptly excised toward the extrem-
ity. ■'The male, for instance, of ^^^^^^^^^
Selasphorus platijcercus, when

adult, has the first primary wing- ^ig. 44 Primary winpr-feather
»., /„ A A\ 11 •^•1 oia humminj; bird, the Sekis-

feather (ng. 44) thus excised. phorvs platycerc-'s (from a

While flyiug from flower to flower f^^_ ^f^-^tmS,: lS?ef

he makes *^a shrill, almost whist- figure, corresponding feather

ling noise ;^^t but it did not appear ^^ ^^™^^^-

to Mr. Salvin that the noise was intentionally made.

Lastly, in several species of a sub-genus of Pipra or
Manakin, the males, as described by Mr. Sclater, have their
5e6"o/i(^rtr^ wing-feathers modified in a still more remarkable
manner. In the brilliantly-colored F. deliciosa the first
three secondaries are thick-stemmed and curved toward the
body; in the fourth and fifth (fig. 45, a) the change is
greater; and in the sixth and seventh {by c) the shaft '^is
thickened to an extraordinary degree, forming a solid horny
lump." The barbs also are greatly changed in shape, in
comparison with the corresponding feathers (d, e, f) in the
female. Even the bones of the wing, which support these
singular feathers in the male, are said by Mr. Fraser to be
much thickened. These little birds make an extraordinary
noise, the first " sharp note being not unlike the crack of a
whip."§

*Mr. Salvin, in " Proc. Zool. Soc," 1867, p. 160. I am much
indebted to this distingui^ilied ornitliologist for sketclies of the
feathers of the Chaniaepetes and for other information.

t J^rdon, " Birds of India," vol. iii, pp. 618, 621.

JGould, "Introduction to the Trochilidae," 1861, p. 49. SalriD,
"Proc. Zoolog. Soc ," 1867, p. 160.

^5 Sclater. in "Proc. Zool. Soc," 1860, p. 90, and in "Ibis," voL
iv. 1863, p. 175. Also Salvin, iu " Ibis," 1860, p. 37.

430

THE DESCENT OF MAN.

The diversity of the sounds, both vocal and instrumental,
made by the males of many birds during the breeding-

Fig. 45. Secondary winff-feathers of Hpra delidosa (from Mr. Sclater. in "Proo.
Zool. Soc..'" I80O. The three upper feathers, a, b, c, from the male; the thi-ee
lower corresponding feathers, d, e,f, from the female.
a and d. fifth secondary wing-feather of male and female, upper sui'face.
b and e, sixth secondary, upper surface.
c and/, seventh secondary, upper surface.

season, and the diversity of the means for producing such
sounds, are highly remarkable. We thus gain a high idea
of their importance for sexual purposes, and are reminded
of the conclusion arrived at as to insects. It is not difficult
to imagine the steps by which the notes of a bird, primarily
used as a mere call or for some other purpose, might have

BIBDS. 431

been improved into a melodious love-song. In the case of
the modified feathers, by which the drumming, whistling,
or roaring noises are produced, we know that some
birds during their courtship flutter, shake, or rattle
their unmodified feathers together; and if the females were
led to select the best performers, the males which possessed
the strongest or thickest, or most attenuated feathers,
situated on any part of the body, would be the most suc-
cessful; and thus by slow degrees the feathers might be
modified to almost any extent. The females, of course,
would not notice each slight successive alteration in shape,
but only the sounds thus produced. It is a curious fact
that in the same class of animals, sounds so different as the
drumming of the snipe's tail, the tapping of the wood-
pecker's beak, the harsh trumpet-liUe cry of certain water-
fowl, the cooing of the turtle-dove, and the song of the
nightingale, should all be pleasing to the females of the
several species. Bat we must not judge of the tastes of
distinct species by a uniform standard; nor must we judge
by the standard of man's taste. Even with man, we should
remember what discordant noises, the beating of tomtoms
and the shrill notes of reeds, please the ears of savages.
Sir S. BaUer remarks,* that *' as the stomach of the Arab
prefers the raw meat and reeking liver taken hot from the
animal, so does his ear prefer his equally coarse and dis-
cordant music to all other."

Love Antics and Dances. — The curious love gestures of
some birds have already been incidentally noticed; so
that little need here be added. In Northern Amer-
ica large numbers of a grouse, the Tefrao phnsianellus,
meet every morning during the breeding-season en
a selected level spot, and here they run round and
round in a circle of about fifteen or twenty feet in diam-
eter, so that the ground is worn quite bare, like a fairy-
ring. In these partridge-dances, as they are called by the
hunters, the birds assume the strangest attitudes, and run
round, some to the left and some to the right. Audu-
bon describes the males of. a heron {Anlea hero-
dias) as wallrng about on their long legs with
great dignity before the females, bidding defiance to

* " The i^Ue Tributaries of Abj-ssiiiia," 1867, p. 203

432 THE DESCENT OF MAN,

their rivals. With one of the disgusting carrion-
vultures (Cathartes jot a) the same naturalist states that
** the gesticulations and parade of the males at the begin-
ning of the love season are extremely ludicrous." Certain
birds perform their love antics on the wing, as we have
seen with the black African weaver, iustead of on tho
ground. During the spring our little white throat (Sylvia
cincrca) often rises a few feet or yards in the air above
Bome bush and *' flutters with a fitful and fantastic motion,
singing all the while, and then drops to its perch."' The
great English bustard throws himself into indescribably
odd attitudes while courting the female, as has been figured
by Wolf. An allied Indian bustard (Otis benynleims) at
such times "rises perpendicularly into the air with a
hurried flapping of his wings, raising his crest and puffing
out the feathers of his neck and breast and then drops to
the ground;" he repeats this maneuver several times, at
the same time humming in a peculiar tone. Such females
as happen to be near " obey this saltatory summons," and
when they approach he trails his wings and spreads his tail
like a turkey-cock.*

But the most curious case is afforded by three allied
genera of Australian birds, the famous bower- birds — no
doubt the co-descendants of some ancient species which
first acquired the strange instinct of constructing bowers
for performing their love antics. The bowers (fig. 4G)
which, as we shall hereafter see, are decorated with feath-
ers, shells, bones and leaves, are built on the ground for
the sole purpose of courtship, for their nests are formed in
trees. Both sexes assist in the erection of the bowers, but
the male is the principal workman. So strong is this
instinct that it is practiced under confinement, and Mr.
Strange has described! the habits of some satin bower-birds
which he kept in an aviary in New South Wales. "At

*For Tcti'no pJinsianellifs. see Richardson, '* Fauna. Bor. Amer-
ica," ]). 361, and for further particulars. Capt. Bl':dvi.ston, " Ibis,''
1863, ]). 125. For the Cathartes and Ardea, Audubon, " Ornith.
Bio«;raphy," vol. ii, p. 51, and vol. iii. p. 89. On the white throat,
Macuillivray. "Hist. Britisli Birds," vol. ii, p. 354. Ou the ludiuu
bustard, Jerdon, " Birds of India," vol. iii, p. 618.

■f Gould, "Hand-book to the Birds of Australia," vol. i, pp. 444,
449, 455. The bower of the satin bower-bird may be seen in the
Zoological Society's Gardens, Regent Park.

BIRDS, 433

times tlie male will chase the female all over the ayiary.

then go to the bower, pick up a gay feather or a large leaf,
utter a curious kind of note, set all his feathers erect, run
round the bower and become bo excited that his eyes appear

434 TEW DESCENT OF MAN.

ready to start from his head; he continties opening first one
wing, then the other, uttering a low, whistling note, and,
like tlie domestic cock, seems to be picking up something
from tlie ground, until at last the female goes gently
toward him/' Capt. Stokes has described the habits and
"play-houses" of another species, the great bower-bird,
wi'ich was seen "amusing itself by flying backward and
forward, taking a shell alternately from each side and
carrying it through the archway in its mouth." These
curious structures, formed solely as halls of assemblage,
where both sexes amuse themselves and pay tlieir court,
must cost the birds much labor. The bower, for instance,
of the fawn-breasted species is nearly four feet in length,
eighteen inches in height, and is raised on a thick platform
of sticks.

Decoration. — I will first discuss the cases in which the
males are ornamented either exclusively or in a much
higher degree, than the females, and in a succeeding
chapter those in wiiich both sexes are equally ornamented,
and finally the rare cases in which the female is somewhat
more brightly colored than the male. As with the artificial
ornaments used by savage and civilized men so with the nat-
ural ornaments of birds, the head is the chief seat of
decoration.* The ornaments, as mentioned at tlie com-
mencement of tills chapter, are wonderfully diversified. The
plumes on the front or back of the head consist of variously-
shaped feathers, sometimes capable of erection or expan-
sion, by wliich their beautiful colors are fnlly displayed.
Elegant ear -tufts (see fig. 3'J, ante) are occasionally
presi'Ut. Tlie liead is sometimes covered with velvety
down, as with the pheasant ; or is naked and vividly
colored. The throat, also, is sometimes ;rnamented with
a beard, wattles or caruncles. Such appendages are gen-
erally brightly colored and no doubt serve as ornaments,
though not always ornamental in our eyes; for while the
male^ is in the act of courting the female they often swell
and assume vivid tints, as in the male turkey. At such
times the fleshy appendages about the head of the male
Tragopan pheasant (Cerioi'nis Temnnnckii) swell into a large

*See remarks to this effect, on the "Feeling of Beauty ^mong
Animals," by Mr. J. Shaw, in the " Atlieuaeum," Nov. 24, 1866, p.
681.

BIRDS, 435

lappet on the throat and into two horns, one on each Bide
of the splendid top-knot; and these are then colored of the
most intense blue which I have ever beheld.* The African
hornbill {Bucorax abi/ssiniciis) inflates the scarlet bladder-
like wattle on its neck, and with its wings drooping and
tail expanded ^^ makes quite a grand appearance/'f Even
the iris of the eye is sometimes more brightly colored in
the male than in the female; and this is frequently the
case with the beak, for instance, in our common blackbird.
In Buceros corrugahis the whole beak and immense casque
are colored more conspicuously in the male than in the
female; and ** the oblique grooves upon the sides of the
lower mandible are peculiar to the male sex. "J

The head, again, often supports fleshy appendages, fila-
meuts, and solid protuberances. These, if not common to
both sexes, are always confined to the males. The solid
protuberances have been described in detail by Dr. W.
Marshall, § who shows that they are formed either of can-
cellated bone coated with skin, or of dermal and other
tissues. With m.ammals true horns are always supported
on the frontal bones, but with birds various bones liave
been modified for this purpose; and in species of the same
group the protuberances may have cores of bone, or be
quite destitute of them, with intermediate gradations con-
necting these two extremes. Hence, as Dr. Marshall
justly remarks, variations of the most different kinds have
served for the development through sexual selection of
these ornamental appendages. Elongated feathers or
plumes spring from almost every part of the body. The
feathers on the throat and breast are sometimes developed
into beautiful rufi's and collars. The tail-feathers are fre-
quently increased in length; as we see in the tail-coverts of
the peacock, and in the tail itself of the Argus pheasant.
AVith the peacock even the bones of the tail have been
modified to support the heavy tail-coverts. || The body of

*See Dr. Murie's account with colored figures in " Proc. Zoolog.
Soc," 1872, p. 730.

fMr. Monteiro, "Ibis," vol. iv., 1862, p. 339.

X •' Land and Water," 1868, p. "217.

§"Ueber die Scbiidelbocker," etc., " Niederlandisclien Arcliiv.
furZoologie," B. I., Heft. 2, 1872.

I Dr. W. Marshall, " Ueber den Vogelscliwanz," ibid, B. I., Heft.
2. 1872.

436 TEE DESCENT OF MAN,

the Argus is not larger than that of a fowl; yet the length
from the end of the beak to the extremity of the tail is no
less than five feet three inches,* and that of the beauti-
fnlly ocellated secondary wing- feathers nearly three feet.
In a small African night-jar (Cosmetornis vexillarius) one
of tlie primary wing-feathers, during the breeding-season,
attains a length of twenty-six inches, while the bird itself
is only ten inches in length. lu another closely allied
genus of night-jars, tlie shafts of the elongated wing-
feathers are naked, except at the extremity, where there is
a disk, f Again, in another genus of night-jars, the tail-
feathers are even still more prodigiously developed. In
general the featliers of the tail are more often elongated
than those of the wings, as any great elongation of the
latter impedes flight. We thus see that in closely-allied
birds ornaments of the same kind have been gained
by the males through the development of widely different
feathers.

It is a curious fact that the feathers of species belonging
to very distinct groups have been modified in almost
exactly the same peculiar manner. Thus the wing-feathers
in one of the above-mentioned night-jars are bare along the
shaft, and terminate in a disk; or are, as they are sometimes
called, spoon or racket shaped. Feathers of this kind occur
in the tail of a motmot (Eicmomota super ciliaris), of a king-
fisher, finch, humming-bird, parrot, several Indian drongos
(Dicrurus and Edolius, in one of which the disk stands
vertically), and in the tail of certain birds of paradise.
In these latter birds, similar feathers, beautifully ocellated,
ornament the head, as is likewise the case with some galli-
naceous birds. In an Indian bustard {Sypheotides aiiritiis)
the feathers forming the ear-tufts, which are about four
inches in length, also terminate in disks.]; It is a most
singular fact that the motmots, as Mr. Salvin has clearly
shown, § give to their tail-feathers the racket-shape by
biting oft' the barbs, and, further, that this continued
mutilation has produced a certain amount of inherited
effect.

*Jardine's 'Naturalist Library; Birds," vol. xiv, p. 166.

fSclater, in tlie " Ibis," vol. vi, 1864, p. 114. Livingstone, "Expe-
dition to tbe Zambesi," 1865, p 66.

J Jerdon, " Birds of India," vol. iii, p. 620,

§ " Proc. Zoolog. Sec." 1873. p. 429.

BIRDS. 437

Again, the barbs of the feathers in various widely-distinct
birds ai'e filamentous or plumose, as with some herons.

Fig. 47. Paradisea Papuaua <X. W. Wood).

ibises, birds of paradise, and Galliiiaceae. In other cases the
barbs disappear, leaving the shafts bare from end to' end;

438 THE DESCENT OF MAN,

and these in the tail of the Paradisea apoda attain a
length of thirty-four inches;* in P. Papuana (fig. 47)
they are much shorter and thin. Smaller feathers when
thus denuded appear like bristles, as on the breast of the
turkey-cock. As any fleeting fashion in dress comes to be
admired by man, so with birds a change of almost any
kind in the structure or coloring of the feathers in the
male appears to have been admired by the female. The
fact of the feathers in widely dit^tinct groups having
been modified in an anologous manner no doubt
depends primarily on all the feathers having nearly
the same structure and manner of development, and
consequently tending to vary in the same manner. We
often see a tendency to analogous variability in the
plumage of our domestic breeds belonging to dis-
tinct species. Thus top-knots have appeared in several
species. In an extinct variety of the turkey the top-knot
consisted of bare quills surmounted with plumes of down,
so that they somewhat resembled the racket-shaped feathers
above described. In certain breeds of the pigeon and fowl the
feathers are plumose, with some tendency in the shafts to
be naked. In the Sebastopol goose the scapular feathers
are greatly elongated, curled, or even spirally twisted, with
the margins plumose, f

In regard to color, hardly anything need here be said,
for every one knows how splendid are the tints of many
birds and how harmoniously they are combined. The
colors are often metallic and iridescent. Circular spots
are sometimes surrounded by one or more differently
shaded zones and are thus converted into ocelli. Nor need
much be said on the wonderful difference between the
sexes of many birds. The common peacock oilers a strik-
ing instance. Female birds of paradise are obscurely col-
ored and destitute of all ornaments, while the males are
probably the most highly decorated of all birds, and in so
many different ways that they must be seen to be appro
elated. The elongated and golden-orange plumes which
spring from beneath the wings of the Paradisea apoda
when vertically erected and made to vibrate are described

* Wallace, in "Annals and Mag of Nat. Hist.," vol. xx, 1857, p.
416, and in his " Malay Archipelago," vol. ii, 1869, p. 390.

f See my work on " The*Variation of Animals and Plants uuder
Domestication," vol. i, pp. 289, 293.

BIJID8.

439

as forming a sort of halo, in the center of which the head
** loolis like a little emerald sun with its rays formed by

Fig. 48. Lophornls ornatus, male and female (from Brehm).

the two plumes."* In another most beautiful species the
head is bald '*and of a rich cobalt blue, crossed by several
lines of black velvety feathers. "f

*Q;iot8l from M. de Lafre^naye in "Annals and Mag. of Nat.
Hist.," vol. xiii, 1854. p. 157: see also Mr, Wallace's niucb fuller
account in vol. xx, 1857, p. 412. and in his "Malay Arcliipelago "

f Wallace, " Tlie Malay Ai-cliipelago," vol. ii, 1869, p. 405.

440

THE DESCENT OF MAN.

Male humming-birds (figs. 48 and 49) almost vie with
birds of paradise in their beauty, as every one will admit

Fig. 49. Spathura underwoodi, male and female (from Brehm).

who has seen Mr. Gould's splendid volumes or his rich col-
lection. It is very remarkable in how many different ways

BIBDS, 441

these birds are ornamented. Almost every part of their
plumage has been taken advantage of and modified; and
the modifications have been carried, as Mr. Gould showed
me, to a wonderful extreme in some species belonging tG
nearly every sub-group. Such cases are curiously like
those which we see in our fancy breeds, reared by man for
the sake of ornament; certain individuals originally varied
in one character, and other individuals of the same species
in other characters; and these have been seized on by man
and much augmented, as shown by the tail of the fantail-
pigeon, the hood of the jacobin, the beak and wattle of
the carrier, and so forth. The sole difCerence between these
cases is that in the one the result is due to man's selection,
while in the other, as with humming-birds, birds of para-
dise, etc., it is due to the selection by the females of the
more beautiful males.

I will mention only one other bird, remarkable from the
extreme contrast in color between the sexet^, namely, the
famous bell-bird {Chasmorhynclius iiiveus) of South
America, the note of which can be distinguished at the
distance of nearly three miles, and astonishes every one
when first hearing it. The male is pure white, wliile the
female is dusky-green; and white is a very rare color in ter-
restrial species of moderate size and inoffensive habits.
The male, also, as described by Waterton, has a spiral tube
nearly three inches in length, which rises from the base of
the beak. It is jet-black, dotted over with minute downy
feathers. This tube can be inflated with air, through a
communication with the palate ; and when not inflated
hangs down on one side. The genus consists of four species,
the males of which are very distinct, while the females, aa
described by Mr. Sclater in a very interesting paper, closely
resemble each other, thus offering an excellent instance of
the common rule that within the same group the males
dift'er much more from each other than do the females. In
a second species ( C. nudicolUs) the male is likewise snow-
white, with the exception of a large space of naked skin
on the throat and round the eyes, which during the breed-
ing-season is of a fine green color. In the third speciijs
(C. tricarimcidatus) the head and neck alone of the maio
are white, the rest of the body being chestnut-brown, and
the m.ale of this species is provided with three filamentoua
]^roJ6ctions half as long as the body^ ozxe rising from the

442 THE DESCENT OF MAN.

base of the beak and the two others from the comers of the
mouth.*

The colored plumage and certain other ornaments of the
adult males are either retained for life or are periodically
renewed during the summer and breeding-season. At this
same season the beak and naked skin about the head fre-
quently change color, as with some herons, ibises, gulls,
one of the bell-birds just noticed, etc. In the white ibis,
the cheeks, the inflatable skin of the throat, and the basal
portion of the beak then become crimson, f In one of the
rails, Gallicrex cristatus, a large red caruncle is developed
during this period on the head of the male. So it is with
a thin horny crest on the beak of one of the pelicans, P.
erythrorhynchiis; for, after the breeding-season, these horny
crests are shed, like horns from the heads of stags, and tlie
shore of an island in a lake in Nevada was found covered
with these curious exuviae.;];

Changes of color in the plumage according to the season
depend, firstly on a double annual moult, secondly on an
actual change of color in the feathers themselves, and
thirdly on their dull-colored margins being periodically
shed, or on these three processes more or less combined.
The shedding of the deciduary margins may be compared
with the shedding of their down by very young birds; for
the down in most cases arises from the summits of the first
true feathers. §

With respect to the birds which annually undergo a
double moult, there are, firstly, some kinds, for instance
snipes, swallow-plovers (Glareolae), and curlews, in which
the two sexes resemble each other and do not change color
at any season. I do not know whether the winter plumage
is thicker and warmer than the summer plumage, but
warmth seems the most probable end attained of a double
moult, whero there is no change of color. Secondly, there
-ii'e birds, for instance, certain species of Tetanus and other

•^lii*. Sci^?yi ," Intellectual Observer," Jan., 1867. " Waterton's
*Vaply*^ra/r! " }\ 118. See also Mr. Salvin's interesting paper, with
a plate, in ih^>. " Ibis," 1865, p. 90.

t '' LwQ'a &J/.JI Water," 1867, p. 394.

t Mi-. Id. 'cit. 7:iliot, in " Proc. Zool. Soc," 1869, p. 589.

8 NltJ/x-J. 0 • Pterylograpby," edited by P. L. Sclater. Ray Soc,

BIRDS. 443

Grallatores, the sexes of which resemble each other, but in
which the summer and winter j)lumage differ slightly in
color. The difference, however, in these cases is so small
that it can hardly be an advantage to them; and it may,
perhaps, be attributed to the direct action of the different
conditions to which the birds are exposed during the two
seasons. Thirdly, there are many other birds the sexes of
which are alike, but which are widely different in their
summer and winter plumage. Fourthly, there are birds
the sexes of which differ from each other in color; but the
females, though moulting twice, retain the same colors
throughout the year, while the males undergo a change of
color, sometimes a great one, as with certain bustards.
Fifthly and lastly, there are birds the sexes of which differ
from each other in both their summer and winter plumage;
but the male undergoes a greater amount of change at each
recurrent season than the female — of which the ruff (Ma-
chetes pugiiax) offers a good instance.

With respect to the cause or purpose of the differences
in color between the summer and winter plumage, this may
in some instances, as with the ptarmigan,* serve during
both seasons as a protection. When the difference between
the two plumages is slight it may perhaps be attributed, as
already remarked, to the direct action of the conditions of
life. But with many birds there can hardly be a doubt
that the summer plumage is ornamental, even when both
sexes are alike. We may conclude that this is the case with
many herons, egrets, etc., for they acquire their beautiful
plumes only during the breeding-season. Moreover, such
plumes, top-knots, etc., though possessed by both sexes,
are occasionally a little more developed in the male than in
the female; and they resemble the plumes and ornaments
possessed by the males alone of other birds. It is also known
that confinement, by affecting the reproductive system of
male birds, frequently checks the development of their
secondary sexual characters, but has no immediate influence
on any other characters; and I am informed by Mr. Bart-

* The brown mottled summer plumage of the ptarmigan is of as
much importance to it. as a protection, as the white winter plumage;
for in Scandinavia during the spring, when the snow has disap-
peared, this bird is known to suffer greatly from birds of prej, before
it has acquired its summer dress; see Wilhelm von Wright, in
Uoyd, *' Game Birds of Sweden/' 1867. p. 125.

444 THE DESCENT OF MAN.

lett that eight or nine specimens of the Knot {Tr'inga
canutus) retained their unadorned winter plumage in the
Zoological Gardens throughout the year, from which fact
we may infer that the summer plumage, though common
to both sexes, partakes of the nature of the exclusively
masculine plumage of many other birds.*

From the foregoing facts, more especially from neither
sex of certain birds changing color during either annual
moult, or changing so slightly that the change can hardly
be of any service to them, and from the females of other
species moulting twice yet retaining the same color through-
out the year, we may conclude that the habit of annually
moulting twice has not been acquired in order that the
male should assume an ornamental character during the
breeding-season; but that the double moult, having been
originally acquired for some distinct purpose, has subse-
quently been taken advantage of in certain cases for gaining
a nuptial plumage.

It appears at first sight a surprising circumstance that
some closely-allied species should regularly undergo a
double annual moult, and others only a single one. The
ptarmigan, for instance, moults twice or even thrice in the
year, and the black-cock only once; some of the splen-
didly colored honey-suckers (Nectarinias) of India and
some sub-genera of obscurely colored pipits (Anthus) have
a double, while others have only a single annual moult, f
But the gradations in the manner of moulting, which
are known to occur with various birds, show us
how species or whole groups might have originally
acquired their double annual moult, or having oncej
gained the habit, have again lost it. With certain bus-]
tards and plovers the vernal moult is far from complete,]
some feathers being renewed, and some changed ii
color. There is also reason to believe that with certaii

*In regard totlie previous statements on moulting, see, on snipes,'
etc., Macgillivray, "Hist. Brit. Birds," vol. iv, p. 371; on Glareolae,]
curlews and bustards, Jerdon, "Birds of India," vol. iii, pp. 615,
630, 683; on Totanus, ibid, p. 700; on tlie plumes of herons, ibid, p.
738, and Macgillivray, vol. iv, pp. 435, 444, and Mr. Stafford Allen,
in the "Ibis," vol. v, 1863, p. 33.

f On the moulting of the ptarmigan, see Gould's " Birds of Great.
Britain." On the honey-suckers, Jerdon, "Birds of India," vol. i,|
pp. 359, 365, 369, On the moulting of Anthus, see Blyth, in '* Ibis,'*
1867, p. 33.

BIRDS, 445

bustards and rail-like birds, which properly undergo a
double moult, some of the older males retain their nuptial
plumage throughout the year. A few highly modified
leathers may merely be added during the spring to the
plumage, as occurs with the disk-formed tail-feathers of
certain drongos (Bhringa) in India, and with the elon-

fated feathers on the back, neck, and crest of certain
erons. By such steps as these, the vernal moult might
be rendered more and more complete, until a perfect
double moult was acquired. Some of the birds of paradise
retain their nuptial feathers throughout the year, and thus
have only a single moult ; others cast them directly after
the breeding-season, and thus have a double moult; and
others again cast them at this season during the first year,
but not afterward; so that these latter species are interme-
diate in their manner of moulting. There is also a great
difference with many birds in the length of time during
which the two annual plumages are retained; so that the
one might come to be retained for the whole year, and
the other completely lost. Thus in the spring Machetes
mignax retains his ruff for barely two months. In
Natal the male widow-bird (Chera progne) acquires his
fine plumage and long tail-feathers in December or Janu-
ary, and loses them in March ; so that they are retained
only for about three months. Most species which undergo
a double moult keep their ornamental feathers for about
six months. The male, however, of the wild Gallus han-
kiva retains his neck-hackles for nine or ten months; and
when these are cast off the underlying black feathers on
the neck are fully exposed to view. But with the domesti-
cated descendant of this species the neck-hackles of the
male are immediately replaced by new ones ; so that we
here see, as to part of the plumage, a double moult changed
under domestication into a single moult.* ^

* For tlie foregoing statements in regard to partial moults, and on
old males retaining tbeir nuptial plumage, see Jerdon, on bustards
and plovers, in "Birds of India," vol. iii, pp. 617, 637, 709, 711.
Also Blyth in " Land and Water," 1867, p. 84. On the moulting of
Paradisea, see an interesting article bv Dr. W. Marshall, "Archives
Neerlandaises," torn, vi, 1871. On the Vidua, "Ibis," vol. iii, 1861,
p. 133. On the Drongo shrikes, Jerdon, ibid, vol. i, p. 435. On the
vernal moult of the Herodias bubulcus, Mr. S. S. Allen, in " Ibis,"
1863, p. 33. On Gallus bankiva, Blyth, in " Annals and Mag. of
Nat. Hist.," vol. i, 1848, p. 455; see also on this subject, my " Vari-
ation of Animals under Domestication," vol. i, p. 236.

446 THE DESCENT OF MAN,

The common drake {Anas boschas) after the breeding*
season, is well known to lose his male plumage for a
period of three months, during which time he assumes
that of the female. The male pin-tail duck (Anas aciita)
loses his plumage for the shorter period of six weeks or
two months ; and Montagu remarks that '^ this double
moult within so short a time is a most extraordinary cir-
cumstance that seems to bid defiance to all human reason-
ing/^ But the believer in the gradual modification of
species will be far from feeling surprise at finding grada-
tions of all kinds. If the male pin-tail were to acquire hid
new plumage within a still shorter period the new male
feathers would almost necessarily be mingled with the old^
and both with some proper to the female; and this appar*
ently is the case with the male of a not distantly allied
bird, namely, the Merganser serrator, for the males are
said to " undergo a change of plumage which assimilates
them in some measure to the female." By a little further
acceleration in the process the double moult would be com-
pletely lost.*

Some male birds, as before stated, become more brightly
colored in the spring, not by a vernal moult, but either by
an actual change of color in the feathers or by their
obscurely colored deciduary margins being shed. Changes
of color thus caused may last for a longer or shorter time.
In the Pelecanus onocrotalus a beautiful rosy tint with
lemon-colored marks on the breast overspreads the whole
plumage in the spring; but these tints, as Mr. Sclater
states, " do not last long, disappearing generally in about
six weeks or two months after they have been attained.".
Certain finches shed the margins of their feathers in the!
spring and then become brighter colored, while other]
finches undergo no such change. Thus the Fringillal
tristis of the United States (as well as many other Ameri-j
can species) exhibits its bright colors only when the winter]
is past, while our goldfinch, which exactly represents this'
bird in habits, and our siskin which represents it still more
closely in structure, undergo no such annual change. Bui
a difference of this kind in the plumage of allied species

*See Macgillivray, "Hist. Britisli Birds," (vol. v, pp. 34, 70, 223)
on tlie moulting of the Anatidae, with quotations from Waterton and
Montagu. Also Yarrell, " Hist, of British Birds," vol. iii, p. 243.

BIRDS. 447

is not surprising, for with the common linnet, which
belongs to the same family, the crimson forehead and
breast are displayed only during the summer in England,
while in Madeira these colors are retained throughout the
year. *

Display by Male Birds of Their Plumage. — Ornaments
of all kinds, whether permanently or temporarily gained,
are sedulously displayed by the males, and apparently serve
to excite, attract or fascinate the females. But the males
will sometimes display their ornaments when not in the
presence of the females, as occasionally occurs with grouse
at their balz-places, and as may be noticed with the
peacock; this latter bird, however, evidently wishes for a
spectator of some kind, and, as I have often seen, will show
oft' his finery before poultry, or even pigs, f All naturalists
who have closely attended to the habits of birds, whether
in a state of nature or under confinement, are unani-
mously of opinion that the males take delight in displaying
their beauty. Audubon frequently speaks of the male as
endeavoring in various ways to charm the female. Mr.
Gould, after describing some peculiarities in a male
humming-bird, says he has no doubt that it has the power
of displaying them to the greatest advantage before the
female. Dr. Jerdon]; insists that the beautiful plumage of
the male serves " to fascinate and attract the female.^'
Mr. Bartlett, at the Zoological Gardens, expressed himself
to me in the strongest terms to the same eftect.

It must be a grand siglit in the forests of India " to come
suddenly on twenty or thirty pea-fowl, the males displaying
their gorgeous trains, and strutting about in all the pomp
r of pride before the gratified females.^' The wild turkey-cock
erects his glittering plumage, expands his finely-zoned tail
and barred wing-feathers, and altogether, with his crimson

*0n the pelican, see Sclater, in "Proc. Zool. Soc," 1868, p. 265.
On the American finches, see Audubon, " Ornitli. Biography," vol. i,
pp. 174, 221, and Jerdon, " Birds of India," vol. ii, p. 383. On the
Fringilla cannabina of Madeira, Mr. E. Vernon Harcourt, " Ibis,"
vol. V, 1863. p. 230.

f See also " Ornamental Poultry," by Rev. E. S. Dixon, 1848, p. 8.

J " Birds of India," introduct., vol. i, p. 24, on the peacock, vol.
iii, p. 507. See Gould's ** Introduction to the Trochilidse," 1861, pp.
16, IIL

448

THE DESCENT OP MAN.

and bine wattles, makes a superb, though, to our eyes,
grotesque appearance. Similar facts have already been
given with respect to grouse of various kinds. Turning to
another order. The male Rupicola crocea (fig. 50) is one
of the most beautiful birds in the world, being of a splendid
orange, with some of the feathers curiously truncated and

Fig. 50. Rupicola crocea, male (T. W. Wood).

plumose. The female is brownish -green, shaded with red,
and has a much smaller crest. Sir K. Schomburgk has
described their courtship; he found one of their meeting-
places where ten males and two females were present. The
space was from four to five feet in diameter, and appeared
to have been cleared of every blade of grass and smoothed
as if by human hands. A male *'was capering to the

BIRDS. 449

apparent delight of several others. Now spreading its
wings, throwing up its head, or opening its tail like a fan;
now strutting about with a hopping gait until tired, when
it gabbled some kind of note, and was relieved by another.
Thus tiiree of them successively took the field, and then,
with self -approbation, withdrew to rest." The Indians, in
order to obtain their skins, wait at one of the meeting-
places till the birds are eagerly engaged in dancing, and
then are able to kill with their poisoned arrows four or five
males, one after the other.* AVith birds of paradise a dozen
or more ftill-plumaged males congregate in a tree to hold a
dancing-party, as it is called by the natives; and here they
fly about, raise their wings, elevate their exquisite plumes,
and make them vibrate, and the whole tree seems, as Mr.
Wallace remarks, to be filled with waving plumes. When
thus engaged they become so absorbed that a skillful archer
may shoot nearly the whole party. These birds, when kept
in confinement in the Malay Archipelago, are said to take
much care in keeping their feathers clean; often spreading
them out, examining them, and removing every speck of
dirt. One observer, who kept several pairs alive, did not
doubt that the display of the male was intended to please
the female. \

The gold and Amherst pheasants during their courtship
not only expand and raise their splendid frills but twist
them, as I have myself seen, obliquely toward the female
on whichever side she may be standing, obviously in order
that a large surface may be displayed before her. J They
likewise turn their beautiful tails and tail-coverts a little
toward the same side. Mr. Bartlett has observed a male
Polyplectron (fi^. 51) in the act of courtship, and has
shown me a specimen stuffed in the attitude then assumed.
The tail and wing feathers of this bird are ornamented
with beautiful ocelli, like those on the peacock's train.

* " Journal of R. Geograph. Soc," vol. x, 1840, p. 236.

I " Annals and Mag. of Nat. Hist.," vol. xiii, 1854, p. 157; also
Wallace, ibid, vol. xx, 1857, p. 412, and "The Malay Archipelago,"
vol. ii, 1869, p. 253. Also Dr. Bennett, as quoted by Brehm, " Thier-
leben," B. iii, s. 826.

J Mr. T. W. Wood has given ("The Student," April, 1870, p.
115) a full account of this manner of display by the gold pheasant
and by the Japanese pheasant, Ph. versicolor; and he calls it the
lateral or one-oided display.

450 THE DESCENT OF MAN,

Now when the peacock displays himself he expands and

Fig. 51. Polyplectron chinquis, male (T. W. Wood).

erects his tail transversely to his body, for he stands in
front of the female^ and has to show off at the same time

BIBBS. 451

his rich blue throat and breast. But the breast of the Poly-
plectron is obscurely colored, and tlie ocelli are not con-
fined to the tail-feathers. Consequently the Polyplectron
does not stand in front of the female; but he erects and
expands his tail-feathers a little obliquely, lowering the ex-
panded wing on the same side and raising that on the
opposite side. In this attitude the ocelli over the whole
body are exposed at the same time before the eyes of the
admiring female in one grand bespangled expanse. To
whichever side she may turn the expanded wings and the
obliquely-held tail are turned toward her. The male Trag-
opan pheasant acts in nearly the same manner, for he raises
the feathers of the body, though not the wing itself, on the
side which is opposite to the female, and which would
otherwise be concealed, so that nearly all the beautifully
spotted feathers are exhibited at the same time.

The Argus pheasant affords a much more remarkable
case. The immensely developed secondary wing-feathers
are confined to the male; and each is ornamented with a
row of from twenty to twenty-three ocelli above an inch in
diameter. These feathers are also elegantly marked with
oblique stripes and rows of spots of a dark color, like those
on the skin of a tiger and leopard combined. These beau-
tiful ornaments are hidden until the male shows himself off
before the female. He then erects his tail and expands his
wing-feathers into a great, almost upright, circular fan or
shield, which is carried in front of the body. The neck
and head are held on one side, so that they are concealed
by the fan; but the bird in order to see the female, before
whom he is displaying himself, sometimes pushes his head
between two of the long wing-feathers (as Mr. Bartlett has
seen), and then presents a grotesque appearance. This
must be a frequent habit with tlie bird in a state of nature,
for Mr. Bartlett and his son, on examining some perfect
skins sent from the east, found a place between two of the
feathers which was much frayed, as if the head had here
frequently been pushed through. Mr. Wood thinks that
the male can also peep at the female on one side beyond the
margin of the fan.

The ocelli on the wing-feathers are wonderful objects,
for they are so shaded that, as the Duke of Argyll remarks,*

♦ "The Reign of Law," 1867, p. 208.

462 THE DESCENT OF MAN.

they stand out like balls lying loosely within sockets. When

Wg. 52. Side view of male Argus pheasant, while displaying before tho
female. Observed and sketched from nature by Mr. T. W. Wood.

I looked at the specimen in the British Museum, which is
mounted with the wings expanded and trailing downward,

BIRDS, 403

I was, however, greatly 'disappointed, for the ocelli appeared
flat, or even concave. But Mr. Gould soon made the case
clear to me, for he held the feathers erect, in the position
in which they would naturally be displayed, and now, from
the light shining on tliem from above, each ocellus at once
resembled the ornament called a ball and socket. These
feathers have been shown to several artists, and all have
expressed their admiration at the perfect shading. It may
well be asked, could such artistically shaded ornaments
have been formed by means of sexual selection ? But it
will be convenient to defer giving an answer to this ques-
tion until we treat in the next chapter of the principle of
gradation.

The foregoing remarks relate to the secondary wing-
feathers, but the primary wing-feathers, which in most
gallinaceous birds are uniformly colored, are in the Argus
pheasant equally wonderful. They are of a soft brown tint
with numerous dark spots, each of whicli consists of two or
three black dots with a surrounding dark zone. But the
chief ornament is a space parallel to the dark-blue shaft,
which in outline forms a perfect second featlier lying within
the true feather. Tliis inner part is colored of a ligliter
chestnut, and is thickly dotted witli minute white points.
I have shown this feather to several persons^ and many
have admired it even more than the ball and socket feath-
ers, and have declared that it was more like a work of ari;
than of nature. Kow these feathers are quite hidden on
all ordinary occasions, but are fully displayed, together
with the long secondary feathers, when they are all ex-
panded together so as to form the great fan or shield.

The case of the male Argus pheasant is eminently inter-
esting, because it affords good evidence that the most re-
fined beauty may serve as a sexual charm, and for no other
purpose. We must conclude that this is the case, as the
secondary and primary wing-feathers are not at all dis-
played, and the ball and socket ornaments are not exhibited
m full perfection until the male assumes the attitude of
courtship. The Argus pheasant does not possess brilliant
colors, so that his success in love appears to depend on the
• great size of his plumes and on the elaboration of the most
elegant patterns. Many will declare that it is utterly in-
credible that a female bird should be able to appreciate fine
■hading and exquisite patterns. It is undoubtedly a mar*

454 THE DESQENT OF MAN.

velous fact that she should possess this almost human degree
of taste. He who thinks that he can safely gauge the dis-
crimination and taste of the lower animals may deny that
the female Argus pheasant can appreciate such refined
beauty; but he will then be compelled to admit that the
extraordinary attitudes assumed by the male during the act
of courtship, by which the wonderful beauty of his plum-
age is fully displayed, are purposeless; and this is a conclu-
sion which I for one will never admit.

Although BO many pheasants and allied gallinaceous
birds carefully display their plumage before the females, it
is remarkable, as Mr. Bartlett informs me, that this is not
the case with the dull colored eared and cheer pheasants
{Crossoptilon auritum and Phasianus tvallichii); so that
these birds seem conscious that they have little beauty to
display. Mr. Bartlett has never seen the males of either of
these species fighting together, though he has not had such
good opportunities for observing the cheer as the eared
pheasant. Mr. Jenner Weir, also, finds that all male
birds with rich or strongly-characterized plumage are more
quarrelsome than the dull-colored species belonging to the
same groups. The goldfinch, for instance, is far more
pugnacious than the linnet, and the blackbird than the
thrush. Those birds which undergo a seasonal change of
plumage likewise become much more pugnacious at the
period when they are most gayly ornamented. No doubt
the males of some obscurely colored birds fight desperately
together, but it appears that when sexual selection has
been highly influential, and has given bright colors to the
males of any species, it has also very often given a strong
tendency to pugnacity. We shall meet with nearly analo-
gous cases when we treat of mammals. On the other hand,
with birds the power of song and brilliant colors have
rarely been both acquired by the males of the same species;
but in this case the advantage gained would have been the
same, namely, success in charming the female. Neverthe-
less it must be owned that the males of several brilliantly
colored birds have had their feathers specially modified for
the sake of producing instrumental music, though the
beauty of this cannot be compared, at least according to
our taste, with that of the vocal music of many songsters.

We will now turn to male birds which are not oma-
xnented in any high degree, but which nevertheless display

BIRDB. 465

during their courtship whatever attractions they may pos-
sess. These cases are in some respects more curious than
the foregoing, and have been but little noticed. I owe the
following facts to Mr. Weir, who has long kept confined
birds of many kinds, including all the British Pringillidae
and Emberizidas. The facts have been selected from a
large body of valuable notes kindly sent me by him. The
bullfinch makes his advances in front of the female, and
then pulfs out his breast, so that many more of the crim-
son feathers are seen at once than otherwise would be the
case. At the same time he twists and bows his black
tail from side to side in a ludicrous manner. The male
chaffinch also stands in front of the female, thus show-
ing his red breast and " blue bell," as the fan-
ciers call his head ; the wings at the same time being
slightly expanded, with the pure white bands on the shoul-
ders thus rendered conspicuous. The common linnet dis-
tends his rosy breast, slightly expands his brown wings
and tail, so as to make the best of them by exhibiting their
white edgings. We must, however, be cautious in conclud-
ing that the wings are spread out solely for display, as
some birds do so whose wings are not beautiful. This is
the case with the domestic cock, but it is always the wing
on the side opposite to the female which is expanded, and
at the same time scraped on the ground. The male gold-
finch behaves differently from all other finches; his wings
are beautiful, the shoulders being black, with the dark-
tipped wing-feathers spotted with white and edged with
golden yellow. When he courts the female he sways his
body from side to side, and quickly turns his slightly
expanded wings first to one side then to the other with a
golden flashing effect. Mr. Weir informs me that no other
British finch turns thus from side to side during his court-
ship, not even the closely allied male siskin, for he would
not thus add to his beauty.

Most of the British buntings are plain-colored birds ;
but in the spring the feathers on the head of the male
reed-bunting (Fmheriza scliOBniculus) acquire a fine black
color by the abrasion of the dusky tips; and these are
erected during the act of courtship. Mr. Weir has kept
two species of Amadina from Australia; the A. castanotis
is a very small and chastely colored finch, with a dark tail,
white rump and jet-black upper tail coverts, each of the

456 TBE DESCENT OF MAN,

'\atter being marked with three large conspicuous oval
spots of white.* This species when courting the female
slightly spreads out and vibrates these parti-colored tail
coverts in a very peculiar manner. The male Amadina
Lathami behaves very differently, exhibiting before the
female his brilliantly spotted breast, scarlet rump and
scarlet upper tail coverts. I may here add from Dr.
Jerdon that the Indian bulbul (Pycnonotus hmnorrlioiis)
has its under tail coverts of a crimson color, and these, it
might be thought, could never be well exhibited; but the
bird *^ when excited often spreads them out laterally so
that they can be seen even from above.'^f The crimson
under tail coverts of some other birds, as with one of the
woodpeckers, Picus major, can be seen without any such
display. The common pigeon has iridescent feathers on
the breast, and every one must have seen how the male
inflates his breast while courting the female, thus showing
them ofl: to the best advantage. One of the beautiful
bronze-winged pigeons of Australia {Ocyjoliaps Jojjiwtes)
behaves, as described to me by Mr. Weir, very differently.
The male while standing before the female lowers his head
almost to the ground, spreads out and raises his tail and
half expands his wings. He then alternately and slowly
raises and depresses his body, so that the iridescent
metallic feathers are all seen at once and glitter in the sun.

Sufficient facts have now been given to show with what
care male birds display their various charms, and this they
do with the utmost skill. While preening their feathers
they have frequent opportunities for admiring themselves
and of studying how best to exhibit their beauty. But as
all the males of the same species display themselves in
exactly the same manner it appears that actions, at first
perhaps intentional, have become instinctive. If so, we
ought not to accuse birds of conscious vanity; yet when
we see a peacock strutting about with expanded and
quivering tail feathers he seems the very emblem of pride
and vanity.

The various ornaments possessed by the males are cer-
tainly of the highest importance to them, for in some cases

* For the description of these birds see Gould's " Hand-book to the
Birds of Australia," vol. i, 1865, p. 417.
f " Buds of India," vol. ii, p, 98,

BIRP8. 457

they have been acquired at the expense of greatly impeded
powers of flight or of running. The African night-jar
(Cosmetornis), wliich during the pairing-season has one of
its primary wing-feathers developed into a streamer of very
great length, is thereby much retarded in its flight,
although at other times remarkable for its swiftness. The
*' unwieldy size" of the secondary wing-feathers of the
male Argus pheasant is said *^ almost entirely to deprive
the bird of flight." The fine plumes of male birds of para-
dise trouble them during a high wind. The extremely long
tail-feathers of the male widow-birds (Vidua) of South-
ern Africa render " their flight heavy;" but as soon as these
are cast off they fly as well as the females. As birds always
breed when food is abundant, the males probably do not
suffer much inconvenience in searching for food from their
impeded powers of movement; but there can hardly be a
doubt that they must be much more liable to be struck
down by birds of prey. Nor can we doubt that the long
train of the peacock and the long tail and wing feathers of
the Argus pheasant must render them an easier prey to any
prowling tiger-cat than would otherwise be the case. Even
the bright colors of many male birds cannot fail to make
them conspicuous to their enemies of all kinds. Hence,
as Mr. Gould has remarked, it probably is that such birds
are generally of a shy disposition, as if conscious that their
beauty was a source of danger, and are much more difficult
to discover or approach than the somber colored and com-
paratively tame females or than the young and as yet
unadorned males.*

It is a more curious fact that the males of some birds
which are provided with special weapons for battle, and
which in a state of nature are so pugnacious that they
often kill each other, suffer from possessing certain orna-
ments. Cock-fighters trim the hackles and cut off the
combs and gills of their cocks; and the birds are then said
to be dubbed. An undubbed bird, as Mr. Tegetmeier

*0n the Cosmetornis, see Livingstone's "Expedition to the Zam-
besi," 1865, p. 6(5. On the Argus pheasant, Jardine's " Nat. Hist.
Lib.: Birds," vol. xiv. p. 167. On birds of paradise. Lesson, quoted
by Brehni, " Thierleben," B. iii, s. 325. On the widow-bird, Bar-
row's "Travels in Africa," vol. i, p. 243, and "Ibis," vol. iii, 1861.
p. 133. Mr. Gould, on the shyness of male birds, " Hand-book tQ
3irds of Australia," vol. i, 1865, pp. 210, 457.

458

TBB DESCENT OF MAN.

insists, "is at a fearful disadvantage; the comb and gills
offer an easy hold to his adversary's beak, and as a cock
always strikes where he holds, when once he has seized his
foe, he has him entirely in his power. Even supposing
that the bird is not killed, the loss of blood suffered by an
undubbed cock is much greater than that sustained by one
that has been trimmed/^* Young turkey-cocks in fighting
always seize hold of each other's wattles; and I presume
that the old birds fight in the same manner. It may per-
haps be objected that the comb and wattles are not orna-
mental and cannot be of service to the birds in this way;
but even to our eyes the beauty of the glossy black Spanish
cock is much enhanced by his white face and crimson
comb; and no one who has ever geen the spl ended blue
wattles of the male Tragopan pheasant distended in court-
ship can for a moment doubt that beauty is the object
gained. From the foregoing facts we clearly see that the
plumes and other ornaments of the males must be of the
highest importance to them; and we further see that beauty
is even sometimes more important than success in battle.

*Tegetmeier, " The Poultry Book," 1866, p. 139.

BISDS. 459

CHAPTER XIV.

BIRDS — continued,

Clioice exerted by the female — Length, of courtship — Unpaired birds
— Mental qualities and taste for the beautiful — Preference or
antipathy shown by the female for particular males — Variability
of birds — Variations sometimes abrupt — Laws of variation —
Formation of ocelli — Gradations of character — Case of peacock,
Argus pheasant and Urosticte.

Whei!^ the sexes differ in beauty or in the power of sing-
ing, or in producing what I have called instrumental
music, it is almost invariably the male who surpasses the
female. These qualities, as we have just seen, are evidently
of high importance to the male. When they are gained
for only a part of the year it is always before the breeding-
season. It is the male alone who elaborately displays his
varied attractions, and often performs strange antics on the
ground or in the air, in the presence of the female. Each
male drives away, or, if he can, kills his rivals. Hence we
may conclude that it is the object of the male to induce
the female to pair with him, and for this purpose he tries
to excite or charm her in various ways; and this is the
opinion of all those who have carefully studied the habits
of living birds. But there remains a question which has
an all-important bearing on sexual selection, namely, does
every male of the same species excite and attract the
female equally? Or does she exert a choice and prefer
certain males? This latter question can be answered in the
affirmative by much direct and indirect evidence. It is far
more difficult to decide what qualities determine the choice
of the females; but here again we have some direct and
indirect evidence that it is to a large extent the external
attractions of the male; though no doubt his vigor, cour-
age, and other mental qualities come into play. We will
begin with the indirect evidence.

460 THE DESCENT OF MAN.

Length of Courtship. — The lengthened period during
which both' sexes of certain birds meet day after day at an
appointed place probably depends partly on the courtship
being a prolonged affair, and partly on reiteration in the
act of pairing. Thus in Germany and Scandinavia the
balzing or leks of the black-cocks last from the middle of
March all through April into May. As many as forty or
fifty or even more birds congregate at the leks; and the
same place is often frequented during successive years. The
lek of the capercailzie lasts from the end of March to the
middle or even end of May. In North America '*the
partridge dances" of the Tetrao phasianeUus ^'last for a
month or more." Other kinds of grouse, both in North
America and Eastern Siberia,* follow nearly the same
habits. The fowlers discover the hillocks where the ruffs
congregate by the grass being trampled bare, and this shows
that the same spot is long frequented. The Indians of
Guiana are well acquainted with the cleared arenas, where
they expect to find the beautiful cocks of the rock; and
the natives of New Guinea know the trees where from ten
to twenty male birds of paradise in full plumage congre-
gate. In this latter case it is not expressly stated that the
females meet on the same trees, but the hunters, if not
specially asked, would probably not mention their presence,
as their skins are valueless. Small parties of an African
weaver (Floceus) congregate, during the breeding-season,
and perform for hours their graceful evolutions. Large
numbers of the solitary snipe (Scolopax major) assemble
during dusk in a morass; and the same place is frequented
for the same purpose during successive years; here they
may be seen running about 'Mike so many large rats,"
puffing out their feathers, flapping their wings, and
uttering the strangest cries, f

*Nordman describes ("Bull. Soc. Imp, des Nat. Moscou," 1861,
torn, xxxiv, p. 264) the balzen of Tetrao urogalloides in Amur Land.
He estimated the number of birds assembled at above a hundred, not
counting the females, which lie hid in the surrounding bushes. The
noises uttered differ from those of 2\ urogallus.

•f- With respect to the assemblasfes of the above-named grouse, see
Brehm, '• Thierleben." B. iv, s. 350: also L. Lloyd, "Game Birds of
Sweden," 1867, pp. 19,78. llicharlson, ** Fauna Bor, Americana, :
Birds," p. 362. Kefeiences in j-egard to the assemblages of other
birds have, already been given. On Paradisea, see Wallace, in
•'Annals and Mag. of Nat. Hist.," vol. xx, 1857, p. 412. On the snipe,
Uoyd, ibid, p, 221.

BIEDS, 461

Some of the above birds — the black-cock, capercailzie,
pheasaiit-gronse, ruff, solitary snipe, and perhaps others —
are, as is believed, polygamists. With such birds it might
have been thought that xhe stronger males would simply
have driven away the weaker, and then at once have taken
possession of as many females as possible; but if it be indis-
pensable for the male to excite or please the female, we can
understand the length of the courtship and the congi'ega-
tion of so many individuals of both sexes at the same spot.
Certain strictly monogamous species likewise hold nuptial
assemblages; this seems to be the case in Scandinavia with
one of the ptarmigans, and their leks last from the middle
of March to the middle of May. In Australia the lyre-
birds {Mennra snperba) forms -^ small round hillocks," and
the M. Albert i scratches for itself shallow holes, or, as they
are called by the natives, corroborying places, where it is
believed both sexes assemble. The meetings of the M.
superba are sometimes very large; and an account has
lately been published * by a traveler, who heard in a valley
beneath him, thickly covered with scrub, *^a din which
completely astonished" him: on crawling onward he
beheld, to his amazement, about one hundred and fifty of
the magnificent lyre-cocks ^M'anged in order of battle
and fighting with indescribable fury," The bowers of the
bower-birds are the resort of both sexes during the oreed-
ing-season, and *Miere the males meet and contend with
each other for the favors of the female, and here the latter
assemble and coquet with the males." With two of the
genera, the same bower is resorted to during many years. f

The common magpie (Corvns pica, Linn.), as I have
been informed by the Rev. W. Darwin Fox, used to
assemble from all parts of Delamere forest, in order to
celebrate the ''great magpie marriage." Some years ago
these birds abounded in extraordinary numbers, so that a
gamekeeper killed in one morning nineteen males, and
another killed by a single shot seven birds at roost together.
They then had the habit of assembling very early m the
spring at particular spots, where they could be seen in

♦Quoted by Mr. T, W W^ood in the " Student," April, 1870, p.
125.

f Gould, ** Hand-book to the Birds of Australia," vol. i, pp. 800,
308. 4i8, 451. On the ptarmigan, above alluded to, see Lloyd, ibid,
p. 139.

462 THE DESCENT OF MAN,

flocks, chattering, sometimes fighting, bustling and flying
about the trees. The whole affair was evidently consid-
ered by the birds as one of the highest importance.
Shortly after the meeting they all separated, and were then
observed by Mr. Fox and others to be paired for the
season. In any district in v/hich a species does not exist in
large numbers great assemblages cannot, of course, be
held, and the same species may have different habits in dif-
ferent countries. For example, I have heard of only one
instance, from Mr. Wedderburn, of a regular assemblage
of black game in Scotland, yet these assemblages are so
well known in Germany and Scandinayia that they have
received special names.

Unpaired Birds. — From the facts now given, we may
conclude that the courtship of birds belonging to widely
different groups is often a prolonged, delicate, and trouble-
some affair. There is even reason to suspect, improbable as
this will at first appear, that some males and females of the
same species, inhabiting the same district, do not always
please each other, and consequently do not pair. Many
accounts have been published of either the male or female
of a pair having been shot and quickly replaced by
another. This has been observed more frequently with
the magpie than with any other bird, owing, perhaps,
to its conspicuous appearance and nest. The illustrious
Jenner states that in Wiltshire one of a pair was daily shot
no less than seven times successively, ^' but all to no pur-
pose, for the remaining magpie soon found another mate;''
and the last pair reared their young. A new partner is
generally found on the succeeding day ; but Mr. Thomp-
son gives the case of one being replaced on the
evening of the same day. Even after the eggs are hatched,
if one of the old birds is destroyed a mate will often be
found; this occurred after an interval of two days in a case
recently observed by one of Sir J. Lubbock's keepers.*
The first and most obvious conjecture is that male magpies
must be much more numerous than females; and that in the
above cases, as well as in many others which could be given,
the males alone had been killed. This apparently holds

*0n magpies, Jenner, in "Pliil. Transact.," 1824, p. 21. Macgil-
livray, " Hist. Britisli Birds," vol. i, p. 570. Thompson, m "Annals
Rud Mag. of Nat. Hist.," vol. viii, 1842, p, 494.

BIRDS. 463

ffood in some instances, for the gamekeepers in Delamere
forest assured Mr. Fox that the magpies and carrion-crows
which they formerly killed in succession in large numbers
near their nests were all males; and they accounted for this
fact by the males being easily killed while bringing food to
the sitting females. Macgillivray, however, gives, on the
authority of an excellent observer, an instance of three mag-
pies successively killed on the same nest, which were all
lemales: and another case of six magpies successively killed
while sitting on the same eggs, which renders it probable
that most of them were females; though, as I hear from
Mr. Fox, the male will sit on the eggs when the female is
killed.

Sir J. Lubbock's gamekeeper has repeatedly shot, but
how often he could not say, one of a pair of jays {Garrulus
glandarius), and has never failed shortly afterward to find
the survivor rematched. Mr. Fox, Mr. F. Bond and others
have shot one of a pair of carrion-crows (Corvus corone), but
the nest was soon again tenanted by a pair. These birds
are rather common; but the peregrine-falcon (Falco pere-
grinus) is rare, yet Mr. Thompson states that in Ireland ^* if
either an old male or female be killed in the breeding-
season (not an uncommon circumstance) another mate
is found within a ver}^ few days, so that the eyries, not-
withstanding such casualties, are sure to turn"^ out their
complement of young.'' Mr. Jenner Weir has known the
same thing with the peregrine-falcons at Beachy Head.
The same observer informs me that three kestrels {Falco
tinnujicuhis), all males, were killed, one after the other,
while attending the same nest; two of these were in mature
plumage, but the third was in the plumage of the previous
vear. Even with the rare golden eagle (Aquila clirysaetos),
\lv. Birkbeck was assured by a trustworthy gamekeeper in
Scotland, that if one is killed another is soon found. So
with the white owl {Strix flaminea) *'the survivor readil
found a mate, and the mischief went on."

White of Selborne, who gives the case of the owl, add.
that he knew a man, who, from believing that partridges
when paired were disturbed by the males fighting, used to
shoot them; and though he had widowed the same female
several times, she always soon found a fresh partner. This
same naturalist ordered the sparrows, which deprived the
house-martins of their nests, to be shot; but the one which

464 THE DESCENT OF MAN,

was left, "be it cock or hen, presently procured a mate,
and so for several times following." I could add analogous
cases relating to the chaffinch, nightingale and redstart.
With respect to the latter bird {PJiosnicura riiticilla), a
writer expresses much surprise how the sitting female could
so soon have given eilectual notice that she was a widow, for
the species was not common in the neighborhood. Mr. Jenner
Weir has mentioned to me a nearly similar case; at Blackheath
he never sees or hears the note of the wild bullfinch, yet
when one of his caged males has died a wild one in the
course of a few days has generally come and perched near
the widowed female, whose call-note is not loud. I will
give only one other fact, on the authority of this same
observer; one of a pair of starlings (Shirnus vulgaris) was
shot in the morning; by noon a new mate was found; this
was again shot, but before night the pair was complete; so
that the disconsolate widow or widower was thrice consoled
during the same day. Mr. Engleheart also informs me
that he used during several years to shoot one of a pair of
starlings which built in a hole in a house at Blackheath;
but the loss was always immediately repaired. During one
season he kept an account, and found that he had shot
thirty-five birds from the same nest; these consisted of
both males and females, but in what proportion he could
not say; nevertheless, after all this destruction, a brood was
reared. *

These facts well deserve attention. How is it that there
are birds enough ready to replace immediately a lost mate
of either sex? Magpies, jays, carrion-crows, partridges,
and some other birds are always seen during the spring in
pairs, and never by themselves; and these offer at first sight
the most perplexing cases. But birds of the same sex,
although of course not truly paired, sometimes live in pairs
or in small parties, as is known to be the case with pigeons
and partridges. Birds also sometimes live in triplets, as
has been observed with starlings, carrion-crows, parrots
and partridges. With partridges two females have been

* On tlie peregrine falcon, see Thompson, "Nat. Hist, of Ireland-
Birds," vol. i, 1849, p. 39. On owls, sparrows and partridges, see
White, "Nat. Hist, of Selborne," edit, of 1825, vol, i, p. 139. On
the Phoenieiira, see Loudon's " Mag. of Nat. Hist.," vol. vii, 18.^4, p.
245. Brehm (" Thierleben," B. iv, s. 991) also alludes to cases oi'
birds thrice mated during the same day.

BIRDS, 465

known to live with one male, and two males with one
female. In all such cases it is probable that the un\on
would be easily broken; and one of the three would readily
pair with a widow or widower. The males of certain birds
may occasionally be heard pouring forth their love-song
long after the proper time, showing that they have either
lost or never gained a mate. Death from accident or dis-
ease of one of a pair would leave the other free and single;
and there is reason to believe that female birds during the
breeding-season are especially liable to premature death.
Again, birds which have had their nests destroyed, or
barren pairs, or retarded individuals, would easily be
induced to desert their mates, and would probably be glad
to take what share they could of the pleasures and duties
of rearing offspring, although not their own.* Such con-
tingencies as these probably explain most of the foregoing
cases, t Nevertheless, it is a strange fact that within the
same district, during the height of the breeding-season,
there should be so many males and females always ready to
repair the loss of a mated bird. Why do not such spare
birds immediately pair together? Have we not some reason
to suspect, and the suspicion has occurred to Mr. Jenner
AVeir, that, as the courtship of birds appears to be in many

* See White (" Nat. Hist, of Selborne," 1825, vol. i, p. 140) on tlie
existence, early in the season, of small coveys of male partridges, of
vv^liich fact I liave heard other instances. See Jenner, on the retarded
state of the generative organs in certain birds, in "Phil. Transact."
1824. In regard to birds living in triplets, I owe to Mr. Jenner Weir
the cases of the starlings and parrots, and to Mr. Fox, of partridges;
on carrion-crows, see the " Field," 1868, p. 415. On various male
birds singing after the proper period, see Rev. L. Jenyns, "Ob-
servations in Natural History," 1846, p. 87.

f The following case has been given ("The Times," Aug, 6, 1868)
by the Rev. F. O. Morris, on the authority of the Hon. and Rev. 0.
W. Forester. " The gamekeeper here found a hawk's nest vhis year
with five young ones in it. He took four and killed theni, but left
one with its wings clipped as a decoy to destroy the old ones by.
They were both shot next day in the act of feeding the young one,
and the keeper thought it was done with. The next day he came
again and found two other charitable hawks who had come with an
adopted feeling to succor the orphan. These two he killed and then
left the nest. On returning afterward he found two more charitable
individuals on the same errand of mercy. One of these he killed;
the other he also shot but could not find. No more came on the like
fruitless errand."

466 THE DE8GENT OF MAN.

cases prolonged and tedious, so it occasionally happens that
certain males and females do not succeed, during the proper
season, in exciting 'each other^s love, and consequently do
not pair ? This suspicion will appear somewhat less improba-
ble after we have seen what strong antipathies and prefer-
ences female birds occasionally evince toward particular
males.

Mental Qualities of Birds and TJieir Taste for the
Beautifil. — Before we further discuss the question whether
the females select the more attractive males or accept the
first whom they may encounter, it will be advisable briefly
to consider the mental powers of birds. Their reason is
generally, and perhaps justly, ranked as low; yet some facts
could be given* leading to an opposite conclusion. Low
powers of reasoning, however, are compatible, as we see
with mankind, with strong affections, acute perception,
and a taste for the beautiful; and it is with these latter
qualities that we are here concerned. It has often been
said that parrots become so deeply attached to each other
that when one dies the other pines for a long time; but
Mr. Jenner Weir thinks that with most birds the strength
of their affection has been much exaggerated. Neverthe-
less, when one of a pair in a state of nature has been shot,
the survivor has been heard for days afterward uttering a
plaintive call: and Mr. St. John gives various facts pro^dng
the attachment of mated birds, f Mr. Bennett relates J; that
in China after a drake of the beautiful mandarin teal had
been stolen the duck remained disconsolate, though sedu-
lously courted by another mandarin drake, who displayed

* 1 am indebted to Prof. Newton for the following passage from
Mr. Adam's " Travels of a Naturalist," 1870, p. 278. Speaking of
Japanese nut-liatcbes in confinement, be says: ** Instead of tbe more
yielding fruit of tbe yew, wbicb is tbe usual food of tbe nut-batcb
of Ja])an, at one time I substituted bard bazel-nuts. As tbe bird
was unable to crack tbem, be placed tbem one by one in bis water-
glass, evidently witb tbe notion tbat tbey would in time become
softer — an interesting proof of intelligence on tbe part of tbese
birds."

f " A Tour in Sutberlandsbire," vol. i, 1849, p. 185. Dr. Buller
says ("Birds of New Zealand," 1872, p. 56) tbat a male King Lory
was killed; and tbe female " fretted and moped, refused ber food,
and died of a broken beart."

% " Wanderings in New South Wales," vol. li, 1834, p. 62.

BIRD8. 467

before her all his charms. After an interval of three weeks
the stolen drake was recovered, and instantly the pair
recognized each other with extreme joy. On the other
hand starlings, as we have seen, may be consoled thrice in
the same day for the loss of their mates. Pigeons have
such excellent local memories that they have been known
to return to their former homes after an interval of nine
months, yet, as I hear from Mr. Harrison Weir, if a pair
which naturally would remain mated for life be separated
for a few weeks during the winter, and afterward matched
with other birds, the two, when brought together again,
rarely, if ever, recognize each other.

Birds sometimes exhibit benevolent feelings; they will
feed the deserted young ones even of distinct species, but
this perhaps ought to be considered as a mistaken instinct.
They will feed, as shown in an earlier part of this work,
adult birds of their own species which have become blind.
Mr. Buxton gives a curious account of a parrot which took
care of a frost-bitten and crippled bird of a distinct species,
cleansed her feathers and defended her from the attacks of
the other parrots which roamed freely about his garden.
It is a still more curious fact that these birds apparently
evince some sympathy for the pleasures of their fellows.
When a pair of cockatoos made a nest in an acacia tree '' it
was ridiculous to see the extravagant interest taken in the
matter by the others of the same species. These parrots
also evinced unbounded curiosity and clearly had ^* the
idea of property and possession."* They have good mem-
ories, for in the Zoological Gardens they have plainly
recognized their former masters after an interval of some
months.

Birds possess acute powers of observation. Every mated
bird, of course, recognizes its fellow. Audubon states that
a certain number of mocking-thrushes (Mimus polyglottus)
remain all the year round in Louisiana, while others
migrate to the Eastern States; these latter on their return
are instantly recognized and always attacked by their
southern brethren. Birds under confinement distinguish
different persons, as is proved by the strong and permanent
antipathy or affection which they show without any appar-

* '* Acclimatization of Parrots," by C. Buxton, M. P. "Annals and
Mag. of Nat. Hist.," Nov., 1868, p. 381,

468 THE DESOBNT OP MAIT,

ent cause toward certain individuals. I have heard of

numerous instances with jays, partridges, canaries, and
especially bullfinches. Mr. Hussey has described in how
extraordinary a manner a tamed partridge recognized
everybody; and its likes and dislikes were veiy strong.
This bird seemed **fond of gay colors, and no new gown
or cap could be put on without catching his attention."*
Mr. Hewitt has described the habits of some ducks
(recently descended from wild birds) which at the approach
of a strange dog or cat would rush neadlong into the water
^nd exhaust themselves in their attempts to escape; but
they knew Mr. Hewitt's own dogs and cats so well that
they would lie down and bask in the sun close to them.
They always moved away from a strange man, and so they
would from the lady wlio attended them if she made any
great change in her dress. Audubon relates that he reared
and tamed a wild turkey which always ran away from any
strange dog; this bird escaped into the woods, and some
days afterward Audubon saw, as he thought, a wild turkey
and made his dog chase it; but to his astonishment the
bird did not run away, and the dog when he came up did
not attack the bird, for they mutually recognized each
other as old friends, f

Mr. Jenner Weir is convinced that birds pay particular
attention to the colors of other birds, sometimes out of
jealousy and sometimes as a sign of kinship. Thus he
turned a reed-bunting (Emleriza schoeniculus) , which had
acquired its black head-dress, into his aviary, and the new-
comer was not noticed by any bird except by a bullfinch,
which is likewise black-headed. This bullfinch was a very
quiet bird, and liad never before quarreled with any of its
comrades, including another reed-bunting, which had not
as yet become black-headed ; but the reed-bunting with a
black head was so unmercifully treated that it had to be
removed. S2nza cyanea, during the breeding-season, is of
a bright blue color; and though generally peaceable, it
attacked 8. ciris, which has only the head blue, and com-
pletely scalped the unfortunate bird. Mr. Weir was also

*" The Zoologist," 1847-1848, p. 1602.

f Hewitt on wild ducks, " Journal of Horticulture," Jan. 13, 1863,
p. 39. Audubon on the wild turkey, " Oi-nith, Biography," vol. i, p,
14. On the mocking-thrush, ibid, vol. i, p. 110.

BIRDS, 469

obliged to turn ont a robin, as it fiercely attacked all the
birds in his aviary with any red in their plumage, but no
other kinds; it actually killed a red-brested crossbill and
nearly killed a goldtinch. On tlie other hand, lie has
observed that some birds, when first introduced, fly toward
the species which resemble them most in color, and settle
by their sides.

As male birds display their fine plumage and other orna-
ments with so much care before the females, it is obvi-
ously probable that these appreciate the beauty of their
suitors. It is, however, difficult to obtain direct evidence
of their capacity to appreciate beauty. When birds gaze
at themselves in a looking-glass (of which many instances
have been recorded) we cannot feel sure that it is not from
jealousy of a supposed rival, though this is not the conclu-
sion of some observers. In other cases it is difficult to dis-
tinguish between mere curiosity and admiration. It is
perhaps the former feeling which, as stated by Lord Lil-
ford,* attracts the rulf toward any bright object, so that,
in the Ionian Islands, " it will dart down to a bright-col-
ored handkerchief, regardless of repeated shots. The
common lark is drawn down from the sky, and is caught
in large numbers, by a small mirror made to move and
glitter in the sun. Is it admiration or curiosity which
leads the magpie, raven, and some other birds to steal and
secrete bright objects, such as silver articles or jewels?

Mr. Gould states that certain humming-birds decorate
the outsides of their nests " with the utmost taste ; they
instinctively fasten thereon beautiful pieces of flat lichen,
the larger pieces in the middle, and the smaller on the part
attached to the branch. Now and then a pretty feather
is intertwined or fastened to the outer sides, the stem being
always so placed that the feather stands out beyond the
surface." The best evidence, however, of a taste for the
beautiful is afforded by the three genera of Australian
bower-birds already mentioned. Their bowers (see fig. 46),
where the sexes congregate and play strange antics,
are variously constructed, but what most concerns us is,
that they are decorated by the several species in a different
luanner. The satin bovver-bird collects gayly-colored arti-
cles, such as the blue tail-feathers of paroquets, bleached

•The "Ibis," vol. ii. 1860, p. 344,

470 THE DESCENT OF MAN,

bones and shells, which it sticks between the twigs or
arranges at the entrance. Mr. Gould found in one bower
a neatly- worked stone tomahawk and a slip of blue cotton,
evidently procured from a native encampment. These
objects are continually rearranged, and carried about by
the birds while at play. The bower of the spotted bower-
bird ^' is beautifully lined with tall grasses, so disposed that
the heads nearly meet, and the decorations are very profuse."
Round stones are used to keep the grass-stems in their
proper places and to make divergent paths leading to the
bower. The stones and shells are often brought from a
great distance. The regent bird, as described by Mr.
Kamsay, ornaments its short bower with bleached land-
shells belonging to five or six species, and with " berries of
various colors, blue, red, and black, which give it when
fresh a very pretty appearance. Besides these there were
several newly-picked leaves and young shoots of a pinkish
color, the whole showing a decided taste for the beautiful."
Well may Mr. Gould say. that "these highly decorated
halls of assembly must be regarded as the most wonderful
instances of bird-architecture yet discovered;" and the
taste, as we see, of the several species certainly differs. *

Preference for Particular Males ly the Females. — Having
made these preliminary remarks on the discrimination and
taste of birds, I will give all the facts known to me which
bear on the preference shown by the female for particular
males. It is certain that distinct species of birds occasion-
ally pair in a state of nature and produce hybrids. Many
instances could be given; thus Macgillivray relates how a
male blackbird and female thrush " fell in love with each
other," and produced offspring, f Several years ago eight-
een cases had been recorded of the occurrence m Great
Britain of hybrids between the black grouse and pheasant;];
but most of these cases may perhaps be accounted for by
solitary birds not finding one of their own species to pair
with. With other birds, as Mr. Jenner Weir has reason to

* On the ornamental nests of humming-birds, Gould, "Introduc-
tion to the Trochilidae, 1861, p. 19. On the bower-birds, Gould,
" Hand-book to the Birds of Australia," 1865, vol. i, pp. 444-461.
Ramsay, in the "Ibis," 1867, p. 456.

t " Hist, of British Birds," vol. ii, p. 93.

i" Zoologist," 1853-1854, p. 3940,

BIRDS. 471

believe, hybrids are sometimes the result of the casual inter-
course of birds building in close proximity. But these
remarks do not apply to the many recorded instances of
tamed or domestic birds, belonging to distinct species,
which have become absolutely fascinated with each other,
although living with their own species. Thus Waterton*
states that out of a flock of twenty-three Canada geese, a
female paired with a solitary Bernicle gander, although so
different in appearance and size; and they produced hybrid
offspring. A male wigeon {Mareca penelope) living with
females of the same species has been known to pair with a
pintail duck, Querqiiedula acuta. Lloyd describes the re-
markable attachment between a shield-drake {Tadorna
vulpanser) and a common duck. Many additional instances
could be given; and the Eev. E. S. Dixon remarks that
*' those who have kept many different species of geese
together well know what unaccountable attachments they
are frequently forming, and that they are quite as likely to
pair and rear young with individuals of a race (species)
apparently the most alien to themselves as with their own
stock.''

The Rev. W. D. Fox informs me that he possessed at the
same time a pair of Chinese geese (Anser Cygnoides) and a
common gander with three geese. The two lots kept quite
separate, until the Chinese gander seduced one of the
common geese to live with him. Moreovej, of the young
birds hatched from the eggs of the common geese, only
four were pure, the other eighteen proving hybrids; so that
the Chinese gander seems to have had prepotent charms
over the common gander. I will give only one other case:
Mr. Hewitt states that a wild duck, reared in captivity,
*' after breeding a couple of seasons with her own mallard,
at once shook him off on my placing a male pintail on the
water. It was evidently a case of love at first sight, for
she swam about the new-comer caressingly, though he
appeared evidently alarmed and averse to her overtures of

* Waterton, "Essays on Nat. Hist," 2d series, pp. 42, 117. For
the following statements see on the wigeon, Loudon's " Mag. of Nat.
Hist.," vol. ix, p. 616. L. Lloyd, " Scandinavian Adventures," vol. i,
1854, p. 452. Dixon, "Ornamental and Domestic Poultry," p. 137;
Hewitt, in "Journal of Horticulture," Jan. 13, 1863, p. 40; Bech-
stein, " Stubenvdgel," 1840, s. 230. Mr. Jenner Weir has lately
given me an analogous case with ducks of two species.

in THE DESCENT OF MAN.

affection. From that hour she forgot her old partner.
Winter passed by, and the next spring the pintail seemed
to have become a convert to iier blandishments, for they
nested and produed seven or eight young ones.^'

What the charm may have been in these several cases,
beyond mere novelty, we cannot even conjecture. Ciolor,
however, sometimes comes into play; for in order to raise
hybrids from the siskin {Fringilla spiiius) and the canary,
it is much the best plan, according to Bechstein, to place
birds of the same tint together. Mr. Jenner Weir turned
a female canary into his aviary, where there were male
linnets, goldfinches, siskins, greenfinches, chaffinches and
other birds, in order to see which she would choose; but
there never was any doubt, and the greenfinch carried the
day. They paired and produced hybrid offspring.

The fact of the female preferring to pair with one male
rather than with another of the same species is not so likely
to excite attention as when this occurs, as we have just
seen, between distinct species. The former cases can best
be observed with domesticated or confined birds; but these
are often pampered by high feeding, and sometimes have
their instincts vitiated to an extreme degree. Of this latter
fact I could give sufficient proofs with pigeons, and espe-
cially with fowls, but they cannot be here related. Vitiated
instincts may also account for some of the hybrid unions
above mentioned; but in many of these cases the birds were
allowed to range freely over large ponds, and there is no
reason to suppose that they were unnaturally stimulated by
higli feeding.

With respect to birds in a state of nature, the first and
most obvious supposition which will occur to every one is
that the female at the proper season accepts the first male
whom she may encounter; but she has at least the oppor-
tunity for exerting a choice, as she is almost invariably
pursued by many males. Audubon — and we must remem-
ber that he spent a long life in prowling about the forests
of the United States and observing the birds — does not
doubt that the female deliberately chooses her mate; thus,
speaking of a woodpecker, he says the hen is followed by
half a dozen gay suitors, who continue performing strange
antics, " until a marked preference is shown for one.'^ The
female of the red- winged starling {Agelceus phcenicens) is
likewise pursued by several males; *^ until, becoming

BIRDS. 473

fatigued, she alights, receives their addresses, and soon
makes a choice." He describes also how several male
night-jars repeatedly plunge through the air with astonish-
ing rapidity, suddenly turning, and thus making a singular
noise; '* but no sooner has the female made her choice than
the other males are driven away.';* With one of the
vultures {Oathartes aura) of the United States, parties of
eight, ten, or more males and females assemble on fallen
logs, ^' exhibiting the strongest desire to please mutually,"
and after many caresses each male leads off his partner on
the wing. Audubon likewise carefully observed the wild
flocks of Canada geese {Anser canadensis), and. gives a
graphic description of their love antics; he says that the
birds which had been previously mated "^"^ renewed their
courtship as early as the month of January, while the
others would be contending or coquetting for hours every
day, until all seemed satisfied with the choice they had
made, after which, although they remained together, any
person could easily perceive that they were careful to keep
in pairs. I have observed also that the older the birds the
shorter were the preliminaries of their courtship. The
bachelors and old maids, whether in regret or not caring
to be disturbed by the bustle, quietly moved aside and lay
down at some distance from the rest."* Many similar
statements with respect to other birds could be cited from
this same observer.

Turning now to domesticated and confined birds, I will
commence by giving what little I have learned respecting
the courtship of f owlso I have recieved long letters on this
subject from Messrs. Hewitt and Tegetmeier, and almost
an essay from the late Mr. Brent. It will be admitted by
every one that these gentlemen, so well known from their
published works, are careful and experienced observers.
Ihey do not believe that the females prefer certain males
on account of the beauty of their plumage; but some allow-
ance must be made for the artificial state under which
these birds have long been kept. Mr. Tegetmeier is con-
vinced that a gamecock, though disfigured by being dubbed
and with his hackles trimmed, would be accepted as readily
as a male retaining all his natural ornaments. Mr^ Brent,

♦Audubon, " Ornitliolog. Biography," vol. i, pp. 191, 349; vol. ii,
pp. 42, S70; vol. iii, p^ 2.

474 THE DESCENT OF MAN,

however^ admits that the heauty of the male probably aids
in exciting the female; and her acquiescence is necessary.
Mr, Hewitt is convinced that the union is by no means left
to mere chance, for the female almost invariably prefers
the most vigorous, defiant and mettlesome male; hence it
is almost useless, as he remarks, ^' to attempt true breeding
if a gamecock in good health and condition runs the local-
ity, for almost every hen on leaving the roosting-place will
resort to the gamecock, even though that bird may not
actually drive away the male of her own variety." Under
ordinary circumstances the males and females of the fowl
seem ta come to a mutual understanding by means of cer-
tain gestures, described to me by Mr. Brent. But hens
will often avoid the officious attentions of young males.
Old hens and hens of a pugnacious disj)osition, as the
same writer informs me, dislike strange males, and will not
yield until well beaten into compliance. Ferguson, how-
ever, describes how a quarrelsome hen was subdued by the
gentle courtship of a shanghai cock.*

There is reason to believe that pigeons of both sexes
prefer pairing with birds of the game breed; and dove-cote
pigeons dislike all the highly improved breeds. \ Mr. Har-
rison Weir has lately heard from a trustworthy observer
who keeps blue pigeons that these drive away all other
colored varieties, such as white, red and yellow; and from
another observer, that a female dun carrier could not, after
repeated trials, be matched with, a black male, but imme-
diately paired with a dun. Again, Mr. Tegetmeier had a
female blue turbit that obstinately refused to pair with two
males of the same breed, which were successively shut up
with her for weeks; but on being let out she would have
immediately accepted the first blue dragon that offered.
As she was a valuable bird, she was then shut up for many
weeks with a silver {i. e., very pale blue) male, and at last
mated with him. Nevertheless, as a general rule, color
appears to have little influence on the pairing of pigeons.
Mr. Tegetmeier, at my request, stained some of his birds
with magenta, but they were not much noticed by the
others.

*"Rare and Prize Poultry," 1854, p. 27.

f "The Variatiou of Animals and Plants under Domestication,"
vol. U, p. 103.

BIRDS, 475

Female pigeons occasionally feel a strong antipathy toward
certain males, without any assignable cause. Thus MM.
Boitard and Corbie, whose experience extended over forty-
five years, state: '^Quand une femelle eprouve de Tantip-
athie pour un mdle avec lequel on veut Taccoupler, malgre
tons les feux de Tamour, malgre Falpiste et le chenevis dont
on la nourrit pour augmenter son ardeur, malgre un em-
prisonnement de six mois et meme d'un an, elle refuse con-
stamment ses caresses; les avances empressees, les agaceries,
les tournoiemens. les tendres roucoulemens, rien ne pent lui
plaire ni Temouvoir; gonfl^e, boudeuse, blottie dans un
coin de sa prison, elle n/en sort que pour boire et manger,
ou pour repousser avec une espece de rage des caresses
devenues trop pressantes.^^ * On the other hand, Mr.
Harrison Weir has himself observed and has heard from
several breeders, that a female pigeon will occasionally take
a strong fancy for a particular male, and will desert her
own mate for him. Some females, according to another
experienced observer, Riedel,t are of a profligate disposi-
tion, and prefer almost any stranger to their own mate.
Some amorous males, called by our English fanciers " gay
birds,'' are so successful in their gallantries that, as Mr. H.
Weir informs me, they must be shut up on account of the
mischief which they cause-
Wild turkeys in the United States, according to Audu-
bon, " sometimes pay their addresses to the domesticated
females, and are generally received by them with great
pleasure." So that these females apparently prefer the
wild to their own males. J

Here is a more curious case- Sir R. Heron during many
years kept an account of the habits of the pea-fowl, which
he bred in large numbers. He states that '* the hens have
frequently great preference to a particular peacock. They
were all so fond of an old pied cock that one year, when he
was confined, though still in view, they were constantly
assembled close to the trellised- walls of his prison, and would

* Boitard and Corbie, "Les Pigeons, etc.," 1834, p. 12. Prosper
Lucas ("Traite de I'Hered. Nat.," torn, ii, 1850, p. 296} has himself
observed nearly similar facts with pigeons.

f " Die Taubenzucht,'' 1824, s. 86.

:}:" Ornithological Biography," vol. i, p. 13. See to the same
effect. Dr. Bryant, in "Allen's Mammals and Birds of Florida, " p.
344.

476 THE DESCENT OF MAN.

not suffer a japanned peacock to touch them. On his being
let out in the autumn, the oldest of the hens instantly
courted him and was successful in her courtship. The next
year he was shut up in a stable, and then the hens all
courted his rival. ^^* This rival was a japanned or black-
winged peacock, to our eyes a more beautiful bird than the
common kind.

Lichtenstein, who was a good observer and had excellent
opportunities of observation at the Cape of Good Hope,
assured Rudolphi that the female widow -bird {Cher a
progne) disowns the male when robbed of the long tail
feathers with which he is ornamented during the breeding-
season. I presume that this observation must have been
made on birds under confinement, f Here is an analogous
case: Dr. Jaeger, J; director of the Zoological Gardens of
Vienna, states that a male silver-pheasant who had been
triumphant over all other males and was the accepted lover
of the females had his ornamental plumage spoiled. He
was then immediately superseded by a rival who got the
upper hand and afterward led the flock.

It is a remarkable fact, as showing how important color
is in the courtship of birds, that Mr. Boardman, a well-
known collector and observer of birds for many years in
the Northern United States, has never in his large experi-
ence seen an albino paired with another bird; yet he has
had opportunities of observing many albinos belonging to
several species. § It can hardly be maintained that albinos
in a state of nature are incapable of breeding, as they can
be raised with the greatest facility under confinement. It
appears, therefore, that we must attribute the fact that
they do not pair to their rejection by their normally colored
comrades.

Female birds not only exert a choice, but in some few

*"Proc, Zool. Soc. ," 1835, p. 54. The japanned peacock is con-
sidered by Mr. Sclater as a distinct species, and has been named
Pavo nigripennis; but the evidence seems to me to show that it is
only a variety.

f Rudolphi, " BeytrSge zur Anthropologie," 1812, s. 184.

I "Die Darwin'sche Theorie, und ihre Stellung zu Moral und
Religion," 1869, s. 59.

tThis statement is given by Mr. A. Leith Adams, in his "Field
Forest Rambles," 1873," p. 76, and accords with his own
ejperienc©.

BIRDS. 477

oases they court the male;, or even fight together for his
possession. Sir R. Heron states that with peafowl the first
advances are always made by the female; something of the
same kind takes place, according to Audubon, with the
older females of the wild turkey. With the capercailzie,
the females flit round the male while he is parading at one
of the places of assemblage and solicit his attention.* We
have seen that a tame wild duck seduced an unwilling pin-
tail drake after a long courtship. Mr. Bartlett believes
that the Lophophorns, like many other gallinaceous birds,
is naturally polygamous, but two females cannot be placed
in the same cage with a male as they fight so much
together. The following instance of rivalry is more sur-
prising as it relates to bullfinches, which usually pair for
life. Mr. Jenner Weir introduced a dull-colored and ugly
female into his aviary and she immediately attacked
another mated female so unmercifully that the latter had
to be separated. The new female did all the courtship,
and was at last successful, for she paired with the male;
but after a time she met with a just retribution, for, ceas-
ing to be pugnacious, she was replaced by the old female,
and the male then deserted his new and returned to his old
love.

In all ordinary cases the male is so eager that he will
accept any female, and does not, as far as we can judge,
prefer one to the other ; but, as we shall hereafter see,
exceptions to this rule apparently occur in some few
groups. With domesticated birds I have heard of only one
case of males showing any preference for certain females,
namely, that of the domestic cock, who, according to the
high authority of Mr. Hewitt, prefers the younger to the
older hens. On the other hand, in effecting hybrid unions
between the male pheasant and common hens, Mr. Hewitt is
convinced that the pheasant invariably prefers the older
birds. He does not appear to be in the least influenced by
their color; but "is most capricious in his attachments;'" f
from some inexplicable cause he shows the most determined

*In regard to peafowl, see Sir R. Heron, "Proc. Zoolog. Soc.,**
1835, p. 54, and the Rev. E. S. Dixon, "Ornamental Poultry," 1848,
p. 8. For the turkey, Audubon, ibid, p. 4. For the capercailzie,
Lloyd, " Game Birds of Sweden," 1867, p. 23.

fMr. Hewitt, quoted in " Tegetmeier's Poultry Book" 1866, p
165.

478 THE DESCENT OF MAN.

aversion to certain hens, which no care on the part of the
breeder can overcome. Mr. Hewitt informs me that somo
hens are quite unattractive even to the males of their own
species, so that they may be kept with several cocks during
a whole season, and not one Qgg out of forty or fifty will
prove fertile. On the other hand, with the long-taiLnJ
duck {Harelda glacialis), *'it has been remarked,^' says M.
Ekstrom, ^' that certain females are much more courted
than the rest. Frequently, indeed, one sees an individual
surrounded by six or eight amorous males. '^ Whether
this statement is credible, I know not ; but the native
sportsmen shoot these females in order to stulf them as
decoys.*

With respect to female birds feeling a preference for
particular malea we must bear in mind that we can judge
of choice being exerted only by analogy^ If an inhabitant
of another planet were to behold a number of young
rustics at a fair courting a pretty girl and quarreling about
her, like birds at one of their places of assemblage, he
would, by the eagerness of the wooers to please her and to
display their finery, infer that she had the power of choice.
Now with birds the evidence stands thus; they have acute
powers of observation, and they seem to have some taste
for the beautiful both in color and sound. It is certain
that the females occasionally exhibit, from unknown
causes, the strongest antipathies and preferences for par-
ticular males. When the sexes differ in color or in other
ornaments the males with rare exceptions are the more
decorated, either permanently or temporarily during the
breeding-season. They sedulously display their various
ornaments, exert their voices, and perform strange antics in
the presence of the females. Even well-armed males, who,
it might be thought, would altogether depend for success
on the law of battle, are in most cases highly ornamented ;
and their ornaments have been acquired at the expense of
some loss of power. In other cases ornaments have been
acquired at the cost of increased risk from birds and beasts
of prey. With various species many individuals of both
sexes congregate at the same spot, and their courtship is a
prolonged affair. There is even reason to suspect that tho
males and females within the same district do not always
succeed in pleasing each other and pairing.

* Quoted in Lloyd's " Game Birds of Sweden," p. 345.

BIRDS, 470

What then are we to conclude from these facts and con-
siderations? Does the male parade his charms with so
much pomp and rivalry for no purpose? Are we not justi-
fied in believing that the female exerts a choice, and that
she receives the addresses of the male who pleases her most?
It is not probable ,that she consciously deliberates ; but
she is most excited or attracted by the most beautiful, or
melodious, or gallant males. Nor need it be supposed that
the female studies each stripe or spot of color ; that the
peahen, for instance, admires each detail in the gorgeous
train of the peacock — she is probably struck only by the
general effect. Nevertheless, after hearing how carefully
the male Argus pheasant displays his elegant primary wing-
feathers and erects his ocellated plumes in the right posi-
tion for their full effect; or again, how the male goldfinch
alternately displays his gold-bespangled wings, we ought
not to feel too sure that the female does not attend to each
detail of beauty. We can judge^ as already remarked, of
choice being exerted, only from analogy; and the mental
powers of birds do not dift'er fundamentally from ours.
From these various considerations we may conclude that
the pairing of birds is not left to chance; but that those
males, which are best able by their various charms to please
or excite the female, are under ordinary circumstances
accepted. If this be admitted, there is not much difficulty
in understanding how male birds have gradually acquired
their ornamental characters. All animals present individ-
ual differences, and as man can modify his domesticated
birds by selecting the individuals which appear to him the
most beautiful, so the habitual or even occasional preference
by the female of the more attractive males would almost
certainly lead to their modification; and such modifications
might in the course of time be augmented to almost any
extent, compatible with the existence of the species.

Variahility of Birds, and Especially of TJieir Secondary
Sexual Characters. — Variability and inheritance are the
foundations for the work of selection. That domesticated
birds have varied greatly, their variations being inherited,
is certain. That birds in a state of nature have been modi-
fied into distinct races is now universally admitted. * Vari-

* According to Dr. Blasius ("Ibis," vol. ii, 1860, p. 297), there are
420 indubitable species of birds which breed in Europe, besides sixty

480 THE DESCENT OF MAN

ations may be divided into two classes; those wliicb appeal!
to our ignorance to arise spontaneously, and those which are
directly related to the surrounding conditions, so that all or
nearly all the individuals of the same species are similarly
modified. Cases of the latter kind have recently been observed
with care by Mr. J. A. Allen,* who shows that in the
United States many species of birds gradually become
more strongly colored in proceeding southward, and more
lightly colored in proceeding westward to the arid plains
of the interior. Both sexes seem generally to be affected
in a like manner, but sometimes one sex more than the
other, Tliis result is not incompatible with the belief that
the colors of birds are mainly due to the accumulation of
successive variations through sexual selection ; for even
after the sexes have been greatly differentiated, climate
might produce an equal effect on both sexes, or a greater
effect on one sex than on the other, owing to some consti-
tutional difference.

Individual differences between the members of the same
species are admitted by every one to occur under a state of
nature. Sudden and strongly marked variations are rare ;

forms, which a^e frequently regarded as distinct species. Of the
latter, Biasius thinks that only ten are really doubtful and that the
other fifty ought to be united with their nearest allies; but this
shows that there must be a considerable amount of variation with
some of ^ur European birds. It is also an unsettled point with
naturalists, whether several North American birds ought to be
ranked as specifically distinct from the corresponding European
species. So again many North American forms which until lately
were named as distinct species, are now considered to be local races.

*" Mammals and Birds of East Florida," also an "Ornithological
Reconnaissance of Kansas, etc." Nothwithstanding the influence of
climate on the colors of birds, it is difiicult to account for the dull or
dark tints of almost all the species inhabiting certain countries, for
instance, the Galapagos Islands under the equator, the wide, tem-
perate plains of Patagonia, and, as it appears, Egypt (see Mr. Harts-
horne in the "American Naturalist," 1873, p. 747). These countries
are open and afford little shelter to birds; but it seems doubtfuV
whether the absence of brightly colored species can be explained on
the principle of protection, for on the Pampas, which are equally
open, though covered by green grass, and where the birds would be
equally exposed to danger, many brilliant and conspicuously colored
species are common. I have sometimes speculated whether the pre-
vailing dull tints of the scenery in the above-named countries may
not have affected the appreciation of bright colors by the birds inhab*
iting them.

BIRDS. 481

it is also doubtful whether if beneficial f ,iey would often be
preserved through selection and transn.itted to succeeding
generations.* Nevertheless, it may be worth while to give
the few cases which I have been able to collect, relating
chiefly to color — simple albinism and melanism being
excluded. Mr. Gould is well known to admit the exist-
ence of few varieties, for he esteems very slight differences
as specific; yet he statesf that near Bogota certain hum-
ming-birds belonging to the genus Cynanthus are divided
into two or three races or varieties, which differ from each
other in the coloring of the tail — '' some having the whole of
the feathers blue, while others have the eight central ones
tipped with beautiful green.'' It does not appear that
intermediate gradations have been observed in this or the
following cases. In the males, alone of one of the Austra-
lian paroquets ^' the thighs in some are scarlet, in others
grass-green." In another paroquet of the same country
'' some individuals have the band across the wing-coverts
bright yellow, while in others the same part is tinged with
red. '"J In the United States some few of the males of the
Scarlet Tanager {Tanagra rulra) have "a beautiful trans-
verse band of glowing red on the smaller wing-coverts ;"§
but this variation seems to be somewhat rare, so that its
preservation through sexual selection would follow only
under unusually favorable circumstances. In Bejigal the
honey buzzard {Pernis cristata) has either a small rudi-

*" Origin of Species." 5tli edit., 1869, p. 104. I had always per-
ceived that rare and strongly marked deviations of structure, deserv-
ing to be called monstrosities, could seldom be preserved through
natural selection, and that the preservation of even highly beneficial
variations would depend to a certain extent on chance. I had also
fully appreciated the importance of mere individual differences, and
this led me to insist so strongly on the importance of that unconscious
form of selection by man which follows from the preservation of the
most valued individuals of each breed, without any intention on his
part to modify the characters of the breed. But until I read an able
Article in the " North British Review " (March, 1867, p. 289, etseq.),
which has been of more use to me than any other review, I did not
^ee how great the chances were against the preservation of variations,
whether slight or strongly pronounced, occurring only in single
individuals.

f " Introduct. to the Trochilidge," p, 102.

\. Gould, " Hand-book to Birds of Australia," vol. ii, pp. 32, 68.

§ Audubon, "Omitholog. Biography," 1838, vol. iv, p. 389.

482 THE DESCENT OF MAN,

mental crest on its head, or none at all; so slight a differ-
ence, however, would not have been worth notice, had not
this same species possessed in Southern India a well-marked
occipital crest formed of several graduated feathers/^*

The following case is in some respects more interesting.
A pied variety of the raven, with the head, breast, abdomen,
and parts of the wings and tail-feathers white is con-
fined to the Feroe Islands. It is not very rare there, for
Graba saw during his visit from eight to ten living speci-
mens. Although the characters of this variety are not
quite constant, yet it has been named by several distin-
guished ornithologists as a distinct species. The fact of
the pied birds being pursued and persecuted with much
clamor by the other ravens of the island was the chief
cause which led Briinnich to conclude that they were
specifically distinct; but this is now known to be an error, f
This case seems analogous to that lately given of albino
birds not pairing from being rejected by their comrades.

In various parts of the northern seas a remarkable variety
of the common Guillemot ( Uria troile) is found; and in
Feroe one out of every five birds, according to Grahams esti-
mation, presents this variation. It is characterized^ by a
pure white ring round the eye, with a curved narrow white
line an inch and a half in length extending back from the
ring. This conspicuous character has caused the bird to
be ranked by several ornithologists as a distinct species
under the name of U. lacrymaus, but it is now known to
be merely a variety. It often pairs with the common kind,
yet intermediate gradations have never been seen; nor is
this surprising, for variations which appear suddenly are
often, as I have elsewhere si iown,§ transmitted either unal-
tered or not at all. We thus see that two distinct forms of
the same species may co-exist in the same district, and we
cannot doubt that if the one had possessed any advantage

*Jerdon, "Birds of India," vol. i, p. 108; and Mr. Blytb, in
" Land and Water," 1868, p. 381.

f Graba, "Tagebucli Reise nach Faro," 1830, ss. 51-54. Macgilli-
vray, "Hist. British Birds," vol. iii, p. 745. "Ibis," vol. v, 1863,
p. 469.

:{: Graba, ibid, s. 54. Macgillivray, ibid, vol. v, p. 327.

§" Variation of Animals and Plants under Pomestic»tion,"vol. ii.
p. 9^.

BIRDS. 483

over the other it would soon have been multiplied to the
exclusion of the latter. If, for instance, the male pied
ravens, instead of being persecuted by their comrades, had
been highly attractive (like the above pied peacock) to the
black female ravens their numbers would have rapidly
increased. And this would have been a case of sexual
selection.

With respect to the slight individual differences which
are common, in a greater or less degree, to all the mem-
bers of the same species, we have every reason to believe
that they are by far the most important for the work of
selection" Secondary sexual characters are eminently
liable to vary, both with animals in a state of nature and
under domestication.* There is also reason to believe, as
we have seen in our eighth chapter, that variations are
more apt to occur in the male than in the female sex. All
these contingencies are highly favorable for sexual selexi-
tion. Whether characters thus acquired are transmitted to
one sex or to both sexes depends, as we shall see in the
following chapter, on the form of inheritance which
prevails.

It is sometimes difficult to form an opinion whether cer-
tain slight differences between the sexes of birds are simply
the result of variability with sexually limited inheritance
without the aid of sexual selection or whether they have
been augmented through this latter process. I do not here
refer to the many instances where the male displays splen-
did colors or other ornaments of which the female partakes
to a slight degree; for these are almost certainly due to
characters primarily acquired by the male having been
more or less transferred to the female. But what are we to
conclude with respect to certain birds in which, for
instance, the eyes differ slightly in color in the two sexes ?t
In some cases the eyes differ conspicuously; thus with the
storks of the genus Xenorhynchus, those of the male are
blackish - hazel, while those of the female are gamboge-
yellow; with many hornbills (Buceros), as I hear from Mr.
Blyth,J; the males have intense crimson eyes, and those of

*0n these points see also " Variation of Animals and Plants under
Domestication," vol. i, p. 253; vol. ii, pp. 73, 75.

f See, for instance, on tlie irides of a Podica and Gallicrex in
' Ibis," vol. ii, 1860, p, 206; and vol. v. 1863, p. 426.
i^See also Jerdon, "Birds of India," vol. i, pp. 343-245.

484 THE DESCENT OF MAN.

the females are white. In the Buceros Hcornis, the hind
margin of the casque and a stripe on the crest of the beak
are black in the male, but not so in the female. Are we to
suppose that these black marks and the crimson color of
the eyes have been preserved or augmented through sexual
selection in the males? This is very doubtful; for Mr.
Bartlett showed me in the Zoological Gardens that the
inside of the mouth of this buceros is black in the male
and flesh -colored in the female; and their external appear-
ance or beauty would not be thus affected. I observed in
Chili * that the iris in the condor, when about a year old,
is dark-brown, but changes at maturity into a yellowish-
brown in the male, and into bright red in the female. The
male has also a small, longitudinal, leaden-colored, fleshy
crest or comb. The comb of many gallinaceous birds is
highly ornamental, and assumes vivid colors during the act
of courtship; but what are we to think of the dull-colored
comb of the condor which does not appear to us in the least
ornamental? The same question may be asked in regard to
various other characters, such as the knob on the base of
the beak of the Chinese goose (Anser cygnoides), which is
much larger in the male than in the female. No certain
answer can be given to these questions; but we ought to be
cautious in assuming that knobs and various fleshy appen-
dages cannot be attractive to the female, when we remem-
ber that with savage races of man various hideous
deformities — deep scars on the face with the flesh raised
into protuberances, the septum of the nose pierced by sticks:
or bones, holes in the ears and lips stretched widely open — j
are all admired as ornamental.

Whether or not unimportant differences between theJ
sexes, such as those just specified, have been preserved]
through sexual selection, these differences, as well as all
others, must primarily depend on the laws of variation. On
the principle of correlated development, the plumage often!
varies on different parts of the body, or over the whole
body, in the same manner. We see this well illustrated in J
certain breeds of the fowl. In all the breeds the feathers
on the neck and loins of the males are elongated and are
called hackles; now when both sexes acquire a top-knot,
which is a new character in the genus, the feathers on the

* " Zoology of the Voyage of H. M. S. ' Beagle,' " 1841, p. 0.

BIRDS, 485

head of the male become hackle-shaped, evidently on the
principle of correlation; while those on the head of the
female are of the ordinary si i ape. The color also of
the hackles forming the top-knot of the male is often cor-
related with that of the hackles on the neck and loins, as
may be seen by comparing these feathers in the golden and
silver - spangled Polish, the Houdans and Cr^ve-coeur
breeds. In some natural species we may observe exactly
the same correlation in the colors of these same feathers,
as in the males of the splendid gold and Amherst pheasants.

The structure of each individual feather generally causes
any change in its coloring to be symmetrical; we see this
in the various laced, spangled, and penciled breeds of the
fowl; and on the principle of correlation the feathers over
the whole body are often colored in the same manner. We
are thus enabled without much trouble to rear breeds with
their plumage marked almost as symmetrically as in natural
species. In laced and spangled fowls the colored margins
of the feathers are abruptly defined ; but in a mongrel
raised by me from a black Spanish cock glossed with green,
and a white game-hen, all the feathers were greenish-black,
excepting toward their extremities, which were yellowish-
white; but between the white extremities and the black
bases there was on each feather a symmetrical, curved zone
of dark-brown. In some instances the shaft of the feather
determines the distribution of the tints; thus with the
body-feathers of a mongrel from the same black Spanish
cock and a silver-spangled Polish hen, the shaft, together
with a narrow space on each side, was "greenish-black, and
this was surrounded by a regular zone of dark-brown, edged
with brownish-white. In these cases we have feathers
symmetrically shaded, like those which give so much ele-
gance to the plumage of many natural species. I have
also noticed a variety of the common pigeon with the wing-
bars symmetrically zoned with three bright shades, instead
of being simply black on a slaty-blue ground, as in the
parent-species.

In many groups of birds the plumage is differently col-
ored in the several species, yet certain spots, marks, or
stripes are retained by all. Analogous cases occur with the
breeds of the pigeon, which usually retain the two wing-
bars, though they may be colored red, yellow, white, black,
or blue, the rest of the plumage being of some wholly dif'.

48G THE DESCENT OF MAN,

fereut tint. Here is a more curious case, in which certain
marks are retained, though colored in a manner almost
exactly the opposite of what is natural ; the aboriginal
pigeon has a blue tail, with the terminal halves of the outer
webs of the two outer tail-feathers white ; now there
is a sub - variety having a white instead of a blue tail,
with precisely that part black which is white in the parent-

Formation and VariaUlUy of the Ocelli or Eye-Like
Spots on the Plumage of Birds. — As no ornaments are
more beautiful than the ocelli on the feathers of various
birds, on the hairy coats of some mammals, on the scales of
reptiles and fishes, on the skin of amphibians, on tlie wings
of many Lepidoptera and other insects, they deserve to be
especially noticed. An ocellus consists of a spot within a
ring, of another color, like the pupil within the iris, but
the central spot is often surrouded by additional concentric
zones. The ocelli on the tail-coverts of the peacock offer
a familiar example, as well as those on the wings of the
peacock-butterfly (Vanessa). Mr. Trimen has given me a
description of a South African moth {Gynanisa isis),
allied to our emperor moth, in w^hich a magnificent ocellus
occupies nearly the whole surface of each hinder wing ; it
consists of a black center, including a semi-transparent
crescent-shaped mark, surrounded by successive ocher-
yellow, black, ocher-yellow, pink, white, pink, brown and
whitish zones. Altliough we do not know the steps by
which these wonderfully beautiful and complex orna-
ments have been developed the process has probably been a
simple one, at least with insects; for, as Mr. Trimen writes
to me, " no characters of mere marking or coloration are
so unstable in the Lepidoptera as the ocelli, both in number
and size." Mr. Wallace, who first called my attention to
this subject, showed me a series of specimens of our
common meadow-brown butterfly {Hipparchia janira)
exhibiting numerous gradations from a simple minute black
spot to an elegantly shaded ocellus. In a South African
butterfly (Cyllo leda, Linn.), belonging to the same family,
the ocelli are even still more variable. In some specimens

I
I

*Beclistein, "Naturgeschichte Deutschlands," B. iv, 1795^ s. 31,
on a sub-variety of the Monck pigeon.

1

mnDs.

487

[a, fig. 53) large spaces on the upper surface of the wings
are colored black, and include irregular white marks; and
from this state a complete gradation can be traced into a
tolerably perfect ocellus («^), and this results from the
contraction of the irregular blotches of color. In another
series of specimens a gradation can be followed from
excessively minute white dots, surrounded by a scarcely
visible black line {i), into perfectly symmetrical and large

Fig. 53. Cyllo leda, Linn, from a drawing by Mr. Trimen, showing the extreme
range of variation in the ocelli.

a. Specimen, from Mauritius, upper

surface of fore wing.
a*. Specimen, from Natal, ditto.

b. Specimen, from Java, upper sur-
face of hind wing.
h^. Specimen, from Mauritius, ditto.

ocelli (h^)* In cases like these, the development of a
perfect ocellus does not require a long course of variation
and selection.

With birds and many other animals it seems to follow
from the comparison of allied species that circular spots
are often generated by the breaking up and contraction of
stripes. In the Tragopan pheasant faint white lines in the

* This wood-cut Las been engraved from a beautiful drawing, most
kindly made for me by Mr. Trimen; see also his description of the
wonderful amount of variation in tte coloration and shape of the
wings of this butterfly, in his " Rhopalocera Africee Australis," p.
186.

488 THE DESCENT OF MAIT.

female represent the beautiful white spots in the male-*
and something of the same kind may be observed in the
two sexes of the Argus pheasant. However this may be,
appearances strongly favor the belief that, on the one hand,
a dark spot is often formed by the coloring matter being
drawn toward a central point from a surrounding zone,
which latter is thus rendered lighter; and, on the other
hand, that a white spot is often formed by the color being
driven away from a central point, so that it accumulates in
a surrounding darker zone. In either case an ocellus is the
result. The coloring matter seeiiis to be a nearly constant
quantity, but is redistributed, either centripetally or cen-
trifugally. The feathers of the common guinea-fowl oifer
a good instance of white spots surrounded by darker zones;
and wherever the white spots are large and stand near each
other the surrounding dark zones become confluent. In
the same wing-feather of the Argus pheasant dark spots
may be seen surrounded by a pale zone and white spots by
a dark zone. Thus the formation of an ocellus in its most
elementary state appears to be a simple affair. By what
further steps the more complex ocelli, which are surrounded
by many successive zones of color, have been generated, I
will not pretend to say. But the zoned feathers of the
mongrels from differently colored fowls, and the extraor-
dinary variability of the ocelli on many Lepidoptera, lead
us to conclude that their formation is not a complex
process, but depends on some sliglit and graduated change
in the nature of the adjoining tissues.

Gradation of Secondary Sexual Characters. — Cases of
gradation are important as showing us that highly complex
ornaments may be acquired by small successive steps. In
order to discover the actual steps by which the male of any
existing bird has acquired his magnificent colors or other
ornaments we ought to behold the long line of his extinct
progenitors; but this is obviously impossible. We may,
however, generally gain a clew by comparing all the species
of the same group if it be a large one; for some of them
will probably retain, at least partially, traces of their
former characters. Instead of entering on tedious details
respecting various groups, in which striking instances of

< * Jerdon, " Birds of India," vol, iii, p. 617.

BIRDS. 489

gradation could be given, it seems the best plan to take
one or two strongly marked cases, for instance that of the
peacock, in order to see if light can be thrown on the steps
by which this bird has become so splendidly decorated.
The peacock is chiefly remarkable from the extraordinary
length of his tail-coverts; the tail itself not being much
elongated. The barbs along nearly the whole length of
these featliers stand separate or are decomposed; but this
is the case with the feathers of many species and with some
varieties of the domestic fowl and pigeon. The barbs
coalesce toward the extremity of the shaft forming the
oval disk or ocellus, which is certainly one of the most
beautiful objects in the world. It consists of an iridescent,
intensely blue, indented center, surrounded by a rich green
zone, this by a broad coppery-brown zone, and this by five
other narrow zones of slightly different iridescent shades.
A trifling character in the disk deserves notice; the barbs
for a space along one of the concentric zones are more or
less destitute of their barbules, so that a part of the disk is
surrounded by an almost transparent zone, which gives it a
highly finished aspect. But I have elsewhere described*
an exactly analogous variation in the hackles of a sub-
variety of the gamecock in which the tips, having a metallic
luster, " are separated from the lower part of the feather
by a symmetrically shaped transparent zone composed of
the naked portions of the barbs." The lower margin or
base of the dark blue center of the ocellus is deeply
indented on the line of the shaft. The surrounding zones
likewise show traces, as may be seen in the drawing (fig.
54), of indentations, or rather breaks. These indentations
are common to the Indian and Javan peacocks {Pavo
cristatus and P. muticus) ; and they seem to deserve
particular attention as probably connected with the devel-
opment of the ocellus; but for a long time I could not
conjecture their meaning.

If we admit the principle of gradual evolution there
must formerly have existed many species which presented
every successive step between the wonderfully elongated
tail-coverts of the peacock and the short tail-coverts of all
ordinary birds; and again between the magnificent ocelli

* "Variation of Animals and Plants under Domestication," vol. i,
p, 254.

400

THE DESCENT OF MAN.

of the former and the simpler ocelli or mere colored spots
oil other birds; and so with all the other characters of the
peacock. Let us look to the allied Gallinace^e for any still-
existing gradations. The species and sub-species of Poly-
plectron inhabit countries adjacent to the native land of the
peacock; and they so far resemble this bird that they are
sometimes called peacock-pheasants. I am also informed

I

Fig. 54. Feather of peacock, about two-thirds of natural size, drawn by Mr.
Ford. Tlie transparent zone is represented by the outermost white zone,
confined to the upper end of the disk.

by Mr. Bartlett that they resemble the peacock in their
voice and in some of their habits. During the spring the
males, as previously described, strut about before the com-
paratively plain-colored females, expanding and erecting
their tail and wing feathers, which are ornamented with
numerous ocelli. I request the reader to turn back to the
drawing (fig. 51) of a Polyplectron. In P. napoleonis
the ocelli are confined to the tail, and the back is of a rich

1

BIRDS. 491

metallic blue; in which respects this species approaches the
Java peacock. P. hai'dioichii possesses a peculiar top-knot,
which is also somewhat like that of the Java peacock. In
all the species the ocelli on the wings and tail are either
circular or oval, and consist of a beautiful, iridescent,
greenish-blue or greenish-purple disk with a black border.
This border in P. cMnquis shades into brown, edged with
cream color, so that the ocellus is here surrounded with
variously shaded, though not bright, concentric zones.
The unusual length of the tail-coverts is another remark-
able character in Polyplectron; for in some of the species
they are half and in others two-thirds as long as the true
tail feathers. The tail-coverts are ocellated as in the
peacock. Thus the several species of Polyplectron mani-
festly make a graduated approach to the peacock in the
length of their tail-coverts, in the zoning of the ocelli, and
in some other characters.

Notwithstanding this approach, the first species of Poly-
plectron which I examined almost made me give up the
search; for I found not only that the true tail-feathers which
in the peacock are quite plain, were ornamented with ocelli,
but that the ocelli on all the feathers differed fundament-
ally from those of the peacock, in there being two on the
same feather (fig. 55), one on each side of the shaft.
Hence I concluded that the early progenitors of the pea-
cock could not have resembled a Polyplectron. But on
continuing my search I observed that in some of the spe-
cies the two ocelli stood very near each other; that in the
tail-feathers of P. hardtoickii they touched each other ;
and finally that on the tail-coverts of this same species as
veil as of P, malacce?ise (fig. 56) they were actually con-

iient. As the central part alone is confluent, an indenta-
tion is left at both the upper and lower ends; and the sur-
rounding colored zones are likewise indented. A single
ocellus is thus formed on each tail-covert, though still
plainly betraying its double origin. These confluent ocelli
differ from the single ocelli of the peacock in having an
indentation at both ends instead of only at the lower or
basal end. The explanation, however, of this difference is
not difficult; in some species of Polyplectron the two oval
ocelli on the same feather stand parallel to each other; in
other species (as in P. chinquis) they converge toward one
©nd; now the partial confluence of two convergent ocelli

49^

THE DESCENT OF MAN.

would manifestly leave a much deeper indentation at the
divergent than at the convergent end. It is also manifest
that if the convergence were strongly pronounced and the
confluence complete, the indentation at the convergent end
would tend to disappear.

The tail-feathers in both species of the peacock are en-
tirely destitute of ocelli, and this apparently is related to
their being covered up and concealed by the long tail-
coverts. In this respect they differ remarkably from the

■ t

Fig. 55. Part of a tail-covert of Poly-
plectron chinquis, with the two
ocelli of natural size.

Fig. 56. Part of a tale-covert of Poly-
plectron malaccense, with the two
ocelli, partially confluent, of nat-
ural size.

tail-feathers of Polyplectron, which in most of the species
are ornamented with larger ocelli than those on the tail-
coverts. Hence I was led carefully to examine the tail-
feathers of the several species, in order to discover whether
their ocelli showed any tendency to disappear; and to my
great satisfaction this appeared to be so. The central tail-
feathers of P. napoleonis have the two ocelli on each side
of the shaft perfectly developed; but the inner ocellus be-
comes less and less conspicuous on the more exterior tail-
feathers, until a mere shadow or rudiment is left on the
inner side of the outermost feather. Again^ in F, rnalac*

BIRDS. 493

ce^ifie, the ocelli on the tail-coverts are, as we have seen,
oonfluent; and these feathers are of unusual length, being
two-thirds of the length of the tail-feathers, so that in both
these respects they approach the tail -coverts of the peacock.
Now in P. rnalaccense the two central tail-feathers alone
are ornamented, each with two brightly colored ocelli, the
inner occellus having completely disappeared from all the
other tail-feathers. Consequently the tail-coverts and tail-
feathers of this species of Polyplectron make a near approach
in structure and ornamentation to the corresponding feathers
of the peacock.

As far, then, as gradation throws light on the steps by
which the magnificent train of the peacock has been
acquired, hardly anything more is needed. If we picture
to ourselves a progenitor of the peacock in an almost
exactly intermediate condition between the existing peacock
with his enormously elongated tail-coverts ornamented with
single ocelli, and an ordinary gallinaceous bird with short
tail-coverts merely spotted with some color, we shall see a
bird allied to Polyplectron — that is, with tail-coverts capable
of erection and expansion, ornamented with two partially
confluent ocelli, and long enough almost to conceal the
tail-feathers, the latter having already partially lost their
ocelli. The indentation of the central disk and of the
surrounding zones of the ocellus in both species of peacock
speaks plainly in favor of this view and is otherwise inexpli-
cable. The males of the Polyplectron are no doubt beautiful
birds, but their beauty, when viewed from a little distance,
cannot be compared with that of the peacock. Many female
progenitors of the peacock must, during a long line of
descent, have appreciated this superiority; for they have
unconsciously, by the continued preference of the most
beautiful males, rendered the peacock the most splendid
of living birds.

Argus Pheasant. — Another excellent case for investiga-
tion is offered by the ocelli on the wing-feathers of the
Argus pheasant, which are shaded in so wonderful a
manner as to resemble balls lying loose within sockets and
consequently differ from ordinary ocelli. No one, I pre-
sume, will attribute the shading, which has excited the
admiration of many experienced artists, to chance — to the
fortuitous concourse of atoms of coloring matter. Th^t

494

THE DESCENT OF MAN.

these ornaments should have been formed through the selec-
tion of many successive vari^ions, not one of which was
originally intended to produce the ball-and-socket effect,
seems as incredible as that one of Eaphears Madonnas
should have been formed by the selection of chance daubs

of paint made by a long
ABC succession of young art-
ists, not one of whom
intended at first to draw
the human figure. In
order to discover how
the ocelli have been
developed we cannot
look to a long line of
progenitors nor to many
closely allied forms, for
such do not now exist.
But fortunately the
several feathers on the
wing suffice to give us
a clew to the problem,
and they prove to dem-
onstration that a gra-
dation is at least pos-
sible from a mere spot
to a finished ball-and-
socket ocellus.

The wing - feathers,
bearing the ocelli, are
covered with dark
stripes (fig. 57) or
with rows of dark spots
(fig. 59), each stripe or

Fig. 57. Part of secondary wing-feather of ^^^ ^-c cr^nfa rnmiino-

Argus pheasant, showing two perfect ocelli, ^^W 01 SpotS running

a and b. A, B, C, D, etc., are dark stripes obliquely down the

running obliquely down, each to an ocellus, ^^ter side of the shaft

[Much of the web on both sides, especially -^ ^^_- ^<! x-i^ ^^olli

to the left of the shaft, has been cut off.] tO one 0± the OCelll.

The spots are gen-
erally elongated in a line transverse to the row in which
they stand. They often become confluent either in the line
of the row — and then they form a longitudinal stripe — or
transversely, that is, with the spots in the adjoining rows,
pjid then they form transverse stripes. A spot sometimes

BIRDS.

495

breaks up into smaller spots, which still stand in their proper
places.

It will be convenient first to describe a perfect ball-and-
socket ocellus. This consists of an intensely black circular
ring, surrounding a space shaded so as exactly to resemble
a ball. The figure here given has been admirably drawn
by Mr. Ford and well en-
graved, but a wood-cut
cannot exhibit the exqui-
site shading of the original.
The ring is almost always
slightly broken or inter-
rupted (see fig. 57) at a
point in the upper half a
little to the right of and
above the white shade on
the inclosed ball; it is also
sometimes broken toward
thebase on the right hand.
These little breaks have an
important meaning. The
ring is always much thick-
ened, with the edges ill-
defined toward the left-
hand upper corner, the
feather being held erect in
the position in which it is
here drawn. Beneath this
thickened part there is on
the surface of the ball an ob-
Hque, almost pure white mark which shades off downward
into a pale-leaden hue, and this into yellowish and brown
tints, which insensibly become darker and darker toward tlie
lower part of the ball. It is this shading which gives so
admirably the effect of light shining on a convex surface.
If one of the balls be examined it will be seen that the
lower part is of a brown tint and is indistinctly separated
by a curved oblique line from the upper part, which is yel-
lower and more leaden; this curved oblique line runs at
right angles to the longer axis of the white patch of light,
and indeed of all the shading; but this diffei'ence in color,
which cannot of course be shown in the wood-cut, does not
in the least interfere with the perfect shading of the ball.

Fig. 58. Basal part of the seconflary
wing-feather nearest to the body.

496 THE DESCENT OF MAN.

It should be particularly observed that each ocellus stands
in obvious connection either with a dark stripe or with a
longitudinal row of dark spots, for both occur indifferently
on the same feather. Thus in fig. 57 stripe A runs to
ocellus a; B runs to ocellus d; stripe C is broken in the
upper part and runs down to the next succeeding ocellus,
not represented in the wood-cut; D to the next lower one,
and so with the stripes E and F. Lastly the several ocelli
are separated from each other by a pale surface bearing
irregular black marks.

I will next describe the other extreme of the series,
namely, the first trace of an ocellus. The short secondary
wing-feather (fig. 58^, nearest to the body, is marked like
the other feathers, with oblique, longitudinal, rather irreg-
ular rows of very dark spots. The basal spot, or that near-
est the shaft in the five lower rows (excluding the lowest
one), is a little larger than the other spots of the same row,
and a little more elongated in a transverse direction. It
differs also from the other spots by being bordered on its
upper side with some dull fulvous shading. But this spot
is not in any way more remarkable than those on the plum-
age of many birds, and might easily be overlooked. The
next higher spot does not differ at all from the upper ones
in the same row. The larger basal spots occupy exactly
the same relative position on these feathers as do the per-
fect ocelli on the longer wing-feathers.

By looking to the next two or three succeeding wing-
feathers, an absolutely insensible gradation can be traced
from one of the last described basal spots, together with the
next higher one in the same row, to a curious ornament,
which cannot be called an ocellus, and which I will name,
from the want of a better term, an ^'elliptic ornament."
These are shown in the accompanying figure (fig. 59). We
here see several oblique rows. A, B, C, D, etc. (see the let-
tered diagram on the right hand), of dark spots of the
usual character. Each row of spots runs down to and is
connected with one of the elliptic ornaments, in exactly
the same manner as each stripe in fig. 57 runs down to,
and is connected with, one of the ball-and-socket ocelli.
Looking to any one row, for instance, B, in fig. 59, the
lowest mark {h) is thicker and considerably longer than the
upper spots, and has its left extremity pointed and curved
upward. This black mark is abruptly bordered on its

BIRDS,

m

upper side by a rather broad space of richly shaded tints,
begiuning with a narrow brown zone, which passes into
orange, and this into a pale leaden tint, with the end toward
the shaft much paler. These shaded tints together fill up
the whole inner space of the elliptic ornament. The mark

Fig:. 59. Portion of one of the secondary wine-feathers near the body, showing
the so-called elliptic ornaments. The ri^ht-hand figure is given merely as
a diagram for the sake of the letters of reference.

A, B, C, D, etc. Rows of spots running down to and forming the elliptio

ornaments.
6. Lowest spot or mark in row B.

c. The next succeeding spot or mark in the same row.

d. Apparently a broken prolongation of the spot C in the same row B.

(h) corresponds in every respect with the basal shaded spot
of the simple feather described in the last paragraph (fig.
58), but is more highly developed and more brightly col-
ored. Above and to the right of this spot {i fig. 59), with
its bright shading, there is a long, narrow, black mark {c),
belonging to the same row, and which is arched a little
downward so as to face {h). This mark is sometimes broken
into two portions. It is also narrowly edged on the lower
side with a fulvous tint. To the left of and above (c), in
the same oblique direction, but always more or less distinct

498 THE DESGBNT OF MAN.

from it, there is another black mark (d). This mark is
generally sub- triangular and irregular in shape, but in the
one lettered in the diagram it is unusually narrow, elon-
gated and regular. It apparently consists of a lateral and
broken prolongation of the mark (c), together with its con-
fluence with a broken and prolonged part of the next spot
above; but I do not feel sure of this. These three marks,
{h)f [c) and [d), with the intervening bright shades, form
together the so-called elliptic ornament. These ornaments
placed parallel to the shaft, manifestly correspond in posi-
tion with the ball-and-socket ocelli. Their extremely ele-
gant appearance cannot be appreciated in the drawing, as
the orange and leaden tints, contrasting so well with the
black marks, cannot be shown.

Between one of the elliptic ornaments and a perfect
ball-and-socket ocellus the gradation is so perfect that it is
scarcely possible to decide when the latter term ought to be
used. The passage from the one into the other is effected
by the elongation and greater curvature in the opposite
directions of the lower black mark {b fig. 59), and more
especially of the upper one {c), together with the contrac-
tion of the elongated sub-triangular or narrow mark i^d), so
that at last these three marks become confluent, forming an
irregular elliptic ring. This ring is gradually rendered
more and more circular and regular, increasing at the same
time in diameter. I have here given a drawing (fig. 60) of
the natural size of an ocellus not as yet quite perfect.
The lower part of the black ring is much more curved than is
the lower mark in the elliptic ornament (h fig. 59). The
upper part of the ring consists of two or three separate
portions; and there is only a trace of the thickening of the
portion which forms the black mark above the white shade.
This white shade itself is not as yet much concentrated;
and beneath it the surface is brighter colored than in a per-
fect ball-and-socket ocellus. Even in the most perfect
ocelli traces of the junction of three or four elongated
black marks, by which the ring has been formed, may often
be detected. The irregular sub-triangular or narrow mark
{d fig. 59), manifestly forms, by its contraction and equal-
ization, the thickened portion of the ring above the white
shade on a perfect balhand-socket ocellus. The lower part
of the ring is invariably a little thicker than the other
parts (see fig. 57), and this follows from the lower black

BIRDS,

400

mark of the elliptic ornament {b Us. 59) having originally
been thicker than the upper mark (c). Every step can be
followed in the process of confluence and modification: and
the black ring which sur-
rounds the ball of the ocellus
is unquestionably formed by
the union and modification
of the three black marks, b, c,
dy of the elliptic ornament.
The irregular zigzag black
marks between the successive

Fig. 60.

Fig. 61.

Pig. 60. An ocellus in an intermedate condition between the elliptic ornament

and the perfect ball-and-socket ocellus.
Fig. 61. Portion near summit of one of the secondary wing-feathers, bearing

perfect ball-and-socket ocelli, a. Ornamented upper part. 6. Uppermost.

imperfect ball-and-socket ocellus. (The shading above the white mark on

the summit of the ocellus is here a little too dark.) c. Perfect ocellus.

ooelli (see again fig. 57) are plainly due to the breaking up
of the somewhat more regular but similar marks between
the elliptic ornaments.

The successive steps in the shading of the ball-and-
socket ocelli can be followed out with equal clearness.
The brown, orange and pale-leadened narrow zones which
border the lower black mark of the ellintic ornament can

600 tBE DESCENT OF MAN.

be seen gradually to become more and more softened and
shaded into each other, with the npper lighter part toward
the left-hand corner rendered still lighter, so as to become
almost white and at the same time more contracted. But
even in the most perfect ball-and-socket ocelli a slight dif-
ference in the tints, though not in the shading, between
the upper and lower parts of the ball can be perceived, as
before noticed; and the line of separation is oblique in the
same direction as the bright-colored shades of the elliptic
ornaments. Thus almost every minute detail in the shape
and. coloring of the ball-and-socket ocelli can be shown to
follow from gradual changes in the elliptic ornaments; and
the development of the latter can be traced by equally
small steps from the union of two almost simple spots, the
lower one (fig. 58) having some dull fulvous shading on its
upper side.

The extremities of the longer secondary feathers which
bear the perfect ball-and-socket ocelli are peculiarly orna-
mented (fig. 61). The oblique longitudinal stripes sud-
denly cease upward and become confused; and above this
limit the whole upper end of the feather {a) is covered
with white dots surrounded by little black rings standing
on a dark ground. The oblique stripe belonging to the
uppermost ocellus {h) is barely represented by a very short
irregular black mark with the usual curved, transverse
base. As this strii3e is thus abruptly cut off we can per-
haps understand from what has gone before how it is that
the upper thickened part of the ring is here absent; for, as
before stated, this thickened part apparently stands in
some relation with a broken prolongation from the next
higher spot. From the absence of the upper and thickened
part of the ring the uppermost ocellus, though perfect in
all other respects, appears as if its top had been obliquely
sliced off. It would, I think, perplex any one who believes
that the plumage of the Argus pheasant was created as we
now see it to account for the imperfect condition of the
uppermost ocellus. I should add that on the secondary
wing-feather farthest from the body all the ocelli are
smaller and less perfect than on the other feathers and
have the upper part of the ring deficient, as in the case
just mentioned. The imperfection here seems to be con-
nected with the fact that the spots on this feather show
less tendency than usual to become confluent into stripes;

1

BIBDS, 501

they are, on the contrary, often broken up into smaller
spots, so that two or three rows run down to the same
ocellus.

There still remains another very curious point, first
observed by Mr. T. W. Wood,* which deserves attention.
In a photograph, given me by Mr. Ward, of a specimen
mounted as in the act of display, it may be seen that on the
feathers which are held perpendicularly, the white marks
on the ocelli, representing light reflected from a convex
surface, are at the upper or farther end, that is, are directed
upward; and the bird while displaying himself on the
ground would naturally be illuminated from above. But
here comes the curious point, the outer feathers are held
almost horizontally, and their ocelli ought likewise to
appear as if illuminated from above, and consequently the
white marks ought to be placed on the upper sides of the
ocelli; and, wonderful as is the fact, they are thus placed!
Hence the ocelli on the several feathers, though occupying
very different positions with respect to the light, all appear
as if illuminated, from above, just as an artist would have
shaded them. Nevertheless they are not illuminated from
strictly the same point as they ought to be; for the white
marks on the ocelli of the feathers, which are held almost
horizontally, are placed rather too much toward the farther
end; that is, they are not sufficiently lateral. We have,
however, no right to expect absolute perfection in a part
rendered ornamental through sexual selection, any more
than we have in a part modified through natural selection
for real use; for instance, in that wondrous organ the
human eye. And we know what Helmholtz, the highest
authority in Europe on the subject, has said about the
human eye, that if an optician had sold him an instrument
so carelessly made, he would have thought himself fully
justified in returning it.f

We have now seen that a perfect series can be followed,
from simple spots to the wonderful ball-and-socket orna-
ments. Mr. Gould, who kindly gave me some of these
feathers, fully agrees with me in the completeness of the
gradation. It is obvious that the stages m development

* The '' Field," May 28, 1870.

t " Popular Lectures on Scientific Subjects," Eng. trans., 1873, pp
819 227, 269, 390.

502 THE DESCENT OF MAN.

exhibited by the feathers on the same bird do not at all
necessarily show iis the steps passed through by the extinct
progenitors of the species; but they probably give us the
clue to the actual steps, and they at least prove to demon-
stration that a gradation is possible. Bearing in mind liow
carefully the male Argus pheasant displays his plumes
before the female, as well as the many facts rendering it
probable that female birds prefer the more attractive males,
no one who admits the agency of sexual selection in any
case will deny that a simple dark spot with some fulvous
shading might be converted, through the approximation
and modification of two adjoining spots, together with
some slight increase of color, into one of the so-called ellip-
tic ornaments. These latter ornaments have been shown
to many persons, and all have admitted that they are beau-
tiful, some thinking them even more so than the ball-and-
socket ocelli. As the secondary plumes became lengthened
through sexual selection, and as the elliptic ornaments
increased in diameter, their colors apparently became less
bright; and then the ornamentation of the plumes had to
be gained by an improvement in the pattern and shading ;
and this process was carried on until the wonderful ball-
and-socket ocelli were finally developed. Thus we can
understand — and in no other way as it seems to me — the
present condition and origin of the ornaments on the
wing-feathers of the Argus pheasant.

From the light afforded by the principle of gradation —
from what we know of the laws of variation — from the
changes which have taken place in many of our domesti-
cated birds — and, lastly, from the character (as we shall
hereafter see more clearly) of the immature plumage of
young birds — we can sometimes indicate, with a certain
amount of confidence, the probable steps by which the
males have acquired their brilliant plumage and various
ornaments; yet in many cases we are involved in complete
darkness. Mr. Gould several years ago pointed out to me
a humming-bird, the Urosticte benjammiy remarkable for
the curious differences between the sexes. The male,
besides a splendid gorget, has greenish-black tail-feathers
with the four central ones tipped with white; in the female,
as with most of tiie allied species, the three outer tail-
feathers on each side are tipped with white, so that the

BIRDS. 503

male has the four central, while the female has the six exte-
rior feathers ornamented with white tips. What makes the
case more curious is that, although the coloring of the tail
differs remarkably in both sexes of many kinds of hum-
ming-birds, Mr. Gould does not know a single species,
besides the Urosticte, in which the male has the four central
feathers tipped with white.

The Duke of Argyll, in commenting on this case,*
passes over sexual selection, and asks: ^* What explanation
does the law of natural selection give of such specific
varieties as these ?'' He answers ^' none whatever;" and I
quite agree with him. But can this be so confidently
said of sexual selection ? Seeing in how many ways the
tail-feathers of humming-birds differ, why should not
the four central feathers have varied in this one species alone,
so as to have acquired white tips ? The variations may
have been gradual or somewhat abrupt, as in the case
recently given of the humming-birds near Bogota, in which
certain individuals alone have the " central tail-feathers
tipped with beautiful green." In the female of the Urosticte
I noticed extremely minute or rudimental white tips to the
two outer of the four central black tail-feathers; so that
here we have an indication of change of some kind in the
plumage of this species. If we grant the possibility of the
central tail feathers of the male varying in whiteness, there
is nothing strange in such variations having been sexually
selected. The white tips, together with the small white
ear- tuffs, certainly add, as the Duke of Argyll admits, to
the beauty of the male ; and whiteness is apparently appre-
cited by other birds, as may be inferred from such cases as
the snow-white male of the bell-bird. The statement made
by Sir R. Heron should not be forgetten, namely, that his
peahens, when debarred from access to tlie pied peacock,
would not unite with any other male, and during that season
produced no offspring. Nor is it strange that variations in
the tail-feathers of the Urosticte should have been specially
selected for the sake of ornament, for the next succeeding
genus in the family takes its name of Metallura from the
splendor of these feathers. AVe have, moreover, good
evidence that humming-birds take especial pains in dis-

*" The Reign of Law," 1867, p. 347.

504

THE DESCENT OF MAN.

playing their tail-feathers; Mr. Belt,* after describing the
beauty of the Florisitga mellivora, says: '* I have seen the
female sitting on a branch and two males displaying their
charms in front of her. One would shoot up like a rocket,
then, suddenly expanding the snow-white tail, like an
inverted paracFiute, slowly descend in front of her, turning
round gradually to show off back and front. . . . The
expanded white tail covered more space than all the rest of
the bird, and was evidently the grand feature in the per-
formance. While one male was descending the other
would shoot up and come slowly down expanded. The
entertainment would end in a fight between the two per-
formers; but whether the most beautiful or the most pugna-
cious was the accepted suitor, I know not.^^ Mr. Gould,
after describing the peculiar plumage of the Urosticte,
adds, "^ that ornament and variety is the sole object, I have
myself but little doubt."f If this be admitted, we can per-
ceive that the males which during former times were
decked in the most elegant and novel manner would have
gained an advantage, not in the ordinary struggle for life,
but in rivalry with other males, and would have left a
larger number of off'spring to inherit their newly acquired
beauty.

***Tlie Naturalist in Nicaragua," 1874, p. 112.
f "Introduction to tlie Trochilidje," 1861, p. 110.

BIRDS. 505

CHAPTER XV.

BIRDS — continued.

Discussion as to why tlie males alone of some species, and both sexes
of others, are brightly colored — On sexually limited inheritance,
as applied to various structures and to brightly colored plumage
— Nidification in relation to color — Loss of nuptial plumage dur-
ing the winter.

We have in this chapter to consider why the females of
many birds have not acquired the same ornaments as the
male; and why, on the other hand, both sexes of many
other birds are equally, or almost equally, ornamented? In
the following chapter we shall consider the few cases
in which the female is more conspicuously colored than the
male.

In my *' Origin of Species"* I briefly suggested that
the long tail of the peacock would be inconvenient and the
conspicuous black color of the male capercailzie dangerous
to the female during the period of incubation; and conse-
quently that the transmission of these characters from the
male to the female offspring had been checked through
natural selection. I still think that this may have occurred
in some few instances; but after mature reflection on all
the facts which I have been able to collect, I am now
inclined to believe that when the sexes dilfer the successive
variations have generally been from the first limited in
their transmission to the same sex in which they first
arose. Since my remarks appeared the subject of sexual
coloration has been discussed in some very interesting
papers by Mr. Wallace,! who believes that in almost all
cases the successive variations tended at first to be trans-
mitted equally to both sexes; but that the female was saved,

* Fourth edition, 1866, p. 241.

f " Westminster Review," July, 1867. '* Journal of Travel," vol.
I, 1868, p. 73.

506 THE DESCENT OF MAK,

through natural selection, from acquiring the conspicuous
colors of the male, owing to the danger which she would
thus have incurred during incubation.

This view necessitates a tedious discussion on a difficult
point, namely, whether the transmission of a character
which is at first inherited by both sexes can be subsequently
limited in its transmission to one sex alone by means of
natural selection. We must bear in mind, as shown in the
preliminary chapter on sexual selection, that characters
which are limited in tlieir development to one sex are
always latent in the other. An imaginary illustration vill
best aid us in seeing the difficulty of the case; we may sup-
pose that a fancier wished to make a breed of pigeons, in
which the males alone should be colored of a pale blue,
while the females retained their former slaty tint. As with
pigeons characters of all kinds are usually transmitted to
both sexes equally, the fancier \vould have to try to convert
this latter form of inheritance into sexually limited trans-
mission. All that he could do would be to persevere in
selecting every male pigeon which was in the least degree
of a paler blue; and the natural result of this process, if
steadily carried on for a long time, and if the pale varia-
tions were strongly inherited or often recurred, would be
to make his whole stock of a lighter blue. But our fancier
would be compelled to match, generation after generation,
his pale-blue males with slaty females, for he wishes to keep
the latter of this color. The result would generally be the
production either of a mongrel piebald lot, or more prob-
ably the speedy and complete loss of the pale-blue tint; for
the primordial slaty color would be transmitted with pre-
potent force. Supposing, however, that some pale-blue
males and slaty females were produced during each succes-
sive generation, and were always crossed together, then the
slaty females would have, if I may use the expression, muc
blue blood in their veins, for their fathers, grandfathers,
etc., will all have been blue birds. Under these circum-
stances it is conceivable (though I know of no distinct facti
rendering it probable) that the slaty females might acquire
so strong a latent tendency to pale-blueness that they would
not destroy this color in their male offspring, their femal '
offspring still inheriting the slaty tint. If so, the desired
end of making a breed with the two sexes permanently dif-
ferent in color might be gained.

le

I

i

BIRDS, 507

The extreme importance, or rather necessity, in the
above case of the desired character, namely, pale-blueness,
oeing present though in a latent state in the female, so that
the male offspring should not be deteriorated, will be best
appreciated as follows: the male of Soemmerring's pheasant
has a tail thirty-seven inches in length, while that of the
female is only eight inches; the tail of the male common
pheasant is about twenty inches, ^nd that of the female
twelve inches long. Now if the female Soemmerring pheas-
ant with her sliort tail were crossed with the male common
pheasant there can be no doubt that the male hybrid off-
spring would have a much longer tail than that of th© pure
offspring of the common pheasant. On the other hand, if
the female common pheasant, with a tail much longer than
that of the female Soemmerring pheasant, were crossed with
the male of the latter, the male hybrid offspring would
have a much shorter tail than that of the pure offspring of
Soemmerrin^'s pheasant. *

Our fancier, in order to make his new breed with the
males of a pale-blue tint, and the females unchanged,
would have to continue selecting the males during many
generations; and each stage of paleness would have to be
fixed in the males, and rendered latent in the females. The
task would be an extremely difficult one, and has never
been tried, but might possibly be successfully carried out.
The chief obstacle would be the early and complete loss of
the pale-blue tint, from the necessity of reiterated crosses
with the slaty female, the latter not having at first any
late7it tendency to produce pale-blue offspring.

On the other hand, if one or two males were to vary ever
80 slightly in paleness, and the variations were from the
first limited in their transmission to the male sex, the task
of making a new breed of the desired kind would be easy,
for such males would simply have to . be selected and
matched with ordinary females. An analogous case has
actually occurred, for there are breeds of the pigeon in
Belgium \ in which the males alone are marked with black

* Temminck says tliat the tail of the female Phasianus Smmmer-
ringii is only six inches long, " Planches coloriees," vol. v, 1838, pp.
487, 488; the measurements above given were made for me by Mr.
Sclater. For the common pheasant, see Macgillivray, "Hist. Brit
Birds," vol. i, pp. 118-121.

f Dr. Chapius, " Le Pigeon Vo^ageur Beige," 1865, p. 87.

508 TEE DESCENT OF MAN,

striae. So again Mr. Tegetmeier has recently shown * that
dragons not rarely produce silver-colored birds^ which are
almost always hens; and he himself has bred ten such
females. It is on the other hand a very unusual event
when a silver male is produced; so that nothing would be
easier, if desired, than to make a breed of dragons with
blue males and silver females. This tendency is indeed bo
strong that when Mr. Tegetmeier at last got a silver male
and matched him with one of the silver females he
expected to get a breed with both sexes thus colored ; he
was, however, disappointed, for the young male reverted to
the blue color of his grandfather, the young female alone
being silver. No doubt with patience this tendency to
reversion in the males, reared from an occasional silver male
matched with a silver hen, might be eliminated, and then
both sexes would be colored alike; and this very process has
been followed with success by Mr. Esquilant in the case of
silver turbits.

With fowls, variations of color, limited in their trans-
mission to the male sex, habitually occur. When this form
of inheritance prevails it might well happen that some of
the successive variations would be transferred to the female,
who would then slightly resemble the male, as actually
occurs in some breeds. Or again, the greater number, but
not all, of the successive steps might be transferred to both
sexes, and the female would then closely resemble the
male. There can hardly be a doubt that this is the cause
of the male pouter pigeon having a somewhat larger crop,
and of the male carrier pigeon having somewhat larger
wattles than their respective females ; for fanciers have
not selected one sex more than the other, and have had no
wish that these characters should be more strongly dis-
played in the mj^le than in the female, yet this is the case
with both breeds.

The same process would have to be followed and the
same difficulties encountered if it were desired to make a
breed with the females alone of some new color.

Lastly, our fancier might wish to make a breed with the
two sexes differing from each other, and both from the
parent species. Here the difficulty would be extreme
unless the successive variations were from the first sexually

***Th§ Field," Sept., 1872.

9
I

I

BIRDS. 509

limited on both sides, and then there would be no diffi-
culty. We see this with the fowl; thus the two sexes of
the penciled Hamburghs differ greatly from each other,
and from the two sexes of the aboriginal Gallus hankiva;
and both are now kept constant to their standard of excel-
lence by continued selection which would be impossible
unless the distinctive characters of both were limited in
their transmission.

The Spanish fowl offers a more curious case; the male
has an immense comb, but some of the successive varia-
tions, by the accumulation of which it was acquired, appear
to have been transferred to the female; for she has a comb
many times larger than that of the females of the parent
species. But the comb of the female differs in one respect
from that of the male, for it is apt to lop over; and within a
recent period it has been ordered by the fancy that this
should always be the case, and success has quickly followed
the order. Now the lopping of the comb must be sexually
limited in its transmission, otherwise it would prevent the
comb of the male from being perfectly upright, which
would be abhorrent to every fancier. On the other hand,
the uprightness of the comb in the male must likewise be
a sexually limited character, otherwise it would prevent the
comb of the female from lopping over.

From the foregoing illustrations we see that even with
almost unlimited time at command it would be an ex-
tremely difficult and complex, perhaps an impossible pro-
cess, to change one form of transmission into the other
through selection. Therefore, without distinct evidence
in each case, I am unwilling to admit that this has been
effected in natural species. On the other hand, by means
of successive variations, which were from the first sexually
limited in their transmission, there would not be the least
difficulty in rendering a male bird widely different in color
or in any other character from the female; the latter being
left unaltered, or slightly altered, or specially modified for
the sake of protection.

As bright colors are of service to the males in their
rivalry with other males, such colors would be selected
whether or not they were transmitted exclusively to the
same sex. Consequently the females might be expected
often to partake of the brightness of the males to a greater
or less degree; and this occurs with a host of species.

510 THE DEbGENT OF MAN.

If all tlie successive variations were transmitted onually
to both sexes the females would be indistinguishable from
the males ; and this likewise occurs with many birds.
If, however, dull colors were of high importance for the
safety of the female during incubation, as with many
ground birds, the females which varied in brightness
or which received through inheritance from the males
any marked accession of brightness would sooner or later
be destroyed. Bat the tendency in the males to continue
for an indefinite period transmitting to their female off-
Bpring their own brightness, would have to be eliminated
by a change in the form of inheritance; and this, as shown
by our previous iUustration, would be extremely difficult.
The more probable result of the long-continued destruc-
tion of the more brightly colored females, supposing the
equal form of transmission to prevail, would be the lessen-
ing or annihilation of the bright colors of the males,
owing to their continual crossing with the dulle-r females.
It would be tedious to follow out all the other possible
results; but I may remind the reader that if sexually lim-
ited variations in brightness occurred in the females, even
if they were not in the least injurious to them and conse-
quently were not eliminated, yet they would not be favored
or selected, for the male usually accepts any female, and
does not select the more attractive individuals ; conse-
quently these variations would be liable to be lost, and
would have little influence on the character of the race; and
this will aid in accounting for the females being commonly
duller-colored than the males.

In the eighth chapter instances were given, to which
many might here be added, of variations occurring at vari-
ous ages and inherited at the corresponding age. It was
also shown that variations which occur late in life are com-
monly transmitted to the same sex in which they first
appear; while variations occurring early in life are apt to
be transmitted to both sexes; not that all the cases of sexu-
ally limited transmission can thus be accounted for. It
was further shown that if a male bird varied by becoming
brighter while young, such variations would be of no ser-
vice until the age for reproduction had arrived, and there
was competition between rival males. But in the case of
birds living on the ground and commonly in need of the
protection of dull colors, bright tints would be far more

1

BIRDS. 611

dangerous to the young and inexperienced than to the
adult males. Consequently the males which varied in
brightness while young would suifer much destruction and
be eliminated througli natural selection; on the other hand,
the males which varied in this manner when nearly mature,
notwithstanding that they were exposed to some additional
danger, might survive, and, from being favored through
sexual selection, would procreate their kind. As a relation
often exists between the period of variation and the form
of transmission, if the bright-colored young males were
destroyed and the mature ones were successful in their
courtship, the males alone would acquire brilliant colors
and would transmit them exclusively to their male off-
spring. But I by no means wish to maintain that the
influence of age on the form of transmission is the sole
cause of the great difference in brilliancy between the
sexes of many birds.

When the sexes of birds differ in color it is interesting
to determine whether the males alone have been modified
by sexual selection, the females having been left unchanged
or only partially and indirectly thus changed; or whether
the females have been specially modified through natural
selection for the sake of protection. I will, tlieref ore, dis-
cuss this question at some length, even more fully than its
intrinsic importance deserves; for various curious collateral
points may thus be conveniently considered.

Before we enter on the subject of color, more especially
in reference to Mr. Wallace^s conclusions, it may be
useful to discuss some other sexual differences under a similar
point of view. A breed of fowls formerly existed in Ger-
many * in which the hens were furnished with spurs; they
were good layers, but they so greatly disturbed their nests
with their spurs that they could not be allowed to sit on
their own eggs. Hence at one time it appeared to me
probable that with the females of the wild Gallinacese the
development of spurs had been checked through natural
selection from the injury thus caused to their nests. This
seemed all the more probable, as wing-spurs, "vvhich would
not be injurious during incubation, are often as well
developed in the female as in the male; though in not a

*Beclistein, "Naturgesch. Deutschlands/' 1793, B. iii, s. 339.

512 THE DESCENT OF MAN.

few cases they are rather larger in the male. When the
male is furnished with leg-spurs the female almost always
exhibits rudiments of them — the rudiment sometimes con-
sisting of a mere scale, as in Gallus. Hence it might be
argued that the females had aboriginally been furnished
with well-developed spurs, but that these had subsequently
been lost through disuse or natural selection. But if this
view be admitted it would have to be extended to innumer-
able other cases; and it implies that the female progenitors
of the existing spur-bearing species were once incumbered
with an injurious appendage.

In some few genera and species, as in Galloperdix,
Acomus and the Javan peacock {Pavo miiticus), the
females, as well as the males, possess well-developed leg-
spurs. Are we to infer from this fact that they construct
a different sort of nest from that made by their nearest
allies, and not liable to be injured by their spurs, so that
the spurs have not been removed ? Or are we to suppose
that the females of these several species especially require
spurs for their defense ? It is a more probable conclusion
that both the presence and absence of spurs in the females
result from different laws of inheritance having prevailed,
independently of natural selection. With the many
females in which spurs appear as rudiments we may con-
clude that some few of the successive variations, through
which they were developed in the males, occurred very
early in life and were consequently transferred to the
females. In the other and much rarer cases in which the
females possess fully developed spurs we may conclude
that all the successive variations were transferred to them;
and that they gradually acquired and inherited the habit
of not disturbing their nests.

The vocal organs and the feathers variously modified for
producing sound, as well as the proper instincts for using
them, often differ in the two sexes, but are sometimes the
same in both. Can such differences be accounted for by the
males having acquired these organs and instincts, while the
females have been saved from inheriting them, on account
of the danger to which they would have been exposed by
attracting the attention of birds or beasts of prey? This
does not seem to me probable, when we think of the
multitude of birds which with impunity gladden tliQ

I

Jk

BIRDS. 513

country with their voices during the spring. * It is a safer con-
clusion that, as vocal and instrumental organs are of special
service only to the males during their courtship, these
organs were developed through sexual selection and their
constant use in that sex alone — the successive variations
and the effects of use having been from the first more or less
limited in transmission to the male offspring.

Many analogous cases could be adduced ; those, for
instance, of the plumes on the head being generally longer
in the male than in the female, sometimes of equal length
in both sexes, and occasionally absent in the female — these
several cases occurring in the same group of birds. It
would be difficult to account for such a difference between
the sexes by the female having been benefited by possessing
a slightly shorter crest than the male, and its consequent
diminution or complete suppression through natural selec-
tion. But I will take a more favorable case, namely, the
length of the tail. The long train of the peact)ck would
have been not only inconvenient but dangerous to the
peahen during the period of incubation and while accom-
panying her young. Hence, there is not the least a priori
improbability in the development of her tail having been
checked through natural selection. But the females of
various pheasants, which apparently are exposed on their
open hosts to as much danger as the peahen, have tails of
considerable length. The females as well as the males of
the Menura superha have long tails, and they build a
domed nest, which is a great anomaly in so large a bird.
Naturalists have wondered how the female menura could
manage her tail during incubation; but it is now known f
that she *' enters the nest head first, and then turns round,
with her tail sometimes over her back, but more often bent
round by her side. Thus in time the tail becomes quite
askew, and is a tolerable guide to the length of time the
bird has been sitting.'^ Both sexes of an Australian king-
fisher (Tanysiptera sylvid) have the middle tail-feathers
greatly lengthened, and tne female makes her nest in a

* Daines Barrington, liowever, thought it probable (" Phil. Trans-
act.," 1773, p. 164) that few female birds sing, because the talent
would have been dangerous to them during incubation. He adds
that a similar view may possibly account for the inferiority of the
female to the male in plumage.

fMr. Hamsay, in "Proc. Zoolog. Soc," 1868, p. 50.

614 THE DESCENT OF MAN.

hole; and, as I am informed by Mr. E. B. Sharpe, these

feathers become much crumpled during incubation.

In these two latter cases the great length of the tail-
feathers must be in some degTee inconvenient to the female;
and as in both species the tail-feathers of the female are
somewhat shorter than those of the male, it might be
argued that their full development had been prevented
through natural selection. But if the development of the
tail of the peahen had been checked only when it became
incor veniently or dangerously great she would have retained
a much longer tail than she actually possesses; for her tail
is not nearly so long, relatively to the size of her body, as
that of many female pheasants, nor longer than that of
the female turkey. It must also be borne in mind that, in
accordance with this view, as soon as the tail of the peahen
became dangerously long, and its development was conse-
quently checked, she would have continually reacted on her
male prd^eny, and thus have prevented the peacock from
acquiring his present magnificent train. We may, there-
fore, infer that the length of the tail in the peacock and
its shortness in the peahen are the result of the requisite
variations in the male having been from the first trans-
mitted to the male offspring alone.

We are led to a nearly similar conclusion with respect to
the length of the tail in the various species of pheasants.
In the eared pheasant ( Crossoptilon aicritum) the tail is of
equal length in both sexes, namely, sixteen or seventeen
inches; in the common pheasant it is about twenty inches
long in the male and twelve in the female; in Scemmerring's
pheasant, thirty-seven inches in the male and only eight in
the female; and lastly, in Eeeve's pheasant it is sometimes
actually seventy-two inches long in the male and sixteen
in tlie female. Thus in the several species the tail of the
female differs much in length irrespectively of that of the
male; and this can be accounted for, as it seems to me,
with much more probability, by the laws of inheritance—
that is, by the successive variations having been from the
first more or less closely limited in their transmission to
the male sex than by the agency of natural selection,
resulting from the length of tail being more or less injuri-
ous to the females of these several allied species.

We may now consider Mr. Wallace's arguments in regard

BIRDS. 615

to the sexual coloration of birds. He believes that the
bright tints originally acquired through sexual selection by
the males would in all, or almost all cases, have been trans-
mitted to the females, unless the transference had been
checked through natural selection. I may here remind
the reader that various facts opposed to this view have
already been given under reptiles, amphibians, fishes and
lepidoptera. Mr. Wallace rests his belief chiefly, but not
exclusively, as we shall see in the next chapter, on the fol-
lowing statement,* that when both sexes are colored in a
very conspicuous manner the nest is of such a nature as to
conceal the sitting bird; but when there is a marked con-
trast of color between the sexes, the male being gay and
the female dull colored, the nest is open and exposes the
sitting bird to view. This coincidence, as far as it goes,
certainly seems to favor the belief that the females which
sit on open nests have been specially modified for the sake
of protection; but we shall presently see that there is an-
other and more probable explanation, namely, that con-
spicuous females have acquired the instinct of building
domed nests oftener than dull-colored birds. Mr. Wallace
admits that there are, as might have been expected, some
exceptions to his two rules, but it is a question whether
the exceptions ^e not so numerous as seriously to invalidate
them.

There is, in the first place, much truth in the Duke of
Argyll's remark t that a large domed nest is more con-
spicuous to an enemy, especially to all tree-haunting carniv-
orous animals, than a smaller open nest. Nor must we
forget that with many birds which build open nests the
male sits on the eggs and aids the female in feeding the
young; this is the case, for instance, with Pyranga (Sstiva,X
one of the most splendid birds in the United States, the
male being vermilion and the female light brownish-green.
Now if brilliant colors had been extremely dangerous to
birds while sitting on their open nests the males in these
cases would have suffered greatly. It might, however, be
of such paramount importance to the male to be brilliantly
colored m order to beat his rivals that this may have more
than compensated some additional danger.

♦"Journal of Travel," edited by A. Murray, vol. i, 1868, p. 78.
f "Journal of Travel," edited by A. Murray, vol. i, 1868, p. 281.
I Audubon, " Ornitliological Biography," vol. i, p. 233.

616 THE DESCENT OF MAN.

Mr. Wallace admits that with the king- crows (Dicrurus),
orioles, and Pittidae, the females are conspicuously colored,
yet build open nests; but he urges that the birds of the first
group are highly pugnacious and could defend themselves;
that those of the second group take extreme care in con-
cealing their open nests, but this does not invariably hold
good;* and that with the birds of the third group the
females are brightly colored, chiefly on the under surface.
Besides these cases, pigeons, which are sometimes brightly
and almost always conspicuously colored, and which are
notoriously liable to the attacks of birds of prey, offer a
serious exception to the rule, for they almost always build
open and exposed nests. In another large family, that of
the humming-birds, all the species build open nests, yet
with some of the most gorgeous species the sexes are alike;
and in the majority, the females, though less brilliant than
the males, are brightly colored. Kor can it be maintained
that all female humming-birds, which are brightly
colored, escape detection by their tints being green, for
some display on their upper surfaces red, blue and other
colors, f

In regard to birds which build in holes or construct
domed nests, other advantages, as Mr. Wallace remarks,
besides concealment, are gained, such as shelter from the
rain, greater warmth, and in hot countries protection from
the sun;J: so that it is no valid objection to his view that
many birds having both sexes obscurely colored build con-
cealed nests. § The female horn-bill (Buceros), for instance,

*Jerdon, "Birds of India," vol. ii., p. 108. Gould's "Hand-book
of the Birds of Australia," vol. i., p. 463.

f For instance, the female Eupetomena macroura has the head and
tail dark blue with reddish loins; the female Lampornis porphyru-
ru8 is blackish -green on the upper surface, with the lores and sides
of the throat crimson; the female Eulampis jugularis has the top of
the head and back green, but the loins and the tail are crimson.
Many other instances of highly conspicuous females could be given.
See Mr. Gould's magnificent work on this family.

X Mr. Salvin noticed in Guatemala (" Ibis," 1864, p. 375) that hum-
ming-birds were much more unwilling to leave their nests during
very hot weather, when the sun was shining brightly, as if their
eggs would be thus injured, than during cool, cloudy or rainy
weather.

§ I may specify, as instances of duU colored birds building con-
cealed nests, the species belonging to eight Australian genera
described in Gould's " Hand-book to the Birds of Australia," vol i,
pp. 340, 363, 365, 383, 387. 389, 391, 414.

BIHDS, 617

of India and Africa, is protected during incubation with
extraordinary care, for she plasters up with her own excre-
ment the orifice of the hole in which she sits on her eggs,
leaving only a small orifice through which the male feeds
her; she is thus kept a close prisoner during the whole
period of incubation;* yet female horn-bills are not more
conspicuously colored than many other birds of equal size
which build open nests. It is a more serious objection to
Mr. Wallace's view, as is admitted by him, that in some few
groups the males are brilliantly colored and the females
obscure, and yet the latter hatch their eggs in domed nests.
This is the case with the Grallinae of Australia, the superb
warblers (Maluridae) of the same country, the sun-birds
(Nectarinise), and with several of the Australian honey-
suckers or Meliphagidae. f

If we look to the birds of England we shall see that
there is no close and general relation between the colors of
the female and the nature of the nest which is constructed.
About forty of our British birds (excluding those of
large size which could defend themselves) build in holes in
banks, rocks or trees or construct domed nests. If we take
the colors of the female goldfinch, bullfinch or blackbird
as a standard of the degree of conspicuousness, which* is
not highly dangerous to the sittmg female, then out of the
above forty birds the females ol only twelve can be consid-
ered as conspicuous to a dangerous degree, the remaining
twenty - eight being inconspicuous. J Nor is there any

*Mr. C. Home, "Proc. Zoolog. Soc," 1869, p. 243.

f On the nidification and colors of these latter species, see Gould's
"Hand-book," etc., vol. i, pp. 504, 537.

X\ have consulted, on this subject, Macgillivray's "British Birds,"
and though df ubts may be entertained in some cases in regard to the
degree of concealment of the nest and to the degree of conspicuous-
ness of the female, yet the following birds, which all lay their eggs
in holes or in domed nests, can hardly be considered, by the above
standard, as conspicuous: Passer 2 speciv^c, Sturnus, of which the
female is considerably less brilliant than the male; Cinclus: Motal-
lica boarula (?); Erith.cus (?); Fruticola, 2 sp. Saxicola; Ruticilla, 3
sp.; Sylvia, 3 sp.; Parus, H sp.; Mecistura; Anorthura; Certhia;
Sitta; Yunx; Muscicapa, 2sp.; Hirundo, 3 Sf . ; and Cypselus. The
females of the following 12 birds may be considered as conspicuous
according to the same standard, viz.. Pastor, Motacilla alba, Parus
major and P. caeruleus, Upupa, Pious, 4 sp., Coraciaa, Alcedo and
Weropg,

518 THE DESCENT OF MAN.

close relation within the same genus between a well-pro*
nounced difference in color between the sexes and the
nature of the nest constructed. Thus the male house-
sparrow {Passer domesticus) differs much from the female,
the male tree-sparrow (P. montanits) hardly at all, and yet
both build well-concealed nests. The two sexes of the
common fly-catcher (Miiscicapa grisoJa) can hardly be
distinguished, while the sexes of the pied fly -catcher
{M. luctuosa) differ considerably, and both species build
in holes or conceal their nests. The female blackbird
{Turdus merula) differs much, the female ring-ouzel {T.
torquatus) differs less, and the female common thrush
{T. musicus) hardly at all from their respective males; yet
all build open nests. On the other hand, the not very
distantly allied water-ouzel (Cinclus aquaticus) builds a
domed nest, and the sexes differ about as much as in the
ring-ouzel. The black and red grouse {Tetrao tetrix and
T, scoticiis) build open nests in equally well-concealed
spots, but in the one species the sexes differ greatly, and
in the other very little.

Notwithstanding the foregoing objections, I cannot
doubt, after reading Mr. Wallace^s excellent essay, that
looking to the birds of the world a large majority of the
species in which the females are conspicuously colored (and
in this case the males with rare exceptions are equally
conspicuous) build concealed nests for the sake of protec-
tion. Mr. Wallace enumerates* a long series of groups in
which this rule holds good; but it will suffice here to give
as instances the more familiar groups of kingfishers, tou-
cans, trogons, puff-birds (Capitonidae), plantain - eaters
(Musophagae), woodpeckers and parrots. Mr. Wallace
believes that in these groups, as the males gradually ac-
quired through sexual selection their brilliant colors, these
were transferred to the females and were not eliminated by
natural selection owing to the protection which they already
ejijoyed from their manner of nidification. According to
thia view, their present manner of nesting was acquired
before their present colors. But it seems to me much
more probable that in most cases, as the females were
gradually rendered more and more brilliant from partaking
of the colors of the male, they were gradually led to change

* "Journal of Travel," edited by A. Murray, vol. i, p. 78.

BIUDS. 519

their instincts (supposing that they originally built open
nests) and to seek protection by building domed or con-
cealed nests. No one who studies, for instance, Audubon's
account of the differences in the nests of the same species
in the Northern and Southern United States,* will feel
any great difficulty in admitting that birds, either by a
change (in the strict sense of the word) of their habits, or
through the natural selection of so-called spontaneous
variations of instinct, might readily be led to modify their
manner of nesting.

This way of viewing the relation, as far as it holds good,
between the bright colors of female birds and their manner
of nesting receives some support from certain cases occur-
ring in the Sahara Desert. Here, as in most other deserts,
various birds and many other animals have had their colors
adapted in a wonderful manner to the tints of the surround-
ing surface. Nevertheless there are, as I am informed by
the Rev. Mr. Tristram, some curious exceptions to the rule;
thus the male of the Monticola cyanea is conspicuous from
his bright-blue color, and the female almost equally con-
spicuous from her mottled brown and white plumage; both
eexes of two species of Dromolsea are of a lustrous black; so
that these three species are far from receiving protection
from their colors, yet they are able to survive, for they have
acquired the habit of taking refuge from danger in holes
or crevices in the rocks.

With respect to the above groups in which the females
are conspicuously colored and build concealed nests, it is
not necessary to suppose that each separate species had its
nidifying instinct specially modified; but only that the
early progenitors of each group were gradually led to build
domed or concealed nests, and afterward transmitted this
instinct, together with their bright colors, to their modified
descendants. As far as it can be trusted the conclusion is
interesting, that sexual selection, together with equal or
nearly equal inheritance by both sexes, have indirectly
determined the manner of nidification of whole groups of
birds.

According to Mr. "Wallace, even in the groups in which

* See many statements in tlie '* Ornithological Biography." See
also some curious observations on the nests of Italian birds by
Eugenio Bettoni, in the " Atti della Societa Italiana," vol. xi, 1869,
p. l87.

520 THE DESCENT OF MAN.

the females, from being protected in domed nests during
incubation, have not had their bright colors eliminated
through natural selection, the males often differ in a slight
and occasionally in a considerable degree from the females.
This is a significant fact, for such differences in color must be
accounted for by some of the variations in the males having
been from the first limited in transmission to the same sex;
as it can hardly be maintained that these differences, espe-
cially when very slight, serve as a protection to the female.
Thus all the species in the splendid group of the Trogons
build in holes; and Mr. Gould gives figures * of both sexes
of twenty-five species, in all of wliich, with one partial
exception, the sexes differ sometimes slightly, sometimes
conspicuously in color — the males being always finer than
the females, though the latter are likewise beautiful. All
the species of king-fishers build in holes, and with most of the
species the sexes are equally brilliant, and thus far Mr. Wal-
lace's rule holds good; but in some of the Australian species
the colors of the females are rather less vivid than those
of the male ; and in one splendidly colored species the
sexes differ so much that they were at first thought to be
specifically^ distinct, f Mr. R. B. Sharpe, who has espe-
cially studied this group, has shown me some American
species (Oeryle) in which the breast of the male is belted
with black. Again, in Carcineutes, the difference between
the sexes is conspicuous; in the male the upper surface is
dull-blue banded with black, the lower surface being partly
fawn-colored, and there is much red about the head; in the
female the upper surface is reddish-brown banded with
black, and the lower surface white with black markings.
It is an interesting fact, as showing how the same peculiar
style of sexual coloring often characterizes allied forms,
that in three species of Dacelo the male aiffers from the
female only in the tail being dull-' ' ue banded with black,
while that of the female is brown with blackish bars; so
that here the tail differ^ in color in the two sexes in exactly
the same manner as the whole upper surface in the two
sexes of Carcineutes.

With parrots, which likewise build in holes, we find

*See his "Monograpli of tlie Trogonidse," first edition,
f Namely Cyanalcyon. Gould's "Hand-book to the Birds of Aua*
tralia," vol. i, p. 133; see also pp. 130, 136.

I

BIRDS. 521

analogous cases; in most of the species both sexes are
brilliantly colored and indistinguishable, but in not a few
species the males are colored rather more vividly than the
females, or even very differently from them. Thus, besides
other strongly marked differences, the whole under surface
of the male king lory {Apt'osmicfus scapulatus) is scarlet,
while the throat and chest of the female is green tinged
with red; in the Buphema spUndida there is a similar dif-
ference, the face and wing coverts moreover of the female
being of a paler blue than in the male.* In the family of the
tits (FarincB), which build concealed nests, the female
of our common blue tomtit {Parus ccBruUus) is '^ much
less brightly colored " than the male ; and in the
magnificent Sultan yellow tit of India the difference is
greater, f

Again, in the great group of the woodpeckers, J the sexes
are generally nearly alike, but in the Megapicus validus all
those parts of the head, neck and breast which are crimson
in the male are pale-brown in the female. As in several
woodpeckers the head of the male is bright crimson, while
that of the female is plain, it occurred to me that this color
might possibly make the female dangerously conspicuous
whenever she put her head out of the hole containing her
nest, and consequently that this color, in accordance with
Mr. Wallace's belief, had been eliminated. This view is
strengthened by what Malherbe states with respect to
Indopicus carlotta; namely, that the young females, like the
young males, have some crimson about their heads, but that
this color disappears in the adult female, while it is intensi-
fied in the adult male. Nevertheless, the following con-
siderations render this view extremely doubtful ; the male
takes a fair share in incubation, § and would be thus almost
equally exposed to danger; both sexes of many species have
their heads of an equally bright crimson; in other species

* Every gradation of difference between the sexes may be followed
in tbe parrots of Australia. See Gould's "Hand-book," etc., vol. ii,
pp. 14-102.

f Macgillivray's "British Birds," vol. ii, p. 433. Jerdon, *' Birds
of India," vol. ii, p. 282.

X All the following facts are taken from M. Malherbe's magnificent
"Monographie des Picidees," 1861.

§ Audubon's "Ornithological Biography," vol. ii, p. 75; see also
the '• Ibis," vol. i, p. 268.

5^2 ^^^ DESCENT OF MAN.

the difference between the sexes in tlie amount of scarlet is
80 slight that it can hardly make any appreciable difference
in the danger incurred; and lastly, the coloring of the
head in the two sexes often differs slightly in other ways.

The cases, as yet given, of slight and graduated differ-
ences in color between the males and females in the groups,
in which, as a general rule, the sexes resemble each other,
all relate to species which build domed or concealed nests.
But similar gradations may likewise be observed in groups
in which the sexes as a general rule resemble each other,
but which build, open nests.

As I have before instanced the Australian parrots, so I
may here instance, without giving any details, the Austra-
lian pigeons.* It deserves especial notice that in all these
cases the slight differences in plumage between the sexes
are of the same general nature as the occasionally greater
differences. A good illustration of this fact has already
been afforded by those kingfishers in which either the tail
alone or the whole upper surface of the plumage differs in
the same manner in the two sexes. Similar cases may be
observed with parrots and pigeons. The differences in color
between the sexes of the same species are, also, of the same
general nature as the differences in color between the dis-
tinct species of the same group. For when in a group in
which the sexes are usually alike the male differs considera-
bly from the female he is not colored in a quite new style.
Hence we may infer that within the same group the special
colors of both sexes when they are alike, and the colors of
the male when he differs sliglitly or even considerably from
the female, have been in most cases determined by the same
general cause; this being sexual selection.

It is not probable, as has already been remarked, that
differences in color between the sexes, when very slight,
can be of service to the female as a protection. Assuming,
however, that they are of service, they might be thought to
be cases of transition; but we have no reason to believe that
many species at any one time are undergoing change.
Therefore we can hardly admit that the numerous females
which differ very slightly in color from their males are now
all commencing to become obscure for the sake of protection.

* Gould's ** Hand-book to the Birds of Australia," vol. ii, pp.
J09-149.

BIRBa. 523

Even if we consider somewhat more marked sexual differ-
ences, is it probable, for instance, that the head of the
female chaffinch, the crimson on the breast of the female
bullfinch, the green of the female greenfinch, the crest of
the female golden-crested wren have all been rendered less
bright by the slow process of selection for the sake of pro-
tection ? I cannot think so; and still less with the slight
differences between the sexes of those birds which buiid
concealed nests. On the other hand, the differences in
color between the sexes, whether great or small, may to a
large extent be explained on the principle of the successive
variations acquired by the males through sexual selection,
having been from the first more or less limited in their
transmission to the females. That the degree of limitation
should differ in different species of the same group will not
surprise any one who has studied the laws of inheritance,
for they are so complex that they appear to us in our igno-
rance to be capricious in their actions.*

As far as I can discover there are few large groups of
birds in which all the species have both sexes alike and
brilliantly colored, but I hear from Mr. Sclater that this
appears to be the case with the Musophagae or plantain-
eaters. Nor do I believe that any large group exists in
which the sexes of all the species are widely dissimilar in
color. Mr. Wallace informs me that the chatterers of
South America ( Cotingidm) offer one of the best instances;
but with some of the species in which the male has a splen-
did red breast the female exhibits some red on her breast;
and the females of other species show traces of the green
and other colors of the males. Nevertheless we have a
near approach to close sexual similarity or dissimilarity
throughout several groups; and this, from what has just
been said of the fluctuating nature of inheritance, is a
somewhat surprising circumstance. But that the same
laws should largely prevail with allied animals is not sur-
prising. The domestic fowl has produced a great number
of breeds and sub-breeds, and in these the sexes generally
differ in plumage; so that it has been noticed as an un-
usual circumstance when in certain sub -breeds they
resemble each other. On the other hand, the domestic

*See remarks to this effect in my work on "Variation under
Domestication," vol. ii, chap. xii.

524 TBE DESCENT OF MAN.

pigeon has likewise produced a vast number of distinct
breeds and sub-breeds, and in these, with rare exceptions,
the two sexes are identically alike.

Therefore if other species of Gallus and Columba were
domesticated and varied it would not be rash to predict
that similar rules of sexual similarily and dissimilarity
depending on the form of transmission would hold good in
both cases. In like manner the same form of transmission
has generally prevailed under nature throughout the same
groups, although marked exceptions to this rule occur.
Thus within the same family, or even genus, the sexes may
be identically alike or very different in color. Instances
have already been given in the same genus, as with spar-
rows, fly-catchers, thrushes and grouse. In the family of
pheasants the sexes of almost all the species are wonder-
fully dissimilar, but are quite alike in the eared pheasant
or CrossojMon auritum. In two species of Chloephaga,
a genus of geese, the male cannot be distinguished from
the females except by size; while in two others the sexes
are so unlike that they might easily be mistaken for distinct
species. *

The laws of inheritance can alone account for the fol-
lowing cases in which the female acquires late in life
certain characters proper to the male, and ultimately
comes to resemble him more or less completely. Here pro-
tection can hardly have come into play. Mr. Blyth in-
forms me that the females of Oriolus melanocephalus and
of some allied species when sufficiently mature to breed
differ considerably in plumage from the adult males; but
after the second or third moults they differ only in their
beaks having a slight greenish tinge. In the dwarf bitterns
(Ardetta), according to the same authority, " the male
acquires his final livery at the first moult; the female not
before the third or fourth moult; in the meanwhile she pre-
sents an intermediate garb, which is ultimately exchanged
for the same livery as that of the male.^^ So, again, the
female Falco peregrinus acquires her blue plumage more
slowly than the male. Mr. Swinhoe states that w^ith one of
the drongo shrikes {Dicrurus macrocercus) the male, while
almost a nestling, molts his soft brown plumage and
becomes of a uniform glossy greenish-black; but the female

^♦ThQ "Ibis," vol. vi, 1864, p. 132.

I

I

BIRDS. 526

retains for a long time the white striae and spots on the
axiliary feathers; and does not completely assume the uni-
form black color of the male for three years. The same
excellent observer remarks that in the spring of the
second year the female spoon-bill (Platalea) of China
resembles the male of the first year, and that apparently it
is not until the third spring that she acquires the same
adult plumage as that possessed by the male at a much
earlier age. The female Bombycilla carolmensis differs
very little from the male, but the appendages, which like
beads of red sealing-wax ornament the wing-feathers,* are
not developed in her so early in life as in the male. In the
male of an Indian paroquet (Palceornis javanicus) the
upper mandible is coral-red from his earliest youth, but in
the female, as Mr. Blyth has observed with caged and wild
birds, it is at first black and does not become red until the
bird is at least a year old, at which age the sexes resemble
each other in all respects. Both sexes of the wild turkey
are ultimately furnished with a tuft of bristles on the
breast, but in two-year-old birds the tuft is about four
inches long in the male and hardly apparent in the female;
when, however, the latter has reached her fourth year, it is
from four to five inches in length, f

These cases must not be confounded with those where
diseased or old females abnormally assume masculine char-
acters, nor with those where fertile females, while young,
acquire the characters of the male, through variation or
some unknown cause. J But all these cases have so much

* When the male courts the female, these ornaments are vibrated,
and '• are shown off to great advantage," on the outstretched wings:
A. Leith Adams, '* Field and Forest Rambles," 1873, p. 153.

f On Ardetta, Translation of Cuvier's "R^gne Animal," by Mr.
Blyth. foot note p. 159. On the Peregrine Falcon, Mr. Blyth, in
Charlesworth's "Mag. of Nat. Hist./' vol. i, 1837, p. 304. On
Dicrurus, " Ibis,*' 1863, p. 44. On the Platalea, " Ibis," vol. vi, 1864,
p 366 On the Bombycilla, Audubon's " Ornitholog. Biography,"
vol i, p 229. On the Palaeornis, see, also, Jerdon, " Birds of India,"
vol. i, p 263. On the wild turkey, Audubon, ibid, vol. i, p. 15; but
I hear from Judge Caton that in Illinois the female very rarely
acquires a tuft. Analogous cases with the females of Petrocossyphus
are given by Mr. R. Sharpe, " Proc. Zoolog. Soc," 1872, p. 496.

XOt these latter cases Mr, Blyth has recorded (Translation of
Cuvier's "Regne Animal," p. 158) various instances with Lanius,
Ruticilla, Linaria and Anas. Audubon has also recorded a similar
('* Oruith. Biog.," vol. v, p. 519) with Pyranga mstiva.

626 THE DESCENT OF MAN,

in common that they depend, according to the hypothesis
of pangenesis, on gemmules derived from each part of the
male being present, though latent, in the female; their
development following on some slight change in the elective
affinities of her constituent tissues.

A few words must be added on changes of plumage in
relation to the season of the year. From reasons formerly
assigned there can be little doubt that the elegant plumes,
long pendant feathers, crests, etc., of egrets, herons and
many other birds, which are developed and retained only
during the summer, serve for ornamental and nuptial pur-
poses, though common to both sexes. The female is thus ren-
dered more conspicuous during the period of incubation than
during the winter ; but such birds as herons and egrets
would be able to defend themselves. As, however, plumes
would probably be inconvenient and certainly of no use
during the winter, it is possible that the habit of moulting
twice in the year may have been gradually acquired through
natural selection for the sake of casting off inconvenient
ornaments during the winter. But this view cannot be
extended to the many waders, whose summer and winter
plumages differ very little in color. With defenseless spe-
cies, in which both sexes, or the males alone, become
extremely conspicuous during the breeding-season — or
when the males acquire at this season such long wing or
tail feathers as to impede their flight, as with Cosmetornis
and Vidua — it certainly at first appears highly probable
that the second moult has been gained for the special pur-
pose of throwing off these ornaments. We must, however,
remember that many birds, such as some of the birds of
paradise, the Argus pheasant and peacock, do not cast
their plumes during the winter; and it can hardly be
maintained that the constitution of these birds, at least of
the Gallinaceae, renders a double moult impossible, for the
ptarmigan moults thrice in the year. * Hence it must be
considered as doubtful whether the many species which
moult their ornamental plumes or lose their bright colors
during the winter, have acquired this habit on account of
the inconvenience or danger which they would otherwise
have suffered.

* See Gould's " Birds of Great Britain."

BIRDS. 527

I conclude, therefore, that the habit of moulting twice
in the year was in most or all cases first acquired for some
distinct purpose, perhaps for gaining a warmer winter cov-
ering; and that variations in the plumage occurred during
the summer were accumulated through sexual selection,
and transmitted to the offspring at the same season of the
year : that such variations were inherited either by both
sexes or by the males alone, according to the form of inher-
itance which prevailed. This appears more probable than
that the species in all cases originally tended to retain
their ornamental plumage during the winter, but were
saved from this through natural selection, resulting from
the inconvenience or danger thus caused.

I have endeavored in this chapter to show that the argu-
ments are not trustworthy in favor of the view that weap-
ons, bright colors, and various ornaments are now confined
to the males owing to the conversion, by natural selection,
of the equal transmission of characters to both sexes, into
transmission to the male sex alone. It is also doubtful
whether the colors of many female birds are due to the
preservation, for the sake of protection, of variations
which were from the first limited in their transmission to
the female sex. But it will be convenient to defer any
further discussion on this subject until I treat, in the fol-
lowing chapter, of the differences in plumage between the
young and old.

528 THE DESGENT OF MAN,

CHAPTER XYI.

BIRDS — concluded.

The immature plumage in relation to the character of the plumage in
both sexes when adult — Six classes of cases — Sexual differences
between the males of closely allied or representative species —
The female assuming the characters of the male — Plumage of
the young in relation to the summer and winter plumage of the
adults — On the increase of beauty in the birds of the world —
Protective coloring — Conspicuously colored birds — Novelty appre-
ciated— Summary of the four chapters on birds.

We must now consider the transmission of characters as
limited by age, in reference to sexual selection. The truth
and importance of the principle of inheritance at corre-
sponding ages need not here be discussed, as enough has
already been said on the subject. Before giving the several
rather complex rules or classes of cases under which the
differences in plumage between the young and the old, as
far as known to m.e, may be included, it will be well to
make a few preliminary remarks.

With animals of all kinds, when the adults differ in color
from the young, and the colors of the latter are not, as far
as we can see, of any special service, they may generally
be attributed, like various embryological structures, to the
retention of a former character. But this view can be
maintained with confidence only when the young of several
species resemble each other closely, and likewise resemble
other adult species belonging to the same group; for the latter
are the living proofs that such a state of things was formerly
possible. Young lions and pumas are marked with feeble
stripes or rows of spots, and as many allied species both
young and old are similarly marked no believer in evolution
will doubt that the progenitor of the lion and puma was a
striped animal, and that the young have retained vestiges
of the stripes like the kittens of black cats, which are not
in the least striped when grown up. Many species of deer,

fl

BIBDS. 629

which when mature are not spotted^ are while young cov-
ered with white spots, as are likewise some few species in the
adult state. So again the young in the whole family of
pigs (Suidse), and in certain rather distantly allied animals,
such as the tapir, are marked with dark longitudinal
stripes; but here we have a character apparently derived
from an extinct progenitor, and now preserved by the young
alone. In all such cases the old have had their colors
changed in the course of time, while the young have
remained but little altered, and this has been effected
through the principle of inheritance at corresponding ages.
This same principle applies to many birds belonging to
various groups in which the young closely resemble each
other, and differ much from their respective adult parents.
The young of almost all the Gallinaceag and of some distantly
allied birds, such as ostriches, are covered with longitu-
dinally striped down; but this character points back to a
state oi things so remote that it hardly concerns us. Young
cross-bills (Loxia) have at first straight beaks like those of
other finches, and in their immature striated plumage they
resemble the mature redpole and female siskin, as well as the
young of the goldfinch, greenfinch and some other allied
species. The young of many kinds of buntings (Emberiza)
resemble one another, and likewise the adult states of the
common bunting, U. miliaria. In almost the whole large
group of thrushes the young have their breasts spotted — a
character which is retained throughout life by many
species, but is quite lost by others, as by the Tiirdus
migraiorius. So again with "^ many thrushes, the feathers
on the back are mottled before they are moulted for the
first time, and this character is retained for life by certain
eastern species. The young of many species of shrikes
(Lanius), of some woodpeckers and of an Indian pigeon
(Chalcophaps indicus) are transversely striped on the
under surface; and certain allied species or whole genera
are similarly marked when adult. In some closely allied
and resplendent Indian cuckoos (Ohrysococcyx) the mature
species differ considerably from one another in color, but
the young cannot be distinguished. The young of an
Indian goose {Sarkidiornis melanonotus) closely resemble
in plumage an allied genus, Dendrocygna, when mature.*

* In regard to thrushes, shrikes and woodpeckers, see Mr. Blvth,
in Charlesworth's "Mag. of Nat. Hist.," vol. i, 1837, p. 304; 'also

53a THE DESCENT OF MAK

given; it will suffice to call to mind the common plieasant,
duck and house-sparrow. The cases under this class grad-i-
ate into others. Thus the two sexes when adult may differ
so slightly, and the young so slightly from the adults, that
it is douhtful whether such cases ought to come under the
present, or under the third or fourth classes. So, again,
the young of the two sexes, instead of being quite alike,
may diifer in a slight degree from each other, as in our
sixth class. These transitional cases, however, are few,
or at least are not strongly pronounced, in comparison with
those which come strictly under the present class.

The force of the present law is well shown in those
groups, in which, as a general rule, the two sexes and the
young are all alike; for when in these groups the male does
differ from the female, as with certain parrots, kingfishers,
pigeons, etc., the young of both sexes resemble the
adult female.* We see the same fact exhibited still
more clearly in certain anomalous cases; thus the male of
Heliothrix auriculata (one of the humming-birds) differs
conspicuously from the female in having a splendid gorget
and fine ear-tufts, but the female is remarkable from
having a much longer tail than that of the male; now the
young of both sexes resemble (with the exception of the
breast being spotted with bronze) the adult female in all
other respects, including the length of her tail, so that the
tail of the male actually becomes shorter as he reaches
maturity, which is a most unusual circumstance, f Again,
the plumage of the male goosander {Mergus merganser) is
more conspicuously colored than that of the female, with
the scapular and secondary wing- feathers much longer; but

* See, for instance, Mr. Gould's account (" Hand-book to tlie Birds
of Australia," vol. i, p. 133) of Cyanalcyon (one of the kingfisliers),
in wMcli, however, the young male, though resembling the adult
female, is less brilliantly colored. In some species of Dacelo the
males have blue tails, and the females brown ones; and Mr. R. B.^
Sharpe informs me that the tail of the young male of D. gaudichaudi
is at first brown. Mr. Gould has described (ibid, vol. ii, pp. 14, 20,
37) the sexes and the young of certain black cockatoos and of the
King Lory, with which the same rule prevails. Also Jerdon (" Birds
of India," vol. i, p. 260) on the Pal(eornis rosa, in which the young
are more like the female than the male. See Audubon (" Ornith.
Biograph.," vol. ii, p. 475) on the two sexes and the young of Co
lumba passerina.

1 1 owe this information to Mr. Gould, who showed me the speci
jnens; see also his "Introduction to the Trochilidae," 1861, p. 120.

J

BIRDS. 533

differently from what occurs, as far as I know in any other
bird, the crest of the adult male, though broader than that
of the female, is considerably shorter, being only a little
above an inch in length; the crest of the female being two
and a half inches long. Now the young of both sexes
entirely resemble the adult female, so that their crests are
actually of greater length, though narrower than in the
adult male.*

When the young and the females closely resemble each
other and both differ from the males, the most obvious con-
clusion is that the males alone have been modified. Even
in the anomalous cases of the Heliothrix and Mergus, it is
probable that originally both adult sexes were furnished —
the one species with a much elongated tail and the other
with a much elongated crest — these characters having since
been partially lost by the adult males from some unexplained
cause, and transmitted in their diminished state to their
male oft'spring alone, when arrived at the corresponding
age of maturity. The belief that in the present class the
male alon3 has been modified, as far as the differences
between the male and the female together with her young
are concerned, is strongly supported by some remarkable
facts recorded by Mr. Blyth, \ with respect to closely allied
species which represent each other in distinct countries.
For with several of these representative species the adult
males have undergone a certain amount of change and can
be distinguished; the females and the young from the dis-
tinct countries being indistinguishable, and therefore
absolutely unchanged. This is the case with certain
Indian chats (Thamnobia), with certain honey-suckers (Nec-
tarinia), shrikes (Tephrodornis), certain kingfishers (Tany-
siptera), Kalij pheasants (Gallophasis) and tree-partridge&-
(Arboricola).

In some analogous cases, namely, Avith birds having a
different summer and winter plumage, but with the two sexes
nearly alike, certain closely allied species can easily be dis-
tinguished in their summer or nuptial plumage, yet are

* Macgillivray, " Hist. Brit. Birds," vol. v, pp. 207, 214.

\ See his admirable paper in the " Journal of the Asiatic Soc. of
Bengal," vol xix, 1850, p. 223; see also Jerdon, " Birds of India,"
vol. i, introduction, p. 29. In regard to Tanyaiptera, Prof. Schlegel
told Mr. Blyth that he could distinguish several distinct ra^Ges, solely
by compariug the adult males.

532 THE DESCENT OF MAK

given; it will suffice to call to mind the common pheasant,
duck and house-sparrow. The cases under this class grad-i-
ate into others. Thus the two sexes when adult may differ
BO slightly, and the young so slightly from the adults, that
it is doubtful whether such cases ought to come under the
present, or under the third or fourth classes. So, again,
the young of the two sexes, instead of being quite alike,
may differ in a slight degree from each other, as in our
sixth class. These transitional cases, however, are few,
or at least are not strongly pronounced, in comparison with
those which come strictly under the present class.

The force of the present law is well shown in those
groups, in which, as a general rule, the two sexes and the
young are all alike; for when in these groups the male does
differ from the female, as with certain parrots, kingfishers,
pigeons, etc., the young of both sexes resemble the
adult female.* We see the same fact exhibited still
more clearly in certain anomalous cases; thus the male of
Heliothrix auricidata (one of the humming-birds) differs
conspicuously from the female in having a splendid gorget
and fine ear-tufts, but the female is remarkable from
having a much longer tail than that of the male; now the
young of both sexes resemble (with the exception of the
breast being spotted with bronze) the adult female in all
other respects, including the length of her tail, so that the
tail of the male actually becomes shorter as he reaches
maturity, which is a most unusual circumstance, f Again,
the plumage of the male goosander (Mergus merganser) is
more conspicuously colored than that of the female, with
the scapular and secondary wing-feathers much longer; but

* See, for instance, Mr. Gould's account (" Hand-book to the Birds
of Australia " vol. 1, p. 133) of Cyanalcyon (one of the kingfishers),
in which, however, the young male, though resembling the adult
female, is less brilliantly colored. In some species of Dacelo the
males have blue tails, and the females brown ones; and Mr. R. B.
Sharpe informs me that the tail of the young male of D. gaudichaudi
is at first brown. Mr. Gould has described (ibid, vol. ii, pp. 14, 20,
37) the sexes and the young of certain black cockatoos and of the
King Lory, with which the same rule prevails. Also Jerdon (" Birds
of India," vol. i, p. 260) on the Palceornis rosa, in which the young
are more like the female than the male. See Audubon (" Ornith.
Biograph.," vol. ii, p. 475) on the two sexes and the young of Go-
lumba passerina.

f I owe this information to Mr. Gould, who showed me the speci
jaens; see also his "Introduction to the Trochilidae," 1861, p. 120.

J

BIRDS. 533

differently from what occurs, as far as I know in any other
bird, the crest of the adult male, though broader than that
of the female, is considerably shorter, being only a little
above an inch in length; the crest of the female being two
and a half inches long. ]N"ow the young of both sexes
entirely resemble the adult female, so that their crests are
actually of greater length, though narrower than in the
adult male.*

When the young and the females closely resemble each
other and both differ from the males, the most obvious con-
clusion is that the males alone have been modified. Even
in the anomalous cases of the Heliothrix and Mergus, it is
probable that originally both adult sexes were furnished —
the one species with a much elongated tail and the other
with a much elongated crest — these characters having since
been partially lost by the adult males from some unexplained
cause, and transmitted in their diminished state to their
male oft'spring alone, when arrived at the corresponding
age of maturity. The belief that in the present class the
male alon3 has been modified, as far as the differences
between the male and the female together with her young
are concerned, is strongly supported by some remarkable
facts recorded by Mr. Blyth, f with respect to closely allied
species which represent each other in distinct countries.
For with several of these representative species the adult
males have undergone a certain amount of change and can
be distinguished; the females and the young from the dis-
tinct countries being indistinguishable, and therefore
absolutely unchanged. This is the case with certain
Indian chats (Thamnobia), with certain honey-suckers (Nec-
tarinia), shrikes (Tephrodornis), certain kingfishers (Tany-
siptera), Kalij pheasants (Gallophasis) and tree-partridge&-
(Arboricola).

In some analogous cases, namely, with birds having a
different summer and winter plumage, but with the two sexes
nearly alike, certain closely allied species can easily be dis-
tinguislied in their summer or nuptial plumage, yet are

* Macgillivray, " Hist. Brit. Birds," vol. v, pp. 207, 214.

fSee his admirable paper in the "Journal of tlie Asiatic Soc. of
Bengal," vol xix, 1850, p. 223; see also Jerdon, " Birds of India,"
vol. i, introduction, p. 29. In regard to Tanysiptera, Prof. Schlegel
told Mr. Blyth that he could distinguish several distinct r^ces, solely
by comparing the adult males.

534 THE DESCENT OF MAK

indistinguishable in their winter as well as in their imma*
ture plumage. This is the case with some of the closely
allied Indian wag-tails or Motacillae. Mr. Swinhoe *
informs me that three species of Ardeola,. a genus of
heronS;, which represent one another on separate conti-
nents, are *^ most strikingly different " when ornamented
with their summer plumes, but are hardly, if at all, dis-
tinguishable during the winter. The young also of these
three species in their immature plumage closely resemble
the adults in their winter dress. This case is all the
more interesting, because with two other species of Ardeola
both sexes retain, during the winter and summer, nearly
the same plumage as that possessed by the three first spe-
cies during the winter and in their immature state; and
this plumage, which is common to several distinct species
at different ages and seasons, probably shows us how the
progenitors of the genus were colored. In all these cases,
the nuptial plumage which we may assume was originally
acquired by the adult males during the breeding-season,
and transmitted to the adults of both sexes at the corre-
sponding season, has been modified, while the winter and
immature plumages have been left unchanged.

The question naturally arises, how is it that in these
latter cases the winter plumage of both sexes, and in
the former cases the plumage of the adult females, as
well as the immature plumage of the young, have not been
at all affected? The species which represent each other in
distinct countries will almost always have been exposed to
somewhat different conditions, but we can hardly attribute
to this action the modification of the plumage in the males
alone, seeing that the females and the young, though simi-
larly exposed, have not been affected. Hardly any fact
shows us more clearly how subordinate in importance is
the direct action of the conditions of life, in comparison
with the accumulation through selection of indefinite vari-
ations, than the surprising difference between the sexes of
many birds; for both will have consumed the same food,
and have been exposed to the same climate. Nevertheless
we are not precluded from believing that in the course of

*See also Mr. Swinhoe, in "Ibis," July, 1863, p. 131; and a pre-
vious paper, with an extract from a note by Mr. Blyth, in " Ibis,"
Jan, \m\, p. 34.

BIRDS, 535

time new conditions may produce some direct effect either
on both sexes, or from their constitutional differences
chiefly on one sex. We see only that this is subordinate in
importance to the accumulated results of selection. Judg-
ing, however, 'from a wide-spread analogy, when a species
migrates into a new country (and this must precede the
formation of representative species), the changed condi-
tions to which they will almost always have been exposed'
will cause them to undergo a certain amount of fluctuating
variability. In this case sexual selection, which depends
on an element liable to change — the taste or admiration of
the female — will have had new shades of color or other dif-
ferences to act on and accumulate; and as sexual selection
is always at work, it would (from what we know of the
results on domestic animals of man's unintentional selec-
tion) be surprising if animals inhabiting separate districts,
which can never cross and thus blend their newly acquired
characters, were not, after a sufficient lapse of time, differ-
ently modified. These remarks likewise apply to the
nuptial or summer plumage, whether confined to the males
or common to both sexes.

Although the females of the above closely allied or rep-
resentative species, together with their young, differ hardly
at all from one another, so that the males alone can be dis-
tinguished, yet the females of most species within the same
genus obviously differ from each other. The differences,
however, are rarely as great as between the males. We see
this clearly in the whole family of the Gallinacese ; the
females, for instance, of the common and Japan pheasant,
and especially of the gold and Amherst pheasant — of the
silver pheasant and the wild fowl — resemble one another
very closely in color, while the males difl'er to an extraor-
dinary degree. So it is with the females of most of the
Cotingidas, Fringillidae, and many other families. There
can indeed be no doubt that, as a general rule, the females
have been less modified than the males. Some few birds,
however, offer a singular and inexplicable exception; thus
the females of Paradisea apoda and P. pajmmia diff'er from
each other more than do their respective males;* the female
of the latter species having the under surface pure white,
while the female P. apoda is deep brown beneath. So,

* Wallace, " The Malay Archipelago," vol. ii, 1869, p. 394.

536 THE DESCENT OF MAN.

again, as I hear from Prof. Newton, the males of two
species of Oxynotus (shrikes), which represent each other in
the Islands of Mauritius and Bourbon,* differ but little in
color, while the females differ much. In the Bourbon
species the female appears to have partialfy retained an
immature condition of plumage, for at first sight she
"might be taken for the young of the Mauritian species."
These differences may be compared with those inexplicable
ones which occur independently of man^s selection in
certain sub-breeds of the game-fowl, in which the females
are very different, while the males can hardly be distin-
guished, t

As I account so largely by sexual selection for the differ-
ences between the males of allied species, how can the
differences between the females be accounted for in all
ordinary cases? We need not here consider the species
which belong to distinct genera; for with these, adaptation
to different habits of life, and other agencies, will have
come into play. In regard to the differences between the
females within the same genus it appears to me almost cer-
tain, after looking through various large groups, that the
chief agent has been the greater or less transference to the
female of the characters acquired by the males through
sexual selection. In the several British finches the two
sexes differ either very slightly or considerably; and if we
compare the females of the greenfinch, chaffinch, goldfinch,
bullfinch, crossbill, sparrow, etc., we shall see that they
differ from one another chiefly in the points in which they
partially resemble their respective males; and the colors of
the males may safely be attributed to sexual selection.
With many gallinaceous species the sexes differ to an
extreme degree, as with the peacock, pheasant and fowl,
while with other species there has been a partial or even
complete transference of character from the male to the
female. The females of the several species of Polyplectron
exhibit in a dim condition, and chiefly on the tail, the
splendid ocelli of their males. The female partridge differs
from the male only in the red mark on her breast being
smaller; and the female wild turkey only in her colors being

* These species are described with colored figures, by M. F. Pollen,
in "Ibis," 1866, p. 275.
f <* Variation of Animals, etc., under DomesticfttioR/' vol. i, p. 351.

BIRDS. 537

much duller. In the ^linea-fowl the two sexes are indis-
tinguishable. There is no improbability in the plain,
though peculiarly spotted, plumage of this latter bird
having been acquired through sexual selection by the
males, and then transmitted to both sexes; for it is not
essentially different from the mucli more beautifully
spotted plumage, characteristic of the males alone of the
Tragopan pheasants.

It should be observed that i^ some instances the trans-
ference of characters from the male to the female has been
effected apparently at a remote period, the male having
subsequently undergone great changes without transferring
to the female any of his later gained characters. For in-
stance, the female and the young of the black grouse
(Tetrao fetrix) resemble pretty closely both sexes and the
young of the red grouse {T. scoticus); and we may conse-
quently infer that the black grouse is descended from some
ancient species, of which both sexes were colored in nearly
the same manner as the red grouse. As both sexes of this
latter species are more distinctly barred during the breed-
ing-season than at any other time, and as the male differs
slightly from the female in his more strongly pronounced
red and brown tints,* we may conclude tliat his pUimage
has been influenced by sexual selection, at least to a certain
extent. If so, we may further infer that the n^rly similar
plumage of the female black grouse was similarly produced
at some former period. But since this period" the male
black grouse has acquired his fine black plumage with his
forked and outwardly curled tail-feathers; but of these char-
acters there has hardly been any transference to the female,
excepting that she shows in her tail a trace of the curved
fork.

We may therefore conclude that the females of distinct
though allied species have often had their plumage rendered
more or less different by the transference of various degrees
of characters acquired by the males through sexual selec-
tion both during former and recent times. But it deserves
especial attention that brilliant colors have been transferred
much more rarely than other tints. For instance, the
male of the red-throated blue-breast {Cifancciila suecira)
has a rich blue breast, including a sub-triangular red mark;

* Macgillivray, "Hist. Britisli Birds." vol, i, pp. 172-174.

538 THE DESCENT OF MAN.

now marks of nearly the same shape have been transferred
to the female, but the central space is fulvous instead of
red and is surrounded by mottled instead of blue feathers.
The Gallinaceae offer many analogous cases; for none of
the species, such as partridges, quails, guinea-fowl, etc.,
in which the colors of the plumage have been largely trans-
ferred from the male to the female, are brilliantly colored.
This is well exemplified with the pheasants, in which the
male is generally so much more brilliant than the female:
but with the eared and cheer pheasants {Crossoplilon
auritum and Phasiamis tvallichii) the sexes closely resem-
ble each other and their colors are dull. We may go so
far as to believe that if any part of the plumage "in the
males of these two pheasants had been brilliantly colored it
would not have been transferred to the females. These facts
strongly support Mr. "Wallace's view that with birds which
are exposed to much danger during incubation, the trans-
ference of bright colors from the male to the female has
been checked through natural selection. We must not,
however, forget that another explanation, before given, is
possible; namely, that the males which varied and became
bright, while they were young and inexperienced, would
have been exposed to much danger and would generally
have been destroyed; the older and more cautious males, on
the other hand, if they varied in a like manner, would not
only have* been able to survive, but would have been
favored in their rivalry with other males. Now variations
occurring late in life tend to be transmitted exclusively to
the same sex, so that in this case extremely bright tints
would not have been transmitted to the females. On the
other hand, ornaments of a less conspicuous kind, such as
those possessed by the eared and cheer pheasants, would not
have been dangerous, and if they appeared during early
youth would generally have been transmitted to both
sexes.

In addition to the effects of the partial transference of
characters from the males to the females some of the differ-
ences between the females of closely allied species may be
attributed to the direct or definite action of the conditions
of life.* With the males any such action would generally

* See, on this subject, chap, xxiii, in the ** Variation of Animals
and Plants under Domestication."

1

BIRDS. 589

have been masked by the brilliant colors gained through
Bexual selection; but not so with the females. Each of the
endless diversities in plumage which we see in our domes-
ticated birds is, of course, the result of some definite cause;
and, under natural and more uniform conditions, some one
tint, assuming that it was in no way injurious, would almost
certainly sooner or later prevail. The free intercrossing of
the many individuals belonging to the same species would
ultimately tend to make any change of color thus induced
uniform in character.

No one doubts that both sexes of many birds have had
their colors adapted for the sake of protection; and it is
possible that the females alone of some species may have
been modified for this end. Although it would be a difficult,
perhaps an impossible, process, as shown in the last chapter,
to convert one form of transmission into another through
selection, there would not be the least difficulty in adapting
the colors of the female, independently of those of the male,
to surrounding objects, through the accumulation of varia-
tions which were from the first limited in their transmission
to the female sex. If the variations were not thus limited
the bright tints of the male would be deteriorated or de-
stroyed. Whether the females alone of many species have
been thus specially modified is at present very doubtful.
I wish I could follow Mr. Wallace to the full extent;
for the admission would remove some difficulties. Any
variations which were of no service to the female as a
protection would be at once obliterated, instead of being
lost simply by not being selected, or from free intercross-
ing, or from being eliminated when transferred to the malo
and in any way injurious to him. Thus the plumage of the
female would be kept constant in character. It would also
be a relief if we could admit that the obscure tints of both
sexes of many birds had been acquired and preserved for the
sake of protection, for example, of the hedge-warbler or kitty-
wren {Accentor modularis and Troglodytes vulgaris) y with
respect to which we have no sufficient evidence of the
action of sexual selection. We ought, however, to be cau-
tious in concluding that colors which appear to us dull
are not attractive to the females of certain species; we
Rhould bear in mind such cases as that of the common
liouse-sparrow, in which the male differs much from the
female, but does not exhibit any bright tints. Ko one

540 THE DESCENT OF MAN.

probably will dispute that many gallinaceous birds which
live on the open ground have acquired their present
colors, at luast in part, for the sake of protection. "We
know how well they are thus concealed ; we know that
ptarmigans, while changing from their winter to their
summer plumage, both of which are protective, suffer
greatly from birds of prey. But can we believe that the
very slight differences in tints and markings between, for
instance, the female black grouse and red-grouse serve as a
protection? Are partridges, as they are now colored,
better protected than if they had resembled quails? Do the
slight differences between the females of the common
pheasant, the Japan and gold pheasants, serve as a pro-
tection, or might not their plumages liave been inter-
changed with impunity? From what Mr. Wallace has
observed of the habits of certain gallinaceous birds in the
east, he thinks that such slight differences are beneficial.
For myself, I will only say that I am not convinced.

Formerly when I was inclined to lay much stress on pro-
tection as accounting for the duller colors of female birds,
it occurred to me that possibly both sexes and the young
might aboriginally have been equally bright colored ; but
that subsequently, the females from the danger incurred
during incubation, and the j^oungfrom being inexperienced,
had been rendered dull as a protection. But this view is
not supported by any evidence, and is not probable; for
we thus in imagination expose during past times the
females and the young to danger, from which it has sub-
sequently been necessary to shield their modified descend-
ants. We have, also, to reduce, through a gradual process
of selection, the females and the young to almost exactly
the same tints and markings, and to transmit them to the
corresponding sex and period of life. On the supposition
that the females and the young have partaken during each
stage of the process of modification of a tendency to be as
brightly colored as the males, it is also a somewhat strange
fact that the females have never been rendered dull colored
without the young participating in the same change; for
there are no instances, as far as I can discover, of species
with the females dull and the young bright colored. A
partial exception, however, is offered by the young of cer-
tain woodpeckers, for they have "the whole upper part of
the head tinged with red/' which afterward either decreases

BIRDS. 641

into a mere circular red line in the adults of both sexes, or
quite disappears in the adult females.*

Finally, with respect to our present class of cases, the
most probable view appears to be that successive variations
in brightness or in other ornamental characters occurring
in the males at a rather late period of life have alone been
preserved; and that most or all of these variations, owing
to the late period of life at which they appeared,
have been from tlie first transmitted only to the adult male
offspring. Any variations in brightness occurring in the
females or in the young would have been of no service to
them, and would not have been selected; and moreover, if
dangerous would have been eliminated. Thus the females
and the young will either have been left unmodified, or
(as is much more common) will have been partially modi-
fied by receiving through transference from the males some
of his successive variations. Both sexes have perhaps been
directly acted on by the conditions of life to which they
have long been exposed; but tiie females from not being
otherwise much modified will best exhibit any such effects.
These changes and all others will have been kept uniform
by the free intercrossing of many individuals. In some
cases, especially with ground birds, the females and the
young may possibly have been modified, independently of
the males, for the sake of protection so as to have acquired
the same dull-colored plumage.

Class II. WJten the adult female is more cotispicuous
than the adult male the young of hotli sexes in their first
plumage resemble the adult male. — This class is exactly the
reverse of the last, for the females are ijere brighter colored
or more conspicuous than the males; and the young, as far
as they are known, resemble the adult males instead of the
adult females. But the diff'erence between the sexes is
never nearly so great as with many birds in the first class,
and the cases are comparatively rare. Mr. Wallace, who
first called attention to the singular relation which exists
between the less bright colors of the males and their per-
forming the duties of incubation, lays great stress on this

♦Audubon, "Ornitli. Biograpliy," vol. i, p. 193. Macgillivray,
" Hist. Brit. Birds," voL iii, p. 85. See also the case before given of
Indopicus carlvUa.

543 THE DESCENT OF MAN.

point* as a crucial test that obscure colors have been ac-
quired for the sake of protection during the period of nest-
ing. A diiferent view seems to me more probable. As
the cases are curious and not numerous I will briefly give
all that 1 have been able to find.

In one section of the genus Turnix, quail-like birds, the
female is invariably larger than the male ^being nearly
twice as large in one of the Australian species), and this is
an unusual circumstance with the Gallinacese. In most of
the species the female is more distinctly colored and
brighter than the male^f but in some few species the sexes
are alike. In Tiirnix taigoor of India the male '^ wants
the black on the throat and neck, and the whole tone of
the plumage is lighter and less pronounced than that of
the female." The female appears to be noisier, and is cer-
tainly much more pugnacious than the male; so that the
females and not the males are often kept by the natives for
fighting, like gamecocks. As male birds are exposed by
the English bird-catchers for a decoy near a trap, in order
to catch other males by exciting their rivalry, so the females
of this Turnix are employed in India. When thus ex-
posed the females soon begin their '' loud, purring call,
which can be heard a long way olf, and any females within
ear-shot run rapidly to the spot and commence fighting
with the caged bird." In this way from twelve to twenty
birds, all breeding-females, may be caught in the course of
a single day. Tlie natives assert that the females after
laying their eggs associate in flocks, and leave the males to
sit on them. There is no reason to doubt the truth
of this assertion, which is suppoited by some observa-
tions made in China by Mr, Swinhoe.J Mr. Blyth
believes that the young of both sexes resemble the adult
male.

The females of the three species of painted snipes
(Khynchaea, fig. 62) *'are not only larger but much more

*" Westminster Review," July, 1867, and A. Murray, "Journal
of Travel," 1868, p. 83.

f For tlie Australian species, see Gould's " Hand-book," etc., vol.
ii, pp. 178, 180, 186, 188. In tlie British Museum specimens of the
Australian Plain-wanderer {Pedionomus torquatus) may be seen,
showing similar sexual differences.

tJerdon, "Birds of India," vol. iii, p. 596. Mr. Swinhoe, in
" Ibis," 1866, p. 543; 1866, pp. 131, 405.

Binns

543

richly colored than the males/^ * With all other birds in
which the trachea differs in structure in the two sexes it is
more developed and complex in the male than in the
female; but in the RhyncUcea australis it is simple in the
male, while in the female it makes four distinct convolu-

Fig. 62. Rhynchaea capensis (from Brehm).

tions before entering the lungs, f The female, therefore,
of this species has acquired an eminently masculine char-
acter. Mr. Blyth ascertained, by examining many speci-
mens, that the trachea is not convoluted in either sex of
R. bengalensis, which species resembles R. australis so
closely that it can hardly be distinguished except by its
shorter toes. This fact is another striking instance of the

* Jerdon, "Birds of India," vol. iii, p. 677.

f Gould's " Hand-book to the Birds of Australia,'* vol. ii, p. 275.

544 THE DESCENT OF MAN,

law that secondary sexual characters are often v/idely dAt
ferent in closely allied forms, though it is a very rare cir-
cumstance when such differences relate to the female sex.
The young of both sexes of R. lengalensis in their first
plumage are said to resemble the mature male.* There is
also reason to believe that the male undertakes the duty of
incubation, for Mr. Swinhoe f found the females before the
close of the summer associated in flocks, as occurs with the
females of the Tumix.

The females of Phalaropus fidicarius and P. liyperhoreiis
are larger, and in their summer plumage "more gayly
attired than the males.''' But the difference in color between
the sexes is far from conspicuous. According to Prof. Steen-
strup, the male alone of P. fulicarius undertakes the duty of
incubation; this is likewise shown by the state of his
breast-feathers during the breeding-season. The female of
the dotterel plover (Eudromias morinellus) is larger than
the male, and has the red and black tints on the lower sur-
face, the white crescent on the breast and the stripes over
the eyes more strongly pronounced. The male also takes
at least a share in hatching the eggs; but the female like-
wise attends to the young. J; I have not been able to dis-
cover whether with these species the young resemble the
adult males more closely than the adult females; for the
comparison is somewhat diflPicult to make on account of the
double moult.

Turning now to the ostrich order ; the male of the
common cassowary {Casuarius galcatus) would bethought
by any one to be the female, from his smaller size and from
the appendages and naked skin about his head being much
less brightly colored; and I am informed by Mr. Bartlett
that in the Zoological (hardens it is certainly the male alone

* " The Indian Field," Sept., 1858, p. 3.

f " Ibis," 1866, p. 298.

JFor these several statements, see Mr. Gould's "Birds of Great
Britain." Prof. Newton informs me that he has long been convinced,
from his own observations and from those of others, that the males
of the above-named speci'is take either the whole or a large share of
the duties of iucubation, and that they "show much greater devo-
tion toward their young, when in danger, than do the females." So
it is, as he informs me, with Liinosa lapponica and some few other
waders, in which the females are larger and have more strongly con-
trasted colors than the males.

BIRDS. 545

who sits on t.lie eg^gs and taken care of theyonng.* The
female is said by Mr. T. W. Wood f to exhibit during the
breeding-season a most pugnacious disposition ; and her
wattles then become enlarged and more brilliantly colored.
So again the female of one of the emus {Dromceus irroratus)
is considerably larger than the male, and she possesses a slight
top-knot, but is otherwise indistinguishable in plumage.
She appears, however, " to have greater power, when angry
or otherwise excited, of erecting, like a turkey-cock, the
feathers of her neck and breast. She is usually the more
courageous and pugilistic. She makes a deep, hollow, gut-
tural boom especially at night, sounding like a small gong.
The male has a slenderer frame and is more docile, with no
voice beyond a suppressed hiss when angry, or a croak."
He not only performs the whole duty of incubation, bat
has to defend the young from their mother; '' for as soon
as she catches sight of her progeny she becomes violently
agitated, and notwithstanding the resistance of the father
appears to use her utmost endeavors to destroy them. For
months afterward it is unsafe to put the parents together,
violent quarrels being the inevitable result, in which the
female generally comes off conqueror."]; So that with this
emu we have a complete reversal not only of the parental
and incubating instincts, but of the usual moral qualities of
the two sexes; the females being savage, quarrelsome and
noisy, the males gentle and good. The case is very dif-
ferent with the African ostrich, for the male is somewhat
larger than the female and has finer plumes, with more
strongly contrasted colors; nevertheless he undertakes the
whole duty of incubation. §

*Tlie natives of Ceram (Wallace, "Malay Archipelago," vol. ii,
p. 150) assert that the male and female sit alternately on the eggs;
but this assertion, as Mr. Bartlett thinks, may be accoanted for by
the female visiting the nest to lay her eggs.

t " The Student," April. 1870, p. 124.

X See the excellent account of the habits of this bird under con-
finement, by Mr. A. W. Bennett, in "Laud and Water," May, 1868,
p. 233.

§Mr. Sclater, on the incubation of the Struthiones, " Proc. Zool.
Soc," June9, 1863. So it is with the Ilhm darwiiiii: Capt. Mus-
ters says ("At Home with the Patagonians," 1871, p. 123), that the
male is larger, stronger and swifter than the female, and of slightly
darker colors; yet he takes solo charge of the eggs and of the young-
just as does the male of the common species of Rhea^

546 THE DESCENT OF MAN,

I will specify the few other cases known to me, in which
the female is more conspicuously colored than the male,
although nothing is known about the manner of incuba-
tion. With the carrion-hawk of the Falkland Islands
(Milvago leucurus) I was much surprised to find by dissec-
tion that the individuals, which had all their tints strongly
pronounced, with the cere and legs orange-colored, were the
adult females; while those with duller plumage and gray
legs were the males or tlie young. In an Australian tree-
creeper {Climacteris erythrops) the female differs from the
male in ''being adorned with beautiful, radiated, rufous
markings on the throat, the male having this part quite
plain.'' Lastly, in an Australian night-jar ^^the female
always exceeds the male in size and in the brilliance of
her tints; the males, on the other hand, have two white
spots on the primaries more conspicuous than in the
female."*

We thus see that the cases in which female birds are
more conspicuously colored tiian the males, with the young
in their immature plumage resembling the adult males
instead of the adult females, as in the previous class, are
not numerous, though they are distributed in various
orders. The amount of difference, also, between the sexes
is incomparably less than that which frequently occurs in
the last class; so that the cause of the difference, whatever
it may have been, has here acted on the females either less
energetically or less persistently than on the males in the
last class. Mr. Wallace believes that the males have had

* For the Milvago, see "Zoology of the Voyage of the 'Beagie':
Birds," 1841, p. 16. For the Climacteris and night- jar (Eurostopo-
dus), see Gould's " Hand: book to the Birds of Australia," vol. i, pp.
602, 97. The New Zealand shieldrake {Tadorna variegata) offers a
quite anomalous case; the head of the female is pure white, and her
back is redder than that of tlie male; the head of fhe male is of a
rich dark bronzed color, and his back is clothed with finely penciled
slate-colored feathers, so that altogether he may be considered as the
more beautiful of the two. He is larger and more pugnacious than
the female, and does not sit on the eggs. So that in all these respects
this species comes under our first class of cases; but Mr. Sclater
(" Proc. Zool. Soc," 1866, p. 150) was much surprised to observe
that the young of both sexes, when about three months old, resem-
bled in their dark heads and necks the adult males, instead of the
adult females; so that it would appear in this case that the females
have been modified, while the males and the young have retained a
former state of plumage.

BIRDS. 547

their colors rendered less conspicuous for the sake of pro-
tection during the period of incubation; but the difference
between the sexes in hardly any of the foregoing cases
appears sufficiently great for this view to be safely accepted.
In some of the cases the brighter tints of the female are
almost confined to the lower surface, and the males, if thus
colored, would not have been exposed to danger while
sitting on the eggs. It should also be borne in mind that
the males are not only in a slight degree less conspicuously
colored than the females, but are smaller and weaker.
They have, moreover, not only acquired the maternal
instinct of incubation, but are less pugnacious and
vociferous than the females, and in one instance have
simpler vocal organs. Thus, an almost complete transposi-
tion of the instincts, habits, disposition, color, size, and of
some points of structure, has been effected between the two
sexes.

Now, if we might assume that the males in the present
class have lost some of that ardor which is usual to their
sex, so tliat they no longer search eagerly for the females;
or, if we might assume that the females have become much
more numerous than the males — and in the case of one
Indian Turnix the females are said to be " much more
commonly met with than the males " * — then it is not
improbable that the females would have been led to court
the males, instead of being courted by them. This indeed
is the case to a certain extent with some birds, as we have
seen with the peahen, wild turkey, and certain kinds of
grouse. Taking as our guide the habits of most male
birds, the greater size and strength, as well as the extraor-
dinary pugnacity of the females of the Turnix and emu,
must mean that they endeavor to drive away rival females
in order to gain possession of the male; and on this view
all the facts become clear ; for the males would probably
be most charmed or excited by the females which were the
most attractive to them by their bright colors, other orna-
ments, or vocal powers. Sexual selection would then do
its work, steadily adding to the attractions of the females-,
the males and the young being left not at all, or but little,
modified.

Class III. When the adult 7nale resembles the adult

* Jerdon, *'Biids of India," vol. iii, p. 698.

548

THE DESCENT OF MAN

female, the young of loth sexes have a peculiar first plumage
of their oivn. — In this class the sexes when adult resemble
each other and differ from the young. This occurs with
many birds of many kinds. The male robin can hardly be
distinguished from the female, but the young are widely
different, with their mottled dusky- olive and brown plum-
age. The male and female of the splendid scarlet
ibis are alike, while the young are brown; and the scarlet
color, though common to both sexes, is apparently a sexual
character, for it is not well developed in either sex under
confinement ; and a loss of color often occurs with brill-
iant males when they are confined. AVith many species of
herons the young differ greatly from the adults; and the
summer plumage of the latter, though common to both
sexes, clearly has a nuptial character. Young swans are
slate-colored, while the mature birds are pure white; but it
would be superfluous to give additional instances. These
differences between the young and the old apparently
depend, as in the last two classes, on the young having
retained a former or ancient state of plumage, while the old
of both sexes have acquired a new one. When the adults
are brignt colored, we may conclude from the remarks just
made in relation to the scarlet ibis and to many herons, and
frcm the analogy of the species in the first class, that such
colors have been acquired through sexual selection by the
nearly mariire males ; but that, differently from what
occurs in the first two classes, the transmission^ tliough lim-
ited to the same age, has not been limited to the same sex.
Consequently, the sexes when mature resemble each other
and ditt'er from the young.

Class IV. When the adult male resemlles the adult
female, the young of both sexes in their first plumage resem-
ble the adults. — In this class the young and the adults of
both sexes, whether Driiliantly or obscurely colored, resem-
ble each other. Such cases are, I thiiiK, more common
than those in the last class. We have in England instances
in the kingfisher, some woodpeckers, the jay, magpie,
crow, and many small dull-colored birds, such as the
hedge-warbler or kitty-wren. But the similarity in plum-
age between the young and the old is never complete, and
graduates away into dissimilarity. Thus the young of
some members of the kingfisher family are not only less

BIBDS, 549

vividly colored than the adults, but many of the feathers
on the lower surface are edged with brown* — a vestige
probably of a former state of the plumage. Frequently m
the same group of birds, even within the same genus
for instance, in the Australian genus of paroquets
(Platycercus), the young of some species closely resemble,
while the young of other species differ consider-
ably from, their parents of both sexes, which are alike, f
Both sexes and the young of the common jay are closely
similar; but in the Canada jay {Perisoreus canadensis) the
young differ so much from their parents that they were
formerly described as distinct species. J

I may remark before proceeding that, under the present
and next two classes of cases, the facts are so complex and
the conclusions so doubtful that any one who feels no
especial interest in the subject had better pass them over.

Tlie brilliant or conspicuous colors wliicli cliaracterize many birds
in the present class can rarely or never be of service to them as a
protection; so that they have probably been gained by the males
through sexual selection and then transferred to the females and
the young. It is, however, possible that the males may have selected
the more attractive females; and if these transmitted their cha. ackers
to their offspring of both sexes the same results would follow as
from the selection of the more attractive males by the females. But
there is evidence that th's contingency has rarely, if ever, occurred
in any of those groups of birds in which the sexes are generally
alike; for, if even a few of the successive variations had failed to be
transmitted to both sexes, the females would have slightly exceeded
the males in beauty. Exactly the reverse occurs under nature; for,
in almost every large group in which the sexes generally resemble
each other, the males of some few species are in a slight degree more
brightly colored than the females. It is again possible that the
females may have selected the more beautiful males, these males
having reciprocally selected the more beautiful females; but it is
doubtful wliether this double process of selection would be likely to
occur, owing to the greater eagerness of one sex than the other, and
whether it would be more etiicient than selection on one side alone.
It is, therefore, the most probable view that sexual selection has
acted, in the present class, as far as ornamental characters are con-
cerned, in accordance with the general rule throughout the animal
kingdom, that is, on the males; and that these have transmitted their

*Jerdon, "Birds of India," vol. i. pp. 222, 228. Gould's •'Hand-
book to the Birds of Australia," vol. i, pp. 124, 130.
I Gould, ibid, vol. ii, pp. 37, 46, 56.
J Audubon, " Ornitli. Biography," vol. ii, p. 55.

550 THE DESCENT OF MAN.

gradually acquired colors, either equally or almost equally, to their
offspring of both sexes,

Another point is more doubtful, namely, whether the successivo
variations first appeared in the males after they had become nearly
mature or while quite young. In either case sexual selection must
have acted on the male when he had to compete with rivals for the
possession of the female; and in both cases the characters thus
acquired have been transmitted to> both sexes and all ages But
these characters, if acquired by the males when adult, may have been
transmitted at first to the adults alone, and at some subsequent period
transferred to the young. For it is known that when the law of
inheritance at corresponding ages fails the offspring often inherit
characters at an earlier age than that at which they first appeared
in their parents.* Cases apparently of this kind have been observed
with birds in a state of nature. For instance, Mr. Blyth has seen
specimens of Lanius rufus and of Colymbua glacialia which had
assumed while young, in a quite anomalous manner, the adult
plumage of their parents, f Again, the young of the common swan
{Cygnus olor) do not cast off their dark feathers and become white
until eighteen months or two years old; but Dr. F. Forel has
described the case of three vigorous young birds, out of a brood of
four, which were born pure white. These young birds were not
albinos, as shown by the color of their beaks and legs, which nearly
resembled the same parts in the adults. :J:

It may be worth while to illustrate the above three modes by
which, in the present class, the two sexes and the young may have
come to resemble each other, by the curious case of the genas
Passer. § In the house-sparrow (P. domesticus) the male differs
much from the female and from the young. The young and the
females are alike, and resemble to a large extent both sexes and the
young of *\iQ sparrow of Palestine (P. hrachydactylus), as well as of
some allied species. We may therefore assume that the female and
young of the house-sparrow approximately show us the plumage of
the progenitor of the genus. Now with the tree-sparrow (P. mon-
ianus) both sexes and the young closely resemble the male of the
house-sparrow; so that they have all been modified in the same
manner, and all depart from the typical coloring of their early pro-
genitors. This may have been effected by a male ancestor of the tree-
sparrow having varied, firstly, when nearly mature; or, secondly,
while quite young, and by having in either case transmitted his
modified plumage to the females and the young; or, thirdly, he may
have varied when adult and transmitted his plumage to both adult
sexes, and, owing to the failure of the law of inheritance at corre-
sponding ages, at some subsequent period to his young.

It is impossible to decide which of these three modes has generally

* '* Variation of Animals and Plants under Domestication," vol. 11, p. 79.

t Charlesworth's " Mag. of Nat. Hist.," vol. i, 1837, pp. 305, 306.

t" Bulletin de la Soc. Vaudoise des Sc. Nat.," vol. x, 1869, p. 132. The
young of the Polish swan, Cygnvs immutabilis of Yarrell, are always white;
out this species, as Mr. Sclater informs me, is believed to be nothing more than
a variety of the domestic swan ( Cygnus olor).

§ I am Indebted to Mr. Blyth for information in regard to this genus. The
sparrow of Palestine belongs to the sub-genus Petroma.

BIRD8, 551

prevailed throughout the present class of cases. That the males
varied while young and transmitted their variations to their offspring
of both sexes is the most probable. I may here add that 1 have,
with little success, endeavored, by consulting various works, to
decide how far the period of variation in birds has generally deter-
mined the transmission of characters to one sex or to both. The two
rules, often referred to (namely, that variations occurring late in life
are transmitted to one and the same sex, while those which occur
early in lite are transmitted to both sexes), apparently hold good in
the first,* second, and fourth classes of cases; but they fail in the
third, often in the fifth, f and in the sixth small class. They apply,
however, as far as I can judge, to a considerable majority of the
species; and we must not forget the striking generalization by Dr.
W. Marshall with respect to the protuberances on the heads of
birds. Whether or not the two rules generally hold good, we may
conclude from the facts given in the eighth chapter that the period
of variation is one important element in determining the form of
transmission.

With birds it is difficult to decide by what standard we ought to
judge of the earliness or lateness of the period of variation, whether
by the age in reference to the duration of life, or to the power of
reproduction, or to the number of moults through which the species
passes. The moulting of birds, even within the same family, some
times differs much without any assignable cause. Some birds moult
so early that nearly all the body-feathers are cast off before the first
wing-feathers are fully grown; and we cannot believe that this was
the primordial state, of things. When the period of moulting has
been accelerated the age at which the colors of the adult plumage
are Srst developed will falsely appear to us to be earlier than it
really is. This may be illustrated by the practicb followed by some
bird-fanciers, who pull out a few feathers from the breast of nestling
bullfinches, and from the head or neck of young Gold pheasants, in
order to ascertain their sex; for in the males, these feathers are
immediately replaced by colored ones.:}: The actual duration of life
is known in but few birds, so that we can hardly judge by this
standard. And with reference to the period at which the power of
reproduction is gained, it is a remarkable fact that various birds
occasionally breed while retaining their Immature plumage.§

* For instance, the males of Tanagra cestiva and Frinoilla ajanea require
three years, the male of Fiingilla cins four years, to complete their beautful
plumajje, (See Audubon. " Ornith. Biography," vol. i, pp. 233, 280, 378). The
Harlequin duck takes three years (ibid, vol. iii, p. (514). The male of the Gold
pheasant, as I hea. from Mr. Jenner Weir, can be distinguished from the
female when about three months old, but he does not acquire his full splendor
until the end of September in the following year.

+ Thus the Ibis tantalus and Gjnis americamis take four years, the Flamingo
several years, and the Ardea ludovicana two years, before they acquire their
perfect plumage. See Audubon, ibid, vol. i, p. 2<J1; vol. iii, pp. 133, UM. 211.

tMr. Blyth, in Charlesworth's "Mag. of Nat. Hist.," vol. i, 1837, p. 300.
Mr. Bartlett has informed me in regard to Gold pheasants.

% I have noticed the following cases in Audubon's " Ornith. Biography:"
Thei-edstart of America (Mvncapica ruticilUu, vol. 1. p. 203. The Ibis tantalus
takes four years to come to full maturity, but sometimes breeds in the second

?ear (vol. iii, p. 133). The Grus americanvs takes the same time, bat breeds be-
or© acQuhrhig its full plumage (vol. iii, p. 211). The adults ot Ardea comil«n

552 THE DESCENT OF MAN,

The fact of "birds "breeding in their immature plumage seems
opposed to tlie belief tLat sexual selection Las played as important a
part, as I believe it has, in giving ornamental colors, plumes, etc., to
the males, and, by means of equal transmission, to the feu:ales of
many species. 1 he objection would be a "ulid one, if the younger
and less ornamented males were as successful in winning females and
propagating their kind, as the older and more beautiful males. But
we have no reason to suppose that this is the case. Audubon
speaks of the breeding of the immature males of Ihia ta.italus as a
rare event, as does Mr. Swinhoe, in regard to the immature males of
Oriolus.* If the young of any species in their immature plumage
"were more successful in winning partners than the adults, the aduit
plumage would probably soon be lost, as the males would prevail
w hich retained their immature dress for the longest period, and thus
the chaiacter of the species would ultimately be modified. -f If, on
the other hand, the young never succeeded in obtaining a female,
the habit of early reproduction would perhaps be sooner or later
eliminated, from being suj^erliuous and entailing waste of power.

The 1)1 u mage of certain birds goes on increasing in beauty during
many years alter they are fully mature; this is the case with the
train of the jjeacock, with some of the birds of paradise, and with
the crests and plumes of certain herons, for instance, the Ardca
Indoxicana.X But it is doubtful whether the continued development
of such feathers is the result of the selection of successive beneficial
variations (though this is the most probable view with birds of para-
dise) or merely of continuous growth. Most fishes continue increas-
ing in size, as long as they are in good health and have plenty of
food; and a somewhat similar law may prevail with the plumes of
birds.

Class V. When the adults of loth s€(ces have a distinct winter
and summer plumage, ichtther or not the male differs from the
female, the young resemble the adults of both sexes in their winter
dress, or much more rarely in their summer dress, or they resemble

are blue and the youn? white; and white, mottled, and mature blue birds
may all be seen breeding tojjether (vol. iv. p. 5«); but Mr. Blyth :. forms me
that certain lierons apparently are dimorphic, for white and colored iiidivid-
vials of the same ajije may be observed. The Harlequin duck {Anas huiriomca,
Linn.) takes three years to acquire its f ull pluniajre, thoujrh many birds breed
in the second year ivol. iii, p. G14). The white-headed eajjlc (Falco levcocephalvs),
vol. iii p. :i2iO, is likewise known to breed in its i..imature rtate. Some species
of Oriolus (according to Mr. Blyth and Mr. Swinhoe, in " Ibis," July, 1663, p.
38) likewise breed before Ihey attain their full plumage.

* See the last foot-note.

+ Other animals, belonging to quite distinct classes, are either habitually
or occasionally capable of breeding before they have fully acquired their
adult characters. This is the case with the young males of the salmon.
Several amphibians have been known to breed while retaining their larval
structure. Fritz Muller has shown C Facts and Arguments for Uarwin,"
Eng. trans., ]8G!», p. 79) that the males of several amphipod crustaceans become
sexually mature while young; and I infer that this is a case of premature
breeding, because they have not as yet acquired their fully developed claspera.
All such facts are highly interesting, as bearing on one means by which speciea
may undergo great modifications of character.

% Jerdon, " Birds of India," vol. iii, p. 507, on the peacock. Dr. Marshall
thinks that the older and more brilliant males of birds of paradise have an
advantage over the younger males; see ** Archives Neerlandaises," torn, vi,
1871. On Ardea, Audubon, ibid, vol. iii, p. 139,

1

BIRDS, 553

the females alone. Or the young may Jiave an intermediate
character ; or, again, they may differ greatly from the adults iu
both their seasonal plumages. — 'I'lie ca.ses in this class are singularly
complex; nor is this surprising, as they depend on inheritance,
limited in a greater or less degree in three different ways, namely,
by sex, age, and the season of the year. In some cases the
individuals of the same species pass through at least five distinct
states of plumage. With the species in which the male differs
from the female during the summer season alone, or, which is rarer,
during both seasons,* the young generally resemble the females —
as with the so called goldfinch of North America, and apparently
with the splendid Maluri of Australia. f With those species, the
sexes of which are alike during both the summer and winter, the
young may resemble the adults, firstly, in their winter dress ; sec-
ondly, and this is of much rarer occurrence, in their summer dress ;
thirdly, they may be intermediate between these two states ; and,
fourthly, they may differ greatly from the adults at all seasons. We
have an instance of the first of these four cases in one of the egrets
of India {Baphus coromandns), in which the young and the adults of
both sexes are white during the winter, the adults becoming golden-
buff during the summer. Wiih the gaper {Anastomus oscitans) of
India we have a similar case, but the colors are reversed ; for the
young and the adults of both sexes are gray and black during the
winter, the adults becoming white during the summer.:}: As an
instance of the second case, the young of the razor-bill {Alca torda,
Linn.), in an early state of plumage, are colored like the adults dur-
ing the summer; and the young of the white-crowned sparrow of
North America {Fri/igilla leucophrys), assoon astiedged. have elegant
white stripes on their heads, which are lost by the young and the old
during the winter. i^ With respect to the third case, namely, that of
the young having an intermediate character between the summer
and winter adult plumages, Yarrell || insists that this occurs with
many waders. Lastly, in regard to the young differing greatly from
both sexes in tleir adult summer and winter plumages, this occurs
with some hei ms and egrets of North America and India — the
young alone being white.

I will make only a few remarks on these complicated cases. W^hen
the young resemble the females in their summer dress, or the adults
of both sexes in their winter dress, the cases differ from those given
under Classes I and III only in the characters originally acquired

*For illustrative eases see vol. Iv, of Macsrillivray's *' Hist. Brit. Birds;"
on Triiij;a, etc., pp. -^29, ^71; on the Machetes, p. 172; on the Charadrius hiati-
cula, p. 118; on the Charadnus pluvia:is. p. 94.

t For the groldflneh of North America. Fnngilla tristis, Linn., see Audubon,
"Oriiith. Bioirraphy." vol. i, p. 172. For the ilaiuri, Gould's " Hand-book to
the Birds of Australia," vol. i, p. 318.

$ I am indebted to Mr. Blyth for Information as to the Buphus; see also
Jerdoii, '• Birds of India," vol. iii, p. 719. On the Anastomus, see Blyth, ia
*• Ibis," 18(57 p. 173.

§ On the Alca, .see Macerillivray, ** Hist. Brit. Birds," vol. v, p, 347. On the
Fringilla letcophrys, Audubon, ibid, vol. ii, p. 89. I shall have hereafter to
refer to the youn^ of certain herons and egrets being white,

1 History of British Birds," vol. i, 1839, p. 159,

554 THE DESCENT OF MAN,

by the males during the breeding-season having been limited intheii
transmission to the corresponding season. When the adults have i'
distinct summer and winter plumage, an I the young differ from both,
the case is more difficult to understand. We may admit as probable
that the young have retained an ancient state of plumage; we cau
account by sexual selection for the summer or nuptial plumage of the
adults, but how are we to account for their distinct winter plumage ?
If we could admit that this plumage serves in all cases as a protec-
tion, its acquirement would be a simple affair; but there seems no
good reason for this admission. It may be suggested that the
widely different conditions of life during the winter and summer
have acted in a direct manner on the plumage ; this may have had
some effect, but I have not much confidence in so great a difference
as w^e sometimes see between the two plumages having been thus
caused. A more probable explanation is, that an ancient style of
plumage, partially modified through the transference of some char-
acters from the summer plumage, has been retained by the adults
during the winter. Finally, all the cases in our present class appa-
rently depend on characters acquired by the adult males having
been variously limited in their transmission according to age, season,
and sex; but it would not be worth while to attempt to follow out
these complex relations.

Class VI. The young in their first plumage differ from each other
according to sex; the young males resembling more or less closely the
adult males, and the young females more or less closely the adult
females. — The cases in the present class, though occurring in various
groups, are not numerous; yet it seems the most natural thing that
the young should at first somewhat resemble the adults of the same
sex, and gradually become more and more like them. The adult
male blackcap {Sylvia atricapilla) has a black head, that of the
female being reddish-brown; and I am informed by Mr. Blyth, that
the young of both sexes can be distinguished by this character even
as nestlings. In the family of thrushes an unusual number of simi-
lar cases have been noticed ; thus, the male blackbird {Turdus
merula) can be distinguished in the nest from the female. The two
sexes of the modkmg-hivdi {Turdus poly glottus, Linn.) differ very little
from each other, yet the males can easily be distinguished at a very
early age from the females by showing more pure white.* The
males of a forest-thrush and of a rock-thrush {Orocetes erythrogastra
and Petrocincla cyanea) have much of their plumage of a fine blue,
while the females are brown; and the nestling males of both species
have their main wing and tail feathers edged with blue, while those
of the female are edged with brown. f In the young blackbird the
wing-feathers assume their mature character and become black after
the others; on the other hand, in the two species just named the
wing- feathers become blue before the others. The most probable
view with reference to the cases in the present class is that the males,

♦Audubon "Omith. Biography," vol. i, p. 113.

tMr. C. A. Wright, in "Ibis," vol. vi. 1864, p. 65. Jerdon, "Birds of
India," vol. 1, p. 515. See also on the blackbird, Blyth, in Charlesworth's
" Mag. of Nat. History," vol. i, 1837, p. 113.

BIRDS, 566

differently from what occurs in Class I, have transmitted tlieir colors
to their male offspring at an earlier age than tbat at wbicb tb.ey were
first acquired; for, if the ujales had varied while quite young, their
characters would probably have been transmitted to both sexes.*

In A'thurus polytmus, a humming-bird, the male is splendidly
colored black and green, and two of the tail-feathers are immensely
lengthened; the female has an ordinary tail and inconspicuous
colors; now the young males, instead of resembling the adult
female, in accordance with the common rule, begin from the first to
assume the colors proper to their sex, and their tail-feathers soon
become elongated. I owe this information to Mr. Gould, who has
given me the following more striking and as yet unpublished case.
Two humming-birds belonging to the genus Eustephanus, both
beautifully colored, inhabit the small island of Juan Fernandez, and
have always been ranked as specifically distinct. But it has lately
been ascertained that the one which is of a rich chestnut-brown
color with a golden- red head, is the male, while the other, which is
elegantly variegated with green and white, with a metallic green
head, is the female. Now the young from the first somewhat resem-
ble the adults of the corresponding sex, the resemblance gradually
becoming more and more complete.

In considering this last case, if as before we take the plumage of
the young as our guide, it would appear that both sexes have been
rendered beautiful independently; and not that one sex has partially
transferred its beauty to the other. The male apparently has
acquired his bright colors through sexual selection in the same
manner as, for instance, the peacock or pheasant in our first class of
cases; and the female in the same manner as the female Rhynchaea
or Turnix in our second class of cases. But there is much diflaculty
in understanding how this could have been effected at the same time
with the two sexes of the same species. Mr. Salvin states, as we
have seen in the eighth chapter, that with certain humming-birds
the males greatly exceed the females in number, while with other
species inhabiting the same country the females greatly exceed the
males. If, 'hen, we might assume that during some former length-
ened period the males of the Juan Fernandez species had greatly
exceeded the females in number, but that during another lengthened
period the females had far exceeded the males, we could understand
how the males at one time, and the females at another, might have
been rendered beautiful by the selection of the brighter- colored
individuals of either sex; both sexes transmitting their characters to
their young at a rather earlier age than usual. Whether this is the
true explanation I will not pretend to say; but the case is too remark-
able to be passed over without notice.

*The following additional cases may be mentioned: the young males of
Tanagra rubra can be distinguished from the young females (Audubon,
" Ornith. Biography,*' vol. iv, p. 3".i2), and so It is within the nestlings of a blue
nuthatch, Deridrojjhila frontahs, ol India (Jerdon. "Birds of India." vol. i, p.
889). Mr. Blyth also infoj-ms me that the sexes of the stoneohat. Saxicola ri/M-
cola, are distinguishable at a very early age Mr. S;ilvin gives (" Proc. Zoolog.
See," 18^0, p. i;Oe), the case of a humming-bird, like the followiAK one of
£ustephauu8.

556 THE DESCENT OF MA2r.

Wo have now seen in all six classes that an intimate rela-
tion exists between the plumage of the young and the
adults, either- of one sex or both. These relations are
fairly well explained on the principle that one sex — thi?
being in the great majority of cases the male — tirst acquired
through variation and sexual selection bright colors or
other ornaments and transmitted them in various ways in
accordance with the recognized laws of inheritance. \\ hy
variations have occurred at different periods of life, even
sometimes with species of the same group, we do not know,
bu+ with respect to the form of transmission one important
determining cause seems to be the age at which the varia-
tions first appear.

From the principle of inheritance at corresponding ages
and from any variations in color which occurred in the
males at an early age not being then selected — on the con-
trary being often eliminated as dangerous — W-hile similar
variations occurring at or near the period of reproduction
have been preserved, it follows that the plumage of the
young will often have been left unmodified, or but little
inodilied. "We thus get some insight into the coloring of
the progenitors of our existing species. In a vast number
of species in five out of our six classes of cases the adults of
one sex or of both are bright colored, at least during the
breeding-season, while the young are invariably less brightly
colored than the adults, or are quite dull colored; for no
instance is known, as far as I can discover, of the young of
dull-colored species displaying bright colors, or of the young
of bright-colored species being more brilliant than their
parents. In the fourth class, however, in which the young
and the old resemble each other, there are many species
(though by no means all), of which the young are bright
colored, and, as these form old groups, we may infer that
their early progenitors were likewise bright. "With this
exception, if we look to the birds of the world, it appears
that their beauty has been much increased since that
period, of which their immature plumage gives us a partial
record.

On the Color of the Plumage in Belation to Protection. —
It will have been seen that I cannot follow Mr. "Wallace in
the belief that dull colors, when confined to the females,
have been in most cases specially gained for the sake of

BIRDS, 557

protection. There can, however, be no donbt, as formerly
remarked, that both sexes of many birds have had their
colors modified so as to escapj the notice of their enemies;
or in some instances, so as to approach their prey unobserved,
just as owls have had their plumage rendered soft, that
their flight may not be overheard. Mr. Wallace remarks*
that "it is only in tlie tropics, among forests which never
lose their foliage, that we find whole groups of birds whose
chief color is green.'' It will be admitted by eveiy one
who has ever tried how difficult it is to distinguish parrots
in a leaf-covered tree. Neverthelesss, we must remember
that many parrots are ornamented with crimson, blue and
orange tints, which can hardly be protective. Woodpeckers
are eminently arboreal, but besides green species there are
many black and black-and-white kinds — all the species
being apparently exposed to nearly the same dangers. It
is therefore probable that with tree-haunting birds strongly
pronounced colors have been acquired through sexual selec-
tion, but that a green tint has been acquired oftener than
any other from the additional advantage of protection.

In regard to birds which live on the ground, every one
admits that they are colored so as to imitate the surround-
ing surface. How difficult it is to see a partridge, snipe,
woodcock, certain plovers, larks and night-jars when
crouched on ground. Animals inhabiting deserts offer the
most striking cases, for the bare surface affords no conceal-
ment, and nearly all the smaller quadrupeds, reptiles and
birds depend for safety on their colors. Mr. Tristram lias
remarked in regard to the inhabitants of the Sahara, that
all are protected by their '^ isabelline or sand color."f
Calling to my recollection the desert-birds of South
America, as well as most of the ground-birds of (xreat
Britain, it appeared to me that both sexes in such cases
are generally colored nearly alike. Accordingly, I applied
to Mr. Tristram with respect to the birds of the Sahara,
and he has kindly given me the following information:
There are twenty-six species belonging to fifteen genera,
which manifestly have their plumage colored in a protect-

* " Westminster Review," July, 1867, p. 5.

f " Ibis," 1859, vol, i, p. 429, et seq. Dr. Roblfs, however, re-
marks to me in a letter that, according to his experience of the
Sahara, this statement is too strong.

558 THE DESCENT OF MAN.

ive manner; and this coloring is all the more striking, as
with most of these birds it differs from that of their con-
geners. Both sexes of thirteen out of the twenty-six
species are colored in the same manner; but these belong
to genera in which this rule commonly prevails, so that
they tell us nothing about the protective colors being the
same in both sexes of desert-birds. Of tlie other thirteen
species three belojig to genera in which the sexes usually
differ from each other, yet here they have the sexes alike.
In the remaining ten species the male differs from the
female; but the difference is confined chiefly to the under
surface of the plumage, which is concealed when the bird
crouches on the ground; the head and back being of the
same sand-colored hue in the two sexes. So that in these
ten species the upper surfaces of both sexes have been acted
on and rendered alike through natural selection for the
sake of protection; while tlie lower surfaces of the males
alone have been diversified through sexual selection for the
sake of ornament. Here, as both sexes are equally well
protected, we clearly see that the females have not been
prevented by natural selection from inheriting the colors of
their male parents ; so that we must look to the law of
sexually limited transmission.

In all parts of the world both sexes of many soft-billed
birds, especially those which frequent reeds or hedges, are
obscurely colored. No doubt if their colors had been
brilliant, they would have been much more conspicuous to
their enemies; but whether their dull tints have been
specially gained for the sake of protection seems, as far as
I can judge, rather doubtful. It is still more doubtful
whether such dull tints can have been gained for the sake
of ornament. We must, however, bear in mind that male
birds, though dull-colored, often differ much from their
females (as with the common sparrow), and this leads to
the belief that such colors have been gained through sexual
selection from being attractive. Many of the soft-billed
birds are songsters; and a discussion in a former chapter
should not be forgotten, in which it was shown that the
best songsters are rarely ornamented with bright tints. It
would appear that female birds, as a general rule, have
selected their mates either for their sweet voices or gay
colors, but not for both charms combined. Some species
which are manifestly colored for the sake of protection.

I

BIRDS. 559

such as the jack-snipe, woodcock and night- jar, are like-
wise marked and shaded, according to our standard of
taste, with extreme elegance. In such cases we may con-
clude that both natural and sexual selection have acted
conjointly for protection and ornament. Whether any
bird exists which does not possess some special attraction
by which to charm the opposite sex may be doubted.
When both sexes are so obscurely colored that it would
be rash to assume the agency of sexual selection, and when
no direct evidence can be advanced showing that such
colors serve as a protection, it is best to own complete
ignorance of the cause, or, which comes to nearly the same
tiling, to attribute the result to the direct action of the
conditions of life.

Both sexes of many birds are conspicuously, though not
brilliantly, colored, such as the numerous black, white, or
piebald species; and these colors are probably the result of
sexual selection. With the common blackbird, capercailzie,
blackcock, black scoter-duck (Oidemia), and even with one
of the birds of paradise {Lophorina atra) the males alone
are black, while the females are brown or mottled; and
there can hardly be a doubt that blackness in these cases
has been a sexually selected character. Therefore, it is in
some degree probable that the complete or partial blackness
of both sexes in such birds as crows, certain cockatoos,
storks and swans, and many marine birds, is likewise the
result of sexual selection, accompanied by equal transmis-
sion to both sexes; for blackness can hardly serve in any
case as a protection. With several birds, in which the male
alone is black, and in others in which both sexes are black,
the beak or skin about the head is brightly colored, and
the contrast thus aiforded adds much to their beauty; we
see this in the bright yellow beak of the male blackbird, in
the crimson skin over the eyes of the blackcock and caper-
cailzie, in the brightly and variously colored beak of the
scoter-drake (Oidemia), in the red beak of the chough
(Corvus graculvs, Linn.), of the black swan and the black
stork. This leads me to remark that it is not incredible
that toucans may owe the enormous size of their beaks to
sexual selection, for the sake of displaying the diversified
and vivid stripes of color with which these organs are
ornamented.* The naked skin, also, at the base of the

* No satisfactory explanation has ever been offered of the immense

660 THE DESCENT OF MAN.

beak and round the eyes is likewise often brilliantly colored;
and Mr. Gould, in speaking of one species,-^ says that the
colors of the beak "are doubtless in the finest and most
brilliant state during the time of pairing." There is no
greater improbability that toucans should be encumbered
with immense beaks, though rendered as light as possible
by their cancellated structure, for the display of fine
colors (an object falsely appearing to us unimportant),
t!;a!i that the male Argus pheasant and some other birds
•should be encumbered with plumes so long as to impede
their fiight.

In the same manner, as the males alone of various species
are black, the females being dull-colored; so in a few cases
the males alone are either wholly or partially white, as with
the several bell-birds of South America (Chasmorhyiichus),
the Antarctic goose (Bernicla antarctica), the silver pheas-
ant, etc., while the females are brown or obscurely mottled.
Therefore, on the same principle as before, it is probable
that both sexes of many birds, such as wdiite cockatoos,
several egrets with their beautiful plumes, certain ibises,
gulls, terns, etc., have acquired their more or less com-
pletely white plumage through sexual selection. In some
of these cases the plumage becomes white only at maturity.
This is the case with certain gannets, tropic-birds, etc.,
and with the snow-goose {Anser liy per bar ens). As the
latter breeds on the " barren grounds," when not covered
with snow, and as it migrates southward during the winter
there is no reason to suppose that its snow-white adult
plumage serves as a protection. In t\\Q Anastomiis osciians
we have still better evidence that the white plumage is a
nuptial character, for it is developed only during the

size, and still less of tbe briglit colors, of the toucan's beak. Mr.
Kates (" The Naturalist on the Amazons," vol. ii, 1863, p. 341) states
that they use their beaks for reaching fruit at the extreme tips of the
branches; and likewise, as stated by other authors, for extracting
eggs and young birds from the nests of other birds. But, as Mr.
Bates admits, the beak "can scarcely be considered a very perfectly
formed instrument for the end to which it is applied." The great
bulk of the beak, as shown by its breadth, depth, as well as length,
is not intelligible on the view, that it serves merely as an organ of
prehension. Mr. Belt believes (" The Naturalist in Nicaragua," p.
197) that the ])rincipal use of the heak is as a defense against
enemies. esi>ecially to the female while nesting in a hole in a tree.
* liUamphastos carinatus, Gould's " Monograph of Rhamphastidae. "

BIRDS. sei

Bnmmer; the yonng in their immature state and the adults
in their winter dress being gray and black. With many
kinds of gulls (Larus) the head and neck become pure
white during the summer, being gray or mottled daring
the winter and in the young state. On the other hand,
with the smaller gulls, or sea-mews (Gavia) and with some
terns (Sterna) exactly the reverse occurs; for the heads of
the young birds during the first year, and of the adults during
the winter, are either pure white or much paler colored
than during the breeding- season. These latter cases olfer
another instance of the capricious manner in which sexual
selection appears often to have acted.*

That aquatic birds have acquired a white plumage so
much oftener than terrestrial birds probably depends on
their large size and strong powers of flight, so that they
can easily defend themselves or escape from birds of prey,
to which, moreover, they are not much exposed. Conse-
quently sexual selection has not here been interfered with
or guided for the sake of protection, ^o doubt with birds
which roam over the open ocean, the males and females
could find each other much more easily when made con-
spicuous either by being perfectly white or intensely black;
60 that these colors may possibly serve the same end as tlie
call-notes of many land-birds. f A white or black bird
when it discovers and flies down to a carcass floating on the
sea or cast upon the beach, will be seen from a great dis-
tance, and will guide other birds of the same and other
species to the prey; but as this would be a disadvantage to
the first finders, the individuals which were the whitest or
blackest would not thus procure more food than the less
strongly colored individuals. Hence conspicuous colors
cannot have been gradually acquired for this purpose
(through natural selection.

As sexual selection depends on so fluctuating an element

* On Larus, Oavia and Sterna, see Macgiilivray. "Hist Brit.
Birds," vol. v, pp. 515, 584, 626. On the Anser hyperboreus, Audu-
bon, " Ornitb. Biograpby," vol. iv, p. 562. On the Auabtomus, Mr.
Blytt, in " Ibis," 1867, p. 173.

f It may be noticed tbat with vultures, which roam far and wide

high in the air, like marine birds over the ocean, three or four species

^are almost wholly or largely white, and that uiany others are black.

So that here again conspicuous colors may possibly aid the sexes in

j^nding each other daring the breeding season.

662 T^S! DESCENT OF MAN,

as taete, we can understand how it is that, within the same
group of birds having nearly the same habits, there should
exist white or nearly white, as well as black or nearly black,
species — for instance, both white and black cockatoos,
etorks, ibises, swans, terns and petrels. Piebald birds like-
wise sometimes occur in the same groups together with
black and white species; for instance, the black-necked
ewan, certain terns and the common magpie. That a strong
contrast in color is agreeable to birds we may conclude by
looking through any large collection, for the sexes often
differ from each other in the male having the pale parts of
a purer white, and the variously colored dark parts of still
darker tints than the female.

It would even appear that mere novelty, or slight
changes for the sake of change, have sometimes acted on
female birds as a charm, like changes of fashion with us.
Thus the males of some parrots can hardly be said to be
more beautiful than the females, at least according to our
taste, but they differ in such points, as in having a rose-
colored collar instead of "a bright, emeraldine, narrow
green collar;'' or in the male having a black collar instead
of "a yellow demi-coUar in front," with a pale roseate
instead of a plum-blue head.* As so many male birds
have elongated tail-feathers or elongated crests for their
chief ornament, the shortened tail, formerly described in
the male of a humming-bird, and the shortened crest of
the male goosander, seem like one of the many changes of
fashion which we admire in our own dresses.

Some members of the heron family offer a still more
curious case of novelty in coloring, having, as it appears,
been appreciated for the sake of novelty. The young of
the Ardea aslia are white, the adults being dark slate-
colored; and not only the young, but the adults in their
winter plumage, of the allied Buphus coromandus are
white, this color changing into a rich golden-buff during
the breeding-season. It is incredible that the young of
these two species, as well as of some other members of the
Bame family, f should for any special purpose have been

*See Jerdon on the genus Palaeornis, " Birds of India," vol. i, pp.
258-260.

f The young of Ardea rufescens and A. cmnden of the United
States are likewise white, the adults being colored in accordance

BIRDS, 563

rendered pure white and thus made conspicuous to their
enemies; or that the adults of one of these two species
should have been specially rendered white during the
winter in a country which is never covered with snow. On
the other hand, we have good reason to believe that white-
ness has been gained by many birds as a sexual ornament.
We may therefore conclude that some early progenitor oi
the Ardea asJia and the Buphus acquired a white plumage
for nuptial purposes, and transmitted this color to their
young; so that the young and the old became white like
certain existing egrets; and that the whiteness was after-
ward retained by the young, while it was exchanged by the
adults for more strongly ijronounced tints. But if "we
could look still further back to the still earlier progenitors
of these two species we should probably see the adults dark-
colored. I infer that this would be the case from the
analogy of many other birds which are dark while young
and when adult are white; and more especially from the
case of the Ardea gularis, the colors of which are the
reverse of those of A. asha, for the young are dark-colored
and the adults white, the young having retained a forme*?
state of plumage. It appears therefore that during a lonj '
line of descent, the adult progenitors of the Ardea asha^
the Buphus, and of some allies, have undergone the follow-
ing changes of color: fiistly, a dark shade; secondly, pure
white, and thirdly, owing to another change of fashion (if
I may so express myself), their present slaty, reddish, or
golden-buff tints. These successive changes are intelligi-
ble only on the principle of novelty having been admired
by birds for its own sake.

Several writers have objected to the whole theory of
sexual selection by assuming that with animals and savages
the taste of the female for certain colors or other ornaments
would not remain constant for many generations; that first
one color and then another would be admired, and conse-
quently that no permanent effect could be produced. We
may admit that taste is fluctuating, but it is not quite arbi-
trary. It depends much on habit, as we see in mankind ;
and we may infer that this would hold good with birds and

with their specific names. Audubon (" Ornith. Biography," vol. iii,
p. 416; vol. iv, p. 58) seems rather pleased at the thought that thia
remarkable change of plumage will greatly "disconcert the system-
atists."

564 THE DESCENT OF MAN,

other animals. Even in our own dress the general charactei
lasts long, and tlie changes are to a certain extent gradu-
ated. Abundant evidence will be given in two places in a
future chapter that savages of many races have admired for
many generations the same cicatrices on the skin, the same
hideously perforated lips, nostrils, or ears, distorted heads,
etc.; and these deformities present some analogy to the
natural ornaments of various animals. Nevertheless, with
savages such fashions do not endure forever, as we may
infer from the differences in this respect between allied
tribes on the sam^e continent. So, again, the raisers of
fancy animals certainly have admired for many generations
and still admire tiie same breeds; they earnestly desire
slight changes, which are considered as improvements, but
any great or sudden change is looked at as the greatest
blemish. With birds in a state of nature we have no
reason to suppose that they would admire an entirely new
style of coloration, even if great and sudden variations
often occurred, which is far from being the case. We know
that dove-cote pigeons do not willingly associate with the
variously colored fancy breeds; that albino birds do not
commonly get partners in marriage; and that the black
ravens of the Feroe Islands chase away their piebaid
brethren. But this dislike of a sudden change would not
preclude their appreciating slight changes any more than it
does in the case of man. Hence, with respect to taste,
which depends on many elements, but partly on habit and
partly on a love of novelty, there seems no improba-
bility in animals admiring for a very long period the
same general style of ornamentation or other attractions,
and yet appreciating slight ciianges in colors, form, or
sound.

Summary of the Fonr Chapters on Birch. — Most male
birds are highly pugnacious during the breeding-season, and
some possess weapons adapted for fighting with their rivals.
But the most pugnacious and the best armed males rarely
or never depend for success solely on their power to drive
away or kill their rivals, but liave special means for charm-
ing the female. With some it is the power of song, or of
giving forth strange cries, or instrumental music, and the
males in consequence differ from the females in their vocal
organs, or in the structure of certain feathers. From the

BIRDS, 665

curiously diversified means for producing various sounds we
gain a h.\^\\ idea of the importance of this means of court-
ship. Many birds endeavor to charm the females by love
dances or antics performed on the ground or in the air, and
sometimes at prepared places. But ornaments of. many
kinds, the most brilliant tints, combs and wattles, beautiful
plumes, elongated feathers, top-knots, and so forth, are by
far the commonest means. In some cases mere novelty
appears to have acted as a charm. The ornaments of the
males must be highly important to them, for they have
been acquired in not a few cases at the cost of increased
danger from enemies, and even at some loss of power in
lighting with their rivals. The males of very many species
do not assume their ornamental dress until they arrive at
maturity, or they assume it only during the breeding-season,
or the tints then become more vivid. Certain ornamental
appendages become enlarged, turgid, and brightly colored
during the act of courtship. The males display their
charms with elaborate care and to the best effect; and this
is done in the presence of the females. The courtship is
sometimes a prolonged affair, and many males and females
congregate at an appointed place. To suppose that the
females do not appreciate the beauty of the males is to
admit that their splendid decorations, all their pomp and
display, are useless; and this is incredible. Birds have fine
powers of discrimination, and in some few instances it can
be shown that they have a taste for the beautiful. The
females, moreover, are known occasionally to exhibit a
marked preference or antipathy for certain individual
males.

If it be admitted that the females prefer, or are uncon-
sciously excited by the more beautiful males, then the
males would slowly but surely be rendered more and more
attractive through sexual selection. That it is this sex
which has been chiefly modified, we may infer from the
fact that, in almost every genus where the sexes differ, the
males differ much more from one another than do the
females; this is well shown in certain closely allied repre-
sentative species, in which the females can iiardly be dis-
tinguished, while the males are quite distinct. Birds in a
state of nature offer individual differences which would
amply suffice for the work of sexual selection; but we have
seen that they occasionally present more strongly mai'ked

566 THE DESCENT OF MAN.

variations which recur so frequently that they would imme-
diately be fixed, if they served to allure the female. The
laws of variation must determine the nature of the initial
changes, and will have largely influenced the final result.
The gradations, which may be observed between the males
of allied species, indicate the nature of the steps through
which they have passed. They explain also in the most
interesting manner how certain characters have originated,
such as the indented ocelli on the tail-feathers of the pea-
cock, and the ball-and-socket ocelli on the wing-feathers
of the Argus pheasant. It is evident that the brilliant
colors, top-knots, fine plumes, etc., of many male birds
cannot have been acquired as a protection; indeed, they
sometimes lead to danger. That they are not due to the
direct and definite action of the conditions of life, we may
feel assured, because the females have been exposed to the
same conditions, and yet often differ from the males to an
extreme degree. Although it is probable that changed
conditions acting during a lengthened period have in some
cases produced a definite effect on both sexes, or some-
times on one sex alone, the more important result will have
been an increased tendency to vary or to present more
strongly marked individual differences; and such differ-
ences will have afforded an excellent groundwork for the
action of sexual selection.

The laws of inheritance, irrespectively of selection,
appear to have determined whether the characters acquired
by the males for the sake of ornament, for producing vari-
ous sounds and for fighting together, have been transmitted
to the males alone or to both sexes either permanently or
periodically during certain seasons of the year. Why
various characters should have been transmitted sometimes
in one way and sometimes in another is not in most cases
known; but the period of variability seems often to have
been the determining cause. When the two sexes have
inherited all characters in common they necessarily resem-
ble each other; but as the successive variations may be
differently transmitted every possible gradation may be
found, even within the same genus, from the closest simi-
larity to the widest dissimilarity between the sexes. With
many closely allied species, following nearly the same
habits of life, the males have come to differ from each
0th *?r chiefly through the action of sexual selection; while

BIMDS. 567

the females have come to differ chiefly from partaking
more or less of the characters thus acquired by the males.
The effects, moreover, of the definite action of the condi-
tions of life will not have been masked in the females as
in the males by the accumulation through sexual selection
of strongly pronounced colors and other ornaments. The
individuals of both sexes, however affected, will have been
kept at each successive period nearly uniform by the free
intercrossing of many individuals.

With species in which the sexes differ in color it is possi-
ble or probable that some of the successive variations often
tended to be transmitted equally to both sexes; but that
when this occurred the females were prevented from acquir-
ing the bright colors of the males by the destruction which
they suffered during incubation. There is no evidence
that it is possible by natural selection to convert one form
of transmission into another. But there would not be the
least difficulty in rendering a female dull-colored, the male
being still kept bright-colored, by the selection of suc-
cessive variations which were from the first limited in their
transmission to the same sex. Whether the females of
many species have actually been thus modified must at
present remain doubtful. When, through the law of the
equal transmission of characters to both sexes, the females
were rendered as conspicuously colored as the males, their
instincts appear often to have been modified so that they
were led to build domed or concealed nests.

In one small and curious class of cases the characters
and habits of the two sexes have been completely trans-
posed, for the females are larger, stronger, more vociferous
and brighter colored than the males. They have also be-
come so quarrelsome that they often fight together for the
possession of the males like the males of other pugnacious
species for the possession of the females. If, as seems
probable, such females habitually drive aways their rivals,
and by the display of their bright colors or other charms
endeavor to attract the males, we can understand how it is
that they have gradually been rendered by sexual selection
and sexually limited transmission more beautiful than the
males — the latter being left unmodified or only slightly
modified.

Whenever the law of inheritance at corresponding ages

668 THE DESCENT OF MAK

prevails, bnt not that of sexually limited transmission, then
if the parents vary late in life — and we know that this con-
stantly occurs with our poultry and occasionally with other
birds — the young will be left unaffected, while the adults
of both sexes will be modified. If both these laws of
inheritance prevail and either sex varies late in life, that
sex alone will be modified, the other sex and the young
being unaffected. When variations in brightness or in
other conspicuous characters occur early in life, as no doubt
often happens, tliey will not be acted on through sexual
selection until the period of reproduction arrives; conse-
quently if dangerous to the young they will be eliminated
through natural selection. Thus we can understand how
it is that variations arising late in life have so often been
preserved for the ornamentation of the males; the females
and the young being left almost unaffected, and therefore
like each other. With species having a distinct summer
and winter plumage, the males of which either resemble or
differ from the females during both seasons or during the
summer alone, the degrees and kinds of resemblance
between the young and the old are exceedingly complex;
and tills complexity apparently depends on characters, first
acquired by the males, being transmitted in various ways
and degrees, as limited by age, sex and season.

As the young of so many species have been but little
modified in color and in other ornaments, we are enabled
to form some judgment with respect to the plumage of their
early progenitors; and we may infer tliat the beauty of our
existing species, if we look to the whole class, has been
largely increased since that period, of which the immature
plumage gives us an indirect record. Many birds, espe-
cially those which live much on the ground, have undoubt-
edly been obscurely colored for the sake of protection. In
some instances the upper exposed surface of the plumage
has been thus colored in both sexes, while the lower surface
in the males alone has been variously ornamented through
sexual selection. Finally, from the facts given in these
four chapters, we may conclude that weapons for battle,
organs for producing sound, ornaments of many kinds,
bright and conspicuous colors, have generally been acquired
by the males through variation and sexual selection and
have been transmitted in various ways according to the

seTeral laws of inheritance — the females and the young
being left comparatively but little modified.*

*I am greatly indebted to tbe kindness of Mr. Sclater for iiaving
looked over tliese four chapters on birds, and tbe two following ones
on manimals. In this way 1 have been saved from maiung mistakes
about the names of the species, and from stating anytiiing as a fact
"which is known to this distinguished naturalist to be erroneous.
But of course he is not at all answerable for the accuracy of tlio
statements quoted by mo from various authorities.

570

TEE DESCENT OF MAN.

CHAPTER XVII.

6EC0NDAEY SEXUAL CHAKACTERS OF MAMMALS.

The law of battle — Special weapons, confined to the males — Cause of
absence of weapons in tlie female — Weapons common to both
sexes, yet primarily acquired by the male — Other uses of such
weapons — Their high importance — Greater size of the male —
Means of defense — On the preference shown by either sex in the
pairing of quadrupeds.

With mammals the male appears to win the female
much more through the law of battle than through the
display of his charms. The most timid animals, not pro-
vided with any special weapons for fighting, engage in des-
perate conflicts during the season of love. Two male hares
nave been seen to fight together until one was killed; male
moles often fight, and sometimes with fatal results ; male
squirrels engage in frequent contests, " and often wound
each other severely;" as do male beavers, so that ^'hardlv
a skin is without scars."* I observed the same fact witn
the hides of the guanacoes in Patagonia; and on one occa-
sion several were so absorbed in fighting that they fear-
lessly rushed close by me, Livingstone speaks of the males
of the many animals in Southern Africa as almost invari-
ably showing the scars received in former contests.

The law of battle prevails with aquatic as with terrestrial
mammals. It is notorious how desperately male seals fight,
both with their teeth and claws, during the breeding-
season ; and their hides are likewise often covered with
scars. Male sperm-whales are very jealous at this season;
and in their battles *' they often lock their jaws together

*See Waterton's account of two hares fighting, "Zoologist," vol.
i, 1843, p 211. On moles, Bell, "Hist, of British Quadrupeds," 1st
edit., p. 100. On squirrels, Audubon and Bachman, 'Viviparous
Quadrupeds of North America," 1846, p. 269. On beavers, Mr. A.
H. Green, in " Journal of Lin. iSoc Zoolog.," vol. x, 1869, p. 362.

MAMMALS, 571

and turn on their sides and twist about;** so that their
lower jaws often become distorted.*

All male animals which are furnished with special weap-
ons for fighting are well known to engage in fierce battles.
The courage and the desperate conflicts of stags have often
been described; their skeletons have been found in various
parts of the world, with the horns inextricably locked
together, showing how miserably the victor and vanquished
had perished, f No animal in the world is so dangerous as
an elephant in must. Lord Tankerville has given me a
graphic description of the battles between the wild bulls
m Chillingham Park, the descendants, degenerated in size
but not in courage, of the gigantic Jios primigenius.
In 1861 several contended for mastery; and it was observed
that two of the younger bulls attacked in concert tiie old
leader of the herd, overthrew and disabled him, so that he
was believed by the keepers to be lying mortally wounded
in a neighboring wood. But a few days afterward one of
the young bulls approached the wood alone; and then the
"monarch of the chase," who had been lashing himself up
for vengeance, came out, and, in a short time, killed his
antagonist. He then quietly joined the herd, and long held
undisputed sway. Admiral Sir B. J. Sulivan informs ma
that, when he lived in the Falkland Islands, he imported a
young English stallion, which frequented the hills near
rort William with eight mares. On these hills there were
two wild stallions, each with a small troop of mares; " and
it is certain that these stallions would never have approached
each other without fighting. Both had tried singly to fight
the English horse and drive away his mares, but had failed.
One day they came in together and attacked him. This was
seen by the capitan who had charge of the horses, and who,
on riding to the spot, found one of the two stallions

*0n the battles of seals, see Capt. C. Abbott, in ''Proc. Zool,
Soc," 1868, p. 191, also Mr. R. Brown, ibid, 1868, p. 436; also L>
Lloyd, "Game Birds of Sweden," 1867, p. 412, also Pennant. On
tlie sperm-whale see Mr. J. H. Thompson, in "Proc. Zool. Soc,"
1867, p. 246.

f See Scrope ('* Art of Deer-Stalking," p. 17) on the locking of the
horns with the Cervus elaphus. Richardson, in " Fauna Bor. Amer-
icana," 1829, p. 252, says that the wapiti, moose and reindeer have
been found thus locked together. Sir A. Smith found at the Cape
of Good Hope the skeletons of two gnus in the same condition.

572 THE DESCENT OF MAN,

engaged with the English horso, while the other was driv-
ing away the mares, and had already separated four from
the rest. The capitan setded the matter by driving the
whole party into the corral, for the wild stallions would not
leave the mares."

Male aniraals wliich are provided with efficient cutting
or tearing teeth for the ordinary purposes of life, such as
the cariiivora, insectivora, and rodents, are seldom furnished
with weapons especially adapted Icr figliting with their rivals.
The case is very different with the males of many other
animals. We see this in the horns of stags and of certain
kinds of antelopes in which the females are hornless. With
many animals the canine teeth in the upper or lower jaw,
or in both, are much larger in the males than in the
females, or are absent in the latter, with the exception
sometimes of a hidden rudiment. Certain antelopes, the
musk-deer, camel, horse, boar, various apes, seals, and the
walrus, olfer instances. In the females of the walrus the
tusks are sometimes quite absent.* In the male elephant
of India and in the male dugong f the upper incisors form
clfeusive weapons. In the male narwhal the left canine
alone is developed into the well-known, spirally-twisted, so-
called horn, which is sometimes from nine to ten feet in
length. It is believed that the males use tliese horns for
fighting together; for "an unbroken one can rarely be got,
and occasionally one may be found Avith the point of
another jammed into the broken place." | The tooth on
the opposite side of the head in the male consists of a rudi-
ment about ten inches in length, which is embedded in the
jaw; but sometimes, though rarely, both are equally devel-
oped on the two sides. In the female both are always rudi-
mentary. The male cachalot has a larger head than that

* Mr. Laraont ("Seasons Avith tbe Sea-Horses." 1861, p, 143) says
that a good tusk of tbe male walrus weighs four pounds, and is
longer than tlitt of the female, which weighs about three pounds.
The males are described as fighting ferociously. On the occasional
absence of the tusks in the female, see Mr. li. Brown, "Proc. Zool.
Soc," 1868. p. 429.

f Owen, *' Anatomy of Vertebrates," vol. iii, p. 283.

tMr. R. Brown, in '^Proc. Zool. Soc," 1869, p 553. See Prof
Turner, in "Journal of Anat. and Pliys., ' 1872, p. 76, on the iiomo-
logical nature of these tusks. Also Mr. J. W. Clarke on two tusks
being developed in the males, in " Proc. Zoolog. Soc," 1871, p. 43.

MAMMALS, 573

of t"he female, and it no donbt aids him in his aquatic
battles. Lastly, the adult male ornithorhynchus is provided
with a remarkable apparatus, namely, a spur on the fore
leg, closely resembling the poison-fang of a venomous
snake ; but, according to Harting, the secretion from
the gland is not poisonous ; and on the leg of the female
there is a hollow, apparently for the reception of the spur.*

AVhen the males are provided with weapons which in
the females are absent, there can hardly be a doubt that
these serve for fighting with other males; and that they
were acquired through sexual selection and were transmitted
to the male sex alone. It is not probable, at least in most
cases, that the females have been prevented from acquiring
such weapons, on account of their being useless, super-
fluous, or in some way injurious. On the contrary, as they
are often used by the males for various purposes, more espe-
cially as a defense against their enemies, it is a surprising
fact that they are so poorly developed, or quite absent in
the females of so many animals. With female deer the
development during eacli recurrent season of great branch-
ing horns, and with female elephants the development of
immense tusks would be a great waste of vital power, sup-
posing that they were of no use to the females. Conse-
quently they would have tended to be eliminated in the
female through natural selection; that is, if the successive
variations were limited in their transmission to the female
Bex, for otherwise the weapons of the males would have
been injuriously affected, and this would have been a greater
evil. On the whole, and from the consideration of the fol-
lowing facts, it seems probable that when the vari<ius
weapons differ in the two sexes this has generally depended
on the kind of transmission which has prevailed.

As the reindeer is the one species in the whole family of
deer in which the female is furnished with horns, though
they are somewhat smaller, thinner and less branched than
in the male, it might naturally be thought that at least, in
this case, they must be of some special service to her. The
female retains her horns from the time when they are fully
developed, namely, in September, throughout the winter

* Owen on tbe cachalot and Orniiborhynchas, ibid, vol, iii, pp
C3S, 641. Harting- is quoted by Dr. Zouteveen in tbe Dutcb traDslat
of this work, vol. ii, p. 292.

574 THE DESCENT OF MAN.

until April or May, when she brings forth her young. Mr.
Crotch made particular inquiries for me in Norway, and it
appears that the females at this season conceal themselves
for about a fortnight in order to bring forth their young,
and then reappear generally hornless. In Nova Scotia,
however, as I hear from Mr. H. Reeks, the female some-
times retains her horns longer. The male, on the other
hand, casts his horns much earlier, toward the end of
November. As both sexes have the same requirements and
follow the same habits of life, and as the male is destitute
of horns during the winter, it is improbable that they can
be of any special service to the female during this season,
which includes the larger part of the time during which
she is horned. Nor is it probable that she can have
inherited horns from some ancient progenitor of the family
of deer, for, from the fact of the females of so many species
in all quarters of the globe not having horns, we may con-
clude that this was the primordial character of the group.*
The horns of the reindeer are developed at a most
unusually early age; but what the cause of this may be is
not known. The effect has apparently been the transfer-
ence of the horns to both sexes. We should bear in mind
that horns are always transmitted through the female, and
that she has a latent capacity for their development, as we
see in old or diseased females, f Moreover, the females of
some other species of deer exhibit either normally or occa-
sionally rudiments of horns; thus the female of Cervulus
moschatus has ^' bristly tufts, ending in a knob instead of
a horn;" and "in most specimens of the female wapiti
( Cervus canadensis) there is a sharp, bony protuberance in
the place of the horn. "J; From these several considera-

*0n the structure and sliedding of the horns of the reindeer,
Hoffberg. " Ainoenitates Acad.," vol. iv, 1788, p. 149. See Richard-
son, "Fauna Bor. Americana," p. 241, in regard to the American
variety or species; also Maj. W. Ross King, '* The Sportsman in
Canada,' 1866, p. 80.

f Isidore Geoffroy St. H'laire, "Essais de Zoolog. Generale," 1841,
p. 513. Other masculine characters besides the horns, are sometimes
wmilarly transferred to the female; thus Mr. Boner, in speaking of
nn old female chamois ("Chamois Hunting in the Mountains of
Bavaria," 1860. 2nd edit., p. 363) says, "not only was the head very
nmle-looking, but along the back there was a ridge of long hair,
'isuaily to be found only in bucks."

$0u the Cervulus, Dr. Gray, "Catalogue of Mammalia in the

MAMMALS. 675

tions we may conclude that the possession of fairly well-
developed horns by the female reindeer is due to the males
having first acquired them as weapons for fighting with
other males; and secondarily to their development from
some unknown cause at an unusually early age in the males
and their consequent transference to both sexes.

Turning to the sheath-horned ruminants: with ante«
lopes a graduated series can be formed, beginning with
species, the females of which are completely destitute of
horns — passing on to those which have horns so small as to
be almost rudimentary (as with the Antilocapra americanay
in which species they are present in only one out of four
or five females*) — to those which have fairly developed
horns, but manifestly smaller and thinner than in the
male and sometimes of a different shapef — and ending
with those in which both sexes have horns of equal size.
As with the reindeer, so with antelopes, there exists, as
previously shown, a relation between the period of the devel-
opment of the horns and their transmission to one or both
sexes; it is therefore probable that their presence or ab-
sence in the females of some species and their more or less
perfect condition in the females of other species depends,
not on their being of any special use, but simply in inherit-
ance. It accords with this view that even in the same
restricted genus both sexes of some species, and the males
alone of others, are thus provided. It is also a remarkable
fact that, although the females of Antilope hezoartica are
normally destitute of horns, Mr. Blyth has seen no less
than three females thus furnished; and there was no reason
to suppose that they were old or diseased.

In all the wild species of goats and sheep the horns are
larger in the male than in the female, and are sometimes
quite absent in the latter4 In several domestic breeds of
these two animals, the males alone are furnished with

Britisli Museum," part iii, p, 220. On the Cervus canadensis or
wapiti, see Hon. J. D. Caton, " Ottawa Acad, of Nat. Sciences," May,
1868, p. 9.

* I am indebted to Dr, Canfield for this information; see also liis
paper in " Proc. Zoolog. Soc," 1866. p. 105.

+ For instance, the horns of the female Ant. encJiore resemble those
of a distinct species, viz,, the Ant. dorcas var. Corine, see Desmarest,
** Mammalogie," p. 455.

\ Gray. " Catalogue Mamm. Brit. Mus.," part iii, 1852, p. 160.

576 THE DESCENT OF MAN,

horns; and in some breeds, for instance, in the sheep of
North AVales, though both sexes are properly horned, the
ewes are very liable to be hornless. I have been informed
by a trustworthy witness, w^ho purposely inspected a flock
of these same sheep during the lambing season, that the
horns at birth are generally more fully developed in the male
than in the female. Mr. J. Peel crossed his Lonk sheep,
both sexes of which always bear horns, with hornless Lei-
cesters and hornless {Shropshire Downs; and the result was
that the male offspring had their horns considerably
reduced, while the females were wholly destitute of them.
These several facts indicate that, with sheep, the horns are
a much less firmly fixed character in the females than in the
males; and this leads us to look at the horns as properly of
masculine origin.

AVith the adult musk-ox {Ovibos moschatns) the horns
of the male arc larger than those of the female, and in the
latter the bases do not touch.** In regard to ordinary
cattle Mr. Blyth remarks: '' In most of the wild bovine
animals the horns are both longer and thicker in the bull
than in the cow, and in the cowbanteng (Bos sondaicus)
the liorns are remarkably small, and inclined much back-
AViird. In the domestic races of cattle, both of the humped
and humpless types, the horns are short and tiiick in the
bull, longer and more slender in the cow and ox; and in
the Indian buffalo, they are shorter and thicker in the bull,
longer and more slender in the cow. In the wild gaour (B.
gaiirus) the horns are mostly both longer and thicker in
the bull than in the cow.^'f Dr. Forsyth Major also
informs me that a fossil skull, believed to be that of the
female Bos estruscus, has been found in Val d'Aruo,
which is wholly without horns. In the Rhinoceros simns,
as I may add, the horns of the female are generally longer
but less powerful than in the male; and in some other
species of rhinoceros they are said to be shorter in the
female. J From these various facts we may infer as probable
that liorns of all kinils, even when they are equally devel-
oped in the two sexes, were primarily acquired by the male

* HicLardson, " Fauna Bor. Americana," p. 278.
f '• Land and Water,'" 1867. p. 34G.

J Sir Anihew Smitli, "Zoology of S. Africa," pi. xix. Owen,
' Auatomy of Veriebraies," vol. iii, p. 624.

I

MAMMALS. 577

in order to conquer other males, and have been transferred
more or less completely to the female.

The eit'ects of castration deserve notice, as throwinglight on
this same point. Stags after the operation never renew their
horns. The male reindeer, however, must be excepted, as
after castration he does renew tliem. This fact, as well as
the possession of horns by both sexes, seems at first to prove
that the horns in this species do not constitute a sexual
character;* but as they are developed at a very early age,
before the sexes differ iu constitution, it is not surprising
that they should be unaffeitted by castration, even if they
were aboriginally acquired by the male. With sheep
both sexes properly bear horns ; and I am informed
that witli Welsli sheep the horns of the males are con-
siderably reduced by castration ; but the degree depends
much on the age at which the operation is performed, as
is likewise the case with other animals. Merino rams iiave
large horns, while the ewes, *' generally speaking, are with-
out horns;" and in this breed castration seems to produce
a somewhat greater effect, so that if performed at an early
age the horns " remain almost undeveloped.'"! On the
Guinea coast there is a breed in which the females never
bear horns, and, as Mr. Win wood Reade informs me, the
rams after castration are quite destitute of them. With
cattle the horns of the males are much altered by castration;
for, instead of being short and thick,, they become longer
than those of the cow, but otlierwise resemble them. The
Ant Hope hezoartica offers a somewhat analogous case'; the
males have long straight spiral horns nearly parallel to each
other, and directed backward; the females occasionally bear
liorns, but these when present are of a very different si»ape,
for they are not spiral, and spreading widely bend round
with the points forward. Now it is a remarkable fact that
in the castrated male, as Mr. Blyth informs me, the iiorna
are of the same peculiar shape as in the female, but louger

* This is tlie conclusion of Seidlitz, "Die Darwinsche Tiieorie,"
1871. p. 47.

f I am raucU obliged to Prof, Victor Cams for Laving made in-
quiries for me in Saxony on this subiect. H. von Nathusius
(" Vielizucbt." 1872. p. C4) says that the horns of sheep castrated at
an early period, either altogetlier disappear or remain ay nif re rudi-
ments; but 1 do not know wUytUer lie refers to meiiuosor to ordinary'
breeds.

578 THE DESCENT OF MAN,

and thicker. If we may judge from analogy, tlie female
probably siiows us in these two cases of cattle and the
antelope the former condition of the horns in some early
progenitor of each species. But why castration siiould lead
to tlie reappearance of an early condition of the horns
cannot be explained witli any certainty. Nevertheless, it
seems probable, that in nearly the same manner as the con-
stitutional disturbance in the offspring, caused by a cross
between two distinct species or races, often leads to the
reappearance of long-lost characters;* so here the disturb-
ance in the constitution of the individual, resulting from
castration, produces the same effect.

The tusks of the elephant in the different species orraceg
differ according to sex, nearly as do the horns of ruminants.
In India and Malacca the males alone are provided with
well-developed tusks. Tlie elephant of Ceylon is con-
sidered by most naturalists as a distinct race, but by some
as a distinct species, and here ^'' not one in a hundred is
found with tusks, the few that possess them being exclu-
sively males."! The African elephant is undoubtedly dis-
tinct, and the female has large well-developed tusks,
though not so large as those of the male.

These differences in the tusks of the several races and
species of elephants — the great variability of t!ie horns of
deer, as notably in the wild reindeer — the occasional presence
of horns in the female A?itilope Bezoartica and their frequent
absence in the female of Antilocai)ra americana— the pres-
ence of two tusks in some few male narwhals — the complete
absence of tusks in some female walruses — are all instances
of the extreme variability of secondary sexual cliaracters,
and of their liability to differ in closely allied forms.

Although tusks and horns appear in all cases to have
been primarily developed as sexual weapons, they often
. serve other purposes. The elephant uses his tusks in
attacking the tiger; according to Bruce, he scores the
trunks of trees until they can be thrown down easily, and
he likewise thus extracts the farinaceous cores of palms; in

*I Lave given various experiments and other evidence proving
that this is the case, in my '* Variation of Animals and Plants under
Domestication," vol. ii, 1868, pp. 39-47.

f Sir J. Emerson Tennent, "Ceylon," 1859, vol. ii, p. 274. For
Mulacca, "Journal of Indian Archipelago," vol. iv, p. 357.

MAMMALS, 579

Africa lie often uses one tusk, always tlie same, to probe
the ground and thus ascertain whether it will bear his
weight. The common bull defends the herd with his
horns; and the elk in Sweden has been known, according
to Lloyd, to strike a wolf dead with a single blow of his
great horns. Many similar facts could be given. One of
the most curious secondary uses to which the horns of an
animal may be occasionally put is that observed by Capt.
Hutton * with the wild goat (Capra cegagrus) of the Hima-
layas and, as it is also said with the ibex, namely, that
when the male accidentally falls from a height he bends
inward his head, and, by alighting on his massive horns,
breaks the shock. The female cannot thus use her horns,
which are smaller, but from her more quiet disposition she
does not need this strange kind of shield so much.

Each male animal uses his weapons in his own peculiar
fashion. The common ram makes a charge and butts with
such force with the bases of his horns that I have seen a
powerful man knocked over like a child. Goats and cer-
tain species of sheep, for instance the Ovis cydoceros of
Afghanistan,! rear on their hind legs, and then not only
butt, but *' make a cut down and a jerk up, with the ribbed
front of their cimeter-shaped horn, as with a saber. When
the 0. cydocerus attacked a large domestic ram, who was a
noted bruiser, he conquered him by the sheer novelty of
his mode of fighting, always closing at once with his
adversary, and catching him across the face and nose with
a sharp, drawing jerk of the head, and then bou^^ding out
of the way before the blow could be returned." In Pem-
brokeshire a male goat, the master of a flock which during
several generations had run wild, was known to have killed
several males in single combat; this goat possessed enormous
horns, measuring thirty-nine inches in a straight line from
tip to tip. The common bull, as every one knows, gores
and tosses his opponent; but the Italian buffalo is said
never to use his horns; he gives a tremendous blow with
his convex forehead, and then tramples on his fallen enemy
with his knees — an instinct which the common bull doea

» " Calcutta Journal of Nat. Hist.," vol. ii, 1843, p. 526.
Mr. Blyth, in "Land and Water," March, 1867, p. 134, on tha
authority of Capt. Hutton and others. For the wild Pembrokeshire
goMi-. see the "Field." 1869, v 150

682 THE DESCENT OF MAN.

one of which bears the astonishing number of thirty-three
branches and the other twenty-seven, making altogether
Bixty branches. Eichardson figures a pair of antlers of
the wild reindeer with twenty-nine points.* From the
maimer in which the horns are branched, and more espe-
cially from deer being known occasionally to fight together
by kicking with their fore feet,t M. Bailly actually comes
to the conclusion that their horns are more injurious than
useful to them. But this author overlooks the pitched
battles between rival males. As I felt much perplexed about
the use or advantage of the branches I applied to Mr.
McNeill, of Colonsay, who has long and carefully observed
the habits of the red deer, and he informs me that he has
never seen some ^f the branches brought into use, but that
the brow antlers from inclining downward are a great pro-
tection to the forehead, and their points are likewise used
in attack. Sir Philip Egerton also informs me both as to
red deer and fallow deer that in fighting they suddenly
dash together, and, getting their horns fixed against each
other's bodies, a desperate struggle ensues. When one is
at last forced to yield and turn round the victor endeavors
to plunge his brow antlers into his defeated foe. It thus
appears that the upper branches are used chiefly or exclu-
sively for pushing and fencing. Nevertheless, in some
species the upper branches are used as weapons of offense;
when a man was "ttacked by a wapiti deer {Cervus cana-
densis) in Judge Catenas park in Ottawa and several men
tried to rescue him the stag " never raised his head from
the ground; in fact, he kept his face almost flat on the
ground, with his nose nearly between his fore feet, except
when he rolled his head to one side to take a new observa-
tion preparatory to a plunge.'' ^n this position the ends
of the horns were directed against his adversaries. ^^ In
rolling his head he necessarily raised it somewhat, because

*0n the horns of the red deer, Owen, "British Fossil Mammals,"
1846, p. 478; Richardson on the horns of the reindeer, "Fauna Bor.
Americana," 1829, p. 240. I am indebted to Prof. Victor Cams for
the Moritzburg case.

t Hon. J. D. Caton ("Ottawa Acad, of Nat. Science," May, 1868,
p. 9) says that the American deer fight with tlieir fore feet, after
"the question of superiority bar, been once settled and acknowledged
in the herd." Bailly " Sur I'usage des Comes," " Annales des So.
Nat.," torn, ii, 1824, p. 371.

MAMMAL3. 683

his antlers were so long that he could not roll his head
without raising them an one side, while on the other they
touched the ground." The stag by this procedure gradu-
ally drove the party of rescuers backward to a distance

Fig. 64. Strepsiceros Kudu (from Sir Andrew Smith's " Zoology of
South Africa*').

of one hundred and fifty or two hundred feet, and the
attacked man was killed.*

* See a most interesting account in tlie appendix to Hon. J, D.
Caton's paper, as abuve Quoted.

584 THE DESCENT OF MAN.

Although the horns of stags are efficient weapons, there
can, I think, be no doubt that a single point would
have been much more dangerous than a branched antler;
and Judge Caton, who has had large experience with deer,
fully concurs in tliis conclusion. Kor do the branching
horns, though highly important as a means of defense
against rival stags, appear perfectly well adapted for this
purpose, as they are liable to become interlocked. The sus-
picion has, therefore, crossed my mind that they may servo
m part as ornaments. That the branched antlers of stags
as well as the elegant lyrated horns of certain antelopes,
with their graceful double curvature (fig. G4), are orna-
mental in our eyes, no one will dispute. If, then, the
horns, like the splendid accouterments of the knights of
old, add to the noble appearance of stags and antelopes,
they may have been modified partly for this purpose, though
mainly for actual service in battle; but I have no evidence
in favor of this belief.

An interesting case haslately been published, from which
it appears that the horns of a deer in one district in
the United States are now being modified through sexual
and natural selection. A writer in an excellent American
journal * says that he has hunted for the last twenty-one
years in the Adirondacks, where the Cerinis viroininnus
abounds. About fourteen years ago he first heard of spike-
horn bncks. These became from year to year more
common; about five years ago he shot one, and afterward
another, and now they are frequently killed. "' The s^iike-
liorn differs greatly from the common antler of the 0. vir-
gin iamis. It consists of a single spike, moie slender than
the antler, and scarcely half so long, projecting forward
from the brow and terminating in a very sharp point. It
gives a considerable advantage to its possessor over the
common buck. Besides enabling him to run more swiftly
through the thick woods and underbrush (every hunter
knows that does and yearling bucks run much more rapidly
than the large bucks when armed with their cumbrous
antlers), the spike-horn is a more effective weapon than the
(3ommon antler. AVith this advantage the spike- horn
bucks are gaining upon the common bucks, and may, in
time, entirely supersede them in the Adirondacks. Un-

«•* The American XaturriUWJ Dec, 1869, p. 653.

i

MAM^fALS. 585

donbtedly, the first spike -horn buck was merely an acci-
dental freak of nature. But his spike-horns gave bim an
advantage, and enabled liim to propagate his peculiarity.
His descendants, having a like advantage, have propagated
the peculiarity in a constantly increasing ratio, till they are
slowly crowding the antlered deer from the region they
inhabit." A critic has well objected to this account by
asking, why, if the simple horns are now so advantageous,
were the branched antlers of the parent-form ever devel-
oped? To this I can only answer by remarking that a new
mode of attack with new weapons might be a great advant-
age, as sliown by the case of the Ovis cyclGceros, who thus
conquered a domestic ram famous for his fighting power.
Though the branched antlers of a stag are well adapted for
fighting with his rivals, and, though it might be an
advantage to the prong-horned variety slowly to acquire
long and branched horns, if he had to fight only with
others of the same kind, yet it by no means follows that
branched horns would be tiie best fitted for conquering a
foe differently armed. In the foregoing case of the (Jri/x
lencorfjx it is almost certain that the victory would rest
with an antelope having short horns, and who, therefore,
did not need to kneel down, thougli an oryx might profit
by having still longer horns if he fought only with his
proper rivals.

Male quadrupeds, which are furnished with tusks, use
them in various ways, as in the case of horns. The boar
strikes laterally and upward ; the musk-deer downward
with serious eil'ect. ' The walrus, though having so short
a neck and so un wieldly a body, "can strike either upward
or downward or sideways with equal dexterity."f I was
informed by the late Dr. Falconer, that the Indian elephant
fights in a diiferent manner according to the position and
curvature of his tusks. When '.hey are directed forward
and upward he is able to fling a tiger to a great distance —
it is said to even thirty feet; when they are short and
turned downward he endeavors suddenly to pin the tiger to
the ground, and, in consequence, is dangerous to the rider,
who is liable to be jerked oif the howdah.|

* Pallas, **Spicilegia Zoologica," fasc. siii. 1779, p. 18,

f Lainont, *• Seasons with the Sea-Horses," 1861, p. 141.

j:See also Corse ("Pliilosopli. Transact.," 1799, p. 212) on tlie

586 THE DESCENT OF MAIT.

Very few male quadrupeds possess weapons of two dis-
tinct kinds specially adapted for fighting with rival males.
The male muntjac-dcer (Cervulus), however, offers an ex-
ception, as he is provided with horns, and exserted canine
teeth. But we may infer from what follows that one form
of weapon has often been replaced in the course of ages by
another. With ruminants the development of horns gen-
erally stands in an inverse relation with that of even mod-
erately developed canine teeth. Thus camels, guanacoes,
chevrotaiiis and musk-deer are hornless, and they have
efficient canines; these teeth being " always of smaller size
in the females than in the males." The Camelidse have,
in addition to their true canines, a pair of canine-sliaped in-
cisors in their upper jaws.* Male deer and antelopes, on
the other hand, possess horns, and they rarely have canine
teeth; and these, when present, are always of small size, so
that it is doubtful whether they are of any service in theii
battles. In Antilo^oe montana they exist only as rudiments
in the young male, disappearing as he grows old; and they
are absent in the female at all ages; but the females of cer-
tain other antelopes and of certain deer have been known
occasionally to exhibit rudiments of these teeth, f Stallions
have small canine teeth, which are either quite absent or
rudimentary in the mare; but they do not appear to be used
in fighting, for stallions bite with their incisors, and do
not open their mouths wide like camels and guanacoes.
AVhenever the adult male possesses canines, now inefficient,
while the female has either none or mere rudiments, we
may conclude that the early male progenitor of the species
was provided with efficient canines, which have been par-
tially transferred to the females. The reduction of these
teeth in the males seems to have followed from some change

manner in which the short tusked Mooknah variety attacks other
elephants.

*Owen, " Anatomy of Vertebrates," vol. iii, p. 349.

f See Rilppell (in " Proc Zooloer. Soc," Jan. 12, 1836, p. 3) on the
canines in deer and antelopes, with a note by Mr. Martin on a female
American deer. See also Falconer (" Palseont, Memoirs and Notes,"
vol. i, 1868, p, 576) on canines in an adult female deer. In old males
of the musk-deer the canines (Phallus, •"Spic. Zoolog.," fasc. xiii,
1779, p. 18) sometimes grow to the length of three inches, while in
old females a rudiment projects scarcely half an inch above the
gums.

MAMMALS. 58?

in their manner of fighting, often (but not in the horse)
caused by the development of new weapons.

Tusks and horns are manifestly of higli importance to
their possessors, for their development consumes much
organized matter. A single tusk of the Asiatic elephant —
one of the extinct woolly species — and of the African ele-
phant have been known to weigh respectively one hundred
and fifty, one hundred and sixty and one hundred and
eighty pounds; and even greater weights have been given
by some authors.* With deer, in which the horns are peri-
odically renewed, the drain on the constitution must be
greater; the horns, for instance, of the moose weigh from
fifty to sixty pounds, and those of the extinct Irish elk
from sixty to seventy pounds — the skull of the latter
weighing on an average only five pounds and a quarter.
Although the horns are not periodically renewed in sheep,
yet their development, in the opinion of many agricultur-
ists, entails a sensible loss to the breeder. Stags, more-
over, in escaping from beasts of prey are loaded with an
additional weight for the race, and are greatly retarded in
passing through a woody country. The moose, for in-
stance, with horns extending five and a half feet from tip
to tip, although so skillful in their use that lie will not
touch or break a twig when walking quietly, cannot act so
dexterously while rushing away from a pack of wolves.
" During his progress he holds his nose up so as to lay the
horns horizontally back; and in this attitude cannot see
the ground distinctly/'f I'^e tips of the horns of the
great Irish elk were actually eight feet apart! While the
horns are covered with velvet, which lasts with red deer
for about twelve weeks, they are extremely sensitive to a
blow; so that in Germany the stags at this time somewhat
change their habits, and, avoiding dense forests, frequent
jToung woods and low thickets. J; These facts remind us
that male birds have acquired ornamental plumes at the

*Emerson Tennent, "Ceylon," 1859, vol. ii, p. 275; Owen,
"Britisli Fossil Mammals," 1846. p. 245.

f Richardson, "Fauna Bor. Americana," on the moose. Alces pal-
mata, pp. 236, 237; on the expanse of the horns, " Land and Water,"
1869, p. 143. See also Owen, " Briiisk Fossil Mammals," on the
Irish elk, pp. 447, 455.

% ♦* Forest Creatures," by C. Boner, 1861, p. 60.

588 TEE DESCENT OF MAm

cost of retarded fligbt, and other ornaments at the cost ol
some loss of power in their battles with rival male?.

AVith mammals, when, as is often the case, the sexes
differ in size, the males are almost always larger and
stronger. 1 am informed by Mr. Gonld that this holds
good 'in a marked manner with the marsupials of Aus-
tralia, the males of which appear to contimie growing
until an unusually late age. But th<' most extraordiuay,
case is that of one of ;he seals {Callorliinvs ?/?'.<?7'-" ^
a full-grown female weigiiing less than one-sixth of a full-
grown male.* Dr. Gill remarks that it is with the polyg-^^
amous seals, the mtiles of which are well known to fight
savagely together, that the sexes differ much in size; the
monogamous species differing but little. Whales also
afford evidence of the relation existing between the pug-
nacity of the males and theii" large size compared with tliat
ot the females; the males of the right-whales do not fight
togethei, and they aic not larger, but rather smaller, than
their females; on the other hand, male sperm-whales tight
much together, and their bodies are " often found scarred
with the imprint of their rival's teeth," and they are
double the size of the females. Tiie greater strength of
the male, as Hunter long ago remarked, f is invariably dis-
played in those parts of the body Avhich are brought into
action in figlitiug with rival males — for instance, in the
massive neck of the bull. Male (piadrupeds are also more
courageous and pugnacious than the females. There can be
little doubt that these characters have been gained, partly
through sexLial selection, owing to a long series of victo-
ries, by the stronger and more courageous males over the
weaker, and partly through the inherited effects of use.
It ii probable that the successive variations in strength,
size, and courage, whether due to mere variability or to the
effects of use, by the accumulation of which male quadru-
peds have acquired these characteristic cualities, occurred
rather late in life, and were consequently to a large extent
limited in their transmission to the same sex.

* See the very interesting pa])er by Mr. J. A. Allen in "Bull. Mus.
Com}). Zoolog. of Cambridge, United States," vol. ii, No. 1, p. 82.
The weights Avere a.-^certained by a {areful observer, Capt Bryant.
Dr. Gill in •• The American Nattiralist," Jan.. 1871: Prof. Shaler on
the relative size of the sexes of whales, "American Naturalist,"
Jan. 1873.

f " Animal Economy," p. 45

I

MAMMALS. 5S9

From these considerations I was anxious to obtain infor-
mation as to the Scotch deer-hound, the sexes of wliich
ditrer more in size than those of any other breed (though
blood-hounds dilfer considerably), or than in any wild
canine species known to me. Accordingly, I applied to
]\[r. Clippies, well known for his success with this breed,
who has weighed and measured many of ids own dogs, and
who lias witli great kindness collected for me the following
facts from various sources. Fine male dogs, measured at
the shoulder, range from '^8 inches, which is low, to 33 or
even 34 inches in height ; and in weight from 80 pounds,
which is light, to 120 pounds, or even more. The
females range in height from 23 to 2?, or even
to 28 inches ; and in weight from 50 to 70,
or oven 80 pounds.* Mr. Cupples concludes that from
95 to 100 pounds for the male, and 70 for the female,
would be a safe average; but there is reason to believe that
formerly both sexes attained a greater weight. Mr. Cup-
nle.^ has weighed puppies when a fortnight old; in one
litter the average weight of four males exceeded that of
two females by six and a half ounces; in another litter the
average weight of four males exceeded that of one female
by less than one ounce: the same males when three weeks
old exceeded the female by seven and a half ounces, and
at the age of six weeks by nearly fourteen ounces. Mr.
Wright, of Yeldersley House, in a letter to Mr. Cupples
says: '* I have taken notes on the sizes and weights of
puppies of many litters, and, as far as my experience goes,
dog puppies, as a rule, differ very little from bitches till
they arrive at about five or six months old; and then the
do^-s begin to increase, gaining upon the bitches both in
weight and size. At birth and for several weeks afterward
a bitch-pup[>y will occasionally be larger than any of the
dogs, but thev are invariably beaten by them later." Mr.
McNeill, of Colonsay, concludes that "'the males do not
attain their full growth till over two years old, though the
females attain it sooner.'' According to Mr. Cupples'

* See also Richardson's " Mamial on the Dojs," p. 59. Much valu-
able information on ihe Scottish deer hound is given by Mr. Mc-
jNeill. who first called attention to the inequality in size between the
sexes, in Scropt-'s " Art of Deer Stalking." I hope that Mr. Cupples
will kee]> to his intention of publishing a full account and Uistory of
This famous breed.

588 TEE DESCENT OF MAN.

cost of retarded flight, and other ornaments at the cost oi
some loss of power in tlu'ir battles with rival male?.

With mammals, when, as is often the case, the sexes
differ in size, the males are almost always larger and
stronger. 1 am informed by Mr. Gould that this holds
good 'in a marked manner with the marsupials of Aus-
tralia, the males of which appear to contiinie growing
until an unusually late age. But the mopt extiaordiuav,
case is that of one of [he seals {Callorhinns ?/r.<?^^' "^
a full-grown female weighing less than one-sixth of a full-
grown male.* Dr. Gill remarks tl'at it is with the polyg-
amous seals, the mules of which are well known to fight
savagely together, that the sexes differ much in size; the
monogamous species differing but little. Whales also
afford evidence of the relation existing between the pug-
nacity of the males and theii large size compared with tliat
ot the females; the males of the right-whales do not fight
togethei, and they aic not larger, but ratiier smaller, than
their femah's; on the other hand, male sperm-whales fight
much together, and their bodies are ''often found scarred
with the imprint of their rival's tei'th," and they are
double the si'/e of the females. Tiie greater strength of
the male, as Hunter long ago remarked,} is invariably dis-
played in those parts of the body which are brought into
action in fighting with rival males — for instance, in the
massive neck of the bull. Male (juadrupeds are also more
courageous and pugnacious than the females. There can be
little doubt that these characters have been gained, partly
through sexual selection, owing to a long series of victo-
ries, by the stronger and more courageous males over the
weaker, and partly through the inherited effects of use.
It is probable that the successive variations in strength,
size, and courage, whether due to mere variability or to the
effects of use, by the accumulation of which male quadru-
peds have acquired these characteristic cualities, occurred
rather late in life, and were consequently to a large extent
limited in their transmission to the same sex.

*See tbe very interesting pajier b}* Mr. J. A. Allen in " Bull. Mus.
Com}). Zoolog. of '''am bridge, United Stales," vol. ii, No. 1, p. 82.
The weifrljis were ahcertained by a careful observer, Capt Bryant.
Dr. Gill in •• 'J'be American Naturalist," Jan.. 1871: Prof. Sbaler on
ihe relative size of ilie sexes of wliaies, "American 2}aturalist,"
Jan, 1873.

f " Animal Economy," p. 45

MAMMALS. 589

From these considerations I was anxious to obtain infor-
mation as to the Scotch deer-hound, the sexes of wliich
ditfer more in size than those of any other breed (though
blood-hounds dilfer considerably), or than in any wild
canine species I^nown to me. Accordingly, I applied to
IVLr. Clippies, well known for his success with this breed,
Avho has weighed and measured many of Ids own dogs, and
who has with great ivindness collected for mo the following-
facts from various sources. Fine male dogs, measured at
the shoulder, range from '^8 inches, which is low, to 33 or
even 34 inches in height ; and in weight from 80 pounds,
which is light, to 120 pounds, or even more. The
females range in 1 1 eight from 23 to 2?, or even
to 28 inches ; and in weight from 50 to 70,
or even 80 pounds."^ Mr. Cupples concludes that from
95 to 100 pounds for the male, and 70 for the female,
would be a safe average; but there is reason to believe that
formerly both sexes attained a greater weight. Mr. Cup-
ples? has weighed puppies when a fortnight old; in one
litter the average weight of four males exceeded that of
two females by six and a half ounces; in another litter the
average weight of four males exceeded that of one female
by less than one ounce: the same males when three weeks
old exceeded tlie female by seven and a half ounces, and
at the age of six weeks by nearly fourteen ounces. Mr.
Wright, of Yeldersley House, in a letter to Mr. Cupples
says: " I have taken notes on the sizes and weights of
puppios of many litters, and, as far as my experience goes,
dog puppies, as a rule, differ very little from bitches till
they arrive at about five or six months old; and then the
dogs begin to increase, gaining upon the bitches both in
weight and size. At birth and for several weeks afterward
a bitch-puppy will occasionally be larger than any of the
dogs, but thev are invariably beaten by them later." Mr.
McNeill, of Colonsay, concludes that ^* the males do not
attain their full growth till over two years old, though the
females attain it sooner.'' According to Mr. Cupples'

* See also Kicliardson's " Manual on the Do^," p. 59. Mucb valu-
able ill formation on the Scottish deer hound is given by Mr. Mc«
2sei!l, who first called attention to the inequality in size between the
sexes, in Scropt.'s '* Art of Deer Stalking." I hope that Mr. Cupples
will kee]) to hi.s intention of publishing a full account aud history of
this famous breed.

590

TEE DESCENT OF MAN.

experience, male dogs go on growing in stature till they
are from twelve to eighteen months old, and in weight till
from eighteen to twenty-four months old; while the females
cease increasing in stature at the age of from nine to four-
teen or fifteen months, and in weight at the age of from
twelve to fifteen months. From these various statements
it is clear that the full difference in size between the male
and female Scotch deer-hound is not acquired until rather
late in life. The males almost exclusively are used for

(Doursing, for, as Mr. Mc-
Neill informs me, the fe-
males have not sufficient
strength and weight to
pull down a full-grown
deer. From the names
used in old legends it
appears, as I hear from
Mr. Oupples, that at a
very ancient period the
males were the most
celebrated, the females
being mentioned only as
the mothers of famous
dogs. Hence, during
many generations it is the
male which has been chiefly tested for strength, size, speed
and courage, and the best will have been bred from. As,
however, the males do not attain their full dimensions until
rather late in life they will have tended, in accordance
with the law often indicated, to transmit theij characters
to their male offspring alone; and thus the great inequality
in size between the sexes of the Scotch deer-hound may
probably be accounted for.

The males of some few quadrupeds possess organs or
parts developed solely as a means of defense against the
attacks of other males. Some kinds of deer use, as we
have seen, the upper branches of their horns chiefly or
exclusively for defending themselves; and the Oryx ante-
lope, as I am informed by Mr. Bartlett, fences most skill-
fully with his long, gently curved horns ; but these are
likewise used as organs of offense. The same observer
remarks that rhinoceroses in fighting parry each other's
sidelong blows with their hornS;^ which datter loudly

Fig. 65, Head of commcn wild boar, in
prime of life (from Brehm).

MAMMALS.

591

together, as do the tusks of boars. Although wild boars
fight desperately, they seldom, according to Brehm, receive
fatal wounds, as the blows fall on each other's tusks, or on
the layer of gristly skin covering the shoulder, called by
the German hunters the shield; and here we have a part
specially modified for defense. With boars in the prime
of life (fig. 65) the tusks in the lower jaw are used for
fighting, but they become in old age, as Brehm states, so

SkuU of the Babirusa Pig (from Wallace's " Malay Archipelago").

much curved inward and upward over the snout that they
can no longer be used in this way. They may, however,
still serve, and even more effectively, as a means of defense.
In compensation for the loss of the lower tusks as weapons
of offense those in the upper jaw, which always project a
little laterally, increase in old age so much in length and
curve so much upward that they can be used for attack.
Nevertheless, an old boar is not so dangerous to man as
one at the age of six or seven years.*

«Bielmi, •• Tliierleben," B. ii. ss. 729-733.

692

iCHE DESCENT OF MAK.

In the full-grown male BaLimsa pig of Celebes (fig. 66),
the lower tusks are formidable weapons, like those of tlie
European boar in the prime of life, while the upper tusks
are so long and have their points so much curled inward,
sometimes even touching the forehead, that they are utterly
useless as weapons of attack. They more nearly resemble
horns than teeth, and are so manifestly useless as teeth that
the animal was formerly supposed to rest liis head by hook-
ing them on to a branch! Their convex surfaces, however,
if the head were held a little laterally, would serve as art

Fifr. 67. TTead of female ^t'llopian wart-hofr, from "Proc. Zool. Soc." 18G9,
showitig the same characters as the male. tht>u^rli on a reduced scale.

N. B. When the ensrra%ins was first made I was under the impression ttiat it
represented the male.

excellent guard; and hence, perhaps, it is that in old
animals they ** are generally broken off, as if by fighting."*
Here, then, we have the curious case of tlie upper tusks of
the Babirusa regularly assuming during the prime of life a
structure which apparently renders them fitted only for
defense ; while in the European boar the lower tusks
assume in a less degree and only during old age nearly the
same form, and then serve in like manner solely for
defense.

In the wart-hog (PJincochoerus cnthiopiciis) (fig. 67) the

*See Mr. Wallace's intereiiting account of this animal,
Malay Archipelago,"' 1869, vol. i, p. 435.

Tho

MAMMALS. 593

tusks in the upper jaw of the male curve upward during
the prime of life, and from being pointed serve as formid-
able weapons. The tusks in the lower jaw are sharper
than those in the upper, but from their shortness it seems
hardly possible that they can be used as weapons of attack.
They must, however, greatly strengti 5 en those in tlie upper
jaw, from being ground so as to fit closely against their
bases. Neither the upper nor the lower tusks appear to
have been specially modified to act as guards, though no
doubt they are to a certain extent used for this purpose.
But the wart-hog is not destitute of other special means
of protection, for it has on each side of the fact?,
beneath the eyes, a rather stiff, yet flexible cartilaginous
oblong pad (see fig. 67), which projects two or three inches
outward; and it appeared to Mr. Bartlett and myself,
when viewing the living animal, that these pads, when
struck from beneath by the tus'is of an opponent, would
be turned upward, and would thus admirably protect
the somewhat prominent eyes. I may add, on the
authority of Mr. Bartlett, that these boars when fight-
ing stand directly face to face.

Lastly, the African river-hog {Pof,o?nocJioerus penicil-
Jatus) has a liard cartilaginous knob on ea(di side of the
face beneath the eyes, which answers to the flexible pad
of the wart-hog; it has also two bony prominences on the
upper jaw above the nostrils. A boar of this species in
the Zoological Gardens recently broke into the cage of
the wart-hog. They fought all night long, and were
found in the morning much exhausted, but not seriously
wounded. It is a significant fact, as showing tiie purposes
of the above described projections and excrescences, tliat
these were covered with blood, and were scored and abraded
in an extraordinary manner.

Although the males of so many members of the pig
family are provided with weapons, and, as we have just seen,
with means of defense, these weapons seem to have' been
acquired within a rather late geological period. Dr. For-
syth Major specifies* several miocene species, in none of
which do the tusks appear to have been largely developed
in the males; and Prof. Riitimeyer was formerly struck
with this same fact.

Atti della Soc. Italiana di Sc. Nat." 1873, vol. xv, fasc. iv.

594 THE DESCENT OF MAN,

The mane of the lion forms a good defense against the
attacks of rival lions, the one danger to which he is liable;
for the males, as Sir A. Smith informs me, engage in ter-
rible battles, and a young lion dares not approach an
old one. In 1857 a tiger at Bromwich broke into the cage
of a lion and a fearful scene ensued; "the lion's mane
saved his neck and head from being much injured, but the
tiff e I" at last succeeded in ripping up his belly, and in a few
minutes he was dead/' * The broad ruff round the throat
and chin of the Canadian lynx {Fdis canadensis) is much
longer in the male than in the female; but whether it
Serves as a defense I do not know. Male seals are well
known to fight desperately together, and the males of cer-
tain kinds {Otaria jiibata) \ have great manes, while the
females have small ones or none. The male baboon of
the Cape of Good Hope [Cynocephalus porcarius) has a
much longer mane and larger canine teeth than the female;
and the mane probably serves as a protection, for, on
asking the keepers in the Zoological Gardens, without
giving them any clew to my object, whether any of the
monkeys especially attacked each other by the nape of the
neck, I was answered that this was not the case, except
with the above baboon. In the Hamadryas baboon,
Ehrenberg compares the mane of the adult male to that of
a young lion, while in the young of both sexes and in the
female the mane is almost absent.

It appeared to me probable that the immense woolly
mane of the male American bison, which reaches almost to
the ground, and is much more developed in the males than
in the females, served as a protection to them in their ter-
rible battles; but an experienced hunter told Judge Caton
that he had never observed anything which favored this
belief. The stallion has a thicker and fuller mane than
the mare; and I have made particular inquiries of two great
trainers and breeders, who have had charge of many
entire horses, and am assured that they '* invariably

* " The Times," Nov. 10, 1857. In regard to tlie Canada lynx, see
Aadubon and Bacliman, "Quadrupeds of North America," 1846, p.
139.

fDr. Murie, on Otaria, '*Proc. Zoolog. Soc," 1869, p. 109. Mr.
J. A. Allen, in the paper above quoted (p. 75). doubts whether the
hair, which is longer on the neck in the male than in the femal^
deserves to be called a mane.

1

MAMMALS, 595

endeavor to seize one another by the neck/^ It does not,
however, follow from the foregoing statements, that when
the hair on the neck serves as a defense, that it was origi-
nally developed for this purpose, though this is probable in
some cases, as in that of the lion. I am informed by Mr.
McNeill that the long hairs on the throat of the stag
( Cervus elaphus) serve as a great protection to him when
hunted, for tiie dogs generally endeavor to seize him by the
throat; but it is not probable that these hairs were specially
developed for this purpose; otherwise the young and the
females would have been equally protected.

Clioice in Pairing hy Either Sex of Quadrupeds. — Before
describing, in the next chapter, the differences between the
sexes in voice, odors emitted and ornaments, it will be con-
venient here to consider whether the sexes exert any choice
in their unions. Does the female prefer any particular
male, either before or after the males may have fought
together for supremacy; or does the male, when not a
polygamist, select any particular female? The general
impression among breeders seems to be that the male accepts
any female; and this, owing to his eagerness, is, in most
cases, probably the truth. Whether the female, as a
general rule, indifferently accepts any male is much more
doubtful. In the fourteenth chapter, on birds, a consider-
able body of direct and indirect evidence was advanced
showing that the female selects her partner; and it would
be a strange anomaly if female quadrupeds, which stand
higher in the scale and have higher mental powers, did not
generally, or at least often, exert some choice. The female
could in most cases escape, if wooed by a male that did not
please or excite her; and when pursued by several males,
as commonly occurs, she would often have the opportunity,
while tliey were fighting together, of escaping with some
one male, or at least of temporarily pairing with him.
This latter contingency has often been observed in Scot-
land with female red deer, as I am informed by Sir Philip
Egerton and others.*

*Mr. Boner, in his excellent description of the habits of the red-
deer in Germany (" Forest Creatures," 1861, p. 81) sa.ys, "while the
stag is defending his rights against one intruder, another invades the
sanctuary of his harem, and carries off trophy after trophy."
Exactly the same thing occurs with seals. See Mr. J. A. Allen, ibid,
p. 100.

596 THE DESCENT OF MAN.

It is scarcely possible that much should be known about
female quadrupeds in a state of nature making any choice
in their marriage unions. The following curious details
on the courtship of one of the eared seals {Callorliinns
ursiiius) are given* on the authority of Capt. Bryant, who
had ample opportunities for observation. He says: *' Many
of the females on their arrival at the island where they
breed appear desirous of returning to some particular malC;,
and frequently climb the outlying rocks to overlook the
rookcaies, calling out and listening as if for a familiar-
voice. Tiien changing to another place they do the same
again ... As soon as a female reaches the shore, the
nearest male goes down to meet her, making, meanwhile,
a noise like the clucking of a hen to her chickens. He
bows to her and coaxes her until he gets between her and
the water so that she cannot escape him. Then his man-
ner changes and with a harsh growl he drives her to a place
in his harem. This continues until the lower row of
harems is nearly full. Then the males higher up select
the time when their more fortunate neighbors are off their
guard to steal their wives. This they do by taking them in
their mouths and lifting them over the heads of the other
females and carefully placing them in their own harem, ^k
carrying them as cats do their kittens. Those still higher ^m
up pursue the same method until the whole space is occu-
pied. Frequently a struggle ensues between two males for
the possession of the same female, and both seizing her at
once pull her in two or terribly lacerate her with their
teeth. When the space is all filled, the old male walks
around complacently reviewing his family, scolding those
who crowd or disturb the others and fiercely driving off all
intruders. This surveillance always keeps him actively
occupied.^'

As so little is known about the courtship of anima s in a
state of nature, I have endeavored to discover how far our
domesticated quadrupeds evince any choice in their unions.
Dogs offer the best opportunity for observation, as they
are carefully attended to and well understood. Many
breeders have expressed a strong opinion on this head.
Thus, Mr. Mayhew remarks: '' The females are able to

*Mr. J. A. Allen in "Ball. >Ius. Comp. Zoolog. of Cambridge^
United States," vol. ii, No. 1, p. 99.

MAMMALS. 697

bestow their affections ; and tender recollections are as
potent over them as they are known to be in other cases,
where hiorher animals are concerned. Bitches are not
always prudent in their loves, but are apt to fling them-
selves away on curs of low degree. If reared with a com-
panion of vulgar appearance, there often springs up between
the pair a devotion which no time can afterward snbdue.
The passion, for such it really is, becomes of a more than
romantic endurance." Mr. Mayhew, who attended chiefly
to the smaller breeds, is convinced that the females are
strongly attracted by males of a large size.* The well-
known veterinary Blaine statesf that his own female pug
became so attached to a spaniel, and a female setter to a
cur, that in neither case would they pair with a dog of their
own breed until several weeks had elapsed. Two similar
and trustworthy accounts have been given me in regard to
a female retridver and a spaniel, both of which became
enamored with terrier dogs.

Mr. Cupples informs me that he can personally vouch
for the accuracy of tlie following more remarkable case, in
which a valuable and wonderfully intelligent female terrier
loved a retriever bslon^ing to a neighbor to such a degree
that she had often to be dragged away from him. After
their permanent separation, although repeatedly showing
milk in her teats, she would never acknou ledge the court-
ship of any other dog, and, to the regret of her o\\ ner, never
bore puppies. Mr. Cupples also states that, in 1868, a
female deerhound in his kennel thrice produced puppies,
and on each occasion showed a marked preference for one
of the largest and handsomest, but not the most eager, of
four deerhoMnds living with her, all in the prime of life.
Mr. Cupples has observed that the female generally favors
a di)g whom she has associated with and knows; her shy-
ness and timidity at first incline her against a strange dog.
The male, on the contrary, seems rather inclined toward
strange females. It appears to be rare when the male
refuses any particular female, but Mr. Wright, of Yelders-
ley House, a great breeder of dogs, informs me that he has
known some instances; he cites the-case of one of his own

* " Do^s- Their Management," by E. Mayhew, M. R. C. V. S.,
2d edit., 1864, pp. 187-193.

+ Quoted by Alex. Walker, "On Intermarriage," 1838, p. 276; see
also p. 244

598 TEE DESCENT OP MAN.

deerhounds who would not take any notice of a particular
female mastiff, so that another deerhound had to be
employed. It would be superfluous to give, as I could,
other instances, and I will only add that Mr. Barr, who
has carefully bred many bloodhounds, states that in almost
every instance particular individuals of opposite sexes show
a decided preference for each other. Finally, Mr. Cup-
pies, after attending to this subject for another year, has
written to me: ^' I have had full confirmation of my former
statement that dogs in breeding form decided preferences
for each other, being often influenced by size, bright color
and individual characters, as well as by the degree of their
previous familiarity.^'

In regard to horses, Mr. Blenkiron, the greatest breeder
of race- horses in the world, informs me that stallions are
so frequently capricious in their choice, rejecting one mare
and without any apparent cause taking to another, that
various artifices have to be habitually used. The famous
Monarque, for instance, would never consciously look at the
dam of Gladiateur, and a trick had to be practiced. We
can partly see the reason why valuable race-horse stallions,
which are in such demand as to be exhausted, should be so
particular in their choice. Mr. Blenkiron has never known
a mare reject a horse ; but this has occurred in Mr.
Wright's stable, so that the mare had to be cheated.
Prosper Lucas* quotes various statements from French
authorities, and remarks: '''On voit des etalons qui s'epren-
nent d'une jument, et negligent toutes les autres.'' He
gives, on the authority of Baelen, similar facts in regard to
bulls; and Mr. H. Reeks assures me that a famous short-
horn bull, belonging to his father, "invariably refused to
be matched with a black cow.'' Hoffberg, in describing
the domesticated reindeer of Lapland, says: '^Foeminae
majores et fortiores mares prae caeteris admittunt, ad eos
confugiunt, a junioribus agitatae, qui hos in fugam con-
jiciunt." f A clergyman, who has bred many pigs, asserts
that sows often reject one boar and immediately accept
another.

From these facts there can be no doubt that, with most
of our domesticated quadrupeds, strong individual antipa-

* ** Traite de I'Hered. Nat.," torn, ii, 1850, p. 296.
■■■ t ** Amoenitates Acad.," vol. iv, 1788, p. 160.

MAMMALS. 599

thies and preferences are frequently exhibited, and much
more commonly by the female than by the male. This
being the case, it is improbable that the unions of quadru-
peds in a state of nature should be left to mere chance. It
IS much more probable that the females are allured or
excited by particular males who possess certain characters
in a higher degree than other males; but what these char-
apcters are we can seldom or never discover with certainty.

600

THE DESCENT OF MAN.

CHAPTER XVIII.

SECONDARY SEXUAL CHARACTERS OF MAMMALS —

continued.

Voice — Remarkable sexual peculiarities in f^eals — Odor — Develop-
ment of tlie hair — Color of the hair and skin — Anomalous case
of the female being more ornamented than the male — Color and
ornaments due to sexual selecticm — Color acquired for the sake
of protection — Color, though common to both sexes, often due to
sexual selection — On the disappearance of spots and stripes in
adult quadrupeds — On the colors and ornaments of the quad-
rumana — Summary.

Quadrupeds use their voices for various purposes, as a
signal of danger, as a call from one member of a troop to
another, or from the mother to her lost offspring, or from
the latter for protection to tlieir mother; but such uses
need not here be considered. We are concerned only with
the difference between the voices of the sexes; for instance,
between that of the lion and lioness, or of the bull and
cow. Almost all male animals use their voices much more;
during the rutting-season than at any other time; andi
some, as the giraffe and porcupine,* are said to be com-
pletely mute excepting at this season. As the throats {i.e,
of the larynx and thyroid bodies f) of stags periodically!
become enlarged at the beginning of the breeding-season,
it might be thought that their powerful voices must be I
somehow of high importance to them; but this is veiyj
doubtful. From information given to me by two cxperi-j
enced observers, Mr. McNeill and Sir P. Egerton, it seemsl
tliat young stags under three years old do not roar or]
bellow; and that the old ones begin bellowing at the com-]
mencement of the breeding season, at first only occasionally
and moderately, while they restlessly wander about in
search of the females. Their battles are prefaced by loud]

*Owen, "Anatomy of Vertebrates/' vol. iii, p. 585.
t Ibid, p. 595.

MAMMALS. 601

and prolonged bellowing, but during the actual conflict
they are silent. Animals of all kinds wliich habitually use
their voices utter various noises under any strong emotion,
as when enraged and preparing to fight ; but this may
merely be the result of nervous excitement, which leads to
the spasmodic contraction of almost all the muscles of the
body, as when a man grinds his teeth and clenches his fists
in rage or agony. No doubt stags challenge each other to
mortal combat by bellowing; but those with the more
powerful voices, unless at the same time the stronger, better-
armed and more courageous, would not gain any advantage
over their rivals. -

It is possible that the roaring of the lion may bo of
some service to him by striking terror into his adversary; for
when enraged he likewise erects liis mane and thus instinct-
ively tries to make himself appear as terrible as possible.
But it can hardly be supposed that the bellowing of the
stag, even if it be of service to him in this way, can have
been important enough to have led to the periodical
enlargement of the throat. Some writers suggest that the
bellowing serves as a call to the female; but the expe-
rienced observers above quoted inform me that female deer
do not search for the male, thougli the males search
eagerly for the females, as indeed might be expected from
what we know of the habits of other male quadrupeds.
The voice of the female, on the other hand, quickly brings
to her one or more stags,* as is well known to the hunters
who in wild counti'ies imitate her cry. If we could believe
that the male had the power to excite or allure the female
by his voice, the periodical enlargement of his vocal organs
would be intelligible on the principle of sexual selection,
together with inheritance limited to the same sex and
season; but we have no evidence in favor of this view.
As the case stands, the loud voice of the stag during the
breeding-season does not seem to be of any special service
to him. either during his courtship or battles, or in any
other way. But may we not believe that the frequent use
of the voice, under the strong excitement of love, jealousy
and rage, continued during many generations, may at last

* See, for instance, Maj. W. Ross King ("The Sportsman in
Canada," 1866, pp. 53, 131) on the liabits of tli© moose and wild

reindeer.

608 THE DESCENT OF MAN.

have produced an inherited effect on the vocal or| ^s of
the stag as well as of other male animals ? This appears to
me, in our present state of knowledge, the most probable
view.

Til 6 voice of the adult male gorilla is tremendous, and
he is furnished with a laryngeal sack, as is the adult male
orang.* The gibbons rank among the noisiest of monkeys,
and the Sumatra species (//?//o^^r/e.<? syudactylns) are also
furnislied with an air sack; but Mr. Blyth, who has had
opportunities for observation, does not believe that the male
is noiser than the female. Hence, these latter monkeys
probably use their voices as a mutual call ; and this is cer-
tainly the case with somu quadrupeds, for instance the
beaver, f Another gibbon, the H. agilis, is remarkable,
from having the power of giving a complete and correct
octave of musical notes, J which we may reasonably suspect
serves as a sexual charm; but I shall have to recur to this
subject in the next chapter. The vocal organs of thv3
American AI//cefes caraya are one-third larger in the male
than in the female, and are wonderfully powerful. These
monkeys in warm weather make the forests resound at
morning and evening Avith their overwhelming voices.
The maleii begin the dreadful concert and often continue
it during- many hours, the females sometimes joining in
with their lo33-powerful voices. An excellent observer —
Rongger§ — could not perceive that they were excited to
begin by any special cause ; he tliinks that, like many
birds, they delight in their own music, and try to excel each
other. AVliether most of the foregoing monkeys have
acquired their powerful voices in order to beat their rivals
and charm the females — or whether the vocal organs have
been strengthened and enlarged through the inherited
etfects of long-continued use without any particular good
being thus gained — I will not pretend to say; but the
former view, at least in the case of the Uylobates agilis,
seems the most probable.

*0\ven, " Anatomy of Vertebrates," vol. iii, p. 600.

+ Mr. Green, "ii " Journal of Linn. Soc," vol. x, Zoology, 1869, p.
862.

JC. L. Martin, ** General Introduction to the Nat. Hist, of Mamm.
Aninmls," 1S41, p. 431.

§ " Naturgescliiclite der SUufietliiere von Paraguay," 1830, ss.
15. 31

IfAMMALS. 603

I may here mention two very curious sexual peculiarities
occurring in seals, because they have been supposed by
some writers to affect the voice. The nose of the male
sea-elephant (Macrorhiniis pvoboscideus) becomes greatly
elongated during the breeding- season and can then be
erected. In this state it is sometimes a foot in lengtli.
The female is not thus provided at any period of life.
The male makes a wild, hoarse, gurgling noise, which is
audible at a great distance and is believed to be strength-
ened by the proboscis; the voice of the female being differ-
ent. Lesson compares the erection of the proboscis Avith
the swelling of the wattles of male gallinaceous birds
while courting the females. In another allied kind of
seal, the bladder- nose {CysfopJiora cristafa), the head is
covered by a great hood or bladder. This is supported by
the septum of the nose, which is produced far backward
and rises into an internal crest seven inches in height.
The hood is clothed with short hair and is muscular; it
can be inflated until it more than equals the whole head in
size! The males when rutting fight furiously on the ice,
and their roaring '' is said to bo sometimes so loud as to
be heard four miles off'.''^ AVhen attacked they likewise
roar or bellow ; and whenever irritated the bladder is
inflated and quivers. Some naturalists believe that the
voice is thus strengthened, but various other uses have
been assigned to this extraordinary structure. Mr. R.
Brown thinks that it serves as a protection against acci-
dents of all kinds; but this is not probable, for, as I am
assured by Mr. Lament, who killed six hundred of these
animals, the hood is rudimentary in the females and it is
not developed in the males during 3'outh.*

Odo?\ — With some animals, as with the notorious skunk
of America, the overwhelming odor which they emit
appears to serve exclusively as a defense. With shrew-
m.ice (Sorex) both sexes possess abdominal scent-glands,

*0n tlie sea-elepliant, see an article by Lesson, in "Diet. C"lass.
Hist. Nat.," toni. xiii, p. 418. For the Cystopliora, or Stemmatopus,
see Dr. Dekay "Annals of Lyceum of Nat. Hist New York," vol.
i, 1824, p 94. Pennant has also collected informrtion from the
sealers on this animal. Tlie fullest account is given by Mr, Brown,
in " Proc. Zoolog. Soc," 1868, p. 435.

604 THE DESCENT OF MAN

and there can be little doubt, from the rejection of their
bodies by birds and beasts of prey, that the odor is pro-
tective; nevertheless, the glands become enlarged in the
males during the breeding-season. In many other quad-
rupeds the glands are of the same size in both sexes,* but
their uses are not known. In other species the glands are
confined to the males or are more developed than in the
females ; and they almost always become more active
during the rutting-season. At this period the glands on
the sides of the face of the male elephant enlarge and emit
a secretion having a strong musky odor. The males, and
rarely the females, of many kinds of bats have glands and
protrudable sacks situated in various parts; and it is
believed that these are odoriferous.

The rank effluvium of the male goat is well known, and
that of certain male deer is wonderfully strong and per-
sistent. Oil the banks of the Plata I perceived the air
tainted with the odor of tlie male Cervus cawpestris at
half a mile to leeward of a herd; and a silk handkerchief,
in which I carried home a skin, though often used and
washec, retained when first unfolded traces of the odor for
one year and seven months. This animal does not emit
its strong odor nntil more than a year old, and if castrated
while young never emits it.f Besides the general odor
permeating the whole body of certain ruminants (for in-
stance. Bos moscliatus) in the breeding-season, many deer,
antelopes, sheep and goats possess odoriferous glands in
various situations, more especially on their faces. The
so-called tear-sacks, or suborbital pits, come under this
head. These glands secrete a semi-fluid fetid matter which
is sometimes so copious as to stain the whole face, as I
have myself seen in an antelope. They are ^' usually
larger in the male than in the female, and their develop-

*As with the castoreum of tlie heaver, see Mr. L. H. Morgan's
most interesting work. "The American Beaver," 1868, p. 300.
Pallas (•• Spic. Zoolog.," fasc. viii, 1779, p. 23) has well discussed the
odoriferous glands of mammals. Owen ("Anat. of Vertebrates,"
vol. iii, p. 634) also gives an account of these glands, including those
of the elephant, and (p. 763) tho.se of shrew-mice. On hats, Mr.
Dobson in "Proc. Zoolog. Soc," 1873, p. 241.

fRengger, " Naturgeschichte der Saugetmere von Paraguay,"
1830, s. 355. This observer also gives some curious particulars io
reg^ard to the odor,

I

MAMMALS. 605

ment is checked by castration."* According to Desmarest,
they are altogether absent in the female of Antilope sub-
giiikirosa. Hence, there can be no doubt that they stand
in close relation with the reproductive functions. They
are also sometimes present, and sometimes absent, in nearly
allied forms. In the adult male musk deer (Moschus mos-
cUiferiis) a naked space round the tail is bedewed with an
odoriferous fluid, while in the adult female, and in the
male until two years old, this space is covered with hair
and is not odoriferous. The proper musk-sack of tliis
deer is from its position necessarily confined to the male
and forms an additional scent-organ. It is a singular fact
that the matter secreted by this latter gland does not,
according to Pallas, change in consistence or increase in
quantity during the rutting - season ; nevertheless, this
naturalist admits that its presence is in some way con-
nected with the act of reproduction. He gives, however,
only a conjectural and unsatisfactory explanation of its
use. t

In most cases, when only the male emits a strong odor
during the breeding-season, it probably serves to excite or
allure the female. We must not judge on this head by our
own taste, for it is well known that rats are enticed by
certain essential oils, and cats by valerian, substances far
from agreeable to us; and that dogs, though they will not
eat carrion, sniff and roll on it. From the reasons given
when discussing the voice of the stag we may reject the
idea that the odor serves to bring the females from a dis-
tance to the males. Active and long-continued use cannot
here have come into, play, as in the case of the vocal organs.
The odor emitted must be of considerable importance to
the male, inasmuch as large and complex glands, furnished
with muscles ror everting the sack and for closing or open-
ing the orifice, have in 3ome cases been developed. The
davelopment of '.hese organs is intelligible through sexual
selection if the most odoriferous males are the most suc-

*Owen, " Anatomy of Vercebrates," vol. iii, p. 633. See also Dr.
Murie's observationi on tliese glands in the "Proc. Zoolog. Soc,"
1870, p. G40. 1 ' :>smr.rest, on the Antilope subgatturosa, "Maumial-
ogie." 1820, p. 455.

f Pballas, " Spicilegia Zoolog.," fasc. xiii, 1799, p. 24; Desmou-
lins, -'Diet. Class. d'Hist. Nat.," torn, iii, p. 586.

606 THE DESCENT OF MAN.

cessful in winning the females, and in leaving offspring to
inherit their gradually perfected glands and odors.

Development of the Hair. — We have seen that male quad-
rupeds often have the hair on their necks and shoulders
much more developed than the females; and many addi-
tional instances could be given. This sometimes serves as
a defense to the male during his battles; but whether the
hair in most cases has been specially developed for this
purpose is very doubtful. We may feel almost certain that
this is not the case, when only a thin and narrow crest runs
along the back ; for a crest of this kind would afford
scarcely any protection, and the ridge of the back is not
a place likely to be injured; nevertheless such crests are
sometimes confined to the males, or are much more devel-
oped in them than in the females. Two antelopes, the
Tragelcqjhiis scriptus^ (see fig. 70, p. G20) Sind Fortax picta
may be given as instances. AVhen stags and the males of the
wild goat are enraged or terrified these crests stand erect;f
but t cannot be supposed that they have been developed
merely for the sake of exciting fear in their enemies. One
of the above-named antelopes, the Partax lyida, has a large,
well-defined brush of black hair on the throat, and this is
much larger in the male than in the female. In the
Ammotragus tragelaphus of iN". Africa, a member of the
sheep family, the fore legs are almost concealed by an
extraordinary growth of hair, which depends from the
neck and upper halves of the legs; but Mr. Bartlett does
not believe that this mantle is of the least use to the male,
in whom it is much more developed th^n in the female.

Male quadrupeds of many kinds differ from the females
in having more hair, or hair of a different character, on
certain parts of their faces. Thus the bull alone has curled
hair on the forehead. J In three closely allied sub-genera
of the goat family only the males possess beards, sometimes
of large size; in two other sub-genera both sexes have a

* Dr. Gray, " Gleanings from the Menagerie at Knowsley," pi. 28.

f Judge Caton on the Wapiti, "Transact. Ottawa Acad. Xat.
Sciences," 1868, pp. 36,40; Blyth, "Land and Water," on Capra
cegagrus, 1867. p. 37.

X" Hunter's Essays and Observations," edited by Owen, 1861, v<>l.
I, p. 236.

MAMMALS,

607

beard, but it disappears in some of the domestic breeds of
the common goat; and neither sex of the Hemitragus has
a beard. In the ibex the beard is not developed during the
summer, and it is so small at other times that it may be
called rudimentary.* AVith some monkeys the beard is
confined to the male, as in the orang; or is much larger in

Tig. C8. ntheeia satanas, male (from Brehm).

the male tlian in the female, as in the Mycefes car ay a and
Pithecia satanas (fig. C8). So it is with the whiskers of
some species of Macaous,f and, as we have seen, with the
manes of some species of baboons. But- with most kindu
of monkeys the various tufts of hair about the face and
head are alike in both sexes.

*Se« Dr. Gray's "Cat. of Mammalia in Britisli Museum," part iii,
1852, p. 144.

f Rengger, •• SSugetliiere/' etc., s. 14; Desmarest, "Mammal-
ogie," p. 86.

30ft THE DESCENT OF MAN.

The males of various members of the ox family (Boridse),
and of certain antelopes, are furnished with a dewlap or
great fold of skin on the neck, which is much less devel-
oped in the female.

Now, what must we conclude with respect to such sexual
differences as these? No one will pretend that the beards
of certain male goats, or the dewlap of the bull, or the
crests of hair along the backs of certain male antelopes,
are of any use to them in their ordinary habits. It is pos-
sible that the immense beard of the male Pithecia, and the
large beard of the male orang, may protect their throats
when fighting ; for the keepers in the Zoological Gardens
inform me that many monkeys attack each other by the
throat; but it is not probable that the beard has been
developed for a distinct purpose from that served by the
whiskers, mustache and other tufts of hair on the face;
and no one will suppose that these are useful as a protec-
tion. Must we attribute all these appendages of hair or
skin to mere purposeless variability in the male? It cannot
be denied that this is possible; for in many domesticated
quadrupeds certain characters, apparently not derived
through reversion from any wild parent form, are confined
to the males, or are more developed in them than in
females; for instance, the hump on the male zebu-cattle of
India, the tail of fat-tailed rams, the arched outline of the
forehead in the males of several breeds of sheep, and,
lastly, the mane, the long hairs on the hind legs, and the
dewlap of the male of the Berbura goat.* The mane,
which occurs only in the rams of an African breed of
sheep, is a true secondary sexual character, for, as I hear
from Mr. Winwood Reade, it is not developed if the animal
be castrated. Although we ought to be extremely cautious,
as shown in my work on '" Variation under Domestication,"'
in concluding that any character, even with animals kept
by semi-civilized people, has not been subjected to selec-
tion by man, and thus LAigmcnted, yet in the cases just
specified this is improbable; more especially as the charac-
ters are confined to the males, or are more strongly devel-
oped in them than in the females. If it were positively

* See the chapters on these several animals in vol. i, of ray
" Variation o£ Animals under Domestication;" also vol. ii, p. 73; also
cbap. XX, on the practice of selection by semi-civilized people. For
tlie Berbura goat, see Dr. Gray, " Catalogue," ibid, p. 157.

MAMMALS. 609

known that the above African ram is a descendant of the
Bame primitive stock as the other breeds of sheep, and if
the Berbnra male goat, with his mane, dewlap, etc., is
descended from the same stock as other goats, then,
assuming that selection has not been applied to these
characters, they must be due to simple variability, together
with sexually limited inheritance.

Hence it appears reasonable to extend this same view to
all analagous cases with animals in a state of nature.
Nevertheless 1 cannot persuade myself that it generally
holds good, as in the case of the extraordinary development
of hair on the throat and fore legs of the male Ammo-
tragus, or in that of the immense beard of the male
Pithecia. Such study as I have been able tf) give to nature
makes me believe tliat parts or organs which are highly
developed were acquired at some period for a special pur-
pose. With those antelopes in which the adult male is
more strongly colored than the female, and with those
monkeys on Avhich the hair on the face is elegantly arranged
and colored in a diversfied manner, it seems probable that
the crests and tufts of hair were gained as ornaments; and
this I know is the opinion of some naturalists. If this be
correct, there can be little doubt that they were gained or
at least modified through sexual selection ; but how far
the same view may be extended to oiner mammals is
doubtful.

Colo?' of file Hair and of the Naked Shin. — I will first
give briefly all the cases kiiown to mo of male quadrupeds
differing in color from the females. With marsupials, as I
am informed by Mr. Gould, the sexes rarely differ in this
respect; but the great red kangaroo offers a striking excep-
tion, "delicate blue being the prevailing tint in those parts
of the female which in the male are red."* In the
Didelphis ojjos.siini of Cayenne the female is said to be a
little more red than the male. Of the rodents, Dr. Gray
remarks: "African squirrels, especially those found in the
tropical regions, have the fur much brighter and more vivid
at some seasons of the year than at others, and the fur of

*Osphranter rufus, Gould, "Mammals of Australia," 1863, vol,
li. On the Didelphis, Desmarest, ** Mammalogie," p. 356.

610 THE DESCENT OF MAN,

tho male is generally brighter than that of the female."*
Dr. Gray informs me that he specified the African squir-
rels, because, from their unusually bright colors, they best
exhibit this difference. The female of the Muf^ minulus
of Russia is of a paler and dirtier tint than the male. In a
large number of bats the fur of the male is lighter than in
female, f Mr. Dobson also remarks, with respect to these
animals: ^' Diffurences, depending partly or entirely on the
possession by the male of fur of a much more brilliant hue,
or distinguished by different markings or by the greater
length of certain portions, are met only, to any appreciable
extent, in the frugivorous bats in which the sense of sight
is well developed." This last remark deserves attention,
as bearing on the question whether bright colors are ser-
viceable to male animals from being ornamental. In one
genus of sloths it is now established, as Dr. Gray states,
'* that the males are ornamented differently from the
females — that is to say, that they have a patch of soft short
hair between the shoulders, which is generally of a more
or less orange color, and in one species pure white. The
females, on the contrary, are destitute of this mark."

The terrestrial Carnivora and Insectivora rarely exhibit
sexual differences of any kind, including color. The ocelot
(Felis pardaliti), however, is exceptional, for the colors of
the female, compared with those of the male, are *'moins
apparentes, le fauve, etant plus terne, lo blanc moins pur,
les raies ayant moins de largeur et les taches moins de
diametre."J The sexes of the allied Felis mitis also differ,
but in a less degree; the general hues of the female being
rather paler than in the male, with the spots less black.
The marine Carnivora or seals, on the other hand, some-
times differ considerably in color, and they present, as we
have already seen, other remarkable sexual differences.
Thus the male of the Olaria nigrescent of the southern
hemisphere is of a rich brown shade above ; while the

* ' Annals and Mag. of Nat. Hist.," Nov.. 1867. p. 325. On the
Mas miiiutaa, Desmarest, '•Maranialogie," p. 304.

•) J A. Allen, in "Bulletin of Mus. Comp. Zoolog. of Cambridge,
Tjnited States," 1869, p. 207. Mr. Dobson on sexual characters in
the Cliiroptera, " Proc. Zoolog. Soc," 1873, p. 241. Dr. Gray on
sloths, ibid, 1871, p. 436.

t Desniare;?!, '* Maminalogie," 1830, p. 220. On Felis Mitia, Reng-
ger, ibid, s. 194.

MAMMALS. 611

female, who acquires her adult tiuts earlier in life than the
male, is dark-gray above, the young of both sexes being of
a deep chocolate color. The male of the northern Fhoca
ciroeiilandica is tawny gray, with a curious saddle-shaped
dark mark on the back; the female is much smaller and.
has a very ditlereut appearance, being **' dull white or yel-
lowish straw-color, with a tawny hue on the back;" the
young at first are pure white, and can ''hardly be dis-'
tinguished among the icy hummocks and snow, their color
thus acting as a protection."*

With ruminants sexual differences of color occur more
commonly than in any other order. A difference of this
kind is general in the Strepsicerene antelopes; thus the
male nilghau {Portax picta) is bluish-grey and much darker
than the female, with the square white patch on the throat,
the white marks on the fetlocks and the black spots on the
ears all much more distinct. AVe have seen that in this
species the crests and tufts of hair aj-e likewise more devel-
oped in the male than in the ho'rnless female. I am
informed by Mr. Blyth that the male, without shedding
his hair, periodically becomes darker during the breeding-
season. Young males cannot be distinguished from young
females until about twelve months old; and if the male is
emasculated before this period, he never, according to the
same authority, changes color. The importance of this
latter fact, as evidence tiiat the coloring of the Portax is of
sexual origin, becomes obvious when we hearf that neither
the red summer coat nor the blue winter coat of the Virginian
deer is at all affected by emasculation. With most or all of
the highly ornamented species of Tregelaphus the males are
darker than the hornless females, and their crests of hair are
more fully developed. In the male of that magnificent ants-
lope, the Derb3'an eland, the body is redder, the whole neck
much blacker and the white band which separates these
colors broader than in the female. In the Cape eland, also,
the male is slightly darker than the female. |

*Dr. Marie on the Otaria, ** Proc. Zool. Soc," 1869, p. 108. Mr.
R. Brown on the P. groeiilandlca, ibid, 1868, p. 417. See also on the
colors of seals, Desrudrest, ibid. pp. 243, 249.

f Judge Caton, iu "Trans. Ottawa Acad, of Nat. Sciences," 1888,
p. 4.

tDr. Gray, '-Cat. of Mamm. in Brit. Mus.," part iii, 1852, pp.
134-143; also Dt. Qx&y, "(ii©aninff<? Cram tha Menagerie of Knows*

612

THE DESCENT OF MAN,

In tlie Indian black -buck (.4. bezoartica), whicli
belongs to another tribe of antelopes, the male is very
dark, almost black ; while the hornless female is fawn-
colored. We meet in this species, as Mr. Blyth informs
me, with an exactly similar series of facts, as in the
For tax picta, namely, in the male periodically changing
color during the breeding-season, in the eifects of emascu-
lation on this change, and in the young of both sexes being
indistinguishable from each other. In the Aiitilope niger
the male is black, the female, as well as the young of both
sexes, being brown; in A. sing -sing the male is much
brighter-colored than the hornless female, and his chest
and belly are blacker; in the male A. caama the marks
and lines which occur on various parts of the body are
black, instead of brown as in the female; in the brindled
gnu {A. gorgon) '"^ the colors of the male are nearly the
same as those of the female, only deeper and of a brighter
hue.'' * Other analogous cases could be added.

The Banteng bull {Mossondaicvs) of the Malayan Archi-
pelago is almost black, with white legs and buttocks; the
cow is of a bright dun, as are the young males until about
the age of three years, when they rapidly change color.
The emasculated bull reverts to the color of the female. The
female Kemas goat is paler, and both it and the female Capra
mgagrus are said to be more uniformly tinted than their
males. Deer rarely present any sexual differences in color.
Judge Caton, however, informs me that in the males of the
wapiti deer {Cenms canadensis) the heck, belly and legs
are much darker than in the female; but during the
winter the darker tints gradually fade away and disappear.
I may liere mention that Judge Caton has in his park three
races of the Virginian deer which differ slightly in color,
but the differences are almost exclusively confined to the
blue winter or breeding coat; so that this case may be com-

lev," in which there is a splendid drawing of the Oreas derlianus:
see the text on Tragelaphus. For the Cape eland {Oreas carina), see
Andrew Smith, "Zoology of S. Afrif-a," pi. 41, 42, There are also
many of these antelopes in the Zoological Gardens.

*6n the Ant. niger, see "Proc. Zool. Soc," 1850, p. 133. With
respect to an allied species, in which there is an equal sexual differ-
ence in color, see Sir S. Baker, "The Albert Nyanza," 1866. vol. ii,
p. 627. For the A. sing-sing. Gray. "Cat. B. Mus.," p. 100. Des-
marest, "Mammalogie," p. 468, on the A. caama, Andrew Saiitli,
" Zoology of S. Africa," on the gnu.

MAMMALS. 613

pared with those given in a previons chapter of closely
allied or representative species of birds which differ from
each other only in their breeding plumage.* The females
of Cerviis paludosus of South America, as well as the
young of both sexes, do not possess the black stripes on the
nose and the blackish-brown line on the breast which are
characteristic of the adult males, f Lastly, as I am
informed by Mr. Blyth, the mature male of the beautifully
colored and spotted axis deer is considerably darker than
the female ; and this hue the castrated male never
acquires.

The last order which we need consider is that of the
Primates. The male of the Lemur macaco is generally
coal-black, while the female is brown. J Of the Quadru-
mana of the New AVorld, the females and young of Mycetes
caraya are grayish-yellow and like each other; in the second
year the young male becomes reddish-brown; in the third,
black, excepting the stomach, which, however, becomes
quite black in the fourth or fifth year. There is also a
strongly marked difference in color between the sexes of
Mycetes senicuhis and Cebus capucinus; the young of the
former, and I believe of the latter species, resembling the
females. AVith Pitliecia leiicocephala the young likewise
resemble the females, which are brownish-black above and
light rusty-red beneath, the adult males being black. The
ruff' of hair round the face of A teles marginatus is tinted
yellow in the male and white in the female. Turning to
the Old World, the males of Hylobates hoolock are always
black, with the exception of a white band over the brows;
the females vary from whity -brown to a dark tint mixed
with black, but are never wholly black. § In the beautiful

* " Ottawa Academy of Sciences," May 21, 1868, pp. 3, 5.

fS. Miiiler, on the Banteng, "Zool. Indischen Archipel.," 1839-
1844, tab. 35; see aiso Kaffles, as quoted by Mr. Blytb, in " Land
and Water," 1867, p. 476. On goats. Dr. Gray, " Cat. Brit. Mus.,"
p. 146, Desmarest, *' Mamuialogie," p. 482. On the Cervus palu-
dosus, Rengger, ibid, s. 345.

JSclater, *'Proc. Zool. Soc ," 1866, p. 1. The same fact has also
been fullv ascertained bv MM. Pollen and van Dam. See, also. Dr.
Gray in '• Annals and Mag. of Nat. Hist.," May, 1871, p. 340.

§0n Mycetes. Rengger, ibid, s. 14; and Brehm, "Illustrlrtes
Thierleben," B. i, ss. 96, 107. On Ateles Desmarest, "Mammai-
ogie," p. 75. On Kylobates, Blyth, "Land and Water," 1867, p.
185. On the Semnopithecus, S. Miiiler, "Zoog. Indischen ArcM-
peL," tab. x.

614 THE DESCENT OF MAN.

Cercopithec2(s diana, tho head of the adult male is of an
intense black, while that of the female is dark gray; in the
former the far between the thighs is of an elegant fawn-
color, in the latter it is paler. In the beautiful and curious
mustache monkey (6't'r6'C7;i7//eczf6- cephns) the only dilier-
enco between the sexes is that the tail of the male is
chestnut and that of the female gray; but Mr. Bartlett
informs me that all the hues become more pronounced in
the male when adult, while in the female they remain as
they were during youth. According to the colored figures
given by Solomon Miiller, the male of Semnopithecus
chrijsomelas is nearly black, the female being pale brown.
In the Cercopifhecus ci/nosurus and griseovlridis one part
of the body, which is confined to the male sex, is of the
most brilliant blue or green, and contrasts strikingly with
the naked skin on the hinder part of the body, which is
vivid red.

Lastly, in the baboon family, the adult male of Cyno-
cephalns hamadryas differs from the female not only by his
immense mane, but slightly in the colcr of the hair and
of the naked callosities. In the drill {C. leiicophceus) tne
females and young are much paler colored, with less green
than the adult males. Ko other member in the whole
class of mammals is colored in so extraordinary a manner
as the adult male mandrill (C. mormon). The face at this
age becomes of a fine blue, with the ridge and tip of the
nose of the most brilliant red. According to some authors
the face is also marked with whitish stripes, and is shaded
in parts with black, but the colors appear to be variable.
On the forehead there is a crest of hair, and on the chin a
yellow beard. *' Toutes les parties superieures de leurs
cuisses et le grand espace nu de leurs fesses sont ogalement
colores du rouge le plus vif, avec un melange de bleu qui
ne manque reellement pas d'elegance."* When the animal
is excited all the naked parts become much more vividly
tinted. Several authors have used the strongest expres-
sions in describing these resplendent colors, which they com-
pare with those of the most brilliant birds. Another remark-

*Gervais, 'Hist. Nat. des Maramiferes," 1854, p. 103. Figures
are given of the skull of the male. Also Desmarest, " Manimal-
ogie," p. 70. Geoffroy St.-Hilaire and F. Cuvier, "Hist. Nat. des
Mamm.," 1824, torn. i.

MAMMALS. 615

able peculiarity is that when the great canine teeth are
fully developed, immense protuberances of bone are formed
on each cheek, which are deeply farrowed longitudinally,
and the naked skin over them is brilliantly colored, as just
described. (Fig. 69.) In the adult females and in the
young of both sexes these protuberances are scarcely per^

Fif?. 69 Head of male Mandrill (from GeiTais, " Hist. Nat. des Mammiferes ")•

ceptible; and the naked parts are much less bright colored,
the face being almost black, tinged with blue. In the
adult female, however, the nose at certain regular intervals
of time becomes tinted with red.

In all the cases hitherto given the male is more strongly
or brighter colored than the female, and differs from the

616 TEE DESCENT OF MAN,

young of both sexes. But as with some few hv:(\n it is the
female which is brighter colored than the male, so with
the Rhesus monkey (Macaciis rhesus), the female has a
large surface of naked skin round the tail, of a brilliant
carmine red, which, as I was assured by the keepers in the
Zoological Gardens, periodically becomes even yet more
vivid, and her face also is pale red. On the other hand, in
the adult male and in the young of both sexes (as I saw in
the gardens), neither tl'e naked skin at the posterior end
of the body, nor the face, show a trace of red. It appears,
however, from some published accounts, that the male does
occasionall}^ or during certain seasons, exhibit some traces
of the red. Although he is thus less ornamented than the
female, yet in the larger size of his body, larger canine
teeth, more developed whiskers, more prominent super-
ciliary ridges, he follows the common rule of the male ex-
celling the female.

I have now given all the cases known to me of a dif-
ference in color between the sexes of mammals. Some of
these may be the result of variations confined to one sex
and transmitted to the same sex, without any good being
gained, and therefore without the aid of selection. We
have instances of this with our domesticated animals, as in
the males of certain cats being i-usty-red, while the females
are tortoise-shell colored. Analogous cases occur in nature:
Mr. Bartlett has seen many black varieties of the jaguar,
leopard, vulpine phalanger and wombat; and he is certain
that all, or nearly all these animals, were males. On the
other hand, with wolves, foxes, and apparently American
squirrels, both sexes are occasionally born black. Hence
it is quite possible that with some mammals a difference of
color between the sexes, especially when this is congenital,
may simply be the result, without the aid of selection, of
the occurrence of one or more variations, which from the
first were sexually limited in their transmission. Never-
theless it is improbable that the diversified, vivid, and con-
trasted colors of certain quadrupeds, for instance, of the
above monkeys and antelopes, can thus be accounted for.
We should bear in mind that these colors do not appear in
the male at birth, but only at or near maturity; and that,
"vmlike ordinary variations, they are lost if the male be
emasculated. It is on the whole probable that the strongly

JifAMMALS. 617

marked colors and other ornamental characters of male
quadrupeds are beneficial to them in their rivalry with
other males, and have consequently been acquired through
sexual selection. This view is strengthened by the dif-
ferences in color between the sexes occurring almost ex-
clusively, as may be collected from the previous details, in
those groups and sub-groups of mammals which present
other and strongly marked secondary sexual characters;
these being likewise due to sexual selection.

Quadrupeds manifestly take notice of color. Sir S.
Baker repeatedly observed that the African elephant and
rhinoceros attacked white or gray horses with special fury.
I have elsewhere shown* that half-wild horses apparently
pre:£er to pair with those of the same color, and that herds
of fallow-deer of different colors, though living together,
have lonof kept distinct. It is a more significant fact that
a female zebra would not admit the addresses of a male ass
until ho was painted so as to resemble a zebra, and then, as
John Hunter remarks, '^she received him very readily.
In this curious fact, we have instinct excited by mere
color, which had so strong an effect as to get the better of
ev3ry thing else. But the male did not require this; the
female being an animal somewhat similar to himself, was
sufficient to rouse him." f

In an earlier chapter we have seen that the mental
powers of the higher animals do not differ in kind, though
greatly in degree, from the corresponding powers of man,
especially of the lower and barbarous races; and it would
appear that even their taste for the beautiful is not widely
different from that of the Quadrumana. As tlie negro of
Africa raises the flesh on his face into parallel ridges *'or
cicatrices, high above the natural surface, which unsightly
deformities are considered great personal attractions;" J; — as
negroes and savages in many parts of the world paint their
faces with red, blue, white or black bars — so the male man-
drill of Africa appears to have acquired his deeply furrowed
and gaudily colored face from having been thus rendered

*"Tbe Variation of Animals and Plants under Domestication,"
1868, vol. ii, pp. 102, 103.

+ " Essays and Observations by J. Hunter," edited by Owen, 1861,
vol. i, p. 194.

JSir S. Baker, *'Tlie Nile Tributaries of Abyssinia," 1867.

618

THE DESCENT OF MAN,

attractive to the female. !N"o doubt it is to up a most
grotesque notion that the postarior end of the body ^'hould
be colored for the sake of ornament even more brilliantly
than the face; but this is not more strange than that the
tails of many birds sliould be especially decorated.

AVibh mammals we do not at present possess any evidence
that the males take pains to display their charms before
tne female; and the elaborate manner in which this is per-
formed by male birds and other animals is the strongest
argiimeiit in favor of the belief that the females admire,
or are excited by, the ornaments and colors displayed
before them. There is, however, a striking parallelism
between mammals and birds in all their secondary sexual
characters, namely, in their weapons for fighting with rival
males, in their ornamental appendages and in their colors.
In both classes, when the male differs from the female, the
young of both sexes almost always resemble each other, and
in a large majority of cases resemble the adult female. In
both classes the male assumes the characters proper to his
sex shortly before the age of reproduction; and if emas-
culated at an early period loses them. In both classes the
change of color is sometimes seasonal, and the tints of the
naked parts sometimes become more vivid during the act of
courtship. In both classes the male is almost always more
vividly or strongly colored than the female, and is orna-
mented with larger crests of hair or feathers, or other
such appendages. In a few exceptional cases the female in
both classes is more highly ornamented than the male.
AVith many mammals, and at least in the case of one bird,
the male is more odoriferous than the female. In both
classes the voice of the male is more powerful than that of
the female. Considering this parallelism, there can be
little doubt that the same cause, whatever it may be, has
acted on mammals and birds; and the result, as far as
ornamental characters are concerned, may be attributed,
as it appears to me, to the long-continued preference of the
individuals of one sex for certain individuals of the opposite
sex, combined with their success in leaving a larger
number of offspring to inherit their superior attractions.

Equal Transmission of Ornawcutal Characters to Both
Sexes. — With many birds, ornaments, which analogy leads
US to believe were primarily acquired by the males, have

MAMJTALS. 019

been transmitted equally, or almost equally, to both sexes;
and we may now inquire how far this view applies to mam-
mals. With a considerable number of species, especially
of the smaller kinds, both sexes have been colored, inde-
pendently of sexual selection, for the sake of protection;
but not, as far as I can judge, in so many cases, nor in so
striking a manner, a3 in most of the lower classes. Audu-
bon remarks that he often mistook the muskrat,* while
sitting on the banks of a muady ctream, for a clod of earth,
so complete was the resemblr.nce. The hair on her form is
a familiar instance of concealment through color; yet this
principle partly fails in a closely allied species, the rabbit,
for when running to its burrow, it is made conspicuous to
the sportsman, and. no doubt, to all beasts of prey, by its
upturned white tail. No one doubts that the quadrupeds
inhabiting snow-clad regions have been rendered white to
protect them from their enemies, or to favor their stealing
on their prey. In regions where snow never lies for long,
a white coat would be injurious; con£equen!:ly, species of
this color are extremely rare in the hotter parts of the
world. It deserves notice that many quadrupeds inhabit-
ing moderately cold regions, although i-ey do not assume
a white winter dress, become paler during this season; and
this apparently is the direct result of the conditions to
which th<-y have long been exposed. Pallas f states that in
Siberia a change of this nature occurs with the wolf, two
species of Mustela, the domestic horse, the Eqiius hojiiouiis,
the domestic cow, two species of antelopes, the musk-deer,
the roe, elk and reindeer. The roe, for instance, has a red
summer and a grayish- white winter coat; and the latter
may, perhaps, serve as a protection to the animal while
wandering through the leafless thickets, sprinkled with
snow and hoar-frost. If the above-named animals wore
gradually to extend their range into regions perpetually
covered with snow their pale winter coats would probably
be rendered, through natural selection, whiter and whiter^
until they became as white as snow.

Mr. Reeks has given me a curious instance of an animal

"Fiber zibHhicus. Aiululmn and Bacliman, "The Quadrupeds of
North America." 1846, p. 109.

f " Novae species Quadrupednin e Glirinm ordine," 1778, p. 7.
\\' liat 1 have called the roe is the Capreolus sibiricus siibecaitdatus of
Fallas.

620

THE DESCENT OF MAN.

profiting by being peculiarly colored. He raised from fifty
to sixty white and brown piebald rabbits in a large walled
orchard; and he had at the same time some similarly
colored cats in his house. Such cats, as I have often
noticed, are very conspicuous during the day; but, as they

Fig. TO. Tragelaphus scriptus, maie (from the Knowsley Menagerie).

used to lie in watcli during the dusk at the mouths of the
burrows, the rabbits apparently did not distinguish them
from their party-colored brethren. The result was tliat,
within eighteen months, every one of these party-colored
rabbits was destroyed; and there was evidence that this
was effected by the cats. Color seems to be advantageous
to another animal, the skunk, in a maimer of which we
have had many instances in other classes. No animal will
voluntarily attack one of these creatures on account of the
dreadful odor which it emits when irritated; but during the

I

MAMMALS, 621

dusK It would not easily "be recognized and might be attacked
by a beast of prey. Hence it is, as Mr. Belt believes, * that the
skunk is provided with a great white bushy tail, which
serves as a conspicuous warning.

Although we must admit that many quadrupeds have
received their present tints either as a protection, or as an
aid in procuring prey, yet with a host of species, the colors
are far too couspicuous and too singularly arranged to
allow us to suppose that they serve for these purposes. We
may take as an illustration certain antelopes; when we see
the square Avhite patch on the throat, the white marks on
the fetlocks, and the round black spots on the ears, all more
distinct in the male of the Portax picta, than in the
female — when we see that the colors are more vivid, that
the narrow white lines on the flank and the broad white
bar on the shoulder are more distinct in the male Oreas
derhyaiius than in the female — when we see a similar
difl'erence between the sexes of the curiously ornamented
TrafjclapJiiis scriphts (fig. 70) — Ave cannot believe that
difl'ereiices of this kind are of any service to either sex in
their daily habits of life. It seems a much more probable
conclusion that the various marks were first acquired by
the males and their colors intensified through sexual selec-
tion, and then partially transferred to the females. If this
NiQw be admitted, tliere can be little doubt that the equally-
singular colors and marks of many other antelopes, though
common to both sexes, have been gained and transmitted
in a like manner. Both sexes, for instance, of the koodoo
{Strepsiceros kudu) (fig. G4) have narrow white vertical
lines on their hind flanks, and an elegant angular white
mark on their foreheads. Both sexes in the genus Dam-
alis are very oddly colored; in D. pygarga the back and
neck are purplish-red, shading on the flanks into black ;
and these colors are abruptly separated from the white
belly and from a large white S2)ace on the buttocks; the head
is still more oddly colored, a large oblong white mask, nar-
rowly edged with black, covers the face up to the eyes
(fig. 71); there are three white stripes on the forehead and
the ears are marked with white. The fawns of this species
are of a uniform pale yellowish brown. In Damcdis cdbi-
fruns the coloring of the head diflers from that in the last

* " The Naturalist in Nicaragua," p. 249.

G22

THE DESCENT OF MAN.

species in a single white stripe replacing the three stripes,
and ill the ears being almost wholly white.* After having
studied to the best of my ability the sexual differences of
juiimalsbelongmgtoall classes,! cannot avoid the conclusion
that the curiously arranged colors of many antelopes, though

Fig, 71. Damalis pygarga, male (from t'ne Entjwsley Kecagerie).

common to both sexes, are the result of sexual selection
primarily applied to the male.

The same conclusion may perhaps be extended to the
tiger, one of the most beautiful animals in the world, the
sexes of which cannot be distinguished by color, even by
the dealers in wild beasts. Mr. Wallace believesf that the
striped coat of the tiger *' so assimilates with the vertical

*See the fine, plates in A. Smith's "ZoGlogy of S. Africa," and Pr
Gray's " Gleanings from the Menagerie of Kiiowsley."
t "Westminster Review," July 1, 18C7, p. 5.

MAMMALS. 623

stems of the bamboo as to assist greatly in concealing liim
from his approaching prey.'* But this view does not
appear to me satisfactory. We have some slight evidence
that his beauty may be due to sexual selection, for in two
species of Felis the analagous marks and colors arc rather
brighter in the male tlian in the fenuile. The zebi'a is con-
spicuously striped, and stripes cannot atford any protection
on the open plains of S. Africa. Burchell* in describing
a herd says: '' Their sleek ribs glistened in the sun, and the
brightness and regularity of their striped coats presented a
picture of extraordinary beauty, in which probably they are
not surpassed ly any other quadruped." But as thiough-
ont the whole group of the Eqnida3 the sexes are identical
in color we have here no evidence of sexual selection.
Nevertheless he who attributes the white and dark vertical
stripes on the flanks of varions antelopes to this process,
will probably extend the same view to the royal tiger and
beautiful zebra.

AVe have seen in a former chapter that when young ani-
mals belonging to any class follow nearly the same habits
of life as their parents, and yet are colored in a different
manner, it may be inferred that they have retained the
coloring of some ancient and extinct progenitor. In the
family of pigs, and in the tapirs, the young are marked
with longitudinal stripes, and thus differ from all the exist-
ing adult species in these two groups. AVith many kinds of
deer the young are marked with elegant white spots,
of which their parents exhibit not a trace. A graduated
series can be followed from the axis deer, both sexes of
which at all ages and during all seasons are beautifully
spotted (the male being rather more strongly colored than
the f empale), to species in which neither the eld nor the
young are spotted. I will specify some of the steps in this
series. The Mantchurian deer (Cervus waniclturims) is
spotted during the whole year, but, as I have seen in the
Zoological Gardens, the spots are much plainer during the
summer, when the general "color of the coat is lighter than
during the winter, when the general color is darker and the
horns are fully developed. In the hog-deer {Hyelaphns
porcinns) the spots are extremely conspicuous during the
summer when the coat is reddish-brown, but quite disj;p-

* "Travels iu South Africa," 1824, vol. ii, p. 315.

624 THE DESCENT OF MAN,

pear during the winter when the coat is brown.* In both
these species the young are spotted. In the Virginian deer
xhe young are likewise spotted, and about five per cent of the
adult animals living in Judge Cat.on''s park, as I am
informed, by him, temporarily exhibit at the period when
the red summer coat is being replaced by the bluish winter
coat, a row of spots on each flank, which are always the
same in number, though very variable in distinctness.
From this condition there is but a very small step to the
complete absence of spots in the adults at all seasons; and,
lastly, to their absence at all ages and seasons, as occurs
with certain species. From the existence of this perfect
series, and more especially from the fawns of so many
species being spotted, we may conclude that the now living
members of the deer family are the descendants of some
ancient species which, like the axis deer, was spotted at all
ages and seasons. A still more ancient progenitor probably
somewhat resembled the HyomoscJiiis aqiiaficns — for this
animal is spotted, and the hornless males have large
exserted canine teeth, of which some few true deer still
retain rudiments. Hyomoschus, also, offers one of those
interesting cases of a form linking together two groups, for
it is intermediate in certain osteological characters between
the pachyderms and ruminants, which were formerly
thought to be quite distinct, f

A curious difficulty here arises. If we admit that
colored spots and stripes were first acquired as ornaments,
how comes it that so many existing deer, the descendants
of an aborigiually spotted animal, and all the species
of pigs and tapirs, the descendants of an aboriginally
striped animal, have lost in their adult state their former
ornaments ? I cannot satisfactorily answer this question.
We may feel almost sure that the spots and stripes disap-
peared at or near maturity in the progenitors of our exist-
ing species, so that they were still retained by the young;
and, owing to the law of inheritance at corresponding ages,
were transmitted to the young of all succeeding generations.

*Dr. Gray, "Gleanings from tlie Menagerie of Know.?ley," p. 64.
Mr. Blytb. in spealdng (" Land and Water," 1869, p. 42) of the Log-
deer of Ceylon, says it is more briglitly spotted with white than the
common hog-deer, at the season when it renews its horns.

\ Falconer and Cantley, " Proc. Geolog. Soc," 1843: and Falconer's
*Pal. Memoirs," vol. i,'p. 196.

i

MAMMALS.

625

It may have been a great advantage to the lion and puma,
from the open nature of their usual haunts, to have lost
their stripes, and to have been thus rendered less con-
spicuous to their prey; and if the successive variations, by
which this end was gained, occurred rather late in life the
young would have retained their stripes, as is now the case

Fig. 72. Head of Semnopithecus rubicundus. This and the following fiprnres
(from Prof. Gervais) are ffiven to show the odd arrangement and develop
ment of the hair on the head.

As to deer, pigs and tapirs, Fritz Mliller has suggested to
me that these animals, by the removal of tlieir spots or
stripes through natural selection, would have been less
easily seen by their enemies; and that they would have
especially required this protection as soon as the carnivora
increased in size and number during the tertiary periods.
This may be the true explanation, but it is rather strange
that the young should not have been thus protected, and
still more so that the adults of some species should have

626 TEE DESCENT OF MAK

retained their spots, cither partially or completely, during
part of the year. We know that when the domestic ass
varies and becomes reddish-brown, gray or black the stripes
on the shoulders and even on the spine frequently disap-
pear, though we cannot explain the cause. Very few
horses, except dun-colored kinds, have stripes on any part
of their bodies, yet we have good reason to believe that the
aboriginal horse was striped on the legs and spine, and
probably on the shoulders.* Hence the disappearance of
tlie spots and stripes in our adult existing deer, pigs and
tapirs may be due to a change in the general color of their
coats; but whether this change was elfected through sexual
or natural selection, or was due to the direct action of the
conditions of life, or to some other unknown cause, it is
impossible to decide. An observation made by Mr. Sclater
well illustrates our ignorance of the laws which regulate
the appearance and disappearance of stripes; the species of
Asinus which inhabit the Asiatic continent are destitute of
stripes, not having even the cross shoulder-stripe, while
those which inhabit Africa are conspicuously striped, with
the partial exception of J. tceniopiis, which has only the
cross shoulder-stripe and generally some faint bars on the
legs; and this species inhabits the almost intermediate
region of Upper Egypt and Abyssinia. f

Qit'adrumaua. — Before we conclude, it will be well to
add a few remarks on the ornaments of monkeys. In most
of the species the sexes resemble each other in color, but in
some, as we have seen, the males differ from the females,
especially in the color of the naked parts of the skin, in
the development of the beard, whiskers and mane. Many
species are colored either in so extraordinary or so beautiful
a manner, and are turnished with such curious and elegant
crests of hair, that we can hardly avoid looking at these
characters as having been gained for th.e sake of ornament.
The accompanying figures (72 to 7G) serve to show
the arrangement of the hair on the face and head in sev-
eral species. It is scarcely concei^'able that these crests of

*"Tbo Variation of Animal.i and Plants under Domestication,"
1868, vol i, pp. Cl-64.

f "Proc. Zool. Soc.,' 1S62. p. Ifi4. See also, Dr. llanman, "Ann,
d. Landw.," 13d, xiiii, s, ^-22.

MAMMALS.

627

hair and the strongly contrasted colors of tlie fur and skin,
can be the result of mere variability without the aid of se-
lection; and it is inconceivable that they can be of use iu
any ordinary way to these animals. If so, they have
probably been gained through sexual selection,, though
transmitted equally, or almost equally, to both sexes.

Fig. 4 3. Uead of Semnopithecus comatus. Fig. 74. Uead of Cebus capucinua

Fig. 75. Head of Ateles marginatus.

Fig. TG. Head of Cebus vellercsus.

With many of the Qnndrumana, we have additional evi-
dence of the action of sexual selection in the greater size
and strength of the males, and in the greater development
of their canine teeth, in comparison with the females.

A few instances will suffice of the strange manner in
which both sexes of some species are colored and of the
beauty of others. The face of the Cerco^iihecus petaurisia

628 TBB DESCENT OF MAN.

(fig. 77) is black, the whiskers and beard being white, with

Fig. 77. Cercopithecus petaurista (from Brehm).

a defined, round, white spot on the nose, covered with
short white hair, which gives to the animal an almost

MAMMALS. 629

ludicrous aspect. The Semnopitheciis frontafus likewise
has a blackish face with a long black beard, and a large
naked spot on the forehead of a bluish-white color. The
face of Macacus lasiotus is dirty flesh-colored, with a
defined red spot on each cheek. The appearance of
Cercocehiis cethiops is grotesque, with its black face, white
whiskers and collar, chestnut head, and a large naked
white spot over each eyelid. In very many species the
beard, whiskers and crests of hair round the face are of a
different color from the rest of the head, and, when diifer-
ent, are always of a lighter tint,* being often pure white,
sometimes bright yellow or reddish. The whole face of the
South American Brachyuriis calvus is of a ** glowing
scarlet hue;*'' but this color does not appear until the ani-
mal is nearly mature. f The naked skin of the face differs
wonderfully in color in the various species. It is often
brown or flesh-color, with parts perfectly white, and often
as black as that of the most sooty negro. In the Brachyu-
rus the scarlet tint is brighter than that of the most blush-
ing Caucasian damsel. It is sometimes more distinctly
orange than in any Mongolian, and in several species it is
blue, passing into violet or gray. In all the species kno\vn
to Mr. Bartlett, in which the adults of both sexes have
strongly colored faces, the colors are dull or absent during
early youth. This likewise holds good with the mandril
and rhesus, in which the face and the posterior parts of the
body are brilliantly colored in one sex alone. In these
latter cases we have reason to believe that the colors were
acquired through sexual selection; and we are naturally led
to extend the same view to the foregoing species, though
both sexes when adult have* their faces colored in the same
manner.

Although many kinds of monkeys are far from beautiful
according to our taste, other species are universally ad-
mired for their elegant appearance and bright colors. The
Seinnopitlieciis nemcBus, though peculiarly colored, is de-
scribed as extremely pretty; the orange-tinted face is sur-
rounded by long whiskers of glossy whiteness, with a line of

*I observed this fact in tlie Zoological Gardens; and many cases
may be seen in the colored plates in Geoffroy St.-Hilaire and F,
Cuvier, " Hist. Nat. des Mammiferes," tom. i, 1824.

f Bates, " The Naturalist on tlie Amazons," 1863, vol. U, p, 310.

630 THE DESCENT OF MAN.

chestnut-red over the eyebrows; the fur on the back is of a
delicate gray, Avith a square patch on the loins, the tail
and the fore arms being of a pure white; a gorget of chest-
nut surmounts the chest; the thighs are black, with the
legs chestnut-red. I will mention only two other monkeys
for their beauty; and I have selected these as presenting
slight sexual differences in color, which renders it m some
degree probable that both sexes owe their elegant appear-
ance to sexual selection. In the mustache-monkey
(Oercopithecus cephus) the general color of the fur is mot-
tled-greenish with the throat white; in the male the end of
the tail is chestnut, but the face is the most ornamented
part, the skin being chiefly bluish-gray, shading into a
blackish tint beneath the eyes, with the upper lip of a deli-
cate blue, clothed on the lower edge with a thin black
mustache ; the whiskers are orange-colored, with the
upper part black, forming a band which extends back-
ward to the ears, the latter being clothed with whitish
hairs. In the Zoological Society^s Gardens I have often
overheard visitors admiring the beauty of anothor monkey,
deservedly called Oercopithecus diana (fig. 78); the general
color of the fur is gray; the chest and inner surface of the
fore legs are white; a large triangular defined space on the
hinder part of the back is rich chestnut; in the male the
inner sides of the thighs and the abdomen are delicate
fawn-colored, and the top of the head is black; the face
and ears are intensely black, contrasting finely with a white
transverse crest over the eyebrows and a long white peaked
beard, of which the basal portion is black.*

In these and many other monkeys the beauty and sin-
gular arrangement of their cofors, and still more the diver-
sified and elegant arrangement of the crests and tufts of
hair on their heads, force the conviction on my mind
that these characters have been acquired through sexual
selection exclusively as ornaments.

Summary. — The law of battle for the possession of the
female appears to prevail throughout the whole great class
of mammals. Most naturalists will admit that the greater

* I have seen most of the above monkeys in the Zoological
Society's (Javdens The description of the Semnopithecus nemwus is
taken'froin Mr. W. C. xMartin's "Nat. Hist, oi Mammalia," 1841, p,
460; &ee also pp. 475, 533.

MAMMALS,

631

she, strength, courage and png:3acity of the male, his
special weapons of ottense, as well as his special means of
defense, have been acquired or modified through that form
of selection which I have called sexual. This does not
depend on any superiority in the general struggle for life.

Fig. 78. Cercopithecus diana (from Erehm).

bnt on certain individuals of one sex, generally the male,
being successful in conquering other males, and leaving a
larger number of offspring to inherit their superiority than
do the less successful males.
There is another and more peaceful kind of contesfcj in

(^^4 THE DESCENT OF MAN.

which the males endeavor to excite or allure the females by
various charms. This is probably carried on in some cases
by the powerful odors emitted by the males during the
breeding-season; the odoriferous glands having been acquired
through sexual selection. Whether the same view can be
extended to the voice is doubtful, for the vocal organs of
the males must have been strengthened by use during
maturity, under the powerful excitements of love, jealousy
or rage, and will consequently have been transmitted to the
same sex. Various crests, tufts and mantles of hair, which
are either confined to the male, or are more developed in
this sex than in the female, seem in most cases to be merely
ornamental, though they sometimes serve as a defense
against rival males. There is even reason to suspect that
the branching horns of stags and the elegant horns of cer-
tain antelopes, though properly serving as weapons of
offense or defense, have been partly modified for ornament.
When the male differs in color from the female, he gen-
erally exhibits darker and more strongly contrasted tints.
We do not in this class meet with the splendid red, blue,
yellow and green tints so common with male birds and
many other animals. The naked parts, however, of cer-
tain Quadrumana must be excepted; for such parts, often
oddly situated, are brilliantly colored in some species. The
colors of the male in other cases may be due to simple
variation without the aid of selection. But when the colors
are diversified and strongly pronounced, when they are not
developed until near maturity, and when they are lost after
emasculation, we can hardly avoid the conclusion that they
have been acquired through sexual selection for the sake of
ornament and have been transmitted exclusively, or almost
exclusively, to the same sex. When both sexes are colored in
the same manner, and the colors are conspicuous or
curiously arranged, without being of the least apparent use
as a protection, and especially when they are associated
witli various other ornamental appendages, we are led by
analogy to the same conclusion, namely, that they have
been acquired through sexual selection, although trans-
mitted to both sexes. That conspicuous and diversified
colors, whether confined to the males or common to both
sexes, are as a general rule associated in the same groups
and sub-groups with other secondary sexual characters serv-
ing for war or for ornament will be found to hold good, if

f

MAMMALS. 633

we look back to the various cases given in tWs and the
last chapter.

The law of the equal transmission of characters to both
sexes, as far as color and other ornaments are concerned,
has prevailed far more extensively with mammals than with
birds; but weapons, such as horns and tusks, have often
been transmitted either exclusively or much more perfectly
to the males than to the females. This is surprising, for,
as the males generally use their weapons for defense against
enemies of all kinds, their weapons would have been of
service to the females. As far as we can see their absence
in this sex can be accounted for only by the form of inher-
itance which has prevailed. Finally, with quadrupeds the
contest between the individuals of the same sex, whether
peaceful or bloody, has, with the rarest exceptions, been
confined to the males; so that the latter have been modified
through sexual selection, far more r^,ommonly than the
females, either for fighting with each other or for alluring
the opposite sex.

PART III.
SEXUAL SELECTION IN RELATION TO MAN.

CHAPTER XIX.

SECOl^DARY SEXUAL CHARACTERS OF MAN.

Differences between man and woman — Causes of such differences
and of certain characters common to both sexes — Law of battle —
Differences in mental powers and voice — On the influence of
beauty in determinging the marriages of mankind — Attention
paid by savages to ornaments — Their ideas of beauty in woman —
The tendency to exaggerate each natural peculiarity.

With mankind the differences between the sexes are
greater than in most of the Quadrumana, but not so great
as in some, for instance, the mandrill. Man on an average
is considerably taller, heavier and stronger than woman,
with squarer shoulders and more plainly pronounced mus-
cles. Owing to the relation which exists between muscular
development and the projection of the brows,* the super-
ciliary ridge is generally more marked in man than in
woman. His body, and especially his face, is more hairy,
and his voice has a different and more powerful tone.
In certain races the women are said to differ slightly in tint
from the men. For instance, Schweinfurth, in speaking
of a negress belonging to the Monbuttoos, v/ho inhabit the
interior of Africa a few degrees north of the equator,
says: ^*Like all her race, she had a skin several shades
lighter than her husband^s, being something of the color of
half -roasted coffee, "f As the women labor in the fields
and are quite unclothed, it is not likely that they differ in
color from the men owing to less exposure to the weather.

*Schaaffhausen, translation in "Anthropological Review," Oct.,
1868, pp. 419, 420, 427.
t'«The Heart of Africa," English trausl., 1873, voL i„ p. 544

SECONDARY SEXUAL CHARACTERS. 635

European women are perhaps the brighter colored of the
two sexes, as may be seen when both have been equally
exposed.

Man is more courageous, pugnacious and energetic than
woman, and has a more inventive genius. His brain is
absolutely larger, but whether or not proportionately to his
larger body, has not, I believe, been fully ascertained. In
woman the face is rounder; the jaws and the base of the
skull smaller; the outlines of the body rounder, in parts
more prominent; and her pelvis is broader than in min;*
but this latter character may perhaps be considered rather
as a primary than a secondary sexual character. She comes
to maturity at an earlier age than man.

As with animals of all classes, so with man, the dis-
tinctive characters of the male sex are not fully developed
until he is nearly mature; and, if emasculated, they never
appear. The beard, for instance, is a secondary sexual
character, and male children are beardless, though at an
early age they have abundant hair on the head. It is
probably due to the rather late appearance in life of the
successive variations whereby man has acquired his mascu-
line characters that they are transmitted to the male sex
alone. Male and female children resemble each other
closely, like the young of so many other animals in which
the adult sexes differ widely; they likewise resemble the
mature female much more closely than the mature male.
The female, however, ultimately assumes certain distinctive
characters, and, in the formation of her skull, is said to be
intermediate between the child and the man. \ Again, as
the young of closely allied though distinct species do not
diifer nearly so much from each other as do the adults, so
it is with the children of the different races of man. Some
have even maintained that race - differences cannot be
detected i-n the infantile skull. J In regard to color, the
new-born negro child is reddish nut-brown, which soon
becomes slaty -gray; the black color being fully developed

*Ecker, translation in "Anthropological Review," Oct., 1868, pp.
351-356. The comparison of the 'form of the skull in men and
women has been followed out with much care by Welcker.

f Ecker and Welcker, ibid, pp, 353, 355; Vogt, "Lectures on
Man," Eng. translat., p. 81.

i Schaaffhausen, " Anthropolog. Review," ibid, p. 439,

636 THE DESCENT OF MAN,

within a year in the Soudan, but not until three years in
Egypt. The eyes of the negro are at first bhie, and the
hair chestnut-brown rather than black, being curled only
at the ends. The children of the Australians immediately
after birth are yellowish-brown, and become dark at a later
age. Those of the Gunaranys of Paraguay are whitish-
yellow, but they acquire, in the course of a few weeks, the
yellowish-brown tint of their parents. Similar observations
have been made in other parts of America.*

I have specified the foregoing differences between the
male and female sex in mankind, because they are curiously
like those of the Quadrumana. With these animals
the female is mature at an earlier age than the male; at
least this is certainly the case in Cehiis azarce. \ The males
of most species are larger and stronger than the females,
of which fact the gorilla affords a well-known instance.
Even in so trifling a character as the greater prominence
of the superciliary ridge, the males of certain monkeys
differ from the females, J and agree in this respect with
mankind. In the gorilla and certain other monkeys the
cranium of the adult male presents a strongly marked
sagittal crest, which is absent in the female; and Ecker
found a trace of a similar difference between the two sexes
in the Australians. § With monkeys, when there is any
difference in the voice, that of the male is the more pow-
erful. We have seen that certain male monkeys have a
well-developed beard, which is quite deficient,' or much less
developed, in the female. No instance is known of the
beard, whiskers or mustache being larger in the female than
in the male monkey. Even in the color of the beard there
is a curious parallelism between man and the Quadrumana,

*Pruner-Bey, on negro infants, as quoted by Vogt, " Lectures on
Man," Eng. translat,, 1864, p. 189; for further facts on negro infants,
as quoted from Winterbottom and Camper, see Lawrence, " Lectures
on riiys.ology," etc., 1822, p. 451. For tiieinfantsof the Gunaranvs
see Rengger, " Saugetbiere," etc., s. 3. See also Godron, " 6e
I'Espece," torn, ii, 1859, p. 253. For the Australians, Waitz, " Intro-
duct, to Anthropology," Eng. translat., 1863, p. 99.

f Rengger, " Saugethiere," etc,-, 1830, s. 19.

^As in Macaeus cynomolgus (Desmarest, " Mammal ogie," p. 65),
SLad in Ilylobates agilis (Geoffroy St.-Hilaire and F. Cuvier, "Hist.
Nat. des Mamm.," 1824, torn, i, p. 2).

§ " Anthropological Review," Oct., 1868, p. 353.

SECONDARY SEXUAL GHAliACTERS. 637

for with man when the beard differs in color from the hair
of the head, as is commonly the case, it is, I believe, almost
always of a lighter tint, being often reddish. I have
repeatedly observed this fact in England; but two gentle-
men have lately written to me, saying that they form an
exception to the rule. One of these gentlemen accounts
for the fact by the wide difference in color of the hair on the
paternal and maternal sides of his family. Both had long
been aware of this peculiarity (one of them having often been
accused of dyeing his beard), and had been thus led to observe
other men, and were convinced that the exceptions were
very rare. Dr. Hooker attended to this little point for me
in Russia, and found no exception to the rule. In Calcutta
Mr. J. Scott, of the Botanic Gardens, was so kind as to
observe the many races of men to be seen there, as well
as in some other parts of India, namely, two races of
Sikhim, the Bhoteas, Hindoos, Burmese and Chinese, most
of which races have very little hair on the face; and he
always found that when there was any difference in color
between the hair of the head and the beard, the latter was
invariably lighter. Now with monkeys, as has already
been stated, the beard frequently differs strikingly in color
from the hair of the head, and in such cases it is always of
a lighter hue, being often pure white, sometimes yellow or
reddish.*

In regard to the general hairiness of the body, the
women in all races are less hairy than the men ; and in
some few Quadrumana the under side of the body
of the female is less hairy than that of the male.f
Lastly, male monkeys, like men, are bolder and fiercer

* Mr. Bly til informs me that he has only seen one instance of the
beard, whiskers, etc., in a monkey becoming white with old age, as
is so commonly the case with us. This, however, occurred in an
aged Macacus cynomolgus, kept in confinement, whose mustaches
were "remarkably long and human-like." Altogether this old
monkey presented a ludicrous resemblance to one of the reigning
monarchs of Europe, after whom he was universally nick-named.
In certain races of man the hair on the head hardly ever becomes
gray; thus Mr. D. Forbes has never, as he informs me, seen an
instance with the Aymaras and Quchuas of South America.

f This is the case with the females of several species of Hylobates.
See QeofEroy St.-Hilaire and F. Cuvier, "Hist. Nat. des Mamm.,"
torn. i. See, also, on H, lar, "Penny Cyclopedia," vol. ii, pp. 149,
150.

638 THE DESCENT OF MAN.

tlian the females. They lead the troop, and, when there is
danger, come to the front. We thus see how close is the
parallelism between the sexual differences of man and the
Quadrumana. With some few species, however, as with
certain baboons, the orang and the gorilla, there is a con-
siderably greater difference between the sexes, as in the
size of the canine teeth, in the development and color of
the hair, and especially in the color of the naked parts of
the skin, than in mankind.

All the secondary sexual characters of man are highly
variable, even within the limits of the same race; and they
differ much in the several races. These two rules hold
good generally throughout the animal kingdom. In the
excellent observations made on board the ^^Novara,"* the
male Australians were found to exceed the females by only
sixty-five millimeters in height, while with the Javans the
average excess was two hundred and eighteen millimeters;
so that in this latter race the difference in height between the
sexes is more than thrice as great as with the Australians.
Numerous measurements were carefully made of the stat-
ure, the circumference of the neck and chest, the length of
the back-bone and of the arms, in various races; and
nearly all these measurements show that the males differ
much more from one another than do the females. This
fact indicates that, as far as these characters are con-
cerned, it is the male which has been chiefly modified,
since the several races diverged from their common stock.

The development of the beard and the hairiness of the
body differ remarkably in the men of distinct races, and
even in different tribes or families of the same race. We
Europeans see this among ourselves. In the Island of St.
Kilda, according to Martin,! the men do not acquire
beards until the age of thirty or upward, and even
then the beards are very thin. On the Europaeo- Asiatic
continent, beards prevail until we pass beyond India ;
though with the natives of Ceylon they are often absent,
as was noticed in ancient times by Diodorus. X Eastward

* The results were deduced by Dr. Weisbacli from tlie measure-
ments made by Drs. K. Scherzer and Scliwarz. See " Reise der
• Novara :' Antbropolog. Tbeil," 1867, ss. 216, 231, 234, 236. 239. 269.

\ "Voyage to St. Kilda " (3d edit., 1753), p. 37.

% Sir J. E. Tennent, "Ceylon," vol. ii, 1859, p. 107.

SECONDARY SEXUAL GHARACTERS. 639

of India beards disappear, as with the Siamese, Malays,
Kalmucks, Chinese, andJapanese; nevertheless the Ainos,*
who inhabit the northernmost islands of the Japan Archi-
pelago, are the hairiest men in the world. With negroes
the beard is scanty or wanting, and they rarely have
whiskers; in both sexes the body is frequently almost des-
titute of fine down.f On the other hand, the Papauns of
the Malay Archipelago, who are nearly as black as negroes,
possess well-developed beards. I In the Pacific Ocean the
inhabitants of the Fiji Archipelago have large bushy
beards, while those of the not distant archipelagoes of
Tonga and Samoa are beardless; but these men belong to
distinct races. In the Ellice group all the inhabitants
belong to the same race; yet on one island alone, namely
Nunemaya, *'the men have" splendid beards;' while on
the other islands '^ they have, as a rule, a dozen straggling
hairs for a beard. "§

Throughout the great American continent the men may
be said to be beardless; but in almost all the tribes a few
short hairs are apt to appear on the face, especially in old
age. With the tribes of North America, Catlin estimates
that eighteen out of twenty men are- completely destitute
by nature of a beard; but occasionally there may be seen a
a man who has neglected to pluck out the hairs at puberty,
with a soft beard an inch or two in length. The Guaranys
of Paraguay dilfer from all the surrounding tribes in hav-
ing a small beard, and even some hair on the body, but no
whiskers. || I am informed by Mr. D. Forbes, who par-
ticularly attended to this point, that the Aymaras and

* Quatrefages, "Revue des Cours Scientifiques," Aug. 29, 1868, p.
630; Vogt, " Lectures on Man," Eng. translat., p. 127.

f On the beards of negroes, Vogt, " Lectures," etc., p. 127; Waitz,
" Introduct. to Anthronology," Eng. translat., 1863, voL i, p. 96. It
is remarkable that in the United States (" Investigations in Military
and Anthropological Statistics of American Soldiers," 1869, p. 569),
the pure negroes and their crossed offspring seem to have bodies
almost as hairy as Europeans.

t Wallace. " The Malay Arch.," vol. ii, 1869, p. 178.

§ Dr. J. Barnard Davis on *' Oceanic Races," in ** Anthropolog.
Review," April, 1870, pp. 185, 191.

I Catlin, " North American Indians," 3d edit., 1842, vol. ii, p. 227.
On the Guaranys, see Azara, " Voyages dans I'Amerique Merid.,"
torn, ii., 1809, p. 68; also Rengger, "Saugethiere von Para^uav/
6. 8.

640 THE DESCENT OF MAN,

Qiiicliuas of the Cordillera are remarkably hairless, yet in
old age a few straggling hairs occasionally appear on the
chin. The men of these two tribes have very little hair on
the various parts of the body where hair grows abundantly
in Europeans, and the women have none on the corre-
sponding parts. The hair on the head, however, attains
an extraordinary length in both sexes, often reaching
almost to the ground; and this is likewise the case with
8ome of the North American tribes. In the amount of hair
and in the general shape of the body the sexes of the
American aborigines do not differ so much from each other
as in most other races. * This fact is analogous with what
occurs with some closely allied monkeys; thus the sexes of
the chimpanzee are not as different as those of the orang
or gorilla, f

In the previous chapters we have seen that with mam-
mals, birds, fishes, insects, etc., many characters, which
there is every reason to believe were primarily gained
through sexual selection by one sex, have been transferred
to the other. As this same form of transmission has ap-
parently prevailed much with mankind, it will save useless
repetition if we discuss the origin of characters peculiar to
the male sex together with certain other characters com-
mon to both sexes.

Law of Battle. — With savages, for instance, the Aus-
tralians, the women are the constant cause of war both
between members of the same tribe and between distinct
tribes. So no doubt it was in ancient Hmes; ^' nam fuit ante
Helenam mulier teterrima belli causa." "With some of the
North American Indians the contest is reduced to a system.
That excellent observer, Hearne,;|; says: *^It has ever
been the custom among these people for the men to wrestle

*Prof. and Mrs. Agassiz ("Journey in Brazil," p. 530), remark
tliat the sexes of the American Indians differ less than those of the
negroes and of the higher races. See also Rengger, ibid., p. 3, on
the Guaranys.

f Riitimeyer, "Die Grenzen der Thierwelt; eine Betrachtung zu
Darwin's Lehre," 1868, s. 54.

if" A Journey from Prince of Wales Fort,," 8vo. edit., Dublin,
1796, p. 104. Sir J. Lubbock (" Origin of Civilization," 1870, p. 69),
gives other and similar cases in North America. For the Guanas of
South America see Azara, " Voyages," etc., torn, ii, p. 94.

' SECONDARY SEXUAL CHARACTERS. 641

for any woman to whom they are attached; and, of course,
the btrongest party always carries off the prize. A weak man,
unless he be a good hunter and well beloved, is seldom per-
mitted to keep a wife that a stronger man thinks worth his
notice. This custom prevails throughout all the tribes,
and causes a great spirit of emulation among their youth,
who are upon all occasions, from their childhood, trying
their strength and skill in wrestling.'^ With the Guanas
of South America, Azara states that the men rarely marry
till twenty years old or more, as before that age they cannot
conquer their rivals.

Other similar facts could be given; but even if we had
no evidence on this head we might feel almost sure, from
the analogy of the higher Quadrumana,* that the law of
battle had prevailed with man during the early stages of
his development. The occasional appearance at the pres-
ent day of canine teeth which project above the others,
with traces of a diastema or open space for the reception of
the opposite canines, is in all probability a case of reversion to
a former state, when the progenitors of man were provided
with these weapons, like so many existing male Quadrumana.
It was remarked in a former chapter that as man gradually
became erect, and continually used his hands and arms
for fighting with sticks and stones, as well as for the other
purposes of life, he would have used his jaws and teeth
.less and less. The jaws, together with their muscles, would
then have been reduced through disuse, as would the teeth
through the not well understood principles of correlation
and economy of growth; for we everywhere see that parts,
which are no longer of service, are reduced in size. By such
steps the original inequality between the jaws and teeth
in the two sexes of mankind would ultimately have been
obliterated. The case is almost parallel with that of many
male ruminants, in which the canine teeth have been
reduced to mere rudiments, or have disappeared, apparently,
in consequence of the development of horns. As the prodig-
ious difference between the skulls of the two sexes in the
orang and gorilla stands in close relation with the develop-
ment of the immense canine teeth in the males, we may
infer that the reduction of the jaws and teeth in the early

* On tlie figliting of the male gorillas, see Dr. Savage, in ** Boston
Journal of Nat. Hist.," vol v., 1847, p. 433. On Presbytia enteUua,
see the " Indian Field," 1859, p. 146.

642 THE DESCENT OF MAN.

male progenitors of man must have led to a most striking
and favorable change in his appearance.

There can be little doubt that the greater size and
strength of man, in comparison with woman, together with
his broader shoulders, more developed muscles, rugged out-
line of body, his greater courage and pugnacity are all due
in chief part to inheritance from liisha^i- human male ances-
tors. These character^ would, however, have been preserved
or even augmented during the long ages of man^s savagery,
by the success of the strongest and boldest men, both in the
general struggle for life and in their contests for wives; a suc-
cess which would have insured their leaving a ^more numer-
ous progeny than their less favored brethren. It is not proba-
ble that the greater strength of man was primarily acquired
through the inherited effects of his having worked harder
than woman for his own subsistence and that of his family;
for the women in all barbarous nations are compelled
to work at least as hard as the men. With civilized
people the arbitrament of battle for the possession of the
women has long ceased; on the other hand, the men, as a
general rule, have to work harder than the women for their
joint subsistence, and thus their greater strength will have
been kept up.

Difference in the Mental Poiuers of the Two Sexes. — With
respect to differences of this nature between man and
woman it is probable that sexual selection has played a
highly important part. I am aware that some writers
doubt whether there is any such inherent difference ; biit
this is at least probable from the analogy of the lower ani-
mals which present other secondary sexual characters. No
one disputes that the bull differs in disposition from the
cow, the wild-boar from the sow, the stallion from the
mare, and, as is well known to the keepers of menageries,
the males of the larger apes from the females. Woman
seems to differ from man in mental disposition, chiefly in
her greater tenderness and less selfishness; and this holds
good even with savages, as shown by a well-known passage
in '* Mungo Parkas Travels,^" and by statements made by
many other travelers. Woman, owing to her maternal
instincts, displays these qualities toward her infant in an
eminent degree; therefore it is likely that she would often
extend them toward her fellow-creatures. Man is the rival

SECONDARY SEXUAL CHARACTERS. 643

of other men; he delights in competition, and this leads to
ambition which passes too easily into selfishness. These
latter qualities seem to be his natural and unfortunate
birthright. It is generally admitted that with woman the
powers of intuition, of rapid perception, and perhaps of
imitation, are more strongly marked than in man; but
some, at least, of these faculties are characteristic of the
lower races, and, therefore, of a past and lower state of
civilization.

The chief distinction in the intellectual powers of the
two sexes is shown by man^s attaining to a higher eminence,
in whatever he takes up, than can woman — whether requir-
ing deep thought, reason, or imagination, or merely the
use of the senses and hands. If two lists were made of the
most eminent men and women in poetry, painting, sculpt-
ure, music (inclusive both of composition and perform-
ance), history, science and philosophy, with half a dozen
names under each subject, the two lists would not bear
comparison. We may also infer, from the law of the devia-
tion from averages, so well illustrated by Mr. Galton, in
his work on '' Hereditary Genius,^' that if men are capable
of a decided pre-eminence over women in many subjects,
the average of mental power in man must be above that of
woman.

Among the half -human progenitors of man, and among
savages, there have been struggles between the males during
many generations for the possession of the females. But
mere bodily strength and size would do little for victory,
unless associated with courage, perseverence and deter-
mined energy. With social animals the young males have
to pass through many a contest before they win a female,
and the older males have to retain their females by renewed
battles. They have, also, in the case of mankind, to
defend their females, as well as their young, from enemies
of all kinds, and to hunt for their joint subsistence. But
to avoid enemies or to attack them with success, to capture
wild animals, and to fashion weapons, requires the aid of
the higher mental faculties, namely, observation, reason,
invention, or imagination. These various faculties will
thus have been continually put to the test and selected
during manhood; they will, moreover, have been strength-
ened by use during this same period of life. Consequently,
in accordance witlx the larincii^ often alluded to, we

644: TEE DESCENT OF MAN.

might expect that they would at least tend to be trans-
mitted chiefly to the male offspring at the corresponding
period of manhood.

Now, when two men are put into competition, or a man
with a woman, both possessed of every mental quality in
equal perfection, save that one has higher energy, perse-
verance and courage, the latter will generally become more
eminent in every pursuit and will gain the ascendency.*
He may be said to possess genius — for genius has been de-
clared by a great authority to be patience; and patience, in
this sense, means unflinching, undaunted perseverance.
But this view of genius is perhaps deficient; for without
the iiigher powers of the imagination and reason, no
eminent success can be gained in many subjects. These
latter faculties, as well as the former, will have been de-
veloped in man, partly through sexual selection — that is,
through the contest of rival males, and partly through
natural selection — that is, from success in the general
struggle for life; and as in both cases the struggle will have
been during maturity, the characters gained will have been
transmitted more fully to the male than to the female off-
spring. It accords in a striking manner with this view of
the modification and re-enforcement of many of our
mental faculties by sexual selection, that, firstly, they
notoriously undergo a considerable change at puberty, f
and, secondly, that eunuchs remain throughout life inferior
in these same qualities. Thus man has ultimately become
superior to woman. It is, indeed, fortunate that the law
of the equal transmission of characters to both sexes pre-
vails with mammals ; otherwise it is probable that man
would have become as superior in mental endowment to
woman, as the peacock is in ornamental plumage to the
peahen.

It must be borne in mind that the tendency in char-
acters acquired by either sex late in life, to be transmitted
to the same sex at the same age, and of early acquired
characters to be transmitted to both sexes, are rules which,
though general, do not always hold. If they always held

*J. Stuart Mill remarks (" The Subjection of Women," 1869, p.
122); • The things in which man most excels woman are those which
require most plodding, and long hammering at single thoughts^"
What is this but energy and perseverance?

\ Maudsley, •' Mind and Bodyj

SECOND AMY SEXUAL CHARACTERS. 645

good, we might conclude (but I here exceed my proper
bounds) that the inherited effects of the early education of
boys and girls would be transmitted equally to both sexes;
so that the present inequality in mental power between the
sexes would not be effaced by a similar course of early
training; nor can it have been caused by their dissimilar
early training. In order that woman should reach the
same standard as man, she ought, when nearly adult, to be
trained to energy and perseverance and to have her reason
and imagination exercised to the highest point; and then
she would probably transmit these qualities chiefly to her
adult daughters. All women, however, could not be thus
raised, unless during many generations those who excelled
in the above robust virtues were married and produced off-
spring in larger numbers than other women. As before
remarked of bodily strength, although men do not now
fight for their wives, and this form of selection has passed
away, yet during manhood they generally undergo a severe
struggle in order to maintain themselves and their families;
and this will tend to keep up or even increase their mental
powers, and, as a consequence, the present inequality be-
tween the sexes.*

Voice and Musical Poivers. — In some species of Quadru-
mana there is a great difference between the adult sexes,
in the power of their voices and in the development of
the vocal organs; and man appears to have inherited this
difference from his early progenitors. His vocal cords are
about one- third longer than in woman, or than in boys ;
and emasculation produces the same effect on him as on
the lower animals, for it ^* arrests that prominent growth of
the thyroid, etc., which accompanies the elongation of the
cords, ^^t With respect to the cause of this difference
between the sexes, I have nothing to add to the remarks in

* An observation by Vogt bears on this subject: be says, " It is a
remarkable circumstance, that the differences between the sexes, as
regards the cranial cavity, increases with the development of the
race, so that the male European excels much more the female, than
the negro the negress. Welcker confirms this statement of Huschke
from his measurements of negro and German skulls." But Vogt
admits ("Lectures on Man," Eng. translat., 1864, p. 81) that mor§
observations are requisite on this point.

fOwen, "Anatomy of Vertebrates," vol. iii, p. 603.

646 "f^^ DESCENT OF MAN,

the last chapter on the probable effects of the long-contin-
ued use of the vocal organs by the male under the excite-
ment of love, rage and jealousy. According to Sir Duncan
Gibb, * the voice and the form of the larynx differ in the
different races of mankind; but with the Tartars, Chinese,
etc., the voice of the male is said not to differ so much
from that of the female, as in most other races.

The capacity and love for singing or music, thougli not
a sexual character in man, must not here be passsd over.
Although the sounds emitted by animals of all kinds
serve many purposes, a strong case can be made out, that
the vocal organs were primarily used and perfected in rela-
tion to the propagation of the species. Insects and some
few spiders are the lowest animals which voluntarily pro-
duce any sound; and this is generally effected by the aid of
beautifully constructed stridulating organs, which are often
confined to the males. The sounds thus produced consist,
I believe in all cases, of the same note, repeated rhythmi-
cally;! and this is sometimes pleasing even to the ears of
man. The chief and, in some cases, exclusive purpose
appears to be either to call or charm the opposite sex.

The sounds produced by fishes are said in some cases to
be made only by the males during the breeding-season. All
the air-breathing Vertebrata necessarily possess an appa-
ratus for inhaling and expelling air, with a pipe capable of
being closed at one end. Hence when the primeval mem-
bers of this class were strongly excited and their muscles
violently contracted, purposeless sounds would almost cer-
tainly have been produced; and these, if they proved in
any way serviceable, might readily have been modified or
intensified by the preservation of properly adapted vari-
ations. The lowest Vertebrates which breathe air are
Amphibians; and of these, frogs and toads possess vocal
organs, which are incessantly used during the breedings
season, and which are often more highly developed in the
male than in the female. The male alone of the tortoise
utters a noise, and this only during the season of love.
Male alligators roar or bellow during the same season.
Every one knows how much birds use their vocal organs as

♦"Journal of the Anthropolog. Soc," April, 1869, pp. 57, 66.
f Dr. Scudder, "Notes on Stridulation," in " Proc. Boston Soc. of
Nat. Hist.," vol. xi, April, 1868.

r

SECOND AR T SEXUA L GHARACTEnS, 647

a means of courtship; and some species likewise perform
what may be called instrumental music.

In the class of mammals, with which we are here more
particularly concerned, the males of almost all the species
use their voices during the breeding-season much more
than at any other time ; and some are absolutely mute
excepting at this season. With other species both sexes,
or only the females, use their voices as a love-call. Con-
sidering these facts, and that the vocal organs of some
quadrupeds are much more largely developed in the male
than in the female, either permanently or temporarily,
during the breeding-season; and considering that in most
of the lower classes the sounds produced by the males serve
not only to call but to excite or allure the female; it is a
surprising fact that we have not as yet any good evidence
that these organs are used by male mammals to charm the
females. The American Mycetes caraya perhaps forms an
exception, as does the Hylohates agilis, an ape allied to
man. This gibbon has an extremely loud but musical
voice. Mr. Waterhouse states,* " It appeared to me that
in ascending and descending the scale the intervals were
always exactly half-tones; and I am sure that the highest
note was the exact octave to the lowest. The quality of the
notes is very musical; and I do not doubt that a good
violinist would be able to give a correct idea of the gibbon's
composition, excepting as regards its loudness." Mr.
Waterhouse then gives the notes. Prof. Owen, who is a
musician, confirms the foregoing statement, and remarks,
though erroneously, that this gibbon, ^^ alone of brute
mammals, may be said to sing."' It appears to be much
excited after its performance. Unfortunately, its habits
have never been closely observed in a state of nature; but
from the analogy of other animals, it is probable that it
uses its musical powers more especially during the season
of courtship.

This gibbon is not the only species in the genus which
sings, for my son, Francis Darwin, attentively listened in
the Zoological Gardens to H. leuciscus while singing, a
cadence of three notes, in true musical intervals and with
a clear musical tone. It is a more surprising fact that

* Given in W. C. L. Martin's " General Introduction to Nat. Hist,
of Mamm. Animals," 1841, p. 432: Owen "Anatomy of Vertebrates,"
vol. ill, p. 600.

<;4^

THE DESCENT OF MAN,

certain rodents utter musical sounds. Singing mice have
often been mentioned and exhibited, but imposture has
commonly been suspected. We have, however, at last a
clear account by a well-known observer, the Rev. S. Lock-
wood,* of the musical powers of an American species, the
Hesperomys cognahis, belonging to a genus distinct from
that of the English mouse. This little animal was kept in
-confinement, and the performance was repeatedly heard.
In one of the two chief songs, '' the last bar would fre-
quently be prolonged to two or three; and she would some-
times change from C sharp and D to C natural and D, then
warble on these two notes awhile, and wind up with a quick
chirp on C sharp and D. The distinctness between the
semitones was very marked and easily appreciable to a
good ear." Mr. Lockwood gives both songs in musical
notation; and adds that though this little mouse *'Miad no
ear for time, yet she would keep to the key of B (two flats)
and strictly in a major key. . . . Her soft clear
voice falls an octave with all the precision possible; then at
the wind-up it rises again into a quick trill on C sharp
and D."

A critic has asked how the ears of man, and he ought to
have added of other animals, could have been adapted by
selection so as to distinguish musical notes. But this
question shows some confusion on the subject; a noise is the
sensation resulting from the co-existence of several aerial
"simple vibrations" of various periods, each of which
intermits so frequently that its separate existence cannot be
perceived. It is only in the want of continuity of such
vibrations, and in their want of harmony inter se, that a noise
differs from a musical note. Thus an ear to be capable of
discriminating noises — and the high importance of this
power to all animals is admitted by every one — must be
sensitive to musical notes. We have evidence of this
capacity even low down in the animal scale; thus Crusta-
ceans are provided with auditory hairs of different lengths,
which have been seen to vibrate when the proper musical
notes are struck, f As stated in a previous chapter, similar
observations have been made on the hairs of the antennae
of gnats. It has been positively asserted by good observers

*The "American Naturalist," 1871. p. 761.
jHelmboltz, *• Tkeorie Phys. d© ^ ^Usique," 1868, p.

187.

SEGONbAUY SEXUAL GHAItACTBRS. 649

that spiders are attracted by music. It is also well known
that some dogs howl when hearing particular tones.* Seals
apparently appreciate music, and their fondness for it
" was well known to the ancients, and is often taken
advantage of by the hunters at the present day."f

Therefore, as far as the mere perception of musical
notes is concerned, there seems no special difficulty in the
case of man or of any other animal. Helmholtz has explained
on physiological principles why concords are agreeable and
discords disagreeable to the human ear; but we are little
concerned with these, as music in harmony is a late inven-
tion. We are more concerned with melody, and here
again, according to Helmholtz, it is intelligible why the
notes of our musical scale are used. The ear analyzes all
sounds into their component ^' simple vibrations," although
we are not conscious of this analysis. In a musical note
the lowest in pitch of these is generally predominant, and
the others which are less marked are the octave, the
twelfth, the second octave, etc., all harmonies of the
fundamental predominant note; any two notes of our scale
have many of these harmonic over-tones in common. It
seems pretty clear, then, that if an animal always wished
to sing precisely the same song, he would guide himself by
sounding those notes in succession which possess many
over-tones in common — that is, he would choose for his
song notes which belong to our musical scale.

But if it be further asked why musical tones in a certain
order and rhythm give man and other animals pleasure, we
can no more give the reason than for the pleasantness of
certain tastes and smells. That they do give pleasure of
some kind to animals we may infer from their being pro-
duced during the season of courtship by many insects,
spiders, fishes, amphibians and birds ; for unless the
females were able to appreciate such sounds and were
excited or charmed by them, the persevering eiforts of the
males, and the complex structures often possessed by them
alone, would be useless ; and this it is impossible to
believe.

* Several accounts bave been published to this effect. Mr. Peacb
writes to me tbat be bas repeatedly found that an old dog of bis
bowls wben B flat is sounded on tbe flute, and to no other note. I
may add another instance of a dog always wbining, wben one note
on a concertina, which was out of tune, was played.

fMr, R. Brown, m «*Proc. Zool. Soc," 1868, p, 410.

650

THE DBSGENT OF MAN.

Human song is generally admitted to be the basis or
origin of instrumental music. As neither the enjoyment
nor the capacity of producing musical notes are faculties
of the least use to man in reference to his daily habits of
life, they must be ranked among the most mysterious with
which he is endowed. They are present, though in a very
rude condition, in men of all races, even the most savage;
but so different is the taste of the several races that our
music gives no pleasure to savages, and their music is to us
in most cases hideous and unmeaning. Dr. Seemann, in
some interesting remarks on this subject,* " doubts
whether even among the nations of Western Europe,
intimately connected as they are by close and frequent
intercourse, the music of the one is interpreted in the same
sense by the others. By traveling eastward we find that
there is certainly a different language of music. Songs of
joy and dance accompaniments are no longer, as with us,
in the major keys, but always in the minor." Whether or
not the half-human progenitors of man possessed, like the
singing gibbons, the capacity of producing, and, therefore,
no doubt of appreciating, musical notes, we know that
man possessed these faculties at a very remote period. M.
Lartet has described two flutes made out of the bones and
horns of the reindeer, found in caves together with flint
tools and the remains of extinct animals. The arts of
singing and of daT?cing are also very ancient, and are now
practiced by all or nearly all the lowest races of man.
Poetry, which may be considered as the offspring of song,
is likewise so ancient that many persons have felt astonished
that it should have arisen during the earliest ages of which
we have any record.

We see that the musical faculties, which are not wholly
deficient in any race, are capable of prompt and high
development, for Hottentots and negroes have become
excellent musicians, although in their native countries
they rarely practice anything that we should consider
music. Schweinfurth, however, was pleased with some of
the simple melodies which he heard in the interior of
Africa. But there is nothing anomalous in the musical

* "Journal of Antliropolog, Soc," Oct., 1870, p. 155. See also the
several later chapters in Sir John Lubbock's "Prehistoric Times,"
second edition, 1869, which contain an admirable account of the
Juabits of savages.

SECONDART SEXUAL GBARACTERS. 651

faculties lying dormant in man; some species of birds
which never naturally sing, can without much difficulty be
taught to do so; thus a house-sparrow has learned the song
of a linnet. As these two species are closely allied and
belong to the order of Insessores, which includes nearly all
the singing-birds in the world, it is possible that a pro-
genitor of the sparrow may have been a songster. It is
more remarkable that parrots, belonging to a group distinct
from the Insessores, and having differently constructed
vocal organs, can be taught not only to speak, but to pipe
or whistle tunes invented by man, so that they must have
some musical capacity. Nevertheless, it would be very rash
to assume that parrots are descended from some ancient
form which was a songster. Many cases could be advanced
of organs and instincts originally adapted for one purpose,
having been utilized for some distinct purpose. * Hence
the capacity for high musical development which the
savage races of man possess, may be due either to the prac-
tice by our semi-human progenitors of some rude form of
music, or simply to their having acquired the proper vocal
organs for a different purpose. But in this latter case we
must assume, as in the above instance of parrots, and as
seems to occur with many animals, that they already pos-
sessed some sense of melody.

Music arouses in us various emotions, but not the more
terrible ones of horror, fear, rage, etc. It awakens the
gentler feelings of tenderness and love, which readily pass
into devotion. In the Chinese annals it is said: " Music
liath the power of making heaven descend upon earth.'*
It likewise stirs up in us the sense of triumph and the
glorious ardor for war. These powerful and mingled feel-
Higs may well give rise to the sense of sublimity. We can
concentrate, as Dr. Seamann observes, greater intensity of
feeling in a single musical note than in pages of writing.

* Since this chapter was printed, I have seen a valuable article by
Mr. Chauncy Wright (" North American Review," Oct., 1870, p.
293), who, in discussing the above subject, remarks: " There are
many consequences of the ultimate laws or uniformities of nature,
through which the acquisition of one useful power will bring with it
many resulting advantages as well as limiting disadvantages, actual
or possible, which the principle of utility may not have comprehended
in its actions." As I have attempted to show in an early chapter of
this work, this principle has an important bearing on the acquisitioa
by man of some of his mental characteristics.

65^

TBE DESCENT OF MAK.

It is probable that nearly the same emotions, but much
weaker and far less complex, are felt by birds when the
male pours forth his full volume of song, in rivalry with
other males, to captivate the female. Love is still the
commonest theme of our songs. As Herbert Spencer re-
marks, '^ music arouses dormant sentiments of which we
had not conceived the possibility, and do not know the
meaning; or, as Richter says, tells us of things we have not
seen and shall not see." Conversely, when vivid emotions
are felt and expressed by the orator, or even in common
.speech, musical cadences and rhythm are instinctively used,
J The negro in Africa when excited often bursts forth in
song; ^' another will reply in song, while the company, as
if touched by a musical wave, murmur a chorus in perfect
unison."* Even monkeys express strong feelings in dif-
ferent tones — anger and impatience by low, fear and pain
by high notes. \ The sensations and ideas thus excited in
us by music, or expressed by the cadences of oratory, appear
from their vagueness, yet depth, like mental reversions to
the emotions and thoughts of a long past age.

All these facts with respect to music and impassioned
speech become intelligible to a certain extent, if we may
assume that musical tones and rhythm were used by our
half-human ancestors, during the season of courtship,
when animals of all kinds are excited not only by love, but
by the strong passions of jealousy, rivalry, and triumph.
From the deeply laid principle of inherited associations,
musical tones in this case would be likely to call up
vaguely and indefinitely the strong emotions of a long-past
age. As we have every reason to suppose that articulate
speech is one of the latest, as it certainly is the highest, of
the arts acquired by man, and as the instinctive power of
producing musical notes and rhythms is developed low
down in the animal series, it would be altogether opposed
to the principle of evolution, if we were to admit that
man's musical capacity has been developed from the tones
used in impassioned speech. We must suppose that the
rhythms and cadences of oratory are derived from previously

*Winwood Reade, "The Martyrdom of Man," 1872, p. 441, and
"African Sketch-book," 1873, vol. ii, p. 313.
f Rengger, " Saugethiere von Paraguay," s. 49.

SECONDABT 8EXUAL CHARACTERS. 653

developed musical powers.* We can thus understand how
it is that music, dancing, song, and poetry are such very
ancient arts. We may go even further than this, and, as
remarked in a former chapter, believe that musical sounds
afforded one of the bases for the development of language. \
As the males of several quadrumanous animals have their
vocal organs much more developed than in the females, and
as a gibbon, one of the anthropomorphous apes, pours
forth a whole octave of musical notes and may be said to
sing^ it appears probable that the progenitors of man,
either the males or females or both sexes, before acquiring
the power of expressing their mutual love in articulate
language, endeavored to charm each other with musical
notes and rhythm. So little is known about the use of the
voice by the Quadrumana during the season of love, that
we have no means of Judging whether the habit of singing
was first acquired by our male or female ancestors. Women
are generally thought to possess sweeter voices than men,
and as far as this serves as any guide, we may infer that
they first acquired musical powers in order to attract the
other sex. X But, if so, this must have occured long ago,
before our ancestors had become sufficiently human to treat
and value their women merely as useful slaves. Tiie impas-

*See the very interesting discussion on the " Origin and Function
of Music," by Mr. Herbert Spencer, in his collected "Essays," 1858,
p. 359. Mr. Spencer comes to an exactly opposite conclusion to that
at which I have arrived. He concludes, as did Diderot formerly,
that the cadences used in emotional speech afford the foundation
from which music has been developed; while I conclude that musical
notes and rhythms were first acquired by the male or female progen-
itors of mankind for the sake of charming the opposite sex. Thus
musical tones became firmly associated with some of the strongest
passions an animal is capable of feeling, and are consequently used
instinctively, or through association when strong emotions are
expressed in speech. Mr. Spencer does not offer any satisfactory
explanation, nor can I, why high or deep notes should be expressive,
both with man and the lower animals, of certain emotions. Mr.
Spencer gives also an interesting discussion on the relations between
poetry, recitative and song.

f I find in Lord Monboddo's "Origin of Language," vol. i, (1774),
p. 469, that Dr. Blacklock likewise thought " tJhat the first language
among men was music, and that before our ideas were expressed by
articulate sounds they were communicated by tones varied according
to different degrees of gravity and acuteness."

:j:See an interesting discussion on this subject, by Hack el, "Gener-
die Morph," B. ii, 1866, s. 246.

654 THE DESCENT OF MAN.

sioned orator, bard, or musician, when with his varied
tones and cadences he excites the strongest emotions in his
hearers, little suspects that he uses the same means by
which his half -human ancestors long ago aroused each
other's ardent passions, during their courtship and rivalry.

The Influence of Beauty in Determining the Marriages
of Mafibmd. — In civilized life man is largely, but by no
means exclusively, influenced in the choice of his wife by
external appearance; but we are chiefly concerned with
primeval times, and our only means of forming a judgment
on this subject is to study the habits of existing semi-
civilized and savage nations. If it can be shown that the
men of diif erent races prefer women having various char-
acteristics, or conversely with the women, we have then to
inquire whether such choice, continued during many gene-
rations, would produce any sensible efl'ect on the race,
either on one sex or both, according to the form of inherit-
ance which has prevailed.

It will be well first to show in some detail that savages
ay the greatest attention to their personal appearance.*
"hat they have a passion for ornament is notorious; and an
English philosopher goes so far as to maintain that clothes
were first made for ornament and not for warmth. As
Prof. Waitz remarks: '^however poor and miserable man
is he finds a pleasure in adorning himself.'' The extrava-
gance of the naked Indians of South America in decorat-
ing themselves is shown *^ by a man of large stature gain-
ing with difficulty enough by the labor of a fortnight to
procure in exchange the chica necessary to paint himself
red." f The ancient barbarians of Europe, during the

* A full and excellent account of tlie manner in wliicli savages in
all parts of the world ornament themselves, is given by the Italian
traveler, Prof. Mantegazza, "Rio de la Plata, Viaggi e Studi,"
1867, pp. 525-545 ; all the following statements, when other refer-
ences are not given, are taken from this work. See, also, Waitz,
"Introduction to Anthropolog.," Eng. translat., vol. 1, 1863, p. 275,
et passim. Lawrence also gives very full details in his "Lectures
on Physiology," 1822. Since this chapter was written Sir J. Lub-
bock has published his "Origin of Civilization," 1870, in which
there is an interesting chapter on the present subject, and from'
which (pp. 42, 48) I have taken some facts about savages dyeing
their teeth and hair and piercing their teeth.

f Humboldt, "Personal Narrative," Eng. translat., vol. iv, p. 515;
on the imagination shown in painting- the body, p. 522; on modifying
the form of the calf of the leg' p. 466.

^

SECOND AR Y SEX UAL CHAR A GTERS, 655

Reindeer period, brought to their caves any brilliant or
singular objects which they happened to find. Savages at
the present day everywhere deck themselves with plumes,
necklaces, armlets, ear-rings, etc. They paint themselves
in the most diversified manner. ^* If painted nations," as
Humboldt observes, "had been examined with the same
attention as clothed nations, it would have been perceived
that the most fertile imagination and the most mutable
caprice have created the fashions of painting, as well as
those of garments."

In one part of Africa the eyelids are colored black; in
another the nails are colored yellow or purple. In many
places the hair is dyed of various tints. In different coun-
tries the teeth are stained black, red, blue, etc., and in
the Malay Archipelago it is thought shameful to have white
teeth, "like those of a dog." Sot one great country can
be named, from the Polar regions in the north to New
Zealand in the south, in which the aborigines do not tattoo
themselves. This practice was followed by the Jews of old,
and by the ancient Britons. In Africa some of the natives
tattoo themselves, but it is a much more common practice
to raise protuberances by rubbing salt into incisions made
in various parts of the body; and these are considered by
the inhabitants of Kordofan and Darfur "to be great per-
sonal attractions." In the Arab countries no beauty can
be perfect until the cheeks " or temples have been gashed."*
In South America, as Humboldt remarks, "a mother would
be accused of culpable indifference toward her children if
she did not employ artificial means to shape the calf of the
leg after the fashion of the country." In the Old and New
Worlds the shape of the skull was formerly modified during
infancy in the most extraordinary manner, as is still the
case in many places, and such deformities are considered
ornamental. For instance, the savages of Colombiaf
deem a much flattened head " an essential point of beauty."

The hair is treated with especial care in various countries;
it is allowed to grow to full length, so as to reach to the
ground, or is combed into ' ' a compact frizzled mop, which

* " The Nile Tributaries," 1867; " The Albert N'yanza," 1866, voL
i, p. 218.

f Quoted by Prichard. " Pliys. Hist, of Mankind," 4th edit., vol. i,
1851, p. 321.

656 THE DESCENT OF MAN.

is the Papuan's pride and glory."* In Northern Africa " a
man requires a period of from eight to ten years to perfect
his coilfure." With other nations the head is shaved, and in
parts of South America and Africa even the eyebrows and
eyelashes are eradicated. The natives of the Upper Nile
knock out the four front teeth, saying that tliey do not
wish to resemble brutes. Farther south the Batokas knock
out only the two upper incisors, which, as Livingstonef
remarks, gives the face a hideous appearance, owing to the
prominence of the lower jaw; but these people think the
presence of the incisors most unsightly, and on beholding
some Europeans, cried out: ^'^Look at the great teeth \"
The chief Sebituani tried in vain to alter this fashion. In
various parts of Africa and in the Malay Arcliipelago the
natives file the incisors into points like those of a saw, or
pierce them with holes, into which they insert studs.

As the face with us is chiefly admired for its beauty, so
with savages it is the chief seat of mutilation. In all
quarters of the world the septum, and more rarely the
wings of the nose are pierced; rings, sticks, feathers and
other ornaments being inserted into the holes. The ears are
everywhere pierced and similarly ornamented, and with the
Botocudos and Lenguas of South America the hole is
gradually so much enlarged that the lower edge touches
the shoulder. In North and South America and in Africa
either the upper or lower lip is pierced; and with the Boto-
cudos the hole in the lower lip is so large that a disk of wood,
four inches in diameter, is placed in it. Mantegazza gives
a curious account of the shame felt by a South American
native, and of the ridicule which he excited, when he sold his
tembeta — the large colored piece of wood which is passed
through the hole. In Central Africa the women perforate
the lower lip and wear a crystal, which, from the movement
of the tongue, has ^' a wriggling motion, indescribably ludi-
crous during conversation. " T he wife of the chief of Latooka
told Sir S. Baker, J; that Lady Baker ^' would be much im-
proved if she would extract her four front teeth from the
lower jaw and wear the long-pointed polished crystal in her

*0n the Papuans, Wallace, "The Malay Archipelago," vol. ii, p.
445. On the coiffure of the Africans, Sir S. Baker, "The Albert
N'yanza," vol. i, p. 210.

t "Travels," p. 533.

% " The Albert N'yanza," 1866, vol. i, p. 217.

SECOND ART SEXUAL CHARACTERS, 657

under lip." Farther south with the Makalolo, the upper
lip is perforated, and a large metal and bamboo ring, called
apelele, is worn in the hole. ^' This caused the lip in one case
to project two inches beyond the tip of the nose; and when
the lady smiled the contraction of the muscles elevated
it over the eyes. ' Why do the women wear these tilings?'
the venerable cliief, Chinsurdi, was asked. Evidently sur-
prised at such a stupid question, he replied: ^ For beauty .
They are the only beautiful things women have; men have
beards, women have none. What kind of a person would
she be without the pelele? She would not be a woman at
all with a mouth like a man, but no beard.' "*

Hardly any part of the body, which can be unnaturally
modified, has escaped. The amount of suffering thus
caused must have been extreme, for many of the operations
require several years for their completion, so that the idea
of their necessity must be imperative. The motives are
various; the men paint their bodies to make themselves
appear terrible in battle; certain mutilations are connected
with religious rites, or they mark the age of puberty, or the
rank of • the man, or they serve to distinguish the tribes.
Among savages the same fashions prevail for long periods, f
and thus mutilations, from whatever cause first made, soon
come to be valued as distinctive marks. But self -adorn-
ment, vanity and the admiration of others seem to be the
commonest motives. In regard to tattooing, I was told by
the missionaries in New Zealand that when they tried to
persuade some girls to give up the practice they answered:
*' We must just have a few lines on our lips; else when we
grow old we shall be so very ugly." With the men of New
Zealand, a most capable judge J says: "To have fine
tattoed faces was the great ambition of the young, both to
render themselves attractive to the ladies and conspicuous
in war." A star tattooed on the forehead and a spot on

* Livingstone, " British Association," 1860; report given in the
" Athenseum," July 7, 1860, p. 29.

fSir S. Baker (ibid., vol. i, p. 210) speaking of the natives of
Central Africa, says: " Every tribe has a distinct and unchanging
fashion for dressing the hair." See Agassiz ("Journey in Brazil,"
1868, p. 818) on the invariability of the tattooing of the Amazonian
Indians.

t Rev. R. Taylor, " New Zealand and Its Inhabitants," 1855, p,
152.

658 THE DESCENT OF MAN,

the chin are thought by the women in one part of Africa
to be irresistible attractions.* In most, but not all parts of
the world, the men are more ornamented than the women,
and often in a different manner; sometimes, though rarely,
the women are hardly at all ornamented. As the women
are made by savages to perform the greatest share of the
work, and as they are not allowed to eat the best kinds of
food, so it accords with the characteristic selfishness of man
that they should not be allowed to obtain or use the finest
ornaments. Lastly, it is a remarkable fact, as proved by
the foregoing quotations, that the same fashions in modi-
fying the shape of the head, in ornamenting the hair, in
painting, tattooing, in perforating the nose, lips or ears, in
removing or filing the teeth, etc., now prevail, and have
long prevailed, in the most distant quarters of the world.
It is extremely improbable that these practices, followed by
BO many distinct nations, should be due to tradition from
any common source. They indicate the close similarity of
the mind of man, to whatever race he may belong, just as
do the almost universal habits of dancing, masquerading
and making rude pictures.

Having made these preliminary remarks on the admira-
tion felt by savages for various ornaments and for de-
formities most unsightly in our eyes, let us see how far the
men are attracted by the appearance of their women and
what are their ideas of beauty. I have heard it maintained
that savages are quite indifferent about the beauty of their
women, valuing them solely as slaves; it may, therefore, be
well to observe that this conclusion does not at all agree
with the care which the women take in ornamenting them-
selves, or with their vanity. Burchell f gives an amusing
account of a Bush-woman who used as much grease, red
ocher and shining powder ^' as would have ruined any but
a very rich husband." She displayed also " much vanity
and too evident a consciousness of her superiority." Mr.
Winwood Reade informs me that the negroes of the West
Coast often discuss the beauty of their women. Some
cornpetent observers have attributed the fearfully common
practice of infanticide partly to the desire felt by the

*Mantegazza, "Viaggi e Studi," p. 542.
f " Travels in S. Africa," 1834, vol. i, p. 414.

SECONDARY SEXUAL GBARACTEnS. 659

women to retain their good looks.* In several regions the
women wear charms and use love-philters to gain the affec-
tions of the men; and Mr. Brown enumerates four plants
used for this purpose by the women of Northwestern
America, f

Hearne, X an excellent observer, who lived many years
with the American Indians, says, in speaking of the wom^en:
" Ask a Northern Indian what is beauty, and he will
answer, a broad fiat face, small eyes, high cheek-bones,
three or four broad black lines across each cheek, a low
forehead, a large broad chin, a clumsy hook nose, a tawny
hide and breasts hanging down to the belt.'' Pallas, who
visited the northern parts of the Chinese empire, says:
" Those women are preferred who have the Mandschu
form; that is to say, a broad face, high cheek-bones, very
broad noses, and enormous ears;"§ and Vogt remarks that
the obliquity of the eye, which is proper to the Chinese
and Japanese, is exaggerated in their pictures for the pur-
pose, as it " seems, of exhibiting its beauty, as contrasted
with the eye of the red-haired barbarians." It is well
known, as Hue repeatedly remarks, that the Chinese of the
interior think Europeans hideous, with their white
skins and prominent noses. The nose is far from being
too prominent, according to our ideas, in the natives of
Ceylon; yet "the Chinese in the seventh century, accus-
tomed to the flat features of the Mongol races, were sur-
prised at the prominent noses of the Cingalese; and Thsang
described them as having ' the beak of a bird, with the
body of a man.'"

Finlayson, after minutely describing the people of
Cochin China, says that their rounded heads and faces are
their chief characteristics; and, he adds, "the roundness
of the whole countenance is more striking in the women,

* See for references, Gerland ' * Ueber das Aussterben der Natur-
vdlker," 1868, ss. 51, 53, 55; also Azara, "Voyages," etc., torn, ii, p.
116.

f On the vegetable productions used by the Northwestern Ameri-
can Indians, "Pharmaceutical Journal," vol. x.

:{: " A Journey from Prince of Wales Fort," 8vo. edit., 1796, p. 89.

§ Quoted by Prichard, " Phys. Hist, of Mankind," 3d edit., vol. iv,
1844, p. 519; Vogt, " Lectures on Man," Eng. translat. p. 129. On
the opinion of the Chinese on the Cingalese, E. Tennent, "Ceylon,"
1859, vol. ii, p. 107.

660

THE DESCENT OF MAN.

who are reckoned beautiful in proportion as they display
this form of face." The Siamese have small noses with
divergent nostrils, a wide mouth, rather thick lips, a
remarkably large face, with very high and broad cheek-
bones. It is, therefore, not wonderful that *^ beauty,
according to our notion, is a stranger to them. Yet tliey
consider their own females to be much more beautiful than
those of Europe. '''*

It is well known that with many Hottentot women the
posterior part of the body projects in a wonderful manner;
they are steatopygous; and Sir Andrew Smith is certain
that this peculiarity is greatly admired by the men. f He
once saw a woman who was considered a beauty, and she
was so immensely developed behind that when seated on
level ground she could not rise, and had to push herself
along until she came to a slope. Some of the women in
various negro tribes have the same peculiarity; and, accord-
ing to Burton, the Somal men ^'are said to choose their
wives by ranging them in a line and by picking her out
who projects farthest a tergo. Nothing can be more hate-
ful to a negro than the opposite form. "J;

With respect to color, tlie negroes railed Mungo Park
on the whiteness of his skin and the prominence of his
nose, both of which they considered as *^ unsightly and
unnatural conformations." He in return praised the glossy
jet of their skins and the lovely depression of their noses;
this they said was ''^ honey mouth," nevertheless they gave
him food. The African Moors, also, ^^ knitted their brows
and seemed to shudder" at the whiteness of his skin. On
the eastern coast the negro boys when they saw Burton,
cried out: ^' Look at the white man; does he not look like
a white ape?" On the western coast, as Mr. Winwood
Reade informs me, the negroes admire a very black skin
more than one of a lighter tint. But their horror of

*Pricliard, as taken from Crawfurd and Finlayson, "Phys. Hist,
of Mankind," vol. iv, pp. 534, 535.

f Idem illustrissimus viator dixit mihi praecinctorium vel tabulam
foeminae, quod nobis teterrimum est, quondam permagno aestimari ab
liominibus in hac gente. Nunc res mutata est, et censent talem con-
formationem minime optandam esse.

^:"The Anthropological Review," Nov., 1864, p. 237. For addi-
tional reference, see Waitz, " Introduct. to Anthropology," Eng.
translat., 1863, vol. i, p. 105.

SECONDARY SEXUAL CHARACTERS. 661

whiteness may be attributed, according to this same
traveler, partly to the belief held by most negroes that
demons and spirits are white, and partly to their thinking
it a sign of ill-health.

The Banyai of the more southern part of the continent
are negroes, but *^a great many of them are of a light
colfee-and-milk color, and, indeed, this color is considered
handsome throughout the whole country;" so that here we
have a different standard of taste, ''^ith the Kafirs, who
differ much from negroes, '' the skin, except among the
tribes near Delagoa Bay, is not usually black, the prevail-
ing color being a mixture of black and red, the most
common shade being chocolate. Dark complexions as
being most common are naturally held in the highest
esteem. To be told that he is light colored or like a white
man would be deemed a very poor compliment by a Kafir.
I have heard of one unfortunate man who was so very fair
that no girl would marry him."" One of the titles of the
Zulu king is: " You who are black."* Mr. Galton, in
speaking to me about the natives of S. Africa, remarked
that their ideas of beauty seem very different from ours;
for in one tribe two slim, slight and pvetty girls were not
admired by tlie natives.

Turning to other quarters of the world: in Java a yellow,
not a white girl, is considered, according to Madame
Pfeift'er, a beauty. A man of Cochin China " spoke with
contempt of the wife of the English ambassador, that she
had white teeth like a dog and a rosy color like that of
potato flowers." We have seen that the Chinese dislike
our white skin and that the North Americans admire "a,
tawny hide." In South America the Yuracaras, who
inhabit the wooded, damp slopes of the eastern Cordillera,
are remarkably pale colored, as their name in their own
language expresses; nevertheless, they consider European
women as very inferior to their own.f

^Miingo Park's " Travels in Africa," 4to., 1816, pp. 53, 131. Bur-
ton's statement is quoted by Schaaffhausen, " Archiv. fiir Anthro-
polog.," 1866, s. 163. On the Banyai, Livingstone, "Travels," p.
64. On the Kafirs, the Rev. J. Schooter, " The Kafirs of Natal and
the Zulu Country," 1857, p. 1.

f For the Javans and Cocliin-Chinese, see Waitz, "Introduct. to
Anthropology," Eng. translat., vol. i, p. 305. On the Yuracaras, A.
d'Orbigny, as quoted in Prichard, "Phys. Hist, of Mankind," vol. v,
3d edit., p. 476.

662 THE DESCENT OF MAN.

In several of the tribes of North America the hair on the
head gi*ows to a wonderful length; and Catlin gives a
curious proof how much this is esteemed, for the chief of
the Crows was elected to this office from having the longest
hair of any man in the tribe; namely, ten feet and seven
inches. The Aymaras and Quichuas of South America
likewise have very long hair; and this, as Mr. D. Forbes
informs me, is so much valued as a beauty, that cutting it
off was the severest punishment which he could inflict on
them. In both the northern and southern halves of the
continent the natives sometimes increase the apparent
length of their hair by weaving into it fibrous substances.
Although the hair on the head is thus cherished, that on
the face is considered by the North American Indians '' as
very vulgar," and every hair is carefully eradicated. This
practice prevails throughout the American continent from
Vancouver's Island in the north to Terra del Fuego in the
south. When York Minster, a Fuegian on board the
** Beagle," was taken back to his country, the natives told
him he ought to pull out the few short hairs on his face.
They also threatened a young missionary, who was left for
a time with them, to strip him naked and pluck the hairs,
from liis face and body, yet he was far from being a hairy
man. This fashion is carried so far that the Indians of
Paraguay eradicate their eyebrows and eyelashes, saying
that they do not wish to be like horses.*

It is remarkable that throughout the world the races
which are almost completely destitute of a beard dislike
hairs on the face and body, and take pains to eradicate
them. The Kalmucks are beardless and they are well
known, like the Americans, to pluck out all straggling
hairs ; and so it is with the Polynesians, some of the
Malays and the Siamese. Mr. Veitch states that the
Japanese ladies " all objected to our whiskers, considering
them very ugly, and told us to cut them off and be like
Japanese men." The ISTew Zealanders have short, curled
beards; yet they formerly plucked out the hairs on the
face. They had a saying that " there is no woman for a
hairy man;'' but it would appear that the fashion has

*" North American Indians," by G. Catlin, 3d edit. 1842, vol. i, p.
49; vol. ii. p. 227. On the natives of Vancouver's Island, see Sproat,
" Scenes and Studies of Savage Life," 1868, p. 25. On the Indiana
of Paraguay, Azara, "Voyages," torn, li, p, 105.

SECONDARY SEXUAL CHARACTERS, 6G3

changed in New Zealand, perhaps owing to the presence of
Europeans, and I am assured that beards are now admired
by the Maories."*

On the other hand, bearded races admire and greatly
value their beards; among the Anglo-Saxons every part of
the body had a recognized value; ^'the loss of the beard
being estimated at twenty shillings, while the breaking of
a thigh was fixed at only twelve/'f ^^ the east men swear
solemnly by their beards. We have seen that Chinsurdi,
the chief of the Makalolo in Africa, thought that beards
were a great ornament. In the Pacific the Fijian's beard
is '^ profuse and bushy, and is his greatest pride;" while
the inhabitants of the adjacent archipelagoes of Tonga and
Samoa are beardless and abhor a rough chin." In one
island alone of the Ellice group *'the men are heavily
bearded, and not a little proud thereof." X

We thus see how widely the diiferent races of man differ
in their taste for the beautiful. In every nation sufficiently
advanced to have made effigies of their gods or of their
deified rulers, the sculptors no doubt have endeavored to ex-
press their highest ideal of beauty and grandeur. § Under
this point of view it is well to compare in our mind the
Jupiter or Apollo of the Greeks with the Egyptian or
Assyrian statues; and these with the hideous bas-reliefs
on the ruined buildings of Central America.

I have met with very few statements opposed to this
conclusion. Mr. AYinwood Reade, however, who has had
ample opportunities for observation, not only with the
negroes of the west coast of Africa, but with those of the
interior who have never associated with Europeans, is con-
vinced that their ideas of beauty are, on the tvhole, the same
as ours; and Dr. Rohlfs writes to me to the same effect

*Oii the Siamese, Pricliard, ibid, vol. iv, p. 533. On the Japanese,
Veitch in *' Gardeners' Chronicle," 1860, p. 1104. On the New Zeal-
anders, Mantegazza, " Viaggi e Studi," 1867, p. 526. For the other
nations mentioned, see references in Lawrence, "Lectures on Physi-
ology," etc., 1832, p. 272. •

f Lubbock, " Origin of Civilization," 1870, p. 321.

X Dr. Barnard Davis quotes Mr. Prichard and others for these facts
in regard to the Polynesians, in "Anthropological Review," April,
1870. pp. 185, 191.

§ Ch. Comte has remarks to this effect in his " Traite de Legisla-
tion," 8d edit, 1837, p. 136.

664 THE DESCENT OF MAN,

with respect to Borneo and the countries inhabited by the
Pullo tribeSc Mr. Reade found that he agreed with the
negroes in their estimation of the beauty of the native girls;
and that their appreciation of the beauty of European
women corresponded with ours. They admire long hair,
and use artificial means to make it appear abundant; they
admire also a beard, though tliemselves very scantily pro-
vided. Mrc Reade feels doubtful what kind of nose is most
appreciated; a girl has been heard to say: ^*^I do not want
to marry him, he has got no nose;" and this shows that a
very flat nose is not admired. We should, however, bear
in mind that the depressed, broad noses and projecting
jaws of the negroes of the west coast are exceptional types
with the inhabitants of Africa. Notwithstanding the fore-
going statements, Mr, Reade admits that negroes " do not
like the color of our skin; they look on blue eyes with aver-
sion, and they think our noses too long and our lips too
thin." He does not think it probable that negroes would
ever prefer the most beautiful European woman, on the
mere grounds of physical admiration, to a good-looking
negress. *

• The general truth of the principle, long ago insisted on
by Humboldt, t that man admires and often tries to exag-
gerate whatever characters nature may have given him, is
shown in many ways. The practice of beardless races
extirpating every trace of a beard, and often all the hairs
on the body, affords one illustration. The skull has been
greatly modified during ancient and modern times by many
nations; and there can be little doubt that this has been
practiced, especially in North and South America, in order

*Tlie "African Sketch-book," vol. ii, 1873, pp. 253, 394, 521.
The Fuegians, as I have been informed by a missionary wbo long
resided with tbem, consider European women as extremely beautiful;
but from wbat we have seen of the judgment of the other aborigines of
America, I cannot but think that this must be a mistake, unless
indeed the statement refers to the few Fuegians who have lived for
some time with Europeans, and who must consider us as superior
beings. I should add that a most experienced observer, Capt. Bur-
ton, believes that a woman whom we consider beautiful is admired
througliout the world. " Anthropological Eeview," March, 1864, p.
245.

f "Personal Narrative," Eng. translat., vol. iv, p. 518, and else-
where. Mantegazza, in his " Viaggi e Studi," strongly insists on
this same principle.

SECONDARY SEXUAL CHARACTERS. 666

to exaggerate some natural and admired peculiarity. Many
American Indians are known to admire a head so extremely
flattened as to appear to us idiotic. The natives on the
northwestern coast compress the head into a pointed cone;
and it is their constant practice to gather the hair into a
knot on the top of the head, for the sake, as Dr. Wilson
remarks, "of increasing the apparent elevation of the
favorite conoid form.*' The inhabitants of Arakhan
''admire a broad, smooth forehead, and, in order to pro-
duce it, they fasten a plate of lead on the heads of the
new-born children." On the other hand, "abroad, well-
rounded occiput is considered a great beauty" by the
natives of the Fiji Islands.*

As with the skuiJ, so with the nose; the ancierit Huns,
during the age of Attila, were accustomed to flatten the
noses of their infants with bandages, "for the sake of
exaggerating a natural conformation." With the Tahitians,
to be called lo?ig-7iose is considered as an insult, and they
compress the noses and foreheads of their children for the
sake of beauty. The same holds with the Malays of
Sumatra, the Hottentots, certain negroes and the natives
of Brazil, t The Chinese have by nature unusually small
feet; I and it is well known that the women of the upper
classes distort their feet to make them still smaller.
Lastly, Humboldt thinks that the American Indians prefer
coloring their bodies with red paint in order to exaggerate
their natural tint; and until recently European women
added to their naturally bright colors by rouge and
white cosmetics ; but it may be doubted whether barbarous
nations have generally had any such intention in paint-
ing themselves.

*0n the skulls of the American tribes, see Nott and Gliddon,
" Types of Mankind," 1854. p. 440; Prichard, "Phys. Hist, of Man-
kind," vol. i, 3d edit., p. 321 ; on the natives of Arakban, ibid, vol.
iv, p. 537. Wilson, "Physical Ethnology," Smithsonian Institution,
18G3, p. 288; on the Fijians, p. 290. Sir J. Lubbock ("Prehistoric
Times," 2d edit., 1869, p. 506) gives an excellent resume on this sub-
ject.

f On the Huns, Godron, " De I'Espece," torn, ii, 1859, p. 300. On
the Tahitians, Waitz, " Anthropolog.," Eng. translat., vol. i, p. 305.
Marsden, quoted by Prichard, " Phys. Hist, of Mankind," 3d edit-,
vol. V, p. 67. Lawrence, "Lectures on Physiology," p. 837.

tThis fact was ascertained in tli'i " Reise der Novara : Anthropo-
log. Thiel," Dr. VVeia'jach, 18ti7, s. 266.

666 THE DESCENT OF MAN.

In tlie fashions of our own dress we see exactly the same
principle and the same desire to carry every point to an
extreme; we exhibit, also, the same spirit of emulation.
But the fashions of savages are far more permanent than
ours; and whenever their bodies are artiticially modified,
this is necessarily tlio case. The Arab women of the Upper
Nile occupy about three days in dressing their hair; they
never imitate other tribes, *'* but simply vie with each other
in the super lativeness of their own style. ^' Dr. Wilson, in
speaking of the compressed skulls of various American
races, adds, '* such usages are among the least eradicable,
and long survive the shock of revolutions that change
dynasties and efface more important national peculiarities."*
The same principle comes into play in the art of breeding;
and we can thus understand, as I have elsewhere explained,!
the wonderful development of the many races of animals
and plants, which have been kept merely for ornament.
Fanciers always wish each character to be somewhat
increased; they do not admire a medium standard; they cer-
tainly do not desire any great and abrupt change in the
character of their breeds; they admire solely what they are
accustomed to, but they ardently desire to see each char-
acteristic feature a little more developed.

The senses of man and of the lower animais seem to be
BO constituted that brilliant colors and certain forms, as
well as harmonious and rhythmical sounds, give .pleasure
and are called beautiful; but why this should be so we
know not. It is certainly not true that there is in the
mind of man any universal standard of beauty with respect
to the human body. It is, however, possible that certain
tastes may in the course of time become inherited,
though there is no evidence in favor of this belief; and, if
so, each race would possess its own innate ideal standard of
beauty. It has been argued | that ugliness consists in an
approach to the structure of the lower animals, and no
doubt this is partly true with the more civilized nations,
in which intellect is highly appreciated; but this explana-

* " Smitlisonian Institution," 1863, p. 289. On the fashions of
Arab women, Sir S. Baker, *' The Nile Tributaries," 1867, p. 121.

f'The Variation of Animals and Plants under Domestication,"
vol. i, p. 214; vol. ii, p. 240.

X SchaafEhausen, " Archiv. fiir Anthropologie," 1866, s. 164.

BECONDART SEXUAL CHARACTERS, 667

tion will hardly apply to all forms of ugliness. The men
of each race prefer what they are accustomed to; they
carciot endure any great change; but they like variety, and
admire each characteristic carried to a moderate extreme.*
Men accustomed to a nearly oval face, to straight and
regular features and to bright colors, admire, as we Euro-
peans know, these points when strongly developed. On
the other hand, men accustomed to a broad face, with high
cheek-bones, a depressed nose and a black skin admire
tliese peculiarities when strongly marked. No doubt
characters of all kinds may be too much developed for
beauty. Hence a perfect beauty, which implies many
characters modified in a particular manner, will be in every
race a prodigy. As the great anatomist Bichat long ago
said, if every one were cast in the same mold there would
bo no such thing as beauty. If all our women were to
become as beautiful as the Venus de Medici we should
for a time be charmed, but we should soon wish for variety;
and, as soon as we had obtained variety, we should wish
to see certain characters a little exaggerated beyond the
then existing common standard.

* Mr. Bain has collected (" Mental and Moral Science," 1868, pp.
304-314) about a dozen more or less different theories of the idea of
beauty; but none are quite the same as that here given.

668 THE DESCENT OF MAN,

CHAPTER XX.

BECONDAET SEXUAL CHARACTERS OF MAN — COnUtlUed.

On the effects of tlie continued selection of women according to a
different standard of beauty in each race — On the causes which
interfere with sexual selection in civilized and savage nations —
Conditions favorable to sexual selection during primeval times —
On the manner of action of sexual selection with mankind — On
the women in savage tribes having some power to choose their
husbands — Absence of hair on the body and development of the
beard — Color of the skin — Summary.

We have seen in the last chapter that with all barbarous
races ornaments, dress and external appearance are highly
valued; and that the men judge of the beauty of tneir
women by widely different standards. We must next
inquire whether this preference and the consequent selec-
tion, during many generations, of those women which
appear to the men of each race the most attractive, has
altered the character either of the females alone, or of- both
Bexes. With mammals the general rule appears to be that
characters of all kinds are inherited equally by the males
and females; we might, therefore, expect that with man-
kind any characters gained by the females or by the males
through sexual selection would commonly be transferred to
the offspring of both sexes. If any change has thus been
effected it is almost certain that the different races would
be differently ynodified, as each has its own standard of
beauty.

With mankind, especially with savages, many causes
interfere with the action of sexual selection as far as the
bodily frame is concerned. Civilized men are largely
attracted by the mental charms of women, by their wealth,
and especially by their social position; for men rarely
marry into a much lower rank. The men who succeed in
obtaining the more beautiful w^omen will not have a better
chance of leaving a long line of descendants than other

SECONDARY 8EXUAL GHARAC2ER8, 669

inen with plainer wives, save the few who bequeath their
fortunes according to primogeniture. With respect to the
opposite form of selection, namely, of the more attractive
men by the women, although in civilized nations wornen
have free or almost free choice, which is not the case with
barbarous races, yet their choice is largely influenced by
the social position and wealth of the men; and the success
of the latter in life depends much on their intellectual
powers and energy, or on the fruits of these same powers
m their forefathers. No excuse is needed for treating this
subject in some detail; for, as the German philosopher
Schopenhauer remarks, ^^ the final aim of all love intrigues,
be they comic or tragic, is really of more importance than
all other ends in human life. What it all turns upon is
nothing less than the composition of the next genera-
tion. . . . It is not the weal or woe of any one indi-
vidual, but that of the human race to come, which is here
at stake.''* .

There is, however, reason to believe that in certain civil-
ized and semi-civilized nations sexual selection has effected
something in modifying the bodily frame of some of the
members. Many persons are convinced, as it appears to
me with justice, that our aristocracy, including under this
term all wealthy families in which primogeniture has long
prevailed, from having chosen during many generations
from all classes the more beautiful women as their wives,
have become handsomer, according to the European
standard, than the middle classes; yet the middle classes
are placed under equally favorable conditions of life for
the perfect development of the body. Cook remarks that
the superiority in personal appearance " which is observa-
ble in the erees or nobles in all the other islands (of the
Pacific) is found in the Sandwich Islands ;^'' but this
may be chieflv due to their better food and manner of
life.

The old traveler Ohardin, in describing the Persians,
says their '* blood is now highly refined by frequent inter-
mixtures with the Georgians and Circassians, two nations
which surpass all the world in personal beauty. There is
hardly a man of rank in Persia who is not born of a

* •• Schopenliaaer and Darwinism," in "Journal of Anthropology/
Jan., 1871, p. 823.

670 THE DESCENT OF MAN,

Georgian or Circassian mother." He adds that tliey inherit
their beauty^ " not from their ancestors, for without the
above mixture the men of rank in Persia, who are descend-
ants of the Tartars, would be extremely ugly/'* Here is
a more curious case; the priestesses who attended the temple
of Venus Erycina at San Giuliano, in Sicily, were selected
for their beauty out of the whole of Greece; they were not
vestal virgins, and Quatrefages,t who states the foregoing
fact, says that the women of San Giuliano are now famous
as the most beautiful in the island, and are sought by
artists as models. But it is obvious that the evidence in
all the above cases is doubtful.

The following case, though relating to savages, is well
worth giving from its curiosity. Mr. Winwood Reade 'n-
forms me that the Jollofs, a tribe of negroes on the west
coast of Africa, "are remarkable for their uniformly fine
appearance." A friend of his asked one of these men:
'* How is it that every one whom I meet is so fine looking,
not only your men, but your women?" The Jollof an-
swered: **It is very easily explained; it has always been
our custom to pick out our worst-looking slaves and to
sell them." It need hardly be added that with all savages
female slaves serve as concubines. That tliis negro should
have attributed, whether rightly or wrongly, the fine
appearance of his tribe to the long-continued elimination
of the ugly women is not so surprising as it may at first
appear: for I have elsewhere si i own J that negroes fully
appreciate the importance of selection in the breeding of
their domestic animals, and I could give from Mr. Reade
additional evidence on this head.

The Causes Which Prevent or Chech the Action of Sexual
Selection with Savaoes. — The chief causes are, first so-
called communal marriages or promiscuous intercourse ;
secondly, the consequences of female infanticide; thirdly,

* These quotations are taken from Lawrence (" Lectures on Physi-
ology," etc., 1822, p. 393), wlio attributes the beauty of the upper
classes in England to the men having long selected the more beau-
tiful women.

f " Anthropologie," " Revue des Cours Scientifique," Oct., 1868.
p. 721.

The Variation of Animals and Plants under Domestication/*
p. 207.

I

±"T
A. i.

SECONDARY SEXUAL CMAllACTERS. 671

early betrothals; and, lastly, the low estimation in which
women are held as mere slaves. These four points must
be considered in some detail.

It is obvious that as long as the pairing of man or of
any other animal is left to mere chance, with no choice
exerted by either sex, there can be no sexual selection; and
no effect will be produced on the offspring by certain indi-
viduals having had an advantage over others in their court-
ship. Now, it is asserted that tJiere exist at the present clay
tribes which practice what Sir J. Lubbock by courtesy
calls communal marriages; that is, all the men and women
in the tribe are husbands and wives to one another. The
licentiousness of many savages is no doubt astonishing, but
it seems to me that more evidence is requisite, before we
fully admit that their intercourse is in any case promiscu-
ous. Nevertheless, all those who have most closely studied
the subject,* and whose judgment is wortli much more
than mine, believe tliat communal marriage (this ex-
pression being variously guarded) was the original
and universal form throughout the world, including
therein the intermarriage of brothers and sisters.
The late Sir A. Smith, who hud traveled widely
in S. Africa, and knew much about the habits of
savages there and elsewhere, expressed to me the strongest
opinion that no race exists in which woman is considered
as the property of the community. I believe that his judg-
ment was largely determined by what is implied bv the
term marriage. Throughout the following discussion I
use the term in the same sense as wdien naturalists speak of
animals as monogamous, meaning thereby that the male is
accepted by or chooses a single female, and lives with her

*Sir J. Lubbock, " The Origin of Civilization," 1870, cLap. iii,
especially pp. 60-67. Mr. M'Lennan, in bis extremely valuable
work on '' Primitive Marriage," 1865, p 163, speaks of the union of
the sexes "in the earliest times as loose, transitory, and in some
degree promiscuous." Mr. M'Lennan and Sir J. Lubbock have col-
lected much evidence on the extreme licentiousness of savages at
the present time. Mr. L. H. Morgan, in his interesting memoir on
the classificatory system of relationship (" Proc. American Acad, of
Sciences," vol. vli, Feb., 1868, p. 475), concludes that polygamy
and all forms of marriage during primeval times were essentially
unknown. It appears, also, from Sir J. Lubbock's work, that Bach-
ofen likewise believes that communal intercourse originally pre-

67^ THE DESCENT OF MAN.

eitlier during the breeding-season or for the whole year,
keeping possession of her by the law of might; or, as when
they speak of a polygamous species, meaning that the male
Mves with several females. This kiad of marriage is all
that concerns us here, as it suffices for the work of sexual
selection. But I know that some of the writers above
referred to imply by the term marriage a recognized right
protected by the tribe.

The indirect evidence in favor of the belief of the former
prevalence of communal marriages is strong, and rests
chiefly on the terms of relationship which are employed
between the members of the same tribe, implying a con-
nection with the tribe, and not wdth either parent. But
the subject is too large and complex for even an abstract to
be here given, and I will confine myself to a few remarks. It
is evident in the case of such marriages, or where the mar-
riage tie is very loose, that the relationship of the child to its
father cannot be known. But it seems almost incredible
that the relationship of the child to its mother should ever
be completely ignored, especially as the women in most
savage tribes nurse their infants for a long time. Accord-
ingly, in many cases the lines of descent are traced through
the mother alone, to the exclusion of the father. But in
other cases the terms employed express a connection with
the tribe alone, to the exclusion even of the mother. It
seems possible that the connection between the related
members of the same barbarous tribe, exposed to all sorts
of danger, might be so much more important, owing to the
need of mutual protection and aid, than that between the
mother and her child, as to lead to the sole use of terms
expressive of the former relationships; but Mr. Morgan is
convinced tiiat this view is by no means sufficient.

The terms of relationship used in different parts of the
world may be divided, according to the author just quoted,
into two great classes — the classificatory and descriptive —
the latter being employed by us. It is the classificatory
system which so strongly leads to the belief that communal
and other extremely loose forms of marriage were originally
universal. But, as far as I can see, there is no necessity on
this ground for believing in absolutely promiscuous inter-
course; and I am glad to find that this is Sir J. Lubbock's
view. Men and women, like many of the lower animals,
might formerly have entered into strict though temporary

SECONDARY SEXUAL CHARACTERS. 673

unions for each birth, and in this case nearly as much con-
fusion would have arisen in the terms of relationship as in
the case of promiscuous intercourse. As far as sexual
selection is concerned all that is required is that choice
should be exerted before tlie parents unite, and it signifies
little whether the unions .last for life or only for a season.

Besides the evidence derived from the terms of relation-
ship, other lines of reasoning indicate the former wide prev-
alence of communal marriage. Sir J. Lubbock accounts
for the strange and widely extended habit of exogamy —
that is, the men of one tribe taking wives from a distinct
tribe — by communism having been the original form of
intercourse; so that a man never obtained a wife for him-
self unless he captured her from a neighboring and hostile
tribe, and then she would naturally have become his sole
and valuable, property. Thus the practice of capturing
wives might have arisen; and from the honor so gained it
might ultimately have become the universal habit. Ac-
cording to Sir J. Lubbock,* we can also thus understand
'^the necessity of expiation for marriage as an infringe-
jnent of tribal rites, since, according to old ideas, a man
had no right to appropriate to himself that which belonged
to the whole tribe. ^^ Sir J. Lubbock further gives a
curious bodyT>f facts showing that in old times high honor
was bestowed on women who were utterly licentious; and
this, as ho explains, is intelligible, if we admit that pro-
miscuous intercourse was the aboriginal, and therefore long
revered custom of the tribe, f

Although the manner of development of the marriage-
tie is an obscure subject, as we may infer from the diver-
gent opinions on several points between the three authors
who have studied it most closely, namely, Mr. Morgan,
Mr. M'Lennan, and Sir J. Lubbock, yet from the fore-
going and several other lines of evidence it seems probable J

* " Address to British Association on the Social and Religious Con-
dition of the Lower Haces of Man," 1870, p. 20.

\ "" Origin of Civilization," 1870, p. 86. In the several works above
quoted, there will be found copious evidence on relationship through
the females alone, or with the tribe alone.

:|:Mr. C. Staniland Wake argues strongly (" Anthropologie,"
March, 1874, p. 197) against the views held by these three writers
on the former prevalence of almost promiscuous intercourse; and he
thiniis that the classificatory system of relationship can be ether-
wise explained.

674 THE DESCENT OF MAN,

that the habit of marriage, in any strict sense of the word,
has been gradually developed; and that almost promiscu^
ous or very loose intercourse was once extremely common
throughout the world. Nevertheless, from the strength of
the feeling of jealousy all through the animal kingdom, as
well as from the analogy of the lower animals, more partic-
ularly of those which come nearest to man, I cannot
believe that absolutely promiscuous intercourse prevailed in
times past, shortly before man attained to his present rank
in the zoological scale. Man, as I have attempted to show,
is certainly descended from some ape-like creature. With
the existing Quadrumana, as far as their habits are known,
the males of some species are monogamous, but live during
only a part of the year with the females; of this the orang
seems to afford an instance. Several kinds, for example
some of the Indian and American monkeys, are strictly
monogamous, and associate all the year round with their
wives. Others are polygamous, for example the gorilla
and several American species, and each family lives sepa-
rate. Even when this occurs, the families inhabiting the
same district are probably somewhat social ; the chimpanzee,
for instance, is occasionally met with in large bands.
Again, other species are polygamous, but several males,
each with his own females, live associated in a body, as
with several species of baboons.* AVe may indeed conclude
from what we know of the Jealousy of all male quadrupeds
armed, as many of them are, with special weapons for bat-
tling with their rivals, that promiscuous intercourse in a
state of nature is extremely improbable. The pairing may
not last for life, but only for each birth; yet if the males
which are the strongest and best able to defend or other-
wise assist their females and young, were to select the more
attractive females, this would suffice for sexual selection.

Therefore, looking far enough back in the stream of
time, and. Judging from the social habits of man as he now
exists, the most probable view is that he aboriginally lived
in small communities, each with a single wife, or if power-
ful with several, whom he Jealously guarded against all

*Brelira (" lUust. Thierleben," B. i, p. 77) says Cynocephalm
hamadryas live-; in great troops containing' twice as many adult
females as adult males. See Rengger (m American polygamous
species, and Owen (" Anat. of Vertebrates," vol. iii, p. 746) on Amer-
ican monogamous species. Other references might be added.

SECONDARY SEXUAL CHARACTERS, 675

other men, Or he may not have been a social animal, and
yet have lived with several wives, like the gorilla; for all
the natives *^ agree that but one adult male is seen in a
band; when the young male grows up a contest takes place
for mastery, and the strongest, by killing and driving out
the others, establishes himself as the head of the com-
munity/' * The younger males, being thus expelled and
wandering about, would, when at last successful in finding
a partner, prevent too close interbreeding within the limits
of the same family.

Although savages are now extremely licentious, and,
although communal marriages may formerly* have largely
prevailed, yet many tribes practice some form of marriage,
but of a far more lax nature than that of civilized nations.
Polygamy, as just stated, is almost universally followed by
the leading men in every tribe. Nevertheless there are tribes,
standing almost at the bottom of the scale, which are
strictly monogamous. This is the case with the Veddahs
of Ceylon; they have a saying, according to Sir J. Lub-
bock, f ** that death alone can separate husband and wife."
An intelligent Kandyan chief, of course a polygamist,
** was perfectly scandalized at the utter barbarism oi living
with only one wife, and never parting until separated by
death.'' *' It was," he said, " just like the Wanderoo mon-
keys." AYhether savages who now enter into some form of
marriage, either polygamous or monogamous, have re-
tained this habit from primeval times, or whether they
have returned to some form of marriage, after passing
through a stage of promiscuous intercourse, I will not
pretend to conjecture.

Infanticide. — This practice is now very common through--'
out the world, and there is reason to believe that it prC'
vailed much more extensively during former times.]; Bar-
barians find it difficult to support themselves and their
children, and it is a simple plan to kill their infants. In
South America some tribes, according to Azara, formerly

*Dr. Savage, in "Boston Journal of Nat. Hist.," vol. v, 1845-47,
p. 423.

t " Prebistorib Times," 1869, p. 424.

J Mr. M'Lennan, "Primitive Marriage," 1865. See especially on
exogamy and infanticide Dp. I30r ViH^ "^^5.

676 THE DESCENT OF MAN.

destroyed so many infants of both sexes that they were on
the point of extinction. In the Polynesian Islands women
have been known to kill from four or five, to even ten of
their children; and Ellis could not find a single woman
who had not killed at least one. In a village on the
eastern frontier of India Col. McCulloch found not a
single female child. Wherever infanticide* prevails the
struggle for existence will be in so far less severe, and all
the members of the tribe will have an almost equally good
chance of rearing their few surviving children. In most
cases a larger .number of female than of male infants are
destroyed, for it is obvious that the latter are of more value
to the tribe, as they will, when grown up, aid in defending
it, and can support themselves. But the trouble experienced
by the women in rearing children, their consequent loss
of beauty, the higher estimation set on them when few,
and their happier fate, are assigned by the women them-
selves, and by various observers, as additional motives for
infanticide.

When, owing to female infanticide, the women of a tribe
were few, the habit of capturing wives from neighboring
tribes would naturally arise. Sir J. Lubbock, however, as
we have seen, attributes the practice in chief part to the
former existence of communal marriage, and to the men
having consequently captured women from other tribes to
hold as their sole property. Additional causes might be
assigned, such as the communities being very small, in
which case, marriageable women would often be deficient.
That the habit was most extensively practiced during
former times, even by the ancestors of civilized nations, is
clearly shown by the preservation of many curious customs
and ceremonies, of which Mr. McLennan has given an
interesting account. In our own marriages the ''best
man " seems originally to have been the chief abettor of
the bridegroom in the act of capture. Now, as long as
men habitually procured their wives through violence and

*Dr. Gerland (" Ueber das Aussterben der NaturvOlker," 1868)
has collected mucb information on infanticide, see especially ss. 27,
51, 54. Azara ("Voyages," etc., torn, ii, pp. 94, 116) enters in detail
on the motives. See also M'Lennan (ibid, p. 139) for cases in India.
In the former reprints of the 2d edition of this book an incorrect
quotation from Sir G. Grey was unfortunately given in the above
passage and has now been removed from the text.

SECONDARY SEXUAL CHARACTERS 677

craft, they would have been glad to seize on any woman,
and would not have selected the more attractive ones. But
as soon as the practice of procuring wives from a distinct
tribe was effected through barter, as now occurs in many
places, the more attractive women would generally have
been purchased. The incessant crossing, however, between
tribe and tribe, which necessarily follows from any form of
this habit, would tend to keep all the people inhabiting the
same country nearly uniform in character; and this would
interfere with the power of sexual selection in differentiat-
ing the tribes.

The scarcity of women, consequent on female infanti-
cide, leads, also, to another practice, that of polyandry,
still common in several parts of the world, and which
formerly, as Mr. McLennan believes, prevailed almost uni-
versally; but this latter conclusion is doubted by Mr.
Morgan and Sir J. Lubbock.* Whenever two or more men
are compelled to marry one women it is certain that all the
women of the tribe will get married, and there will be no
selection by the men of the more attractive women. But,
under these circumstances, the women no doubt will have
the power of choice, and will prefer the more attractive
men. Azara, for instance, describes how carefully a Guana
woman bargains for all sorts of privileges before accepting
some one or more husbands; and the men in consequence
take unusual care of their personal appearance. So among
the Todas of India, who practice polyandry, the girls can
accept or refuse any man. f A very ugly man in these
cases would, perhaps, altogether fail in getting a wife,
or get one later in life ; but the handsomer men,
although more successful in obtaining wives, would not,
as far as we can see, leave more offspring to inherit
their beauty than the less handsome husbands of the same
women.

Uarly Betrothals and Slavery of Women. — With many
savages it is the custom to betroth the females while mere
infants ; and this would effectually prevent preference

* " Primitive Marriage," p. 208; Sir J, Lubbock, * ' Origin of Civili-
zation," p. 100. See also Mr. Morgan, loc. cit., on the former preva-
lence of polyandry.

f Azara, "Voyages," etc., torn, ii, pp. 93-95, Colonel Marshall
«' Among the Todas," p. 212.

678 THE DESCENT OF MAN.

being exerted on either side according to personal appear-
ance. But it would not prevent the more attractive women
from being afterward stolen or taken by force from their
husbands by the more powerful men; and this often hap-
pens in Australia, America and elsewhere. The same con-
sequences with reference to sexual selection would to a
certain extent follow, when women are valued almost
solely as slaves or beasts of burden, as is the case with
many savages. The men, however, at all times would
prefer the handsomest slaves, according to their standard of
beauty.

We thus see that several customs prevail with savages
which must greatly interfere with, or completely stop, the
action of sexual selection. On the other hand, the con-
ditions of life to which savages are exposed, and some of
their habits, are favorable to natural selection; and this
comes into play at the same time with sexual selection.
Savages are known to suffer severely from recurrent famines;
they do not increase their food by artificial means; they
rarely refrain from marriage,* and generally marry while
young. Consequently they must be subjected to occasional
hard struggles for existence, and the favored individuals
will alone survive.

At a very early period, before man attained to his present
rank in the scale, many of his conditions would be differ-
ent from what now obtains among savages. Judging from
the analogy of the lower animals, he would then either live
with a single female, or be a polygamist. The most pow-
erful and able males would succeed best in obtaining attrac-
tive females. They would also succeed best in the general
struggle for life, and in defending their females, as well as
their offspring, from enemies of all kinds. At this early
period the ancestors of man would not be sufficiently ad-
vanced in intellect to look forward to distant contingencies;
they would not foresee that the rearing of their children,
especially their female children, would make the struggle
for life severer for the tribe. They would be governed
more by their instincts and less by their reason than are

*Burcliell saj'sC Travels in S. Africa," vol. ii, 1824, p. 58), that
among the wild nations of Soutliern Africa, neither n)en nor women
ever pass tbeir lives in a state of celibacy. Azara (" Voyages dans
rAmeriqiie Merid.," torn, ii, 1809, p. 21) makes precisely the same
remark in regard to the wild Indians of South America.

SECONDARY SEXUAL CHARACTERS, 679

savages at the present day, Tliey would not at that
period have partially lost one of the strongest of all
instincts common to all lower animals, namely, tho love of
their young offspring ; and consequently they would not
have practiced female infanticide. Women would not
have been thus rendered scarce, and polyandry wo^^ld not
have been practiced; for hardly any other cause except the
scarcity of women seems sufficient to break down the nat-
ural and widely prevalent feeling of jealousy and the desire
of each male to possess a female for himself. Polyandry
would be a natural stepping-stone to communal marriages
or almost promiscuous intercourse; though the best authori-
ties believe that this latter habit preceded polyandry.
During primordial times there would be no early betroth-
als, for this implies foresight. Nor would womei be
valued merely as useful slaves or beasts of burden. Both
sexes, if the females as well as the males were peri^'tted to
exert any choice^ would choose their partners not .*"or
mental charms, or property, or social position, but almost
solely from external appearance. All the adults would
marry or pair, and all the offspring, as far as that was
possible, would be reared; so that the struggle for exist-
ence would be periodically excessively severe. Thus, "".unng
these times all the conditions for sexual selection would
have been more favorable than at a later period, when man
had advanced in his intellectual powers but had retro-
graded in his instincts. Therefore, whatever influence
sexual selection may have had in producing the differences
between the races of man and between man and the higher
Quadrumana, this influence would have been more power-
ful at a remote period than at the present day, though
probably not yet wholly lost.

The Manner of Action of Sexual Selection with Man-
kind. — AVith primeval man under the favorable conditions
Just stated, and with those savages who at the present time
enter into any marriage tie, sexual selection has probably
acted in the following manner, subject to greater oi ies.i
interference from female infanticide, early betrothals, etc.
The strongest and most vigorous men — those who could
best defend and hunt for thtir families, who were pro-
vided with the best weapons and possessed the most prop-
erty, such as a large number of dogs or other animals—

6B0 TEB DESCENT OF MAN.

would succeed in rearing a greater average number of off-
spring than the weaker and poorer members of the same
tribe. There can, also, be no doubt that such men would
generally be able to select the more attractive women. At
present the chiefs of nearly every tribe throughout the
world succeed in obtaining more than one wife. I hear
from Mr. Mantell that until recently almost every girl in
l^ew Zealand who was pretty or promised to be pretty was
tapu to some chief. With the Kafirs, as Mr. C. Hamilton
states,* *^the chiefs generally have the pick of the women
for many miles round and are most persevering in estab-
lishing or confirming their privilege." We have seen that
each race has its own style of beauty, and w^e know that it
is natural to man to admire each characteristic point in
his domestic animals, dress, ornaments and personal appear-
ance when carried a little beyond the average. If, then,
the several foregoing propositions be admitted, and I
cannot see that they are doubtful, it would be an inex-
plicable circumstance if the selection of the more attractive
women by the more powerful men of each tribe who would
rear on an average a greater number of children did not
after the lapse of many generations somewhat modify the
character of the tribe.

When a foreign breed of our domestic animals is intro-
duced into a new country, or when a native breed is long
and carefully attended to, either for use or ornament, it is
found after several generations to have undergone a greater
or less amount of change whenever the means of compari-
son exist. This follows from unconscious selection during
a long series of generations — that is, the preservation of the
most approved individuals — without any wish or expecta-
tion of such a result on the part of the breeder. So again,
if during many years two careful breeders rear animals ol
the same family, and do not compare them together or
with a common standard, the animals are found to have
become, to the surprise of their owners, slightly different, f
Each breeder has impressed, as Von Nathusius well ex-
presses it, the character of his own mind — his own taste
and judgment — on his animals. What reason, then, can

*" Anthropological Review," Jan., 1870, p. xvi.
f •* The Variation of Animals and Plants under Domestication," vol.
ii, pp. 210-217.

\

SECOSDAUY SEXUAL CHARACTERS. 681

1)6 assigned why similar results should not follow from the
long-continued selection of the most admired women by
those men of each tribe who were able to rear the greatest
number of children? This would be unconscious selection,
for an effect would be produced, independently of any wish
or expectation on the part of the men who preferred cer-
tain women to others.

Let us suppose the members of a tribe, practicing som^
form of marriage, to spread over an unoccupied continent,
they would soon split up into distinct hordes, separated
from each other by various barriers, and still more effectu-
ally by the incessant wars between all barbarous nations.
The hordes would thus be exposed to slightly different
conditions and habits of life and would sooner or later come
to differ in some small degree. As soon as this occurred,
each isolated tribe would form for itself a slightly different
standard of beauty;* and then unconscious selection would
come into action through the more powerful and leading
men preferring certain women to others. Thus the dif-
ferences between the tribes, at first very slight, would
gradually and inevitably be more or less increased.

With animals in a state of nature, many characters
proper to the males, such as size, strength, special weapons,
courage and pugnacity, have been acquired through the
law of battle. The semi-human progenitors of man, like
their allies the Quadrumana, will almost certainly have
been thus modified; and, as savages still fight for the pos-
session of their women, a similar process of selection has
probably gone on in a greater or less degree to the present
day. Other characters proper to the males of the lower
animals, such as bright colors and various ornaments, have
been acquired by the more attractive males having been
preferred bj the females. There are, however, exceptional
cases in which the males are the selectors, instead of having
been the selected. We recognize such cases by the females
being more highly ornamented than the males — their orna-
mental characters having been transmitted exclusively or

* An ingenious writer argues, from a comparison of the pictures of
Raphael, Rubens, and modern French artists, that the idea of beauty
is not absolutely the same even throughout Europe; see the " Lives
of Haydn and Mozart," by Bombet (otherwise M. Beyiei, Enffljc^
translat.,p. 278. ~

683 THE DESCENT OF MAN,

chiefly to their female offspring. One such case has been
described in the order to which man belongs, that of the
Rhesus monkey.

Man is more powerful in body and mind than woman,
and in the savage state he keeps her in a far more abject
state of bondage than does the male of any other animal;
therefore it is not surprising that he should have gained
the power of selection. Women are everywhere conscious
of the value of th(dr own beauty; and when they have the
means, they take more delight in decorating themselves '
with all sorts of ornaments than do men. They borrow
the plumes of male birds, with which nature has decked
this sex in order to cliarm the females. As women have
long been selected for beauty, it is not surprising that some
of their successive variations should have been transmitted
exclusively to the same sex; consequently that they should
have transmitted beauty in a somewhat higher degree to
their female than to their male offspring, and thus have
become more beautiful, according to general oi3inion, than
men. "Women, however, certainly transmit most of their
characters, including some beauty, to their offspring of both
sexes; so that the continued preference by the men of each,
race for the more attractive women, according to their
standard of taste, will have tended to modify in the same
manner all the individuals of both sexes belonging to the
race.

With respect to the other form of sexual selection (which
with the lower animals is much the more common), namely^
when the females are the selectors, and accept only those
males which excite or charm them most, we have reason to
believe that it formerly acted on our progenitors. Man in
a!l probability owes his beard, and perhaps some other char-
acters, to inheritance from an ancient progenitor who thus
gained his ornaments. But this form of selection may
have occasionally acted during later times; for in utterly
barbarous tribes the women have more power in choosing,
rejecting and tempting their levers, or of afterward chang-
ing their husbands than might have been expected. As
this is a point of some importance, I will give in detail
such evidence as I have been able to collect.

Hearne describes how a woman in one of the tribes oL
Arctic America repeatedly ran away from her husband and
jpinedher lover; and with the Charruas of KSouth America,

SECONDARY SEXUAL CHARACTERS. 683

according to Azara, divorce is quite optional. Among tlio
Abipoues, a man on choosing a wife bargains with the parents
about the price. But *' it frequently happens that the girl
rescinds what has been agreed upon between the parents
and the bridegroom, obstinately rejecting the very men-
tion of marriage. '^ She often runs away, hides herself and
tlius eludes the bridegroom. Capt. Musters, who lived with
the Patagonians, says that their marriages are always
settled by inclination; *'if the parents make a match con-
trary to the daughter's will, she refuses and is never com-
pelled to comply.'' In Tierra del Fuego a young man first
obtains the consent of the parents by doing them some
service, and then he attempts carry off the girl; *^but if she
is unwilling, she hides herself in the woods until her admirer
is heartily tired of looking for her and gives up the pur-
suit; but this seldom happens." In the Fiji Islands the
man seizes on the woman whom he wishes for his wife by
actual or pretended force; but ^' on reaching the home of
her abductor, should she not approve of the match, she
runs to some one who can protect her; if, however, she is
satisfied, the matter is settled forthwith." With the Kal-
mucks there is a regular race between the bride and bride-
groom, the former having a fair start; and Clarke *' was
assured that no instance occurs of a girl being caught,
unless she has a partiality to the pursuer." Among the
wild tribes of the Malay Archipelago there is also a racing
match; and it appears from M. Bourien's account, as Sir
J. Lubbock remarks, that "the race 'is not to the swift,
nor the battle to the strong,' but to the young man who
has the good fortune to please his intended bride." A sim-
ilar custom, with the same result, prevails with the Korarks
of Northeastern Asia.

Turning to Africa — the Kafirs buy their wives, and girls
are severely beaten by their fathers if they will not accept
a chosen husband; but it is manifest from many facts given
by the Rev. Mr. Shooter, that they have considerable
power of choice. Thus, very ugly, though rich men, have
been known to fail in getting wives. The girls, before con-
senting to be betrothed, compel the men to show them-
selves off first in front and then behind, and " exhibit their
paces." They have been known to propose to z. man, and
they not rarely run away with a favored lover. So, again,
Mr. Leslie, who was intimately acquainted with the Kafirs,

684 THE DESCENT OF MAN.

says: '* It is a mistake to imagine that a girl is sold by her
father in the same manner, and with the same authority,
with which he would dispose of a cow." Among the
degraded Bushmen of S. Africa, *' when a girl has grown
up to womanhood without having been betrothed, which,
however, does not often happen, her lover must gain her
approbation as well as that of the parents."* Mr. Winwood
Reade made inquiries for me with respect to the negroes of
Western Africa, and he informs me that **the women, at
least among the more intelligent Pagan tribes, have no dif-
ficulty in getting the husbands whom^ they may desire,
although it is considered unwomanly to ask a man to marry
them. They are quite capable of falling in love and of
forming tender, passionate and faithful attachments."
Additional cases could be given.

We thus see that with savages the women are not in
quite so abject a state in relation to marriage as has often
been supposed. They can tempt the men whom they
prefer, and can sometimes reject those whom they dislike,
either before or after marriage. Preference on the part of
women, steadily acting in any one direction, would ulti-
mately affect the character of the tribe; for the women
would generally choose not merely the handsomest men,
according to their standard of taste, but those who were at
the same time best able to defend and support them. Such
well-endowed pairs would commonly rear a larger number
of offspring than the less favored. The same result would
obviously follow in a still more marked manner if there
was selection on both sides; that is, if the more attractive,
and, at the same time, more powerful, men were to prefer,
and were preferred by, the more attractive women. And
this double form of selection seems actually to have

*Azara "Voyages," etc., torn, ii, p. 23. Dobrizlioffer, "An Ac-
count of the Abi pones," vol. ii, 1822, p. 207. Capt. Musters, in
"Proc. R. Geograph. Soc," vol. xv, p. 47. Williams on the Fiji
Islanders, as quoted by Lubbock, '* Origin of Civilization," 1870. p.
79. On the Fuegians, King and Fitzroy, " Voyages of the 'Advent-
ure' and ' Beagle," " vol. ii, 1839, p. 182. On the Kalmucks, quoted by
M'Lennan, " Primitive Marriage," 1865, p. 32. On the Malays, Lub-
bock, ibid, p. 76. The Rev. J. Shooter, "On the Kafirs of Natal,"
1857, pp. 52-60. Mr. D. Leslie, " Kafir Character and Customs,"
1871, p. 4. On the Bushmen, Burchell, " Travels in S. Africa," vol.
ii, 1824, p. 59. On the Koraks by McKennan, as quoted by Mr.
Wake, in " Anthropologia," Oct., 1873, p. 75.

SECONDARY SEXUAL CHARACTERS, 685

occurred, especially during tlie earlier periods of our long
history.

We will now examine a little more closely some of the
characters which distinguish the several races of man from
one another and from the lower animals, namely, the
greater or less deficiency of hair on the body and the color
of the skin. We need say nothing about the great diversity
in the shape of the features and of the skull between the
different races, as we have seen in the last chapter how dif-
ferent is the standard of beauty in these respects. These
characters will, therefore, probably have been acted on
through sexual selection; but we have no means of judging
whether they have been acted on chiefly from the male or
female side. The musical faculties of man have likewise
been already discussed.

Absence of Hair on the Body and Ita Development on
the Face and Head. — From the presence of the woolly hair
or lanugo on the human fetus, and of rudimentary hairs
scattered over the body during maturity, we may infer that
man is descended from some animal which was born hairy
and remained so during life. The loss of bair is an incon-
venience and probably an injury to man, even in a hot
climate, for he is thus exposed to the scorch mg of the sun,
and to sudden chills, especially during wet weather. As
Mr. Wallace remarks, the natives in all counrnes are glad
to protect their naked backs and shoulder? with some
slight covering. No one supposes that the n^jkedness of
the skin is any direct advantage to man; his body, there-
fore, cannot have been divested of hair through natural
selection.* Nor, as shown in a former chapter, have we
any evidence that this can be due to the direct actioTi of
climate, or that it is the result of correlated development.

The absence of hair on the body is to a certain extent s

*" Contributions to the Theory of Natural Selection," 1870, p.
346. Mr, Wallace believes (p. 350) "that some intelligent power
has guided or determined the development of man ;" and he con-
siders the hairless condition of the skin as coming under this
head. The Rev, T. R. Stebbing, in commentmg on this view
("Transactions of Devonshire Assoc, for Science/' 1870) remarks,
that had Mr. Wallace "employed his usual ingenuity on the ques-
tion of man's hairless skin lie might have seen the pcssibiUty of its'
selection through its superior beauty or the healtb fcftVgA'Uing to
superior cleanliness."

686 THE DESCENT OF MAN.

secondary sexual character; for in all parts of the world
women are less hairy than the men. Therefore we may
reasonably suspect that this character has been gained
through sexual selection. AVe know that the faces of
several species of monkeys, and large surfaces at the
posterior end of the body of other species, have been
denuded of hair; and this we may safely attribute to
sexual selection, for these surfaces are not only vividly
colored, but sometimes, as with the male mandrill and
female rhesus, much more vividly in the one sex than in
the other, especially during the breeding-season. I am
informed by Mr. B.irtlett that, as these animals gradually
reach maturity, the naked surfaces grow larger compared
with the size of their bodies. The hair, however, appears
to have been removed, not for the sake of nudity, but that
the color of the skin may be more fully displayed. So,
again, with many birds, it appears as if the head and neck
had been divested of feathers, through sexual selection, to
exhibit the brightly colored skin.

^s the body in woman is less hairy than in man, and as
this character is common to all races, we may conclude
thai U was our female semi- human ancestors who were first
di vested of har, and that tliis occurred at an extremely re-
mote }»eriod bsfore tlie several races had diverged from a
common stock. While our female ancestors were gradually
acquiring this new character of nudity they must have
transmitted it almost equally to their offspring of both
sexes while young; so that its transmission, as with the
ornaments of many mammals and birds, luis not been
limited either by sex or age. There is nothing surprising
in a partial loss of hair having been esteemed as an orna-
ment by our ape-like progenitors, for we have seen that in-
numerable strange characters have been thus esteemed by
animals of all kinds and have consequently been gained
tiirough sexual selection. Kor is it surprising that a
slightly injurious character should have been thus acquired;
for we know that this is the case with the plumes of certain
birds, and with the horns of certain stags.

The females of some of the anthropoid apes, as stated in
a former chapter, are somewhat less hairy on the under
surface than the males; and here we have what might have
afforded a commencement for the process of denudation.
With respect to the completi<JU_ol the process through

BBCONDART SEXUAL CHARACTERS, 687

sexual selection, it is well to bear in mind the New Zea-
land proverb: *' There is no woman for a hairy man/^ All
who have seen photographs of the Siamese haii*y family
will admit how ludicrously hideous is the opposite extreme
of excessive hairiness. And the king of Siam had to bribe
a man to marry the first hairy woman in the family; and
she transmitted this character to her young offspring of
both sexes.*

Some races arc much more hairy than others, cspeciallj^ >f
the males; but it must not be assumed that the more hairy-
races, such as the Europeans, have retained their primor-
dial condition more completely than the naked races, such
as the Kalmucks or Americans. It is more probable that
the hairiness of the former is due tc partial reversion; for
characters which have been at some former period long in-
herited are always apt to return. We have seen that idiots
are often very hairy, and they are apt to revert in other
characters to a lower animal type. It does not appear that
a cold climate has been influential in leading to "this kind
of reversion; excepting perhaps with the negroes, who have
been reared during several generations in the United
States, t and possibly with the Ainos, who inhabit the
northern islands of the Japan archipelago. Bit the laws
of inheritance are so complex that we can seldom under-
stand their action. If the greater hairiness of certain
races be the result of reversion, unchecked by any form of
selection, its extreme variability, even within the limits of
the same race, ceases to be remarkable. J

**'Tlie Variation of Animals and Plants under Domestication,"
vol. ii, 1868, p. 327.

f " Investigations into Military and Anthropological Statistics of
American Soldiers," by B. A. Gould, 1869, p. 568: — Observations
were carefully made on the liairiness of 2,129 black and colored
soldiers, while they were bathing; and by looking to the publisbed
table, " it is manifest at a glance that there is but little, if any. dif-
ference between the white and the black races in this respect." It is,
however, certain that negroes in their native and much hotter land
of Africa, have remarkably smooth bodies. It should be particularly
observed, that both pure blacks and mulattoes were included in
the above enumeration: and this is an unfortunate circumstance, as
in accordance with a principle, the truth of which I have elsewhere
proved, crossed races of man would be eminently liable to revert to
the primordial hairy character of their early ape-like progenitors.

X Hardly any view advanced in this work has mtt with so much
dif.f aver (see for instance, Spengel, "Die Fortschritte des Darwia-

688 THE DESCENT OF MAN.

With respect to the beard in man, if we turn to our best
guide, the Quadrumana, we find beards equally developed
in both sexes of many species, but in some, either confined
to the males, or more developed in them than in the females.
From this fact and from the curious arrangement, as well
as the bright colors of the hair about the heads of many
monkeys, it is highly probable, as before explained, that
the males first acquired their beards through sexual selec-
tion as an ornament, transmitting them in most cases,
equally or nearly so, to their offspring of both sexes. We
know from Eschricht* that with mankind the female as
well as the male fetus is furnished with much hair on the
face, especially round the mouth; and this indicates that
we are descended from progenitors of whom both sexes
were bearded. It appears, therefore, at first sight probable
that man has retained his beard from a very early period,
while woman lost her beard at the same time that her body
became almost completely divested of hair. Even the color
of our beards seems to have been inherited from an ape-
like progenitor; for when there is any difference in tint
between the hair of the head and the beard, the latter is
lighter colored in all. monkeys and in man. In those
Quadrumana in which the male lias a larger beard than
that of the female, it is fully developed only at maturity,
just as with mankind; and it is possible that only the latei
stages of development have been retained by man. In op-
position to this view of the retention of the beard from an
early period is the fact of its great variability in differeni
races, and even within the same race; for this indicates
reversion — long lost characters being very apt to vary on
reappearance.

Nor must we overlook the part which sexual selection
may have played in later times; for we know that with
savages the men of the beardless races take infinite pains
in eradicating every hair from their faces as something
odious, while the men of the bearded races feel the greatest

ismus," 1874, p. 80) as the above explanation of the loss of hair in
mankind through sexual selection; but none of the opposed argu-
ments seem to me of much weight, in comparison with the facts
showing that the nudity of the skin is to a certain extent a secon-
dary sexual character in man and in some of the Quadrumana.

* " Ueber die Richtung der Haare am Menschlichen K6rper/' in
MuUer's " Archiv filr Anat. und Phys.," 1837, s. 40.

SECONDARY SEXUAL CHARACTERS. 689

pride in their beards. The women, no doubt, participate
m these feelings, and if so sexual selection can hardly have
failed to have effected something in the course of later
times. It is also possible that the long-continued habit ol.
eradicating the hair may have produced an inherited effect.
Dr. Brown-Sequard has shown that if certain animals are
operated on in a particular manner their offspring are
affected. Further evidsnce could be given of the inherit-
ance of the effects of mutilations; but a fact lately ascer-
by Mr. Salvin * has a more direct bearing on the present
question; for he has shown that the motmots, which are
known habitually to bite off the barbs of the two central
tail-feathers, have the barbs of these feathers naturally
somewhat reduced. f Nevertheless, with mankind the
habit of eradicating the beard and the hairs on the body
would probably not have arisen until these had already
])ecome by some means reduced.

It is difficult to form any judgment as to how the hair
on the head became developed to its present great length
in many races. Eschricht| states that in the human fetus
the hair on the face during the fifth month is longer than
that on the head; and this indicates that our semi-human
progenitors were not furnished with long tresses, which
must, therefore, have been a late acquisition. This is like-
wise indicated by the extraordinary difference in the length
of the hair in the different races; in the negro the hair
forms a mere curly mat; with us it is of great length, and
Avith the American natives it not rarely reaches to the
ground. Some species of Semnopithecus have their heads
covered with moderately long hair, and this probably serves
as an ornament and was acquired through sexual selection.
The same view may, perhaps, be extended to mankind, for
we know that long tresses are now and were formerly much
admired, as may be observed in the works of almost every
poet. St. Paul says: "If. a woman have long hair it is a

* On the tail-feathers of Momotus, " Proc. Zoolog. Soc," 1873, p.
429

f Mr. Sproat has suggested (" Scenes and Studies of Savage Life,**
1868, p. 25) this same view. Some distinguished ethnologists, among
others M. Gosse of Geneva, believe that artificial modifications of the
skull tend to be inherited.

I " Uber die Richtung," ibid, s. 4^.

690 THE DESCENT OF MAN.

glory to her;" and we have seen that in North America a
chief was elected solely from the length of his hair.

Color of the Skin. — The hest kind of evidence that in
man the color of the skin has been modified through sexual
selection is scanty; for in most races the sexes do not differ
in this respect, and only slightly, as we have seen, in
others. AVe know, however, from the many facts already
given that the color of the skin is regarded by tlie men of
all races as a highly important element in their beauty; so
that it is a character which would be likely to have been
modified through selection, as has occurred in innumerable
instances with the lower animals. It seems at first sight a
monstrous supposition that the jet blackness of the negro
should have been gained through sexual selection; but
this view is supported by various analogies, and we know
that negroes admire their own color. With mammals
when the sexes differ in color the male is often black or
much darker than the female; and it depends merely on
the form of inheritance whether this or any other tint is
transmitted to both sexes or to one alone. The resemblance
to a negro in miniature of Pithecia satanas with his
jet-black skin, white rolling eyeballs and hair parted on
the top of the head is almost ludicrous.

The color of the face differs much more widely in the
various kinds of monkeys than it does in the races of man;
and we have some reason to believe that the red, blue,
orange, almost white and black tints of their skin, even
when common to both sexes, as well as the bright colors of
their fur and the ornamental tufts about the head, have
all been acquired through sexual selection. As the order
of development during growth generally indicates the order
in which the characters of a species have bean developed
and modified during previous generations, and as the
newly born infants of the various races of man do not differ
nearly as much in color as do the adults, although their
bodies are as completely destitute of hair, we have some
slight evidence that the tints of the different races were
acquired at a period subsequent to the removal of the hair,
which must have occurred at a very early period in the
history of man.

Summary. — We may conclude ^that the greater size,

SECONDARY SEXUAL CEARACTERS. 691

strength, courage, pugnacity, and energy of man, in com-
parison with women, were acquired during primeval times,
and have subsequently been augmented, chiefly through
the contests of rival males fortlie possession of the females.
The greater intellectual vigor and power of invention in
man is probably due to natural selection, combined with
the inherited effects of habit, for the most able men will
have succeeded best in defending and providing for them-
selves and for their wives and offspring. As far as the ex-
treme intricacy of the subject permits us to judge, it
appears that our male ape-like progenitors acquired their
beards as an ornament to charm or excite the opposite sex,
and transmitted them only to their male offspring. The
females apparently first had their bodies denuded of hair,
also as a sexual ornament; but they transmitted this char-
acter almost equally to both sexes. It is notvimprobable
that tlie females were modified in other respects for the
same purpose and by the same means; so that women have
acquired sweeter voices and become more beautiful than
men.

It deserves attention that with mankind the conditions
were in many respects much" more favorable for sexual
selection, during a very early period, when man had only
just attained to the rank of manhood, than during later
times. For he would then, as we may safely conclude,
have been guided more by his instinctive passions, and
less by foresight or reason. He would have jealousy
guarded his wife or wives. He would not have practiced
ijiianticide; nor valued his wives merely as useful slaves;
nor have been betrothed to them during infancy. Hence
we may infer that the races of men were differentiated, as
far as sexual selection is concerned, in chief part at a very
remote epoch ; and this conclusion throws light on the
remarkable fact that at the most ancient period, of which
we have as yet any record, the races of man had already
come to differ nearly or quite as much as they do at the
present day.

The views here advanced, on the part which sexual selec-
tion has played in the history of man, want scientific pre-
cision. He who does not admit this agency in the case of
the lower animals, will disn-gard all that I have written in
the later chapters on man. We cannot positively say that
this character, but not that, has been thus modified; it has.

692 TBE DESCENT OF MAN.

however, been shown that the races of man differ fiom
each other and from their nearest allies, in certain charac-
ters which are of no service to them in their daily habits
of life, and which it is extremely probable would have
been modified through sexual selection. We have seen that
with the lowest savages the people of each tribe admire their
own characteristic qualities — the shape of the head and
face, the squareness of the cheek-bones, the prominence or
depression of the nose, the color of the skin, the length of
the hair on the head, the absence of hair on the face and
body, or the presence of a great beard, and so forth. Hence
these and other such points could hardly fail to be slowly
and gradually exaggerated from the more powerful and able
men in each tribe, who would succeed in rearing the largest
number of offspring, having selected during many genera-
tions for their wives the most strongly characterized and
therefore most attractive women. For my own part I con-
clude that of all the causes which have led to the differ-
ences in external appearance between the races of man, and
to a certain extent between man and the lower animals,
sexual selection has been the most efficient.

GENERAL SUMMARY AND CONCLUSION. 693

CHAPTER XXI.

GENERAL SUMMARY AND CONCLUSION.

Main conclusion that man is descended from some lower form —
Manner of development — Genealogy of man — Intellectual and
moral faculties — Sexual selection — Concluding remarks.

A BRIEF suramary will be sufficient to recall to the
reader's mind the more salient points in this work. Many
of the views which have been advanced are highly specula-
tive, and some no doubt will prove erroneous; but I have
in every case given the reasons which have led me to one
view rather than to another. It seemed worth while to try
how far the principle of evolution would throw light on
some of the more complex problems in the natural history
of man. False facts are highly injurious to the progress
of science, for they often endure long; but false views, if
supported by some evidence, do little harm, for every one
takes a salutary pleasure in proving their falseness; and,
when this is done, one path toward error is closed and the
road to truth is often at the same time opened.

The main conclusion here arrived at, and now held by
many naturalists, wlio are well competent to form a sound
judgment, is that man is descended from some less highly
organized form. The grounds upon which this conclusion
rests will never be shaken, for the close similarity between
man and the lower animals in embryonic development,
as well as in innumerable points of structure and constitu-
tion, both of high and of the most trifling importance — the
rndiments which he retains, and the abnormal reversions to
which he is occasionally liable — are facts which cannot be
disputed. They have long been known, but, until recently,
they told us nothing with respect to the origin of man.
Now, when viewed by the light of our knowledge of the
whole organic world, their meaning is unmistakable. The
great principle of evolution stands up clear and firm when
these groups of facts are considered in connection with

6M THE DESCENT OF MAN.

others, such as the mutual affinities of the members of the
same group, their geographical distribution in past and
present times, and their geological succession. It isincl-edi-
ble that all these facts should speak falsely. He who is not
content to look, like a savage, at the phenomena of nature
as disconnected, cannot any longer believe that man is the
work of a separate act of creation. He will be forced to
admit that the close resemblance of the embryo of man to
that, for instance, of a dog — the construction of his skull,
limbs and whole frame on the same plan with that of other
mammals, independently of the uses to which the parts
may be put — the occasional reappearance of various
structures, for instance of several muscles, which man
does not normally possess, but which are common to ti^e
Quadrumana — and a crowd of analogous facts — all point
in tlie plainest manner to the conclusion that man is
the CO - descendant with other mammals of a common
progenitor.

We have seen that man incessantly presents individual
differences in all parts of his body and in his mental
faculties. These ditferences or variations seem to be
induced by the same general causes, and to obey the same
laws as with the lower animals. In both cases similar laws
of inheritance prevail. Man tends to increase at a greater
rate than his means of subsistence; consequently he is occa-
sionally subjected to a severe struggle for existence, and
natural selection will have effected whatever lies within its
scope. A succession of strongly marked variations of a
similar nature is by no means requisite; slight fluctuating
differences in the individual suffice for the work of natural
selection; not that we have any reason to suppose that in
the same species all parts of the organization tend to vary
to the same degree. We may feel assured that the inherited
effects of the long-continued use or disuse of parts will
have done much in the same direction with natural selec-
tion. Modifications formerly of importance, though no
louger of any special use, are long-inherited. When one
part is modified other parts change through the principle
of correlation, of which we have instances in many curious
cases of correlated monstrosities. Something may be
attributed to the direct and definite action of the surround-
ing conditions of life, such as abundant food, heat or
moisture; and, lastly, many characters ol slight physio-

GENERAL BUMMARY AND CONCLUSION. 695

logical importance, some indeed of considerable importance,
have been gained through sexual selection.

No doubt man, as well as every other animal, presents
structures, which seem to our limited knowledge, not to be
now of any service to liim, nor to have been so formerly,
either for the general conditions of life, or in the relations
of one sex to the other. Such structures cannot be
accounted for by any form of selection, or by the inherited
effects of the use and disuse of parts. We know, however,
that many strange and strongly marked peculiarities of
structure occasionally appear in our domesticated produc-
tions, and if their unknown causes were to act more uni-
formly, they would probably become common to all the
individuals of the species. We may hope hereafter to
understand something about the causes of such occasional
modifications, especially through the study of monstrosities;
hence, the labors of experimentalists, such as those of M.
Camille Dareste, are full of promise for the future. In
general we can only say that the cause of each slight varia-
tion and of each monstrosity lies much more in the con-
stitution of the organism than in the nature of the sur-
rounding conditions; though new and changed conditions
certainly play an important part in exciting organic
changes of many kinds.

Through the means just specified, aided perhaps by
others as yet undiscovered, man has been raised to his
present state. But since he attained to the rank of man-
hood, he has diverged into distinct races, or, as they may
be more fitly called, sub-species. Some of these, such as
the negro and European, are so distinct that, if specimens
had been brought to a naturalist without any further in-
formation, they would undoubtedly have been considered
by him as good and true species. Nevertheless, all the
races agree in so many unimportant Hetails of structure and
in so many mental peculiarities that these can be ac-
counted for only by inheritance from a common progenitor;
and a progenitor thus characterized would probably deserve
to rank as man.

It must not be supposed that the divergence of each race
from the other races and of all from a common stock can
be traced back to any one pair of progenitors. On the con-
trary, at every stage in the process of modification, all the
individuals which were in any way better fitted for their

696 THE DESCENT OF MAN.

conditions of life, though in different degrees, would have
survived in greater numbers than the less well-fitted. The
process would have been like that followed by man, when
he does not intentionally select particular individuals, but
breeds from all the superior individuals and neglects the
inferior. He thus slowly but surely modifies his stock and
unconsciously forms a new strain. So with respect to
modifications acquired independently of selection, and due
to variations arising from the nature of the organism and
the action of the surrounding conditions, or from changed
habits of life, no single pair will have been modified much
more than the other pairs inhabiting the same country, for
all will have been continually blended through free inter-
crossing.

By considering the embryological structure of man — the
homologies which he presents with the lower animals — the
rudiments which he retains — and the reversions to which
he is liable, we can partly recall in imagination the former
condition of our early progenitors; and can approximately
place them in their proper place in the zoological series.
we thus learn that man is descended from a hairy, tailed
quadruped, probably arboreal in its habits and an inhabi-
tant of the Old World. This creature, if its whole
structure had been examined by a naturalist, would have
been classed among the Quadrumana, as surely as the still
more ancient progenitor of the Old and JSTew World mon-
keys. The Quadrumana and all the higher mammals are
probably derived from an ancient marsupial animal and
this through a long line of diversified, forms, from some
amphibian-like creature, and this again from some fish-like
animal. In the dim obscurity of the past we can see that
the early progenitor of all the Vertebrata must have been an
aquatic animal, provided with branchiae, with the two sexes
united in the same individual, and with the most important
organs of the body (such as the brain and heart) imper-
fectly or not at all developed. This animal seems to have
been more like the larvae of the existing marine Ascidians
than any other known form.

The high standard of our intellectual powers and moral dis-
position is the greatest difficulty which presents itself, after
we have been driven to this conclusion on the origin of
man. But every one who admits the principle of evolutiou

eEITERAL SUMMARY AND CONCLUSION, 697

must see that the mental powers of the' higher animals,
which are the same in kind with those of man, though so
different in degree, are capable of advancement. Thus
the interval between the mental powers of one of the
higlier apes and of a fish, or between those of an ant and
scale-insect, is immense ; yet their development does not
offer any special difficulty ; for with our domesticated
animals the mental faculties are certainly variable, and
the variations are inherited. No one doubts that they are
of the utmost importance to animals in a state of nature.
Therefore, the conditions are favorable for their develop-
ment through natural selection. The same conclusion
may be extended to man; the intellect must have been all-
important to him, even at a very remote period, as enabling
him to invent and use language, to make weapons, tools,
traps, etc., whereby with the aid of his social habits he
long ago became the most dominant of all living creatures.

A great stride in the development of the intellect will
have followed, as soon as the half-art and half-instinct
of language cams into use; for the continued use of lan-
guage will have reacted on the brain and produced an
inherited effect; and this again will have reacted on the
improvement of language. As Mr. Chauncey AV right* has
well remarked, the largeness of the brain in man relatively
to his bod>r compared with the lower animals, may be
attributed in chief part to the early use of some simple
form of language — that wonderful engine which affixes
signs to all sorts of objects and qualities, and excites trains
of thought which would never arise from the mere impression
of the senses, or if they did arise could not be followed out.
The higher intellectual powers of man, such as those of
ratiocination, abstraction, self-consciousness, etc., probably
follow from the continued improvement and exercise of the
other mental faculties.

The development of the moral qualities is a more inter-
esting problem. The foundation lies in the social instincts,
including under this term the family ties. These instincts
are highly complex, and in the case of the lower animals
give special tendencies toward certain definite actions; but
the more important elements are love and the distinct

* " On the Limits of Natural Selection," iu tlie " North Amerioaa
llcview," Oct., 1870, p. 295.

698 THE DESCENT OF MAN.

emotion of sympathy. Animals endowed with the social
instincts take pleasure in one another's company, warn one
another of danger, defend and aid one another in many
ways. These instincts do not extend to all the individuals
of the species, but only to those of the same community.
As they are highly beneficial to the species they have in all
probability been acquired through natural selection.

A moral being is one who is capable of reflecting on his
past actions and their motives — of approving of some and
disapproving of others; and the fact that man is the one
being who certainly deserves this designation is the great-
est of all distinctions between him and the lower animals.
But in the fourth chapter I have endeavored, to show that
the moral sense follows, firstly, from the enduring and ever-
present nature of the social instincts; secondly, from man's
appreciation of the approbation and disapprobation of his
follows; and, thirdly, from the high activity of his mental
faculties, with past impressions extremely vivid; and in
these latter respects he differs from the lower animals.
Owing to this condition of mind, man cannot avoid look-
ing both backward and forward and comparing past im-
pressions. Hence after some temporary desire or passion
has mastered his social instincts, he reilects and compares
the now weakened impression of such past impulses with
the ever-present social instincts ; and he then feels that
sense of dissatisfaction which all unsatisfied instincts leave
behind them, he therefore resolves to act differently for
the future — and this is conscience. Any instinct perma-
nently stronger or more enduring than another gives rise
to a feeling which we express by saying that it ought to be
obeyed. A pointer dog if able to reflect on his past con-
duct would say to himself, I ought (as indeed we say of
him) to have pointed at that hare and not have yielded to
the passing temptation of hunting it.

Social animals are impelled partly by a w^sh to aid the
members of their community in a general manner, but
more commonly to perform certain definite actions. Man
is impelled by the same general wish to aid his fellows;
but has few or no special instincts. He differs also from
the lower animals in the power of expressing his desires by
words, which thus become a guide to the aid required and
bestowed. The motive to give aid is likewise much modi-
fied in man; it no longer consists solely of a blind instinct-

GENERAL SUMMARY AND CONCLUSION. 699

ive impulse, but is much influenced by the praise or blame
of his fellows. The appreciation and the bestowal of
praise and blame both rest on sympathy; and this emotion,
as we have seen, is one of the most important elements of
the social instincts. Sympathy, though gained as an in-
stinct, is also much strengthened by exercise or habit. As
all m.en desire their own happiness, praise or blame is
bestowed on actions and motives according as they lead to
this end; and as happiness is an essential part of the gen-
eral good the greatest-happiness principle indirectly serves
as a nearly safe standard of right and wrong. As the rea-
soning powers advance and experience is gained the remoter
effects of certain lines of conduct on the character of the
individual and on the general good are perceived; and then
the self-regarding virtues come within the scope of public
opinion and receive praise and their opposites blame. But
with the less civilized nations reason often errs, and many
bad customs and base superstitions come within the same
scope and are then esteemed as high virtues and their
breach as heavy crimes.

The moral faculties are generally and justly esteemed as
of higher value than the intellectual powers. But we
should bear in mind that the activity of the mind in vividly
recalling past impressions is one of the fundamental though
secondary bases of conscience. This affords the strongest
argument for educating and stimulating in all possible
ways the intellectual faculties of every human being. No
doubt a man with a torpid mind, if his social affections and
sympathies are well developed, will be led to good actions,
and may have a fairly sensitive conscience. But whatever
renders the imagination more vivid and strengthens the
habit of recalling and comparing past impressions will make
the conscience more sensitive, and may even somewhat
compensate for weak social affections and sympathies.

The moral nature of man has reached its present stand-
ard partly through the advancement of his reasoning powers
and consequently of a just public opinion, but especially
from his sympathies having been rendered more tender ana
widely diffused through the effects of habit, example,
instruction and reflection. It is not improbable that after
long practice virtuous tendencies may be inherited. "With
the more civilized races the conviction of the existence of
an all-seeing Deity has had a potent influence on the

700 THE DESCENT OF MAN,

advance of morality. Ultimately man does not accept tho
praise or blame of his fellows as his sole guide, though
few escape this influence, but his liabitual convictions, con-
trolled by reason, afi'ord him the safest rule. His con-
science then becomes the supreme judge and monitor.
Nevertheless, the first foundation or origin of the moral senso
lies in the social instincts, including sympathy; and these
instincts no doubt v/ere primarily gained, as in the case of
the lower animals, through natural selection.

The belief in God has often been advanced as not only
the greatest but the most complete of all the distinctions
between man and the lower animals. It is, however, im-
possible, as we have seen, to maintain that this belief is
innate or instinctive in man. On the otiier hand, a belief
in all-pervading spiritual agencies seems to be universal;
and apparently follows from a considerable advance in
man's reason, and from a still greater advance in his
faculties of imagination, curiosity and wonder. I am
aware that the assumed instinctive belief in God has been
used by many persons as an argument for His existence.
But this is a rash argument, as we should thus be compelled
to believe in the existence of many cruel and malignant
spirits, only a little more powerful than man; for the
belief in them is far more general than in a beneficient Deity.
The idea of a universal and beneficient Creator does not
seem to arise in the mind of man until he has been elevated
by long-continued culture.

• He who believes in the advancement of man from some
low organized form will naturally ask, How does this bear
on the belief in the immortality of the soul? The barbar-
ous races of man, as Sir Jc Lubbock has shown, possess no
clear belief of this kind ; but arguments derived from the
primeval beliefs of savages are, as we have just seen, of
little or no avail. Few persons feel any anxiety from the
impossibility of determining at what precise period in the
development of the individual, from the first trace of a
minute germinal vesicle, man becomes an immortal being;
and there is no greater cause for anxiety because the
period cannot possibly be determined in the gradually
ascending organic scale.*

*Tbe Kev. J. A. Picton ^ives a discussion to this effect in his
" New Theories and the Old Faith." 18T0.

GENERAL SUMMARY AND CONCL USION, 701

I am aware that the conchisions arrived at in this work
will be denounced by some as highly irreligious; but he
who denounces them is bound to show why it is more irre-
ligious to explain the origin of man as a distinct species by
descent from some lower form, through the laws of varia-
tion and natural selection, than to explain the birth of the
individual through the laws of ordinary reproduction.
The birth both of the species and of the individual are equally
parts of that grand sequence of events, which our minds
refuse to accept as the result of blind chance. The under-
standing revolts at such a conclusion, whether or not we
are able to believe that every slight variation of structure,
the union of each pair in marriage, the dissemination of
eacii seed, and other such events have all been ordained for
Gome special purpose.

Sexual selection has been treated at great length in this
work; for, as I have attempted to show, it has played an
important part in the history of the organic world. I am
aware that much remains doubtful, but I have endeavored
to give a fair view of the whole case. In the lower divis-
ions of the animal kingdom sexual selection seems to have
done nothing; such animals are often affixed for life to the
same spot, or have the sexes combined in tlie same indi-
vidual, or, what is still more important, their perceptive and
intellectual faculties are not sufficiently advanced to allow
of the feelings of love and jealousy, or of the exertion of
choice. When, however,, we come to the Arthropoda and
Vertebrata, even to the lowest classes in these two great
Bub-ldngdoms, sexual selection has effected much.

In the several great classes of the animal kingdom — in
mammals, birds, reptiles, fishes, insects and even crusta-
ceans— the differences between the sexes follow nearly the
same rules. The males are almost always the wooers; and
they alone are armed with special weapons for fighting with
their rivals. They are generally stronger and larger than
the females, and are endowed with the requisite qualities
of courage and pugnacity. They are provided, either
exclusively or in a much higher degree than the females,
with organs for vocal or instrumental music, and with
odoriferous glands. They are ornamented with infinitely
diversified appendages, and with the most brilliant or con-
Bpicuous colors, often arranged in elegant patterns, while

702 THE DESCENT OF MAN.

the females are unadorned. AVhen the sexes differ in more
important structures it is the male which is provided with
special sense-organs for discovering the female, with loco-
motive organs for reaching her, and often with prehensile
organs for holding her. These various structures for charm-
ing or securing the female are often developed in the male
during only part of the year; namely, the breeding-season.
They have in many cases been more or less transferred to
the females; and in the latter case tliey often appear in her
as mere rudiments. They are lost or never gained by the
males after emasculation. Generally they are not developed
in the male during early youth, but appear a short time
before the age for reproduction. Hence, in most cases th6
young of both sexes resemble each other; and the female
somewhat resembles her young offspring throughout life.
In almost every great class a few anomalous cases occur,
where there has been an almost complete transposition of
the characters proper to the two sexes; the females assum-
ing characters which properly belong to the males. This
surprising uniformity in the laws regulating the differences
between the sexes in so many and such widely separated
classes is intelligible if we admit the action of one common
cause; namely, sexual selection.

Sexual selection depends on the success of certain indi-
viduals over others of the same sex, in relation to the prop-
agation of the species; while natural selection depends on
the success of both sexes, at all ages, in relation to the gen-
eral conditions of life. The sexual struggle is of two
kinds; in the one it is between the individuals of* the same
sex, generally the males, in order to drive away or kill their
rivals, the females remaining passive; while in the other,
the struggle is likewise between the individuals of the
same sex, in order to excite or charm those of the opposite
sex, generally the females, which no longer remain passive,
but select the more agreeable partners. This latter kind
of selection is closely analogous to that which man unin-
tentionally, yet effectually, brings to bear on his domesti-
cated productions, when he preserves during a long period
the most pleasing or useful individuals, without any wish to
modify the breed.

The laws of inheritance determine whether characters
gained through sexual selection by either sex shall be trans-
mitted to the same sex, or to both; as well as the age at

QENEUAL SUMMARY AND CONCLUSION. %^

wliicli they shall be developed. It appears that variatio72S
arising late in life are commonly transmitted to one and
the same sex. Variability is the necessary basis for tlie
action of selection and is wholly independent of it. It fol-
lows from this, that variations of the same general nature
have often been taken advantage of and accumulated
through sexual selection in relation to the propagation of
the species, as well as through natural selection in relation
to the general purposes of life. Hence secondary sexual
characters, when equally transmitted to both sexes, can be
distinguished from ordinary specific characters only by the
light of analogy. The modifications acquired through
sexual selection are often so strongly pronounced that the
two sexes have frequently been ranked as distinct species,
or even as distinct genera. Such strongly marked differ-
ences must be in some manner highly important; and we
know that they have been acquired in some instances at
the cost not only of inconvenience, but of exposure to
actual danger.

The belief in the power of sexual selection rests chiefly
on the following considerations. Certain characters are
confined to one sex; and this alone renders it probable that
in most cases they are connected with the act of reproduc-
tion. In innumerable instances these characters are fully
developed only at maturity, and often during only a part of
the year, which is always the breeding season. The males
(passing over a few exceptional cases) are the more active
in courtship; they are the better armed, and are rendered
the more attractive in various ways. It is to be especially
observed that the males display their attractions with
elaborate care in the presence of the females; and that
they rarely or never display them excepting during the
season of love. It is incredible that all this should be pur-
poseless. Lastly, we have distinct evidence with some
quadrupeds and birds that the individuals of one sex are
capable of feeling a strong antipathy or preference for
certain individuals of the other sex.

Bearing in mind these facts and the marked results of
man's unconscious selection when applied to domesticated
animals and cultivated plants it seems to me almost cer-
tain that if the individuals of one sex were during a long
series of generations to prefer pairing with certain indi-
viduals of the other sex, characterized in some peculiar

704 THE DESCElTT OF MAK,

manner, the offspring would elowly but surely become
modified in this same manner. I have not attempted to
conceal that, excepting when the males are more numerous
thi.n the females, or when polygamy prevails, it is doubtful
how the miOre attractive males succeed in leaving a larger
number of oll'spring to inherit their superiority in orna-
ments ov other charms than the less attractive males; but
I have shown that this would probably follow from the
females— especially the more vigorous ones, which would
Le the first to breed — preferring not only the more attract-
ive but at the same time the more vigorous and victorious
males.

Altliough we have some positive evidence that birds
appreciate bright and beautiful objects, as with the bower-
birds of Australia, and although they certainly appreciate
the power of song, yet I fully admit that it is astonishing
that tiie females of many birds and some mammals should
be endowed with sufficient taste to appreciate ornaments
which we have reason to attribute to sexual selection; and
this is even more astonishing in the case of reptiles, fish
and insects. But we really know little about the minds of
the lower animals. It cannot be supposed, for instance, that
male birds of paradise or peacocks should take such pains
in erecting, spreading and vibrating their beautiful plumes
before the females for no purpose. AVe should remember
the fact given on excellent authority in a former chapter
that several peahens, when debarred from an admired male,
remained widov.-s during a whole season rather than pair
with another bird.

Nevertheless, I know of no fact in natural history more
wonderful than that the female Argus pheasant should
appreciate the exquisite shading of the ball-am! -socket
ornaments and the elegant patterns on the wing-feathers
of the male. He who thinks that the male was created as
he now exists must admit that the great plumes, which
prevent the wings from being used for flight and which
are displayed during courtship and at no other time in a
manner quite peculiar to this one species, were given to
him as an ornament. If so, he must likewise admit that
the female was created and endowed with the capacity of
appreciating such ornaments. I differ only in the convic-
tion that the male Argus pheasant acquired his beauty
gradually, through the prefeieace of the females during

GENEBAL SUMMARY AND CONCLUSIGIT 705

many generations for the more highly ornamented males;
the esthetic capacity of the females having been advanced
through exercise or habit just as our own taste is gradually
improved. In the male, through the iortunate chance of a
few feathers being left unchanged, we can distinctly trace
how simple spots with a little fulvous shading on cue side
may have been developed by small steps irtc the ^vonderful
ball-and socket ornaments; and it is probable that they
were actually thus developed.

Every one who admits the principle of evolution, and
yet feels great diffi..ulty in admitting that female mammalSj
birds, reptiles una fish, could have acquired the high taste
implied by the joauty of the males, and which generally
coincides with our own standard, should reflec*- that the
nerve eel Is of the oiain in the highest as well as in the
lowest members ol the Vertebrate series, are derived from
those of the common progenitor of this great hingdom.
For we can thus see how it has come to pass that certain
mental faculties, in various and widely distinct groups ol
animalS; have been developed in nearly the same mannei
and to nearlv in^ same 'legree.

The reader wuO has taken the trouble ^:o gc chrough the
several cnap^'.ers devoted tc sexual selection will be able to
judge nov/ far .he conclusions at which i have arrived are
supported by sufficient ividencec If hp accepts these con
elusions he may, i thinKc safely extend them tc mankind^
buc it would be superfluous here to repear wnr t i ha^e so
lately said on the manner in which sexual seleccion appar-
ently has acted on man., both on the male and female sid3,
causing the two sexes to diifer in body and mind, and the
several races tc diifer from each other in various characters,
as wesi as from their ancient and louly organized pro-
genitors.

Il3 who admits the principle of sexual selection will be
led to the remarkabb conclusion that the nervous system
not only regulates most of the existing functions oi the
body, but has indirectly in.iuenced the progressive develop-
ment of various bodily structures and of certain mental
qualities. Courage, pugnacity, perseverance, strength and
size of body, weapons of all kinds, musical organs, both
vocal and instrumental, bright colors and ornamental ap-
pendages, have all been indirectly gained by the one sex or
the other, through the exertion of choice, the influence ol

roc THE DESCENT OF MAN,

love and jealousy and the appreciation of the beautiful in
Boundj color or form; and these powers of the mind mani-
festly depend on the development of the brain.

Man scans with scrupulous care the character and pedi-
gree of his horses^ cattle and dogs before he matches them;
but when he comes to his own marriage lie rarely, or never,
takes any such care. He is impelled by nearly the same
motives as the lower animals^ when they are left to their
own free choice, though he is in so fai superior to them
that he highly values mental charms and virtues. On the
other hand he is strongly attracted by mere wealth or rank.
Yet he might by selection do something not only for the
bodily constitution and frame of his offspring, but for their
intellectual and moral qualities. Both sexes ought to re-
frain from marriage if they are in any marked degree in-
ferior in body or mind; but such hopes are Utopian and
will never be even partially realized until the laws of in-
heritance are thoroughly known Every one does good
service, who aids toward this end. When the principles of
breeding ana inheritance are better: understood, we shall
not hear ignorant memberr of our legislature rejecting with
scorn a plan ior ascertaining FUether or not consanguineous
marriages are injurious to man.

The advancement of the welfare of mankind is a most
intricate problem; all ought to refrain from marriage who
cannot avoid abject poverty for their children; for poverty
is not only a grea: evu, but tends to its owr increase by
leaaing to recklessness ii: marriage On the other hand,
as Mr. Galton hasremaiKed, if the prudent avoid marriage,
while the reckless many, the inferior members tend to
supplant the better members of society. Man, like every
other animal, has no doubt advanced to his present high
condition through a struggle for existence conseouent on
his rapid multiplication ; and if he is to advance still higher,
it is to be feared that he must remain subject to a severe
struggle. Otherwise he would sink into indolence, and the
more gifted men would not be more successfu! in the battle
of life than the loss gifted. Hence our natural rate of
increase, thoi-.gh leading to many and obvious evils, must
not be greatly dimir.ished by any means. There should
be open competition for all men; and the most able should
not be prevented by laws or customs from succeeding

GENERAL SUMMARY AND CONCLUSION, 70?

best and rearing the largest number of offspring. Impor-
tant as the struggle for existence has been and even still is,
yet as far as the highest part of man's nature is concerned
there are other agencies more important. For the moral
qualities are advanced,, either directly or indirectly, much
more through the effects of habit, the reasoning powers,
instruction, religion, etc., than through natural selection;
though to this latter agency may be safely attributed the
social instincts which afforded the basis for the develop-
ment of the moral sense.

The main conclusion arrived at in this work, namely,
that man is descended from some lowly organized form,
will, I regret to think, be highly distasteful to many. But
there can hardly be a doubt that we are descended from
barbarians. The astonishment which I felt on first seeing
a party of Fuegians on a wild and broken shore will never
be forgotten by me, for the reflection at once rushed into
my mind — such were our ancestors. These men were
absolutely naked and bedaubed with paint, their long hair
was tangled, their mouths frothed with excitement, and
their expression was wild, startled and distrustful. They
possessed hardly any arts, and like wild animals lived on
what they could catch; they had no government, and were
merciless to every one not of their own small tribe. He
who has seen a savage in his native land will not feel much
shame, if forced to acknowledge that the blood of some
more humble creature flows in his veins. For my own part
I would as soon be descenaed from that heroic little mon-
key who braved his dreaded enemy in order to save the
life of his keeper, or from that old baboon, who, descend-
ing from the mountains, carried away in triumph his
young comrade from a crowd of astonished dogs — as from
a savage who delights to torture his enemies, offers up
bloody sacrifices, practices infanticide without remorse,
treats his wives like slaves, knows no decency, and is
haunted by the grossest superstitions.

Man may be excused for feeling some pride at having
risen, though not through his own exertions, to the very
summit of the organic scale; and the fact of his having
thus risen, instead of having been aboriginally placed there,
may give him hope for a still higher destiny in the distant
future. But we aie not here concerned with hopes or fears.

703 THE DESCENT OF MAN,

only with the truth as far as our reason permits us to dis-
cover it; and I have given the evidence to the best of my
ability. We must, however, acknowledge, as it seems to
me, that man, with all his noble qualities, with sympathy
which feels for the most debased, with benevolence which
extends not only to other men but to the humblest living
creature, with his godlike intellect which has penetrated
into the movements and constitution of tl:c solar system —
with all these exalted powers — man still bears in his bodily
frame the indelible stamp of his lowly origin.

SUPPLEMENTAL NOTE, 70O

SUPPLEMENTAL NOTE

ON

SEXUAL SELECTION IN RELATION TO MONKEYS.
[Reprinted from Nature, November 2, 1870, p. 18.]

In the discnssion on sexual selection in my "Descent of
Man;" no case interested and perplexed me so much as the
brio-hily colored hinder ends and adjoining parts of certain
monkeys. As these parts are more briglitly colored in one
BOX tlian the other, and as they become more brilliant
daring the season of love, I concluded that the colors had
been gained as a sexual attraction. I was well aware that
I thus hiid myself open to ridicule; though in fact it is not
more surprising that a monkey should display his bright-
red hinder end than that a peacock should display his mag-
nificent tail. I had, however, at that time no evidence of
monkeys exhibiting tliis part of their bodies during their
courtship ; and such display in the case of birds
affords the best evidence that the ornaments of the
males are of service to them by attracting or
exciting the females. I have lately read an article
by Joh. von Fischer, of Gotha, published in '*Der
Zoologisclie Garten," April, 1876, on the expression of
monkeys under various emotions, which is well worthy of
study by any one interested in the subject, and which
shows that the author is a careful and acute observer. In
this article there is an account of the behavior of a young
male mandrill when he first beheld liiniself in a looking-
glass, and it is added that after a time he turned round
and presented his red hinder end to the glass. Accord-
ingly I wrote to Herr J. von Fischer to ask what he sup-
posed'was the meaning of this strange action, and he haa
sent me two long letters full of new and curious details,
which will, I hope, be hereafter published. He says that

ri 0 THE DESCENT OF MAN.

he was himself at first perplexed by the above action, and
was thus led carefully to observe several individuals of
various other species of monkeys, which he has long kept
in his house. He finds that not only the mandrill (C'l/no-
ceplialus inormnn) but the drill (6'. leiico^jhcens) and three
other kinds of baboons {C.haniadryas sphinx and baboiiin),
also Cijnnpitliecus niger, and Macacus rhesus and nenies-
trinus, turn this part of their bodies, which in all these
species is more or less brightly colored, to him when they
are pleased, and to other persons as a sort of greeting. He
took pains to cure a Macacus rhesus, which he had. kept
for five years, of this indecorous habit, and at last suc-
ceeded. These monkeys are particularly apt to act in this
manner, grinning at the same time, when first introduced
to a new monkey, but often also to their old monkey
friends; and after this mutual display they begin to play
together. The young mandrill ceased spontaneously after
a time to act in this manner toward his master. Von
Pischer, but continued to do so toward persons who Avere
strangers and to new monkeys. A young Cynopilhecus
niger never acted, excepting on one occasion, in this way
toward his master, but frequently toward strangers,
and continues to do so up to the present time. From
these facts Von Fisciier concludes that the monke3^s
which behaved in this manner before a looking-glass
(viz., the mandrill, drill, Cynopithecus niyer, Maca-
cus rhesus and nemestrinus) acted as if their reflec-
tion were a new acquaintance. The mandrill and drill,
which have their hinder ends especially ornamented,
display it even while quite young, more frequently and
more ostentatiously than do the other kinds. Next in
order comes Cynocephalus hamadryas, while the other
species act in this manner seldomer. The individuals,
however, of the same species vary in this respect, and some
which were very shy never displayed their hinder ends. It
deserves especial attention that Von Fischer has never
!seen any species purposely exhibit the hinder part of its
body, if not at all colored. This remark applies to many
individuals of Macacus cynomolgus and Cercocebus racli-
akis (which, is closely allied to J/, rhesus), to three species
•of Cercopithecus and several American monkeys. The
'finbit of turning the hinder ends as a greeting to an old
friend or new acquaintance, which seems to us so odd, is

SUPPLEMENTAL NOTE. til

not really more so than the habits of many savages, for
instance that of rubbing their bellies with their hands, or
rubbing noses together. The habit with the mandrill and
drill seems to be instinctive or inherited, as it was followed
by very young animals; but it is modified or guided, like
BO many other instincts, by observation, for Von Fischer
says that they take pains to make their display fully; and
if made before two observers^. they turn to him who seems
to pay the most attention.

With respect to the orio^in of the habit, Von Fischer
remarks that his monkeys like to have their naked hinder
ends patted or stroked, and that they then grunt with
pleasure. They often also turn this part of their bodies
to other monkeys to have bits of dirt picked off, aud so
no doubt it would be with respect to thorns. But the
habit with adult animals is connected to a certain extent
with sexual feelings, for Von Fischer watched through a
glass door a female Cynopithecns niger, and she, during
several days, ••'umdrehto und dem Milnnchen mit gur-
gelnden Tonen die stark gerothete Sitzflache zeigte. was
ich friiher nie an diesem Thier bemerkt hatte. Beim
Anblick dieses Gegenstandes erregte sich das Milnnchen
sichtlich. denn es polterte heftig an den Stilben, ebenfalls
gurgelnde Laute ausstossend.^' As all the monkeys which
have the hinder parts of their bodies more or less brightly
colored live, according to Von Fischer, in open rocky
places, he thinks that these colors serve to render one sex
conspicuous at a distance to the other; but as monkeys are
such gregarious animals I should have thought that there
was no need for the sexes to recognize each other at a dis-
tance. It seems to me more probable that the l3right
colors, whether on the face or hinder end, or, as in the
' mandrill, on both, serve as a sexual ornament and attrac-
tion. Anyhow, as we now know that monkeys have the
habit of turning their hinder ends toward other monkeys,
it ceases to be at all surprising that it should have been
this part of their bodies which has been more or less
decorated. The fact that it is only the monkeys thus
characterized whicli. as far as at present known, act in this
manner as a greeting toward other monkeys renders it
doubtful whether the habit was first acquired from some
independent cause, and that afterward the parts in ques-
tion were colored as a sexual ornament; or whether the

712 THE DESCENT OF MAN.

coloring and tho habit of turning round were first acquired
through variation and sexual selection, and that afterward
the habit was retained as a sign of pleasure or as a greet-
ing through the principle of inherited association. This
principle apparently comes into play on many occasions;
thus it is generally admitted that the songs of birds serve
mainly as an attraction during tlie season of love, and that
the lekfi, or great congregations of the black grouse, are
connected with their courtship; but the habit of singing
has been retained by some birds when they feel happy, for
instance, by the common robin, and the iiabit of congre-
gating has been retained by the black grouse during other
seasons of tho year.

I beg leave to refer to one other point in relation to
sexual selection. It has been objected that this form of
selection, as far as the ornaments of the males are con-
corned, implies that all the females within the same dis-
trict must possess and exercise exactly the same taste. It
should, however, be observed, in the first place, that
altliongh the range of variation of a species may be very
large it is by no means indefinite. I have elsewhere given a
good instance of this fact in tlie pigeon, of which there arc
at least a hundred varieties differing widely in their colors,
and at least a score of varieties of the* fowl differing in
the same kind of way; bnt the range of color in these
two species is extremely distinct. Therefore the females of
natural species cannot have an unlimited scope for their
taste. In the second place, I presume that no supporter of
the principle of sexual selection believes that the females
select particular points of beauty in the males; they are
merely excited or attracted in a greater degree by one male
than by another, and this seems often to depend, especially
with birds, on brilliant coloring. Even man, excepting
perhaps an artist, does not analyze the slight differences in
the features of the woman whom he may admire, on which
her beauty depends. The male mandrill has not only the
hinder end of his body, but his face gorgeously colored and
marked with oblique ridges, a yellow beard and ether orna-
ments. AVe may infer from what we see of the variation
of animals under domestication that the above several
ornaments of the mandrill were gradually acquired by one
individual varying a little in one way and another indi-
vidual in another way. The males wliicli were the hau(i*

SUPPLEMENTAL NOTE, 713

somest or the most attractive in any manner to the females
would pair cftenest, and would leave rather more offspring
than other males. The offspring of the former, although
variously intercrossed, would either inherit the peculiarities
of their fathers or transmit an increased tendency to vary
in the same manner. Consequently the whole body of
males inhabiting the same country would tend from the
eifects of constant intercrossing to become modified almost
uniformly, but sometimes a little more in one character and
sometimes in another, though at an extremely slow rate; all
ultimately being thus rendered more attractive to the
females. The process is like that which I have called
unconscious selection by man, and of which I have given
several instances. In one country the inhabitants value a
fleet or light dog or horse, and in another country a heavier
and more powerful one; in neither country is there any
selection of individual animals with lighter or stronger
bodies and limbs; nevertheless, after a considerable lapse
of time, the individuals are found to have been modified in
the desired manner almost uniformly, though differently in
each country. In two absolutely distinct countries inhab-
ited by the same species, the individuals of which can
never, during long ages, have intermigrated and inter-
crossed, and where, moreover, the variations will probably-
not have been identically the same, sexual selection might
cause the males to diff'er. Nor does the belief appear to
me altogetlier fanciful that two sets of females, surrounded
by a very different environment, would be apt to acquire
somewhat different tastes with respect to form, sound or
color. However this may be, I have given in my *' Descent
of Man" instances of closely allied birds inhabiting dis-
tinct countries, of which the young and the females cannot
be distinguished, while the adult males differ considerably,
and this may be attributed with much probability to the
action of sexual selection.

INDEX.

Abbott, C, on the battles of seals, 571.

Abductor of the fifth metatarsal, presence of, in man, 47.

Abercrombie, Dr., on disease of the brain affecting speech, 100.

Abipones, marriage customs of the, 683.

Abortion, prevalence of the practice of, 53.

Abou-Simbel, caves of, 191.

Abramis brama, 282,

Abstraction, power of, in animals, 93.

Acalk'S, stridulation of, 346.

Acanthodactylus capensis, sexual differences of color in, 405.

Accentor moclalarlK, 539.

Acclimatization, difference of, in different races of men, 191.

Achetidae, stridulation of the, 320, 321, 323; rudimentary stridulat-
ing organs in female, 326.

Acltius aulcatus, elytra of the female, 313.

Acomus, development of spurs in the female of, 512.

Acridiidse, stridulation of the, 320, 324; rudimentary stridulating
organs in female, 326.

Acromio basilar muscle, and quadrupetal gait, 47.

Acting, 203.

Actinim, bright colors of, 294.

Adams, Mr., migration of birds, 122; intelligence of nut-liatcli,
466; on the Bombycilla carolinenm, 525.

Admiral buttertly, 353.

Adoption of the young of other animals by female monkeys, 79.

Advancement in the organic scale, Von Baer's definition of, 186.

Aeby, on the difference between the skulls of man and the
quad rum ana, 170.

Esthetic faculty, not highly developed in savages, 105.

Affection, maternal, 79; manifestation of, by animals. 79; parental
and filial, partly the result of natural selection, 120; mutual, of
birds, 407; shown by birds in confinement, for certain persons, 467.

Africa, probably the birthplace of man, 177; South, crossed popu-
lation of, 198, South, retention of color by the Dutch in, 219; South,
proportion of the sexes in the butterflies of, 283; tattooing practiced
in, .654; Northern, coiffure of natives of, 655.

Agassiz L,, on conscience in dogs. 117; on the coincidence of the
races of man with zoological provinces, 193; on the number of
species of man, 198; on the courtship of the land-snails, 297; on the
brightness of the colors of male fishes during the breeding-season,
385; on the frontal protuberance of the males of Oeophagus and
Cichla, 385, 392; male fishes hatchiuij; ova in their mouths, 391;

716 INDEX.

sexual differences in color of cliromids, 392; on the slight sexual
difference.s of the South Americans, G40; on the tattooing of the
Amazonian Indians, 657.

Age, in relation to the transmission of characters in birds, 528;
variation in accordance vvitli, in birds, 551.

Agdceus phceniceus, 2o5, 472.

Ayeronidferouia, noise produced by, 349.

Ayrion, dimorphism in, 328, 329.

Ay lion Ramhuiii, sexes of, 328.

Agrionidae, dilfertnce in the sexes of, 328.

Ayrutis exdamationis, 358.

Ague, tertian, dog suffering from, 8.

Ainos, hairiness of the, 639.

Aitchison, Mr., on sheep, 279.

jVithuruH polytmus, young of, 555.

Albino birds, 476.

Alra tarda, young of, 553.

Alccft paluKitd, 587.

Alder and Hancock, MM., on the nudi-brancli mollusca, 298.

Allen, J. A., vigor of birds earliest hatched, 240, 241; effect of
difference of temperature, light, etc., on Ijirds, 254, colors of birds,
480; on the relative size of the sexes of Cidlorldiius uvb-invH, 588; on
the name of OUirid jubdta, 594; on tlie pairing of seals, 596; on
sexual differences in tlie color of bats, 610; Allen, S., on the habits
of Jlaploptcruii, 414: on the plumes of Herons, 444, on the vernal
moult of IL'.rod'uisbiihidcuH, 445.

Alligator, court.-ihip of tlie male, 250, 398; roaring of the male,
646.

Amadavat. pugnacity of male, 416.
Am((diu<i Lathaiiii, disjjlay of plumage by the male, 456; amadina
caddiiotift, display of plumage by the male, 455

Amazous, butterflies of the, 283; tislies of the, 389.

Ameiica, variation in the skulls of aborigines of, 29; wide range
of aborigines of, 193; lice of the natives of, 193; general beardless-
iiess of the native.3 of, 639; North, butterflies of, 283; Indians of,
women a cauj-e of .strife among the. 640; Indians of, their notions of
feraa-le beauty, 659, 662; South, character of the natives of, 191;
population of parts of, 197; piles of stone in, 204; extinction of tbe
fossil horse of. 218, desert birds of, 558; sliglit srcxual difference of
the aborigines of, 640; prevalence of infanticide in, 675.

American languiiges, often highly artificial, 103.

Americans, wide geographical range of, 33; native, variability of,
198; and negroes, difference of, 224; aversion of, to hair ou the face,
C62.

AmmopIiUn, on the jaws of, 312.

AmmotrdfjiiH trageUiphns, iiairy forelegs of, 606, 609.

Amphibia, affinity of, to the ganoid fishes, 180; vocal organs cf
the. 646.

Ami)bibians, 187, 394; breeding while immature, 551.

Ainphioxtis, 181.

Amphipoda, males sexually mature while young, 552l

Amnnoph III, negro character of features of, 192,

Anal appendages of insects, 313k

INDEX. 717

Analogous variation in tlie plumage of birds, 438.

Anas, 525; aiuis ticuta, male plumage of, 446; anas boacJuis, male
plumage of, 446; aiui.s hidrijitica, 552; anas punctata, 425.

Anastomus oscitans, sexes and >ouug of, 553; white nuptial plum-
age of, 560.

Anatidae, voices of, 435.

Annxjanius, differences in tlie sexes of, 328.

Andaman islanders, susceptible to change of climate, 214.

Anderson. Dr., on the tail of Macacas bruiineus, 66; the Bufo
siki/nmensis, 396; sounds of £'chis carinata, 400.

A iidra^na fuloa, 331.

Anglo-Saxons, estimation of the beard among the, 663.

Animals, domesticated, more fertile than wild, 50; cruelty of
savages to, 133; characters common to man and, 166; domestic,
change of breeds of, 680.

Annelida, 299: colors of, 299.

Anobium tessellatum, sounds produced by, 347.

Anolis cnstateUus, male, crest of, 401; pugnacity of the male, 4.01;
throat-pouch of. 402.

Anser canadensis, 473; anser cygnoides, 471; knob at the base of
the beak of, 484; anser hifperboreus, whiteness of, 560.

Antelope, prong-horned, horns of, 265.

Antelopes, generally polygamous. 246; horns of, 265, 575; canine
teeth of some male, 572; use of horns of, 580; dorsel crests in, 606;
dewlaps of, 608; winter change of two species of, 619; peculiar
markings of, 621.

Antennae, furnished with cushions in the male of Penthe, 313.

Anthidiinn manicatuni, large male of, 316.

Anthocharis cardamines, 350, 354; sexual difference of color in,
364; anthocharis genutia, 'SUA; anthocharis sara, 354.

Aathophora acervorvm, large male of, 316; antho'phora return,
difference of the sexes in, 331.

Anthropiclse, 173.

Anihns, molting of, 444.

Antics of birds, 431.

Antigua, Dr. Nicholson's observations on yellow fever in, 223.

Antilocapra americana, horns of, 265, 575, 578.

Aiitilope bczoartica, horned females of, 575, 577, 578; sexual differ-
ence in tbe color of, 611: auiilope Dorcas euchore, 575.

Antilope euchore, horns of, 580; antilope montana, rudimentary
canines in tbe young male of, 586; antilope niger, sing-sing, caama
ami gorgon, sexual differences in the colors of, 61 2; antilope areas,
horns df, 265; antilope saiga, polygamous habits of, 246; antilope
strcpsiceros, horns of, 265; antilope subgutturosa, absence of suborbital
pits in, 604.

Antipatliy, shown by birds in confinement, to certain persons, 467.

Ants. 167; large size of cerebral ganglia in, 60; soldier, large jaws
of, 70; playing together, 77; memory in, 83; intercommunication of,
by means of the antenna?, 101: habits of, 167; difference of the
sexes in. 330; recognition of each other by, after separation, 830;
white, habits of, 330.

Anura, 395.

Apatania muliebns, male unknown, 287.

718 INDEX.

Apathus, difference of tlie sexes in, 331.

Apatura Iris, 348, 350.

Apes, difference of the young, from the adult, 9; semi-erect atti-
tude of some, 58; mastoid processes of, 59; influences of the jaw-
muscles on tbe physiognomy of, 60; female, destitute of large
canines, 71; building platforms, 93; imitative faculties of, 146;
anthropomorphous, 175; probable speedy extermination of the, 177;
Gratiolet on the evolution of, 202; canine teeth of male, 672;
females of some, less hairy beneath than the males, 686; long-
armed, their mode of progression, 58.

Aphasia, Dr. Bateman on, 100.

Apis mellijica, large male of, 316.

Apollo, Greek statues of, 663.

Apuplexy in Ccbus Azarce, 7.

Appendages, anal, of insects, 313.

Approbation, influence of the love of, 124, 132, 148.

Aprosmictns scnpulatus, 521.

Apiis, proportion of sexes, 287.

Aquatic birds, frequency of white plumage in, 561.

Aquila chrymetoH, 463.

Arab women, elaborate and peculiar coiffure of, 666.

Arabs, fertility of crosses with other races, 195; gashing of clieeks
and temples among the, 655.

Arachnida, 307.

Arakhan, artificial widening of tlie forehead by the natives
of, 665.

Arhoncoln, young of, 533.

Archcopteryx, 180.

Arctiidae, coloration of the, 356.

Ardea a^ha, rufescens and ccerulea, change of color in, 562, 563;
ardea ccpvvlea, breeding in immature plumage, 552; ardea rjularis,
change of plumage in, 563; ardea herodias, love-ge.stures of tlie male,
431; ardea ludoviciana, age of mature plumage in, 551; continued
growth of crest and plumes in the male of, 552; ardea nycticorax,
cries of, 417.

Ardeola, young of, 534.

Ardetta, changes of plumage in, 524.

Argenteuil, 24.

Argus pheasant, 435, 457, 526; display of plumage by the male,
451; ocellated spots of the, 488; gradation of characters in the, 494.

Argyll, Duke of, on the physical weakness of man, 71: the fash-
ioning of implements peculiar to man, 92; on the contest in man
between right and wrong, 141; on the primitive civilization of man,
162; on the plumage of the male Argus pheasant, 451; on Urosticte
Benjamini, 503; on the nests of birds, 515.

Argynnis, coloring of the lower surface of, 356.

Aricoris epitus, sexual differences in the wings of, 314.

Aristocracy, increased beauty of the, 669.

Arms, proportions of, in soldiers and sailors, 36; direction of the
hair on the, 177; and hands, free use of, indirectly correlated with
diminution of canines, 60.

Arrest of development, 40, 41.

Arrow-heads, stone, general resemblance of, 203.

INDEX. 719

Arrows, use of, 203.

Arteries, variations in tlie course of tLe, 30.

Artery, effect of tying, upon the lateral channels, 36.

Arthropoda, 299. *

Arts practiced by savages, 203.

Ascension, colored incrustation on the rocks of, 298.

Ascidia, affinity of the lancelet to, 181; tadpole-like larvae of, 181.

Ascidians, 296; bright colors of some, 295.

Asinus, Asiatic and African species of, 626, asinus tceniopus, 626.

Ass, color variations of the, 626.

Aides, effects of brandy on an, 8; absence of the thumb in, ST;
ateles beelzebuth, ears of 16; ateles marginatas, color of the ruff of
613; hair on the head of, 627.

Ateuchus cicatricosus, habits of, 340.

Ateuchus, stridulation of, 346.

Athalia, proportions of the sexes in, 286.

Atropus pulsatorius, 330.

Attention, manifestations of, in animals, 83.

Audouin, V., on a hymenopterous parasite with a sedentary male,
251.

Audubon, J. J., on the pinioned goose, 119; on the speculum of
Mergus cuciiUntus, 267; on the pugnacity of male birds, 411, 4l4;
on courtship of Caprimulgus, 416; on Tetrao cupido, 417; on Ardea
nycticorax, 417; on Sturnella ludoviciana, 417; on the vocal organs
of Tetrao cupido, 422; on the drumming of the male Tetrao umbel-
his, 426; on sounds produced by the nightjar, 426, 427; on Ardea
herodias and Cathartes jota, 431, 432; on Mimus polyglottus, 686; on
display in male birds, 447; on the spring change of color in some
finches, 446; on migration of mocking thrushes, 467; recognition of
a dog by a turkey, 468; selection of mate by female birds, 472; on
the turkey, 468; on variation in the male scarlet tanager, 481; on the
musk-rat, 619; on the habits of Pyranga aatioa, 515; on local differ-
ences in the nests of the same species of birds, 519; on the habits of
woodpeckers, 521 ; on BombycUla carolinensis, 525 ; on young
females of Pyranga cestioa acquiring male characters, 525; on the
immature plumage of thrushes, 530; on the immature plumage of
birds, 530; et seq., on birds breeding in immature plumage. 551; on
the growth of the crest and plumes in the male Ardea ludoviciana,
551; on the change of color in some species of Ardea, 562.

Audubon and Bachman, MM., on squirrels fighting, 570; on the
Canadian lynx, 594.

Aughey, Prof., on rattlesnakes, 401.

Austen, N. L., on Anolis cristatellas, 401.

Australia, not the birthplace of man, 176; half-castes killed by the
natives of. 194; lice of the natives of, 193.

Australia, South, variation in the skulls of aborigines of, 28.

Australians, color of new-born children of, 636; relative height of
the sexes of, 638; women a cause of war among the. 640.

Axis deer, sexual difference in the Ci)lor of the, 612.

Aymaras, measurements of the, 39; no giey hair among the, 637;
hairiessness of the face in the. 639; long hair of the, 662.

Azara, on the ])roportion of men and women among the Guaranys,
376; on Palamedea cornuta, 412; on the beards of the Guaranys,

730 INDEX.

639; on strife for women amon^ the Guanas, 640 ; on infanticide,
659, 675; on the eradication of tlie eyebrows and eyelashes by the
Indians of Paniguay, 6d2; on ])()lyaudry among the Guanas, 677; celi-
bacy unlvuown among- the savages of South America, 678; on the
freedom of divorce among the Charnias, 6d3.

Babbage, C, on the greater proportion of illegitimate female
births, 276.

Babirusa, tusks of the, 593,

Baboon, revenge in a, 78; rage excited in, by reading, 80; mani-
festation of memory l)y a, 83; employing a mat for shelter against
the sun. 93; protected from punishment by its companions. 117;
Cape, mane of the male, 594; Hamadryas, mane of the male, 594.

Baboon, effects of intoxicating liquors on, 8; ears of. 17; diversity
of tiie mental faculties in, 30; hands of, 56; habits of, 57; variability
of the tail in, 65; manifestation of maternal affection by, 79; using
stones and sticks as weapons, 93; co-operation of, 115; silence of,
on plundering expeditions, 118; apparent polygamy of, 245; polyga-
mous and social habits of, 674.

Baboons, courtship of, 710.

Bachmau, Dr., on the fertility of mulattoes, 194.

Baer, K. E. von, on embryonic development, 9; definition of
advancement in the organic scale, 186.

Bagehot, \V., on the social virtues among primitive men, 133;
slavery formerly beneficial, 133; on the value of obedience, 147; on
human progress, 150; on the persistence of savage tribes in classical
times. 208.

Bailey, E. M., on the mode of fighting of the Italian buffalo, 580;
on the fighting of stags, 583.

Bain, A., on the sense of duty. 111; aid springing from sympathy,
116; on tne basis of sympathy, 130; on the love of approbation, etc.,
124; on the idea of beauty. 667.

Baird. W., on a difference in color between the males and females
of some Entozoa, 394.

Baker. Mr., observation on the proportion of the sexes in pheas-
ant-chicks, 3d0: Sir S., on the fondness of the Arabs for discordant
music, 431; on sexual difference in the colors of an antelope, 612;
on the elfi)]iant and rhinoferos attacking white or grey horses, 617;
on the disfigurements practiced by the negroes. 617; on the gashing
of the cheeks and temples practiced in Arab countries, 655; (m the
coiffure of the North Africans, 656; on the perforation of the lower
lip by the women of Latooka 656; on the distinctive characters of
the coift'ure of central African tribes, 656; on the coiffure of Arab
women, iSijQ.

" Bal/. ' of the black cock. 413, 460.

Bantam, Sebright, 239, 270.

Banteng, horns of, 576 : sexual differences in the colors of the,
613.

Banyal, color of the, 661.

Barbarism, primitive, of civilized nations. 163.

Barbs, filamentous, of the feathers, in certain birds, 437, 489.

Barr, Mr., on sexual preference in dogs, 598.

Barrago, F., on the Simian resemblances of man, 3.

Barrington, Daines, on the language of birds, 97; on the duckling

INDEX, 721

of the lien, 418; on tlie object of tlie song of birds, 419; on the sing-
ing of female birds, 420; on birds acquiring tbe songs of other
birds, 420; on the muscles of the larynx in song birds, 421; on the
want of the power of song by female birds, 513.

Barrow, on the widow-bird, 457.

Bartels, Dr., supernumerary mamma? in men, 43.

Bartlett, A. D,, period of hatching of bird's eggs, 187; on the
tragopan, 249; on the development of the spurs in Vrossaptilun
auritum, 267; on the fighting of the males of Flectropteriia gamheu
sis, 414; on the knot, 444; on display in male birds, 447; on tbe dis-
play of plumage by the male Polyplcctron, 449 ; on CrussoptiUni
auritum aud Phasiaiius Wallichii, 454; on tbe babits of Lophophorus,
477; on the color of the moutb in Buceros bicornis, 4b4; on tlie incu-
bation of the cassowary, 544; on the Cape Buffalo, 5b0; on the use
of tbe horns of antelopes, 580; on the fighting of male wart-bogs,
593; on Ammotragus tragelaphus, 606; on the colors of Cevcupithecus
cephus, 614; on tbe colors of the faces of monkeys, 029; on the
naked surfaces of monkeys, 686.

Bartlett, on courting of Argus pheasant, 454.

Bartram, on tbe courtship of the male allegator, 898.

Basque language, highly artificial, 102.

Bate, C. S., on the superior activity of male Crustacea, 250; on the
proportions of tbe sexes in crabs, 288; on tbe cbelae of crustacea, 301;
on the relative size of the sexes in crustacea, 302; on tbe colors of
Crustacea, 306.

Bateman, Dr., tendency to imitation in certain diseased states, 82;
on Aphasia, 100.

Bates, H. W., on variations in the form of the head of Amazonian
Indians, 32; on the proportion of sexes among Amazonian butter-
flies, 283; on sexual differences in the wings of butterflies, 314; on
the field-cricket, 321; on Pyrodes pukherrimus, 333; on tbe borns of
Lamellicorn beetles, 334, 336; on the colors of Epicalice, etc., 350; on
the coloration of tropical butterflies, 352: on the variability of Pdpilio
Sesostris and Childrence, 362; on male and female butterflies inbubit-
ing different stations, 864; on mimicry, 366; on the caterpillar of a
Sphinx, 369; on the vocal organs of tbe umbrella-bird, 423; on tbe
toucans, 560; on BrachyuruH calvus, 629.

Batokas, knocking out two upper incisors, G56.

Batracbia, 395; eagerness of male, 250.

Bats, scent-glands, 604; sexual differences in the color of, CIO; fur
of male frugivorous, 610.

Battle, law of, 163; among beetles, 839; among birds, 408; among
mammals, 570 et seg.; in man, 640.

Beak, sexual difference in the forms of the, 408; in the color of
the, 435.

Beaks, of birds, brigbt colors of, 559.

Beard, development of, in man, 63.1; analogy of the, in man and
the quadrumana, 636; variation of tbe development of tbe, in dif-
ferent races of men, 637; estimation of, among bearded nations 063;
probable origin of tbe, 688; in monkeys, 171; of mammal^!, 607

Beautiful, taste for tbe, in birds, 466; in tbe quadrumana, 617.

Beauty, sense of, in animals, 104; apiireciation of, by birds. 4G9;
influence of, 654, 657; variability of tbe standard of, 681; sense of,
sufficiently permanent for action of sexual selection, 563, 712.

722 INDEX.

Beavan, Lieut., on the development of the horns in Cervus Eldi, 265;

Beaver, instinct and intelligence of the, 75, 77; voice of the, 602.
castoreum of the, 604.

Beavers, battles of male, 570.

Becbstein, on female birds choosing the best singers among the
males, 418; on rivalry in song-birds, 419; on the singing of female
birds, 420; on birds acquiring the songs of other birds, 420; on pair-
ing the canary and si.skin, 472; on a sub- variety of the monk pigeon,
472; on spurred hens, 511.

Beddoe, Dr., on causes of difference in stature, 35.

Beeeater, 421.

Bees, 113; pollen-baskets and stings of, 70; destruction of drones
and queens by, 120; female, secondary sexual characters of, ^85;
proportion of sexes, 286; difference of the sexes in color and sexual
selection, 331.

Beetle, luminous larva of a, 314.

Beetles, 333; size of the cerebral ganglia in, 61; dilatation of the
fore tarsi in male, 312; blind, 333; stridulation of, 341.

Belgium, ancient inhabitants of, 207.

Bell, Sir C, on the emotional muscles in man, 4; "snarling mus-
cles," 46; on the hand, 57; Bell, T., on the numerical proportion of
the sexes in moles, 279; on the newts, 394; on the croaking ot" the
frog, 395; on the difference in the coloration of the sexes in Zootoca
vivipara, 405; on moles fighting, 570.

Bell-bird, sexual difference in the color of the, 440.

Bell -birds, colors of. 560.

Belt, Mr., on the nakedness of tropical mankind, 64; on a spider-
monkey and eagle, 115; habits of ants, 16^; Lanipyridae distasteful
to mammals. 314; mimicry of Leptfdides, 368; colors of Nicaraguan
frogs, 396; display of humming-birds, 503; on the toucans, 560; pro-
tective coloring of skunk, 621.

Benevolence manifested by birds, 467.

Bennett, A. W., attachment of mated birds, 466; on the habits of
Dromceus irrorntuft, 545; Bennett, D., on birds of paradise, 449.

Berbers, fertility of crosses with other races, 195.

Bernicla antarctica, colors of, 560.

Bernicle gander pairing with a Canada goose, 471.

Bert, M., crustaceans distinguish colors, 806.

Bettoni, E., on local differences in the nests of Italian birds, 519.

Beyle, M., see Bom bet.

Bhoteas, color of the beard in, 637.

Bhringa, disciform tail-feathers of, 445.

Bianconi, Prof., on structures as explained through mechanical
principles, 27.

Bibio, sexual differences in the genus, 317.

Bichat, on beauty, 667.

Bickes, proportion of sexes in man, 274.

Bile, colored in many animals, 296.

Bimana, 170.

Birds, imitations of the songs of other birds by, 82: dreaming, 84;
killed by telegraph wires. 90; lano:uage of, 97: sense of beauty in,
104; pleasure of, in incubation. 119; male, incubation by, 185; and
reptiles, alliance of, 187; sexual differences in the beak of some, 236;

INDEX, 723'

migratory, arrival of the male before the female, 241; apparent rela-
tion between polygamy and marked sexual differences in, 248;
monogamous, becoming polygamous under domestication, 249;
eagerness of male in pursuit of the female, 250; wild, numerical
proportion of the sexes in, 280; secondary sexual characters of, 407;
difference of size in the sexes of, 411; fights of male, witnessed by
females, 414; display of male, to captivate the females, 416; close
attention of, to the songs of others, 418; acquiring the song of their
foster parents, 420; Lrilliant, rarely good songsters, 421; love-antics
and dances of, 431; coloration of, 438 et seq.; moulting of, 442 ei seg.;
unpaired, 462; male, singing out of season, 465; mutual affection of,
466; in confinement, distinguish persons, 467; hybrid, production of,
470; Albino, 476; European, number of species of, 479; variability
of, 479; geographical distributicm of coloring, 480; gradation of
secondary sexual characters in, 488; obscurely colored, building con-
cealed nests, 516; young female, acquiring male characters, 525;
breeding in immature i)lumage, 551; moulting of, 551; aquatic, fre-
quency of white plumage in, 561; vocal courtship of, 646; naked
skin of the head and neck in, 686.

Birgus Intro, habits of, 305.

Birkbeck, Mr., on the finding of new mates by golden eagles, 463.

Birthplace of man, 176.

Births, numerical proportions of the sexes in, in animals and
man, 243, 244; male and female, numerical proportion of, in England,
274.

Bischoff, Prof., on the .agreement between the brains of man and
of the orang, 6; figure of the embryo of the dog, 11; on the convo-
lutions of the brain in the human fetus, 10; on the difference
between the skulls of man and the quadrumana, 170; resemblance
between the ape's and man's, 227.

Bishop, J., on the vocal organs of frogs, 397; on the vocal organs
of corvine birds, 421; on the trachea of the Merganser, 425.

Bison, American, co-operation of, 115; mane of the male, 594.

Bitterns, dwarf, coloration of the sexes of. 524.

Biziura lobcita, musky odor of the male, 407; large size of male,
411.

Blackbird, sexual differences in the, 248; proportion of the sexes
in the, 281; acquisition of a song by, 421; color of the beak in the
sexes of the, 435, 559; pairing with a thrush, 470; colors and niditi-
cation of the, 517; young of the, 554, 555; sexual difference in colora-
tion of the, 559.

Black-buck, Indian, sexual difference in the color of the, 612.

Blackcap, arrival of the male, before the female, 240; young of
the, 554.

Black-cock, polygamous, 248; proportion of the sexes in the, 279;
pugnacity and love-dance of the, 412; call of the, 425 ; moulting of
the, 444; duration of the courtship of the, 460 ; and pheasant,
hybrids of, 125; sexual difference in coloration of the, 559; crimson
eye-cere of the. 559.

Black-grouse, characters of young, 530, 537.

Blacklock, Dr., on nmsic, 653.

Blackwall, J., on the speaking of the magpie, 101; on the deser-
tion of their young by swallows, 122; on the superior activity of

724 mBEX.

male spiders, 250; on tlie proportion of the sexes in spiders, 287; on
sexual variation of color in^])iders, 307; on male spiders, 307.

Bladder-nose Seal, hood of tbe, 603.

Blaine, on the affections of dogs, 597.

Blair, Dr., on the relative liability of Europeans to yellow fever,
221

Blal<e, C. C, on the jaw from La Naulette, 46.

Blakistoii, C'apt., on the American snipe, 428; on the dances of
Tetrao phadnneUus, 431.

Bitusius, Dr., on tbe species of Eiiropf^an birds, 480.

Blediai< titurus, hornlike processes of male, 338.

Bleeding, tendency to pri)fiise, 268.

BlenUiron, Mr., on sexual preference in horses, 598.

Blennies, crest developed on the head of male, during the breeding
season, 385.

Bletldsa mvltlpunctata, stridulation of, 343.

Bloch, on the proportions of the sexes in fishes, 281.

Blood, arterial, red color of, 296; pheasant, number of spurs in,
413.

Blow-fly, sounds made hy, 318.

Bluebreast, red-throated, sexual differences of the, 537.

Blumenbacb, on Man, 32; on the large size of the nasal cavities in
American aborigines, 38; on the position of man, 170; on the number
of species of man, 199.

BIyth, E., on the structure of the hand in the species of Ilylohntex,
57; observations on Indian crows, 116; on the development of the
horns in the Koodoo and Eland antelopes, 265; on the pugnacity of
the males of Gfdlicrex criddtns, 409; on the presence of spurs in the
it:msi]e Eirploaimics eri/throphthnlmi(s, 4V6; on the pugnacity of the
amadavat, 415; on the spoonbill, 425; on the moulting of Anthus,
444; on the moulting of bustards, plovers, and Qallus bankiva, 445;
on the Indian hcmey-buzzard, 481 ; on sexual differences in the
the color of the eyes of hornbills, 483; on Oriolns mcUDiocephnlus,
524; on Pnlteornis javanicus, 525; on the genus Ardetta, 524; on the
peregrine falcon, 525; on young female birds acquiring male charac-
ters, 524; on the innnature plumage of birds, 529; on representative
species of birds. 533; on the young of Turi/Lr, 543; on anomalous
young of Ldidns rufus and (Joli/mbus (/larinlu, ^oO; on the sexes
and young of tbe sparrows, 550; on diniori)hism in some herons, 552;
on the ascertainment of tbe sex of nestling bullfinches by pulling
out breast feathers, 551; on orioles breeding in immature ])luniage,
552; on the sexes and young of Buphns and Annstomus, 553; on the
young of tbe blackcap and blackbird, 554. 555; on tbe young of the
stonecbat, 555; on the white ])lumage of Anndomns, 561; on tbe
horns of Bovine animals, 575; on the horns of Antilopehezoartica,
575, 577; on the mode of fighting of Otis cyclocerofi, 579; on the voice
of tbe Gibbons, 602; on the crewt of the male wild goat, 606; <m the
colors of Portax pictn, 611; on the colors of Antilope hezonrtica, 612;
on the color of the Axis deer, 613; on sexual difference of color in
Hylobates hoolock, 613 ; on the hog deer, 624 ; on the beard and
whiskers in a monkey becoming white with age, 637.

Boar, wild, polvgamous ia India, 246; use of the tusks by the,
586; fighting of, 591.

INDEX. 7«5ji

Boardman, Mr., Albino birds in U. S., 476.

Boitard and Corbie, MM., on the transniission of sexual peculiari-
ties in pigeons, 261; on tbe antipatby sbouuby some female pigeons
to ce)tain n:ales, 414.

Bold, Mr., on tbe singing of a sterile bybrid canary. 419.

Bombet, on tbe variability of tbe standard of beauty in Europe,
681.

Bombus, difference of tbe sexes in. 331.

Bombycidae, coloration of, 355; pairing of tbe. 360, colors of, 361.

Bomhycllla carolinensis, red appendage.s of, 525.

Bomhyx ci/nt/iia, 315; proportion of tbe sexes in, 282, 285; pairing
of, 360; bombyx mori, difference of size of tbe male and female
cocoons of, 315; pairing of, cCO; homhyx j^crnyi, propoition of pexes
of, 285; bombyx yamamai, 315; M, Personal on, 283; proportion of
sexes of, 285.

Bonaparte, C. L., on tbe call-notes of tbe wild turkey, 425.

Bond, F. , on tbe finding of new mates by crows, 463.

Bone, implements of, skill displayed in making, 55.

Boner, C, on tbe transfer of male cbaracters to an old female
cbamois, 574; on tbe babits of stags, 587; on tbe pairing of red deer,
595.

Bones, increase of, in lengtb and tbickness, wben carrying a
greater weigbt, 36.

Bonizzi, P., difference of color in sexes of pigeons, 261.

Bonnet monkey, 171.

Bonwick, J., extinction of Tasmanians, 209.

Boomerang, 164.

Borevs hyemalu, scarcity of tbe male, 287.

Bory St. Vincent, on tbe number of species of man, 199; on tbe
colors of Labrus pato, 388.

Bos et?ni8r,u,% 576; bos gaurvs, borns of, 576; bos moschntns, 604;
hos pnmiyenius, 571; bos sondaicus,\iovc\so^, 576; colors of, 612.

Botocudos. 163; mode of life of, 224; disfigurement of tbe ears
and lower lip of tbe, 656.

Boucber de Pertbes, J. C. de, on tbe antiquity of man, 2.

Bourbon, proportion of tbe sexes in a species of Papilio from, 283.

Bourien, on tbe marriage customs of tbe savages of tbe Malay
Arcbipelago, 683.

Bovidae, dewlaps of, 608.

Bower-birds, 461; babits of tbe, 432; ornamented playing-places
of, 104, 469.

Bows, use of, 203.

Bracbycei)balic structure, possible explanation of, 68.

Bracbyura, 304.

Brachyurus cakvs, scarlet face of, 629.

Bradley, Mr., abductor ossis metatarsi quinti in man, 47.

Brain, of man, agreement of tbe, witb tbat of lower animals, 6;
convolutions of, in tbe buman fetus, 10; influence of development
of mental faculties upon tbe size of tbe, 60; influence of tbe devel-
opment of, on tbe spinal column and skull, 62; larger in some exist-
ing mammals tban in tbelr teitiary prototypes, 91; relation of tbe
development of tbe, to tbe progress of language, S9; disease of tbo.
afEectiug speecb, 99; difference in tbe convolutions of^ in different

726 INDEX.

races of men. 191; supplement on, by Prof. Huxley, 227; develop-
ment of the gyri and sulci, 231.

Brakenridge, Dr., on the influence of climate, 36.

Brandt, A., on bairy men, 21.

Braubacb, Prof , on tbe quasi-religious feeling of a dog toward
liis master, 108; on tbe self-restraint of dogs, 117.

Brauer, F., on dimorpbism in Neuruthemis, 329.

Brazil, skulls found in caves of, 192; population of, 197; compres-
sion of tbe nose by tbe natives of, 665.

Break between man and tbe apes, 177.

Bream, proportion of tbe sexes in tbe, 282.

Breeding, age of, in birds, 552; breeding season, sexual cbaracters
making tbeir appearance in tbe, in birds, 443.

Brebm, on tbe effects of intoxicating liquors on monkeys, 8; on
tbe recognition of women by male Cpiocephali, 8; on tbe diversity of
tbe mental faculties of monkeys, 31; on tbe babits of baboons,' 57;
on revenge taken by monkeys, 78; on manifestations of maternal
affection by monkeys and baboons, 79; on tbe instinctive dread of
monkeys for serpents, 80; on tbe use of stones as missils by baboons,
92; on a baboon using a mat for sbelter from tbe sun, 93; on tbe
signal-cries of monkeys, 98; on sentinels posted by monkeys, 114; on
co-operation of animals, 114; on an eagle attacking a young Cerco-
pithecus, 114; on baboons in confinement protecting one of tbeir
number from punisbment, 117; on tbe babits of baboons wben
plundering, 108; on polygamy in Cynocepho.lus and Cebus, 246; on
the numerical proportion of tbe sexes in birds, 280; on tbe love-
dance of tbe blackcock, 412; Palamedea cornuta, 414; on the babits
of tbe black-grouse, 416; on sounds produced by birds of paradise,
427; on assemblages of grouse, 460; on tbe finding of new mates by
birds, 464; on tbe fighting of wild boars, 591; on sexual differences
in Mycetes, 613; on tbe babits of Cynocephalus hamadryas, 674.

Brent, Mr., on the courtship of fowls. 473.

Breslau, numerical proportion of male and female births in, 275.

Bridgman. Laura, 99.

Brimstone butteifly, 354; sexual difference of color in tbe, 365.

British, ancient, tattooing practiced by, 655.

Broca, Prof., on the occurrence of tbe supra-condyloid foramen in
the human humerus, 24; anthropomorphous apes more bipedal than
quadrupedal, 59; on the capacity of Parisian skulls at different
periods, 61; comparison of modern and mediaeval skulls, 61; on trils
of quadrupeds. 65; on the influence of natural selection, 68; on
hybridity in man. 194; on human remains from Les Eyzies, 207; on
tlie cause of the difference between Europeans and Hindoos, 218.

Brodie, Sir B., on tbe origin of tbe moral sense in man, 111.

Bronn, H. (if., on the copulation of insects of distinct species, 312.

Bronze period, men of, in Europe, 145.

Brown, K., sentinels of seals generally females, 114; on the bat-
tles of seals, 571; on the narwhal. 573; on the occasional absence of
the tusks in tbe female walrus, 572; on the bladder-nose seal, 603; on
tbe colors of tbe sexes in Phoca Grccrdandica, 611; on the apprecia-
tion of music by seals, 649; on plants used as love-philters, by North
American women, 659.

Browne, Dr. Cricbton, injury to infants during parturition, 276.

INDEX. 727

Brown-Sequard. Dr., on the inheritance of tlie effects of opera-
tions by guinea- pigs, 67, 689.

Bruce, on the use of the elephant's tusks. 578.

Brulerie, P. de lu, on the habits of Ateuchus cicatricosu8^ 340; on
the stridulutiou of Ateuchus, 346.

Brlinnich, on the ])ied ravens of the Feroe Islands, 482.

Bryant, Dr., preference of tame pigeon for wild mate, 475; Bry-
ant, Capt., on the '-ourtship of Callorhiaus ui'sitius, 596.

Biibas bison, thoracic i)r()jection of, 337.

Bubuhis caffer, use of horns, 580.

Bucephalus capends, diiference of the sexes of. in color, 398.

Buceros, nidification and incubation of, 516 ; buceros bicornis,
sexual differences in the coloring of the casque, beak, and mouth in,
484; buceros corrugatus, sexual differences in the beak, 435.

Biichner, L., on the origin of man, 3; on the use of the human
foot as a prehensile organ, 58; on the mode of proge?sion of the
apes, 58; on want of self -consciousness, etc.. in savages, 94.

Bucholz. Dr., quarrels of chamaeleons, 405.

Buckinghamshire, numerical proportion of male and female births
in, 274.

Buckland, F., on the numerical proportion of the sexes in rats,
279; on tlie in-oportion of the sexes in the trout, 282; on Chimcera
monsti'osa, 385.

Buckland, VV., on the complexity of crinoids, 103.

Buckler, \V., [)roportion of sexes of Lepidoptera reared by, 285.

Bitcovdx nbyiidnicus, inflation of the neck-wattle of the male
during courtshij), 435.

Budijtes Ran, 240.

Bulfjilo, Cape, 580; Indian, horns of the, 576; Italian, mode of
fighting of the. 580.

Buffon, on the number of species of man, 199.

Bnfo dkimmenniif, 396.

Bugs, 318.

Buist, R., on the proportion of the sexes in salmon, 281; on the
pugnacity of the male salmon, 377.

Bulbul, pugnacity of the male, 409; display of under tail-coverts
by the male, 456.
'Bull, mode of fighting of the, 579: curled frontal hair of the, C08.

Buller, Dr.. on the Huia, 236; the attachment of bird.^, 466.

Bullfinch, sexual differences in the, 248; ])iping, 418; female,
singing of the, 420; courtship of the, 455; widowed, finding a new
mate, 464; attacking a reed-bunting, 468; nestling, sex ascertained
by pulling out breast feathers, 551.

Bullfinches, distinguishing persons, 467; rivalry of female. 477.

Bulls, two young, attacking an old one, 115; wild, battles of. 571.

Bull trout, nuile, coloring of, during the breeding-season. 386.

Bunting, reed, head feathers of the male, 455; attacked by a bull-
finch, 468.

Buntings, characters of young, 529.

Buphus coromandus, sex'es and young of, 553; change of color in,
o63.

Biirehell, Dr., on the zebra, 623; on the extravagance of a Bush-
woman in adorning herself, 658; celibacy unknown among the

738 INDEX.

savages of Soutli Africa, 678; on tbo marriage-customs of tlio Basilv
women, 684.

Buvke, oil the nninber of species of man, 199.

Burmese, color of the beard in, 637.

Burton, Cui)t.. on ueo:ro ideas of female beauty, 660; on a universal
ideal of beauty, 664.

Bushmen, 72; marriage among, 684.

Busliwoman, extravagant ornamentation of a, 658.

Bubhwomen, hair of, 191; marriage-customs of . 684.

Bustard, tliroat-pouch of the male, 428; humming noise produced
by a ma'e, 429; Indian, ear-tufts of, 436.

Bustartls, occuirence of sexual differences and of polygamy among
the, 248; love-gestures of the male, 432; double moult in, 443, 444.

Jiutler, A, (i., on sexual differences in the wings of Arie.oris epitus,
314; courtship, of butterflies, 348; on the coloring of the sexes in
species of T/ieda, 3-51; on the resemblance of Iphias glaucippe to a,
leaf, 354; on the rejection of certain moths and caterpillars by lizards
and frogs, 370.

Butterliy, noise produced by a, 349; Emperor, 348, 350; meadow
brown, instability of the oscellated spots of, 486.

Buiterllies, proportion of the sexes in, 283; forelegs atrophied in
some males, 314; sexual difference in the neuration of the wings of,
314; pugnacity of male. 348; protective resemblances of the lower
surface of, 353; display of the wings by, 356; white, alighting upon
bits of i)aper, 359; attracted by a dead si)ecimcn of the same species,
360; courtship of, 360; male and female inhabiting different stations,
364.

Buxton, C. observations on macaws, 115; on an instance of benev.
olence in a i)arrot, 467.

Buz/anI, Indian honey, variation the crest of, 481.

Cabbage buttertiies, 354.

Cachalot, large head of the male. 573.

Cadences, musical ))erception of, by animals, 648.

Csecum, 22; large, in the early i)rogenitors of man, 183.

Cdirina vioschata, pugnacity of the male, 411.

Californian Indians, decrease of, 291.

CnlWinassa, chelae of, figured, 302.

Callidrydn, colors of sexes, 361.

Vallioit'ymas li/ra, characters of the male, 381.

Cnllorhiuus urninus, relative size of the sexes of, 588; courtsliip
of, 596.

Calotes maria, 406; Calotes nigrildbris, sexual difference in the
color of, 405.

Cambridge, O. Pickard, on the sexes of spiders, 287; on the size of
male NfjjhUn, 309.

Camel, canine teeth of male, 572, 536.

Campbell, J., on the Indian elephant, 246; on the proportion of
male and female births in the harems of Siam, 277.

Cninjji/lopterus heinilevcuriis, 281.

Canaries distingushing persons, 467.

Canary, ])olygamy of the, 249; change of plnmage in, after moult-
ing, 269*; female, selecting the best singing male, 418; sterile liybrid,
singing of a, 419; female, singing of the, 420; selecting a greenfinch,
472; and siskin, pairing; of, 472.

INDEX. 729

Cancer pagurus, 301.

Caiiestrini, G., on rudimentary characters and tlie origin of
man, 8; on rudinientaiy characters, 12; on the movement of iho ear
in man, 15; on the variability of the vermiform appendage in man,
2ij; on the abnormal division of the malar bono in n.an, 44; on
abnormal conditions of the human uterus, 44; on the persistence of
the frontal suture in man, 44; on the pro])orti()n of the t exes in silk-
motbe, 283, 284; sectmdary sexual characters of spiders, 307.

Canfield, Dr., on the horns of the Autilocapra, 265.

Canine teetb in man, 45; diminution of, in man, GO; diminution of,
in horses, 60; disappearance of, in male rum'nants, CO; large in iho
early progenitors of man, 182.

Canines and horns, inverse development of, 586.

Canoes, use of, 54, 205.

Caiitharis, difference of color in the sexes of a species of, 333.

CantharuH lineatus, 386.

Capercailzie, polygamous, 248; proportion of the sexes in the, 280;
pugnacity of the male, 412; pairing of the, 416; autumn meetings of
the, 420; call of the, 425; duration of the court!>hi])of, 460; behaviour
of the female, 476; inconvenience of black color to the feuiale, 505;
sexual difference in the coloration of the, 559; crimson eyecere of the
male, 559.

Capitonida?, colors and nidification of the, 518.

Capra cngagrus, 579; crest of the male, 606; sexual difference in
the color of, 612.

Capreolus Sibiricus suhecaudatus, 619.

Caprice, common to man and animals. 105.

Caprimulgus, noise made by the males of some species of, witn
their wings, 426: Capiimulgus urgiuiauus, pairing of, 416.

Carabidae, 343.

Carbonnier, on the natural history of the pike, 281 ; on the rela-
tive size of the sexes in fishes, 380; courtship of Chinese Macropus,
387.

Carcineuies, sexual difference of color in, 520.

Carcmiis mce/ias, 303. 304.

Cardiiinlis virgi/uanus, 255.

Carduelis elegans, sexual differences of the beak in. 408.

Carnivora, marine, polygamous habits of, 247 , sexual differences
in the colors of, 610.

Carp, numerical ])roportion of the sexes in the, 283.

Carr, II., on the peewit, 414.

Carrier pigeon, hite development of the wattle in the, 209.

Carrion beetles, stridulation of, 342.

Carrion-hawk, bright colored female of, 546.

Cams, Prof. V., on the development of the horns in merino sheep,
266; cm antlers of red deer, 581.

Cassowary, sexes and incubation of the, 544.

Castnia, mode of holding wings, 357.

Castoreum, 604.

Castration, effects of, 577.

Casuarius gakatus, 544.

Cat, convoluted body in the extremity of a tail of a, 20; sick, sym*
pathy of a dog with a, 110.

730 INDEX.

Cataract in Cebus Azarm, 7.

Catarrh, liability of Cehus Azaras to, 7.

Catarrliiue moukeys, 174.

Caterpillars, bright colors of, 368.

Cathartcs aura, 473; cathartes jota, love-gestures of tLe male, 482.

Catlin, U., correlation of color and texture of hair in the Mandans,
225; on the developnient of the beard among North American In-
dians, C39; on the great length of the hair in some North American
tribes, 062.

Caton, J. D., on the development of the horns in Cerxus Virginia-
Jilts and stroiigyloceros, 265; on the wild turkey, 525; on the pres-
ence of traces of horns in the female wapiti, 575; on the fighting of
deer. 582; on the crest of the male wapiti, C06; on the c-^lors of the
Virginian deer, 611; on sexual differences of color in the wapiti, 612;
on the spots of the Viginian deer, 024.

Cats, dreaming, 84; tortoise-shell, 260, 262, 269; enticed by val-
erian. C05; colors of, 020.

Cattle, rapid increase of, in South America, 53; domestic, lighter in
winter in Siberia, 260; horns of, 266, 576; ("omestic, sexual differ-
ences of, late developed, 269, numerical proportion of the sexes in,
279.

Caudal vertebra?, number of, in macaques and baboons, 65; basal
of monkeys, imbedded in the body, 66.

Cavolini, observations on Serranus, 184.

Cebus, maternal affection in a, 79; gradation of species of, 199;
cehus apella, 238; cehus azaroR, liability of, to the same diseases as
man, 7; distinct sounds produced Ly (,5; tarly maturity of the
female, 636; cebus capuciaus, polygamous. 245; sexual differences of
color in, 613; hair on the head of, C27; cebus tellerosus, hair on the
head of. 627.

CecidomyiidaB, proportions of the sexes in, 286.

Celibacy, unknown among the savages of South Africa and South
America, 678.

Centi])edes, 310.

Cei)halopoda, absence of secondary sexual characters in, 297.

Cephalopterus oriiatus, 423; cephalopterus penduliger, 424.

Ceramhyx heros, stridulant organ of, 343.

Ceratodus. paddle of, 42.

Cerdtophora aspera, nasal appendages of, 403 ; ceratophora ttocU
dartii, nasal horn of, 403.

Cerceris, habits of, 330.

Cercocebus (Hthiops, whiskers, etc., of, 629.

Cercopithecus, young, seized by an eagle and rescued by the troop,
115; definition of species of, 199; cercopithecus cephns, sexual differ,
enc^ of color in, 614, 630; cercopithecus cynosurvs and griseo-viridis,
color of the scrotum in, 614; eercopithecvs Diana, sexual differences
of color in, 614. 630; eercopithecvs griseo-viridis, 114; cercopithecus
petaurista, whiskers, etc., of, 627.

Ceres, of birds, bright colors of, 559.

Cerioriiis Temminckii, swelling of the wattles of the male during
courtship, 434.

C'rculus, weapons of, 586; cervulus moschatus, rudimentary horns
of the female, 574.

INDEX, 731

CerGus dices, 265; cervus eampestria, odor of, QOiicervus canadensis,
traces of horns in the female, 574; attacking a man, 582; sexual dif-
ference in the color of, 612; cervus elaphus, battles of male, 571;
horns of, with numerous points, 581; long hairs on the throat of,
595; cervus eldi, 265.

Cervus mantchuricus, 623; cervus paludosus, colors of, 613;
cermis stroagyloceros, 265 ; cervus virginianus, 265 ; horns of, in
course of modification, 584.

Ceryle, male black-belted in some species of, 520.

Cetacea, nakedness of, 63.

Ceylon, frequent absence of beard in the natives of, 638.

Chaffinch, proportion of the sexes in the, 280; courtship of the, 455.

Chaffinches, 419; new mates found by, 464.

Chalcophaps iiidicas, characters of young, 529.

Chalcosomii atlas, sexual differences of, 334.

Ghamodeo, sexual differences in the genus, 403; combats of, 405;
Mf ureas, 403, 404; Owenii, 404; pumilus, 405.

0 hamcepetes unicolor, modified wing- feather in the male, 428.

Chameleons, 402.

Chamois, danger-signals of, 114; transfer of male characters to an
old female, 574.

Champneys, Mr., acromio-basilar muscle and quadrupedal gait, 47.

Chapman, Dr., on stridulation in Scolytus, 342.

Chapuis, Dr., on the transmission of sexual peculiarites in pigeons,
261 ; on streaked Belgian pigeons, 269, 507.

Char, male, coloring of, during the breeding season, 386.

Characters, male, developed in females, 257; secondary sexual,
transmitted through both sexes, 257; natural, artificial, exaggeration
of, by man, 664.

Charadrias hiaticula and pluvidlis sexes and young of, 553.

Chardin on the Persians, 669.

Charms, worn by women, 659,

Charruas. freedom of divorce amomg the, 683.

ChasmorhynchuK, difference of color in the sexes of, 441; colors
of, 560; chasmorhynchus nioeus,Ai\; chasmorhynchus nudicollis, ^ii;
chasmorhynchus tricar uncidat us, 441.

Chastity, early estimation of, 134.

Chatterers, sexual differences in, 248.

Cheever, Kev= H. T., census of the Sandwich Islands. 290.

Cheiropetra, absence of secondary sexual characters in, 247.

Chelae of Crustacea, 301, 307.

Ghelonia, sexual differences in, 397.

Chenalopex cegyptiacus, wing-knobs of, 414.

Chera progne, 445, 476.

Chest, proportions of, in soldiers and sailors, 37; large, cf the
Quechua and Aymara Indians, 38.

Chevrotains, canine teeth of, 586.

Chiasogiiathus, stridulation of, 346; chiasognathus grantii, mand-
ibles of, 340.

Children, legitimate and illegitimate, proportion of the sexes
in, 276.

Cliiloe lice of the natives of, 193; population of, 197.

Chimara inonstrosa, bony process ou the head of the male, 385.

732 INDEX.

Cliiiiijeroid fisLes, preLensile organs of male, 375.

Chimpaiizee, 640: ears of tbe, 16; representatives of the eyebrows
in the, 21; bands of the, 56; absence of mastoid processes in the, 59;
plntforius built by the, 75; cracking nuts with a stone, 91; direction
of the hair on tbe arms of the. 172; supposed evolution of the, 202;
polygamous and social ]ial)its of the, 674.

C'liina, North, idea of female beauty in, 659; China, Southern, in-
habitants of, 224.

Chinese, use of Hint tools by the, 164; difficulty of distinguishing
the races of the, 190. color of the beard in, 637, general beardless-
ness of the, 639; opinions of the, on the appearance of Europeans and
Cingalese, 659; compression of the feet of, 665.

cTiinsurdi, his opinion of beards, 657, 663.

C hldinydera maculatn, 433.

C hloedii, ])edunculated eyes of the male of, 311.

ChloephagK, coloration of the sexes in, 524.

Chlorocceius tanana (figured), 323.

Chorda dorsalis, 183.

Chough, red beak of the, 559.

Chromidae, frontal protuberance in male, 385; sexual differences in
color of, 392.

Chrysemys picta, long claws of the male, 397.

C hrysoeoccyx, characters of young of, 529.

Chrysomelidae, stridulation of, 342.

Cicada pruinosa, 320; cicada septendecim, 319.

Cicadae, songs of the, 319; rudimentary sound-organs in females of,
326.

Cicatrix of a burn, causing modification of the facial bones, 63.

Gichla, frontal protuberance of male, 385.

Cimetiere du Sud, Paris, 24.

Cincloramphus cruralis, large size of male, 411.

Cinclnti aquatiois, 518.

Cingalese, Chinese opinion of the appearance of the, 659.

Cirripedes, complemental males of, 235.

Civilization, effects of, upon natural selection, 151; influence of, in
the competition of nations, 208.

Clanging of geese, etc., 418.

Claparede, E., on natural selection applied to man, 53.

C'larke, on the marriage-customs of Kalmucks, 683.

Classification, 168.

Claus, C, on the sexes of Saphirina, 306.

Cleft-palate, inherited, 40.
, Cliniacteris erythrops, sexes of, 546.

Climate, 35; cool, favorable to human progress, 150; power of
supporting extremes of, by man, 207; want of connection of. with
color, 219; direct action of, on colors of birds, 480.

Cloaca, existence of a. in the early progenitors of man, 182.

Cloaca! passage existing in the human embryo, 10.

Clubs, used as weapons before dispersion of mankind, 204.

Clucking of fowls, 417.

Clythra 4-pj/nctata, stridulation of, 342.

Coan, Mr., Sandwich Islanders, 213.

Cobbe, Mis»; on morality in hypothetical bee-community, 113.

INDEX. 733

Cobra, ingenuity of a, 399.

Coccus, 167.

Coccyx, 25; in the human embryo, 10; convoluted body at the
extremity of the, 25; imbedded in the body, 6(5.

Cochin-China, notions of beauty of the inhabitants of, 659, 661.

Cock, blind, fed by its companion, 116; game, killing a kite, 412;
comb and wattles of the. 457; preference shown by the, for the
young hens, 477; game, transparent zone in the hackles of a, 489.

Cock of the rock, 460.

Cockatoos, 559, 560, 562; nestling, 467; black, immature plumage
of, 532.

Coelenterata, absence of secondary sexual characters in, 494.

Coffee, fondness of monkeys for, 7.

Cold, supposed effects of, 35; power of supporting, by man. 207.

Coloptera, 333; stridulation of, 322; stridulant organs of, discussed,
344.

Colias edusa and ht/ale, 361.

Collingwood, C, on the pugnacity of the butterflies of Borneo, 348;
on butterflies being attracted by a dead specimen of the same
species, 360.

Colobus, absence of the thumb, 57.

Colombia, flattened heads of savages of, 655.

Colonists, success of the English as, 160.

Coloration, protective, in birds, 556.

Color, supposed to be dependent on light and heat, 36; correlation
of. with immunity from certain poisons and parasites, 220; purpose
of, in lepidoptera, 359; relation of, to sexual functions in fishes, 388;
difference of, in the sexes of snakes, 398; sexual differences of, in
lizards, 405; influence of, in the pairing of birds of different species,
472; relation of, to nidification, 515, 519; sexual differences of, in
mammals, 609, 616; recognition of, by quadrupeds, 617; of children,
in different races of man, 635; of theskin in man, 690.

Colors, admired alike by man and animals, 104; bright, due to
sexual selection, 295; bright, among the lower animals, 295, 296;
bright, protective to butterflies and motlis, 354; bright, in male
fishes, 380, 385; transmission of, in birds, 509.

Colquhoun, example of reasoning in a retriever, 88.

Columba 2)ffsserin((, young of, 532.

Cvlymhva glacialis, anomalous young of, 550.

Comb, developuient of, in fowls, 270.

Combs and wattles in male birds, 457.

Community, preservation of variations useful to the, by natural
selection, 70.

Complexion, different in men and women, in an African tribe 63^.

Compositae, gradation of species among the, liiO.

Comte, C, on the expression of the ideal of beauty by sculpture,
663.

Conditions of life, action of changed, upon man, 34; influence of,
on plumage of birds, 538.

Condor, eyes and comb of the, 484.

Conjugations, origin of, 103.

C(«iscience, 110, 131, 143; absence of, in some criminals, 13\.

Constitution, difference of, in different races of men, 191.

734 INDEX.

Consumption, liability of Cebus Azarm to, 7; connection bet;veeu
complexion and, 221.

Convergence of characters, 201.

Cooing of pigeons and doves, 425.

Cook, Capt. , on the nobles of tbe Sandwicb Islands, 669.

Cope, E. D., on tbe Dinosauria, 180.

CopJiotis ceylanica, sexual differences of, 402, 405.

C'opris, 386; copris isidis, sexnal differences of, 335; copris lunaris,
stridulation of, 343.

Corals, bright colors of, 295.

Coral-snakes, 400.

Cordylus, sexual difference of color in a species of, 405.

Corfu, habits of tbe chaffinch in, 281.

Cornelius, on tbe proportion of the sexes in Lucanus Cemus, 286.

Corpora Woitfina, 183; agreement of, with the kidneys of fishes, 10.

Correlated variation, 49.

Correlation, influence of, in tbe production of races, 225.

Corse, on the mode of fighting of tbe elephant, 585.

Corvus co7'one, 463 ; Corvvs graculus, red beak of, 559 ; Corvus
pica, nuptial assembly of, 461.

Corydalis cornvtus, large jaws of tbe male, 313.

Cosmetornis, 457, 526.

Cosmetornis veaillarius, elongation of wing-feathers in, 436, 457.

Cotingidae, sexual differences in, 248; coloration of the sexes of,
623; resemblance of the females of distinct species of, 535.

Cottus scorpius, sexual differences in, 382.

Coulter, Dr., on the Californian Indians, 291.

Counting, origin of, 163; limited power of, in primeval man, 205.

Courage, variability of, in the same species, 78; universal high
appreciation of, 139; importance of, 147; characteristic of men, 644.

Courtship, greater eagerness of males in, 250; of fishes, 376, 386;
of birds, 417, 426, 460.

Cow, winter change of color, 619.

Crab, devil, 304; crab, shore, habits of, 803.

Crabro cribraiius, dilated tibiae of the male, 313.

Crabs, proportions of the sexes in, 288.

Cranz, on the inheritance of dexterity in seal-catching, 37t

Crawfurd, on the number of species of man, 199.

Crenilabrus mnssa and C. melops, nests, built by, 391.

Crest, origin of, in Polish fowls, 261.

Crests, of birds, difference of, in the sexes, 533; dorsal hairy, of
mammals, 606.

Cricket, field, stridulr*tion of the, 320, 321; pugnacity of male, 327;
cricket, house, sinduiarions of the, 321.

Crickets, sexual jV.iterences in, 328.

Crinoids, ccmplexi-^y of, 103.

Crioceridap, stridulal;^a of the, 343.

Cruaking of frogs, 397.

Crocodiles, musky odor of, during the breeding season, 898.

Crocodilia, 398.

Crossbills, characters of young, 529.

Crosses in man, 196. '

Crossing of races, effects of tbe, 218.

INDEX. 735

Crossoptilon auritum, 454, 514, 538; adornment of botli sexes of,
207; sexes alike in, 524.

Crotch, tJ. R., on tlie stridulation of beetles, 342, 345, on the
stridulation of Hdiopathes, 345; on the stridulation of Acalles, 346;
habit of female deer at breeding time, 574.

Crow Indians, long hair of the, 662; young of the, 549.

Crows, 559; vocal organs of the, 421; living in triplets, 465; crows,
carrion, new mates found by, 463; crows, Indian, feeding their blind
companions, 116.

Cruelty of savages to animals, 133.

Crustacea, parasitic, loss of limbs by female, 235; prehensible feet
and antennae of, 237; male, more active than female, 250; partheno-
genesis in, 287; secondary sexual characters of, 299; amphipod, males
sexually mature while young, 552; auditory hairs of, 648.

Crystal worn in the lower lip by some Central African women, 656.

Cuckoo fowls, 270.

Culicidae, 235, 318; attracted by each other's humming, 318.

Cullen, Dr., on the throat-pouch of the male bustard, 423.

Cultivation of plants, probable origin of, 151.

Cupples, Mr., on the numerical proportion of the sexes in dogs,
sheep and cattle. 279; on the Scotch deerhound, 589; on sexual
preference in dogs, 597,

Curculionidae, sexual difference in length of snout in some, 236;
hornlike processes in male, 338; musical, 341, 342.

Curiosity manifestations of, by animals, 80.

Curlews, double moult in, 442.

Cursores. comparative absence of sexual differences among the, 248.

Curtis, J., on the proportion of the sexes in Athalin, 286.

Cuvier, F., on the recognition of women by male quadrumana, 9;
Cuvier, G., <m the number of caudal vertebrae in thn mandril, 65; on
instinct and intelligence, 75; views of, as to the position of man, 170;
on the position of the seals, 170; on Hectocotyle, 297.

Cynnalcyon, sexual difference in colors of, 520; immature plumage
of, 532.

Cyanecula suecica, sexual differences of, 537.

Cychrus, sounds produced by, 345.

Cycnia mendica, sexual difference of, in color, 358.

Cygnus ferus, trachea of, 424; cygiius immutabilis, 550; cygnus
olor, whit« young of, 550,

Cyllo Leda, instability of the ocellated spots of, 486.

Cynanthnu , vaiiation in the genus, 481.

Cynipidae, proportion of the sexes in, 286.

Cynocephalus, difference of the young from the adult, 9; male
recognition of women by, 9; polygamous habits of sjjecies of, 246;
cynocephalus babouin, 710; cynocephalus chacma, 79; cynocephalus
gelada, 93; cynocephalus hainadryas, 92, 674; sexual difference of
color in, 614, 710; cynocephalus leucophus, colors of the sexes of,
614, 710; cynocephalus mormon, colors of the male, 614, 710 ; Cyno-
cephalus porcarius, mane of the male, 5^i; cynocephalus sphinx, 710.

Vynopithecus nigei\ ear of, 18.

('ypridina, proportions of the sexes in, 287.

Cyprinidae, proportion of the sexes in the, 282; cyprinidae, Indian,
389.

736 mDEX.

Cyprinodontklae, sexual differences in tlie, 380, 383.

t'ypriaus auratns, 388.

Cijpris, relations of the sexes in, 287.

Cyrtudactylus rubidus, 402.

Cystophora cristata, liood of, 603.

iJaceto, sexual difference of color in, 520; dacelo gaudichaudi,
young- uuile of, 532.

Dul-ripa, a kind of ptarmigan, 280.

Dnmulis albifrons, peculiar markings of, 621 ; damalis pygarga,
peculiar markings of, 621.

Dam])ness of climate, supposed influence of, on the color of tlie
skin, 35, 220.

Danaidae, 350.

Dances of birds, 431.

Dancing, universality of, 203.

Danger signals of animal, 114.

Daniel 1, Dr., his experience of residence in West Africa, 222.

Darfur, protuberances artificially produced by natives of, 655.

Darwin. F., on the stridulation of Dermestes mtmnvs, 342.

Dasyc/nra pudihunda, sexual difference of color in, 358.

Davis, A. H., on the pugnacity of the male stag-beetle, 339; Davis,
J. B,, on the capacity of the skull in various races of men, 60; on
the beards of the Polvnesians, 630.

Death's Head Sphinx, 349.

Death-rate higher in towns than in rural districts, 157.

Death-tick. 347.

De Caudolle, Alph., on a case of inherited power of moving the
scalp, 14.

Declensions, origin of, 103.

Decoration in birds, 434.

Decticus, 323.

Deer, 265. development of the horns in, 265; spots of young, 529,
624; horns of, 573, 578; use of horns of, 582, 590; horns of a, in
course of modification, 584; size of the horns of. 587, female, pair-
ing with one male, while others are fighting for her, 595; male,
attracted by the voice of the female, 600; male, odor emitted by 605;
Axis, sexual difference in the color of the. 612; fallow, different
colored herds of, 617; Mantchurian, 623; Virginian, 624; color of
the, not affected by castration, 611; colors of, 612.

Deerbound, Scotch, greater size of the male, 269, 589.

l>efensive orders of mammals, 590.

De (jeer, C, on a female spider destroying a male, 308.

De Kay. Dr.. on the bladder-nose seal, 603.

Delorenzi, U., division of malar bone, 44.

Demerara, yellow fever in, 221.

Deitdrocyyiia, 529.

JJe/tdrophUa frontalis, young of, 555.

Denison, Sir W.. manner of ridding themselves of vermin among
the Australians, 64; extinction of Tasmanians, 209.

Denny. H., on the lice of domestic animals, 193.

Dermestes mviinus, stridulation of, 342.

De.scent traced through the mother alone, 672,

Deserts, protective coloring of animals inhabiting, 557.

INDEX, ';[ZJ

Desmarest. on tlie absence of suborbital pits in Antilope sulguttu-
rosa, GOo; on the whiskers of Macacus, COT; on tLe color of tbo
opossum, 609; on the colors of tbo sexes of Muk wiinitus, 610; on
tlie coloring of tbe ocelot, 610; on the colore of seals, 610; on Anti-
lo2Je caama, 612; on tbe colors of goats, 618; on sexual difference of
color in Aides viayr/inatus, 6l3; on tbe mandrill, 614; on Macacus
cynomulgus, 636.

Desmoulins, on tbe number of species of man, 199; on tbe musk-
deer, 605.

Desor, on tbe imitation of man by monkeys, 82.

Despine, P., on criuiinuls destitute of conscious, 131.

Develoi)ment, embryonic, of man, 9, 10, 12; correlated, 484.

Devil, not believed in bv tbe Fuegians, 107.

Devil-crab, 304.

Devonian, fossil insect from tbe, 827.

Dewlai)s, of cattle and antelojjes, 608.

Diadema, sexual differences of coloring in tbe species of, 350.

Diamond-beetles, brigbt colors of, 333.

Diastema, occurrence of, in man. 46.

Diastylidae, proportion of tbe sexes in, 287.

Dicrurvs, racket-sbaped featbers in, 438 ; nidificatlon of, 516;
dicrurus 7nac racer cus, cbange of plumage in, 524.

Didelphin oponsum, sexual difference in tbe color of, 609.

Differences, comparative, between different species of birds of tbo
same sex , 586.

Digits, cupernunierary. more frequent in men tban in women,
253 ; supernumerary, inberitance of, 262 ; supernumerary, early
development of, 268.

Dimorpbism in females of water-beetles, 313; in Neurothcmis avid
Jgrioii, 329.

Diodorus, on tbe absence of beard in tbe natives of Ceylon, 638.

Dipelicus Lantori, sexual differences of, 835.

Diplopoda, prebensile limbs of tbe male, 81 0.

Dipsats cynodon, sexual difference in tbe color of, 398.

Diptera, 317.

Disease, generated by tbe contact of distinct peoples, 208.

Diseases, common to man and tbe lower animals, 7; difference of
liability to, in different races of men, 191; new, effects of, upon
savages. 208; sexually limited, 268.

Displav, coloration *of Lepidoptera for, 356; of plumage by male
birds, 447, 456.

Distribution, wide, of man, 54; geographical, as evidence of
specific distinctness in man, 192.

Disuse, effects of, in producing rudimentary organs. 13; and use
of parts, effects of, 36; of parts, influence of, on tbe races of men,
224.

Divorce, freedom of, among tbe Cbarruas, 682.

Dixon, E. S. on tbe ])airing of different species of geese, 471; on
tbe courtship of peafowl, 477.

Dobrizhoffer, on the marriage customs of tbe Abipones, 684.

Dobson, Dr., on tbo Cheiroptera, 247; scent-glands of bats, 604;
frugivorous bats, 610.

Dogs, suffering from tertian ague, 8; memory of, 83; dreaming,

738 INDEX.

84; diverging when drawing sledges over thin ice, 85;. exercise of
reasoning faculties by, 88; domestic, progress of, in moral qualities,
90; distinct tones uttered by, 95; parallelism between his affection
for his master and religious feeling, 108 ; sociability of the, 113;
sympathy of, with a sick cat, 116; sympathy of, with his master,
116: their possession of conscience, 117; possible use of the hair
on the fore legs of the, 172; races of the, 201; numerical proportion
of male and female births in, 278; sexual affection between individ-
uals of, 215; howling at certain notes, 649; rolling in carrion, 605.

Dolichocephalic structure, possible cause of, 63.

Dolphins, nakedness of, 63.

Domestic animals, races of, 201; change of breeds of, 680.

Domestication, influence of, in removing the sterility of hybrids,
196.

D'Orbigny, A., on the influence of dampness and dryness on the
color of the" skin, 220; on the Yuracaras, 661.

Dotterel, 544.

Doubleday, E., on sexual differences in the wings of butterflies,
314; H., on the porportion of the sexes in the smaller moths, 284;
males of Lasiocampa qvercus and on the attraction of the Satvrnia
carpini by the female, 284 ; on the proportion of the sexes in the
Lepidoptera, 284; on the ticking of Anobium tesselatum, 347; on the
structure of Agerouia feronia, 349; on white butterflies alighting
upon paper, 359.

Douglas, J. VV-, on the sexual differences of the Hemiptera, 818;
colors of British Homoptera, 318.

Down, of birds, 442.

Draco, gular appendages of, 402.

Dragonet, Gemmeous, 381.

Dragon-flies, caudal appendages of male, 313 ; relative size of the
sexes of, 316; difference in the sexes of, 328; want of pugnacity by
the male, 330.

Drake, breeding plumage of the, 446.

Dreams, 84; possible source of the belief in spiritual agencies, 107.

Drill, sexual difference of color in the, 614.

Drommis irroratus, 545.

Dromolma, Saharan species of, 519.

Drongo shrike. 524.

Drongos, racket-shaped feathers in the tails of, 486, 445.

Dryness of climate, supposed influence of, on the color of the
skin.* 220.

DryopWiecufi, 177.

Duck, harlequin, uge of mature plumage in the, 552; breeding in
immature ])lumage, 552: long tailed, preference of male, for certain
females, 478; pintail, pairing with a widgeon, 471; voice of the. 425;
pairing with a shield-drake, 471 ; immature plumage of the. 532;
wild, sexual differences in the, 248; speculum and male characters of,
267: pairing with a pintail drake, 471.

Ducks, wild, becoming polygamous under partial domestication,
249; dogs and cats recognized by, 468.

Dufosse, Dr., sounds produced by flsh, 393.

Dugong, nakedness of, 63; tusks of, 572.

Dujardin, on the relative size of the cerebral ganglia in insects, 61

INDEX, 739

Duncan, Dr., on tlie fertility of early marriages, 150, comparative
health of married and single, l.VJ.

Diipont, M., on the occurrence of the supra condyloid foramen in
the Imnierus of man, 24.

Durand, J. P.. on causes of variation, 34.

Uureau de hi Malle, on the songs of birds, 97; on the acquisition
of an air by blaclc birds, 421.

Dutch, retention of their color by the, in South Africa, 219.

Duty, sense of 110.

Duv'aucel, female llyldbates Avashing her young, 79.

Dyaks. pride of, in mere homicide, 133.

D//nt(.'ite.s, large si/e of males of, 316.

Dynastini, stridulation of, 344.

Dj/ti.sn /(.'<, diiuorphism of females of, 313; grooved elytra of the
female. 313,

Eagle, young Cercopithecus rescued shell, by the troop, 115; cer-
copUhecu.s, white headed, breeding in immature plumage, 552.

Eagles, golden, new mates found by, 403.

Ear. motion of the, 15; external form of the, useless in man, 15;
rudimentary point of the, in man, 10.

Ears, more variable in men than women, 253; piercing and oma
mentation of the, 056.

Earwigs, parental feeling in, 120.

Kchidiui, 178.

Kchiiii, bright colors of some, 295.

Echinodermata, absence of secondary sexual characters in, 294.

KchiH carinnta, 400.

Ecker, figure of the human embryo, 11; on the development of the
gyri and sulci of the brain, 232; on the sexual differences in the
l^elvis in man, 035; on the presence of a .sagittal crest in Australians,
036.

Edentata, former wide range of, in America, 193; absence of secon
dary sexual characters in, 246.

Kdolias, racket-shaped feathers in, 436.

Edwards, Mr., on the proportion of the sexes in North American
species of Papilio, 283.

Eels, hermaphroditism of, 184.

Egerton, Sir P., on the use of the antlers of deer, 581, 583; on the
pairing of red deer, 595; on the bellowing of stags, 601.

Eggs, hatched by male fishes, 391.

Egret, Indian, sexes and young of, 553.

P^i>rets. breeding i)luinage of, 442; white, 560.

Ebrenberg, on the mane of the male Hamadryas baboon, 594.

EkstWim, M., on Jlarckla f/lacinlis, 478.

KlacIuHta rafociiievea, habits f)f male, 234.

Elaml, develoi)ment of the horns of the, 263.

Elands, sexual differences of color in, 611.

Kl(iphomyi((, sexual differences in, 317.

KhtphniH uligiiioHus, stridulation of, 343.

Enps, 400.

Elateridce, proportion of the sexes in, 280.

Elaters, luminous, 315.

Elephant, 178; rate of increase of the, 53; nakedness of the, 63;

740 INDEX.

using a fan. 91; Indian, forbearance to Lis keeper, 117; polygamoug
habits of the, 246; pugnacity of the male, 571; tusks of, 572, 573,
678, 5S7; Indian, mode of fighting, of the, 585; male, odor emitted
by the. 604; attacking white or grey horses, 617.

Elevation of abode, modifying influence of, 89.

Elimination of inferior individuals, 155.

Elk, 579. winter change of the, 619; Irish, horns of the, 587.

Ell ice Islands, beards of the natives, 639, 663.

Elliot, D. O., on Felecauus evythrorhyitchas, 442; I?., on the nu-
merical i)rop()rtion of tlie sexes in young rats, 279; on the proportion
of the sexes in sheep, 278; Sir VV^. on the polygamous habits of the
Indian wild boar, 246.

Ellis, on the prevalence of infanticide in Polynesia, 676.

Elphinstone, Mr., on local difference of stature among the Hlndoes,
35; on the difficulty of distinguishing the native races of India, 190.

Elytra, of the fern -lies of DytiHcns, Acilius.IIydmporus, 813.

Bmberiza, characters of young, 529; Eniberiza miliaria, 529;
Emberiza .schniitidas, 463; head-feathers of the male, 455.

Embryo of man, 10, 11; of the dog, 11.

Embryos of mammals, resemblance of the, 28.

Emigration, 155.

Emotions experienced by the lower animals in common with man,
77; manifested l)y animals, 80.

Emperor butterfly, 348.

Emperor moth, 858.

Emu, sexes ami incubation of, 545.

Emulation of singing birds, 419.

Endurance, estimation of, 134.

Energy, a characteristic of men, 645.

England, numerical proportion of male and female births in, 274.

Engieheart, Mr., on the finding of new mates by starlings, 464.

Enjrlisli, success of, as colonists, 160.

Engravers, short-sighted, 37.

Entomostraca. 804.

Entozoa, difference of color between the males and females of
some, 294.

Environment, direct action of the, in causing differences between
the sexes, 254.

Envy. ])ersistenceof, 127.

Eocene period, possible divergence of men during the, 177.

Eolid.e. colors of, produced by the biliary glands, 296.

Epeira niyrrf, small size of the male of, 808.

Ephemerie, 811.

Ephemeridte, 328.

Ephippif/cr citinm. stridulating organs of, 322, 820.

Epicalifi, sexual differences of coloring in the species of, 350.

Eqinis hemionna, winter change of, 619.

Erateina, coloration of, 357.

Ercolani, Prof., hermaphroditism in eels, 184.

Erect attitude of man, 57, 58.

h'ridnlis, courting of 818.

Eschricht, on the development of hair in man, 20; on a lanuginous
mustache in a female fetus, 21; on the want of delinitiou between

INDEX, 741

tlie scalp and tlie foreliead in some children, 171; on tLe arrange-
ment of the bair in the human fetus, 172; on the Lairyuess of the
face in the human fetus of both sexes, GdS, 889.

Ji'ismeruldd, difference of color in the sexes of, 334.

Knox luciuti, 281; esox retkiildtiin, 380.

Esciuimaux, 72, 150; their belief in tbe inheritance of dexterity in
Beal-catching, 37; mode of life of, 224.

Ji'fftrelda aimimhicn, pugnacity of the male, 415.

Kubayis, sexual differences of coloring in the species of, 35L

JKiic/iiras loiKjiiiuinus, sound produced by. 344.

Kudroml((x iKoriHcllms, 544.

J<ulan>imjii(jul(uiH, colors of the female, 510.

Euler, on the rate of increase in the U. S., 50.

KnmomoUi sxpercUiaris, racket-shai)ed feathers in the tail of, 436.

h'updomenn macrouvti, colors of the female, 510.

EupheiiKi ffplaiihfht, 521,

Kuplocamus erytluophthalmus, possession of spurs by the female,
4I3.

Europe, ancient inhabitants of, 200.

Europeans, difference of, from Hindoos, 218; Lairynesd of, proba-
bly due to reversion, 087.

JCuroHtopoduH, sexes of . 540.

Kuvy(ju(dhu!5, different proportions of the head in the sexes of,
814.

Kuiitephaniu, sexual differences of species of, 408; young of, 555.

Exaggeration of natural characters by man, 004.

Exogamy, 073, 075.

Exi)erience, acquisition of, by animals, 90.

Expression, resemblances in. between man and the apes, 171.

Extinction of races, causes of, 200.

Eye, destruction of the, 30; change of position in, 62; obliquity
of, regarded as a beauty by the Chinese and Japanese, 059.

Eyel rows, elevatirni of, 14; develo]iment of long hairs in, 20; in
monkeys. 171; eradicated in parts of South America and Africa, 050;
eradication of, by the Indians of Paraguay, 002.

Eyelashes, eradication of, by the Indians of Paraguay, 002.

Eyelids, colored black, in ])art of Africa. 055.

Eyes, pillared, of the male of Chlo'eon, 311; difference in the color
of, in the sexes of birds, 483.

Eyton, T. ('., observations on the development of the horns in the
fallow deer, 205.

Eyzies, Les, human remains from, 207.

Fabrt*, M., on the habits of Cerceiia, 330.

Facial bones, causes of modification of the, 03.

Faculties, diversity of, iu the same race of men, 30; Inheritance
of, 31; diversity of, in animals of the same si)ecie,s, 31; mental varia-
tion of, in the same si)ecies, 74; of birds, 400.

Fakins, Indian, tortures undergone by. 134.

Ftdco leucoce2)halu8, 552; Jalco percynnuit, 463, Z2A\ faUo iinnun-
cuius, 403.

Falcon, peregrine, new mate found by, 4G3.

Falconer, H., on the mode of fighting of the Indian elephant, 585;
on canines iu a female deer, 580; ou Ilyuinoschas aquaticus, 024.

7i2 INDEX,

Falkland Islands, liorses of, 20G.

Fallow deer, ditferent colored berds of, 617.

Famines, frequency of, among savages, 51.

Farr, Dr., on the effects of profligacy, 155; on tlie influence of
marriage on mortality, 157, 158.

Farrar, F. VV., on Ibe origin of language, 98; on tlie crossing or
bl en ling of languages, 102; on tbe absence of tbe idea of Uod in
certain races of nien, 105; on early marriages of tbe poor, 156; on
tbe middle ages, 160.

Farre, Dr., on tbe structure of tbe uterus, 43.

Fasbions, long prevalence of, among savages, 658, 666.

Faye, Prof., on tbe numerical i)roportion of male and female birtbs
in Norway and Russia. 275; on tbe greater mortality of male cbildren
at and before birtb, 275.

Featbers, modified, producing sounds, 427 c^ Stq., 512; elongated,
in male birds, 485, 457; racket-sbaped, 436; barbless and witb fila-
mentous barbs in certain birds, 437; sbedding of margins of, 446.

Feeding, bigb, probable influence of, in tbe pairing of birds of
different species, 472.

Feet, tbickening of tbe skin on tbe soles of tbe, 37; modification
of, in man, 58.

Fdis caiuidenfds, tbroat-ruff of, 594; felis pardalis and F. mitis,
sexual difference in tbe coloring of, 610.

Female, bebavior of tbe, during courtsbip, 178; birds, differences
of, 536.

Females, presence of rudimentary male organs in. 184; preference
of, for certain males, 242; pursuit of, by males, 250; occurrence of
secondary sexual cbaracters in, 255; development of male cbaracter
by, 257. *

Females and males, comparative numbers of, 241, 244; compar-
ative mortality of, wbile young, 244.

Femur and tibia, proportions of, in tbe Aymara Indians, 39.

Fenton, Mr., decrease of Maories, 210 ; infanticide among tbe
Maories, 289.

Ferguson, Mr., on tbe courtsbip of fowls, 474.

Fertilization, pbenomena of, in plants, 251; in tbe lower animals,
251.

Fertility lessened under cbanged conditions, 214.

Fevers, immunity of negroes and mulattoes from, 220.

Fiber zibethiciis, protective coloring of it, 619.

Fick. H., effect of conscription for military service, 152.

Fidelity, in tbe elepbant, 117; of savages to one anotber, 133;
importance of, 141.

Field slaves, difference of, from bouse slaves, 224.

Fiji Arcbipelago, population of tbe, 198; Fiji Islands, beards of
tbe natives, 639, 603; marriage customs of tbe, 683.

Fijians, burying tbeir old and sick parents alive, 116; estimation
of tbe beard among tbe, 663; admiration of, for a broad occiput, 665,

Filial affection, partly tbe result of natural selection, 119.

Filum terminale, 25.

Fincb. racket-sbaped featbers in tbe tail of a, 436.

Fincbes, spring cbange of color in, 447; Britisb, females of tbe, 586

Fingers, partially coberent, in species of U^lobates, 57.

INDEX, 743

Finlayson, on tbe Cocliin Chinese, 659

Fire, use of, 54, 164. 204.

Fischer, on the pugnacity of the male of, Lethrus cepJinlotea, 340.

Fisclier, F. Voii, on display of brightly colored parts by uioukey.s
in courtship, 709.

Fish, eagerness of inale, 250; proportion of tha sexes in, 281;
sounds produced by, 393.

Fishes, kidneys of, represented by Corpora Wolffiana in the human
embryo, 10; male hatching ova in their mouths, 185. receptacles ft»x
ova possessed by, 235; relative size of the sexes in, 380, fresh water,
of the tropics, 389; protective resemblance in, 390; change of color
in, 390, nest-building, 391; spawning of, 392; sounds produced by,
393, 040; continued growth of, 552.

Flamingo, age of mature plumage, 551.

Flexor pollicis longiiit. similar variation of, in man, 48.

Flies, humming of, 318.

Flint tools, 104.

Flints, difficulty of chipping into form, 56.

Florida, Quixcdliat m<(jor in, 281.

Flonumja mdlicova, 504.

Flounder, coloration ot the, 390.

Flower, VV. H , on the abductor of the fifth metatarsal in apes,
47, on the position of the seals, 170; on the Pithecia mouachus, 229;
on the throat pouch of the maie bustard, 423.

Fly catchers, colors and nidification of, 518.

Fetus, human, woolly covering of the, 21; arrangement of the
hair on, 172.

Food, influence of, upon stature, 35.

Foot, prehen.'-ile power of the, retained in some savages, 58; pre-
hensile, in the early progenitors of man, 182.

Foramen, supra -condyloid, excei)tional occurrence of in the
humerus of man, 24, 49. in tlie early progenitors of man, 179.

Forbes, D.. on the Aymara Indians, 39; on local variation of color
in the Quichuas, 223: on the hairlessness of the Aymaras and
Quichuas, 639; on the long hair of the Aymaras and Quichuas, 037,
662

Forel, F., on white young swans, 550.

Forester, Hon. O. W.. on an orphan hawk, 465.

Fonnicd rnfii, size of the cerebral ganglia in, 61.

Fossils, absence of, connecting man with the apes, 178.

Fowl, occurrence of spurs in the female, 257. game, early pugnac-
ity of, 270, Polish, early development of cranial peculiarities of, 270;
variations in plumage of. 438; examples of correlated development iu
the, 484, domestic, breeds and sub breeds of, 523.

Fowls spangled Hamburg. 259, 270, inheritance of changes of p' i-
mage by, 259, sexual peculiarities in, transmitted only to the samo
sex, 260, loss of secondary sexual characters by male. 261 ; Polish,
origin of the crest in, 261, period of inheritance of characters by, 269;
cuckoo, 270, develoi)ment of the comb in, 270, numerical proportjon
of the sexes in 280 , c«)urtship of, 473 ; mongrel, between n black
Spanish cock and different hens. 485. penciled Hamburg, dilTeience
of the sexes in, 509, Spanish, sexual differences of the comb in, 609;
spurred, in both sexes, 511

744 mDEX.

Fox, W. D., on some Lai f tamed wUd ducks becoming- polygamous
and on polygamy in the guinea fowl and canary-bird, 249; "U the
jjroportion oi" the sexes in cattl«^ 280 ; on the i)ugnaciTy ol the pea-
cock. 413, on a nuptial assembly of magpies, 401 , on the finding of
new mates by crows, 463, on ])artridges living in tni)iets, 4Go; on the
l>airing of a goose with a (.'liinese gander. 471.

Fwses. wariness of young, in hunting districts, 90, black. GIG.

Fraser. C, on the different colors of the sexes in a species of
&jhiU((, 306. Fraser, (i., colors of Tliedn. 3;");!

Frere, Ilookham, quoting Theognis on selection in mankir.d. 33.

FniKjdln c.iiniO)iini, 447. fnnydUt ciru, age of mature ])luniage in,
5;)1, JniKjilla cyaiiea, age of mature ])lumage in, hT){ , frinyiUa
leucopltri/x, young of, 503; JriurjiUa spiinia 472; JruKjiUa in.siin,
change of color in, in spring, 446; young of, 553

FringiUiilje, resemblance of the females of distinct species of, 535.

Frog, bright colored and distasteful to birds. 396.

Frogs, 335, male, temporary receptacles for ova possessed by, 235;
reaily to breed before the females, 240, fighing of, 396; vocal organs
of, 397.

Frontal bone, persistance of the suture in, 44.

Fruits, jjoisonous. avoided by aniuuils, 75.

Fuegians, 150, 163, difference of htatuie r.irong the, 35; power of
sight in the. 38, skill of, in stone throwing, 55. resistance of the,
t.) their severe diuuite, 71, 207. mental capacity of the, 73, quasi-
leligious .sentiments of the, 107; resemblance of, in mental charac
ters. to Europeans. 203, nu)de of life of the, 224; aversion of, to hair
on the face, 662; sai<l to admire European women, 664.

Fnlgoridje. songs of the, 319.

Fur, whiteness of. in arctic animals in winter. 260.

Fur-bearing aninuds, accjuired sagacity of, CO.

G'llUcrt'.r. .'-exual differei ce in the color of the irides in, 483; f/nlli-
ever rristdtus, pugnacity of male, 409, red caruncle occurring in the
ma'e during the bieeding-season, 442.

(iailinaceic. frecpiency of i)olygamous habits and of sexual differ-
ences in the. 248. love gestures of, 432; decomi)osed feathers in, 437:
stripes of young, 529. con!])arative sexual differences between the
species of. 536 phnnage of, 537.

(iallinaceous birds, weapons of the male, 412; racket shaped feath-
ers on the heads of. 436.

Call ill iilii chlurpiis, ])ugnacity of the male, 409.

G'jllopercILv, spura of, 413; development of spurs in the female,
512.

GnllopliafdH, young of, 533.

(ialls, 68.

GidliiH bdnkUd, neck-hackles of, 445; gnllus Btnnleyi, pugnacity of
the male, 412.

(jralton, Mr., on hereditary genius, 31; gregarlousness and inde-
pendence in animals, 118: on the struggle between the social and
personal iutpulses, 141; ow the effects of natural selection on civilized
nations, 151; on the sterility of sole daughters, 153; on the degree
of fertility of ])eople of genius, 154; on the early marriages of the
poor, 156; on the ancient (ireeks, 159; on the Middle Ages, 160; on
the progress of tUu U. tS., 161; ou tS. African uotioub of beauty, G61.

INDEX, ;*45

Gammnrns, use of tlie clielac of, 303; gammarus marinus, 305.

Ijijumets, wliitf only wLeu mature, 500.

Cjuuoid HsLes, 180. 'l87.

Ciuoiir. lioins oT the, 570.

(isip between man and the apes. 177.

liaper, sexes and young ol, 553.

(iardner, on an example of rationality in a OelasimilS, 305.

iiiirrnLns yliunhnius, 403

(iartner. on bterility of hybrid plants, 19G.

(iasteroixxla, 297. j)ulnioniferous, courtship of, 297.

Gddero.stens, 249, niditication ol'. 391; (jddtronttus leiurus, 376,
380, 391, fjiffitcrodci/.s tnn'hnru.s, 370.

(jddroplwrd, wings of. brightly colored beneath, 357.

(jiauchos, want of humanity among the, 139.

CJaudry, M., on a fossil monkey, 175.

GfiL'ui', seasonal change of })lumage in, 561.

(iee.se, clanging noise made by, 418. pairing of different species of,
471; Canada, selection of niates by, 471, 473.

(iegenbaur, C, <m the number of digits in the IcLtLyopterygia,
42, on the hermaphroditism of the remote progenitors of the verte-
biata, 183; two types of nipi)le in mammals, 184.

Giiddiuns, proi)urtions ol the sexes in a s])ecies of, 288; use of the
enlarged chelie of the male, 303; i)ugnacity of males of, 305;
rational actions of a, 305; difference of color iu the sexes of a species
of, 307.

(ienimules, dormant in one sex. 261.

(ienius, 31; hereditary, 043. 644, fertility of men and women of,
154.

(jleofFroy-Saint Ililaire. Isid., on the recognition of women by male
quadrumaiia, 9 ; on monstrosities, 33 ; coincidences of arrested
development with ])()Iydactylism, 42; on animal-like anomalies in the
human structure, 45. on tlie correlation of monstrosities. 49; on the
distribution of hair in man and monkeys, 04. on the caudal vertebra?
of monkeys, 05; on correlated variability. C8; on the classification of
man, 167;' on the long hair on ihw heads of species of ISemiKqyitliecvft,
171; on the hair in monkeys, 172. on the development of h«iins in
female deer, 574; and F. Cuvier, on the mandrill, 014; on liylobates,
030. 037

(leographical distribution, as evidence of specific distinctions in
man, 192.

(jeometnp, brightly colored beneath, 357.

GeophayiiH, frontai piotubeiance of male, 385, 392; eggs Latclied
by the male, in the mouth or branchial cavity, 392

'(ieorgia. change of color in (iermans settled in, 223.

Geotrf/pes, stridulation of, 343, 345.

(ieibe, M., on the nest-building of Crcnilahus massn and C. melopt
891.

Cierland, Dr., on tlie prevalence of infanticide, 132, 659, 070; on
tlie extinction of races. 207.

(lervais, P., on the hairiness of the gorilla, 04; on tLe mandrill,
014.

(lesture language, 203.

Uliosi-motli, wjxual difference of color in tlie, 358.

nG INDEX.

Giard, M., disputes descent of vertebrates from Ascidians, 182
color of sponges and Ascidians, 29o; musky odor of Spbiux, 349.

Gibbon, voice of, G02. C47.

(iibbou, Hoolock, nose of, 171.

(Jibbs, Sir D., on diflereuces of the voice indifferent races of men,
646

Gill, Dr., male seals larger tlian females, 247; sexual differences
in seals. 588.

Giraffe, its mode of using the liorns, 580; mute, except in the rut-
ting season, 600.

(.iiraud 'IVulon, on the cause of short sigbt. 38.

(i landers, coniniun'cable to man from tbe lower animals, 7.

Glands, odoriferous, in mannnals, 604, €05.

Glanola, double moult in, 442.

GUnneris limbatu, difference of color in tbe sexes of. 810.

(ilow-worm. female apterous, 235, luminosity of tbe, 314.

(inants, dances of. 318; auditory powers of, 648.

Gnu, skeletons of. found locked togetber, 571, sexual differences
in tbe color of tbe, 612.

(loat, male, wild, falling on Lis boms, 579, male, odor, emittted
by, 604; male, wild ciest of tbe. COS, Berbura. mane, dewlap, etc.,
of tbe male. GC8: Kemas, sexual difference in tbe color of tbe, 612,

Goals, sexual differences in tbe borns of, 260, bonis of, 266; mode
of tigbting of. 579, domestic, fcexual differences of, late developed,
269; beard -5 of. 606.

Goatsucker. Virginian, pairing of tbe, 416.

(lobies. nidification of. 391.

(iod. want of tbe idea of, in some races of men, 105.

(iodron M , on variability. 83; on difference of stature, 35; on tbe
want of connection between climate and tbe color of tbe skin, 219;
on tbe color of tbe skin, 225: on tbe color of infants. 636.

(loldfincb. 421, 446: projwrtion of tbe sexes in tbe. 281; sexual
differences of tbe beak in tbe, 409; courtsbip of tbe, 455; Isortb
American, voung of. 553

Gol{lfisb.'388. 389

Chiniphns. proportions of tbe sexes in, 287; difference in tbe sexes
of. 328

G-'/iepten/r Tkhnmni, 354, pexual difference of color in, 365.

(loodsir. Prof., on tbe affinity of tbe lancelet to tbe ascidians, 181.

(loosander. young of. 532.

(ioose. Antarctic, colors of tbe. 560: Canada, pairing witb a Ber-
nlcle gander. 471; C'binese. knob on tbe beak of tbe, 484: Egyptian,
414: Sebastopol, plumage of, 438; snow, wbiteness of tbe, 561; spur-
winged, 414

(iorilla. 640; semi-erect attitude of tbe. 58; ma.stoid processes of
tbe, 59; ])r()tecting himself from tbe rain witb bisbands, 172; manner
of sitting, 172: su])posed to be a kind of mandrill, 202: ])olygamy of
tbe, 245, 647, 675; voice of tbe, C02; cranium of, 636; fighting of
male, 641.

Gosse, P. II., on the pugnacity of tbe male humming-bird, 409;
Gosse, M., on tbe inheritance of aitiHcial modifications of tbe skull,
689.

Uould, B. A., on variation in the length of the legs in man, 29;

INDEX, -^^Y

measurements of American soldiers, 34, 36; on tlie proportions of
The body and capacity of the lungs in different races of men, 190; on
tlie inferior vitality of mulattoes, 195; Gould, J., on migration of
swifts, 122; on the arrival of mule snipes before the females, 240;
on the numerical proportion of the sexes in birds, 280; on Neomorpha
Grypus, 40b; on the species of Eustephauiis, 408; on the Australian
musk-duck, 466; on the relative size of the sexes in Bnziuva lobatii
and Ciiicloiuimphus craralu, 411; on Lubicauellus lobntus, 414; on
the habits of Meiiura Alberti, 421; on the rarity of song in brilliant
birds, 421; on JSelasphorun platycei'cu.s, 429; on the bovver-birds, 482,
4(51; on the ornamental plumage of the liuniming-birds, 440; on the
moulting of the ptarmigan, 444; on the display of plumage by the
male humming-birds, 447; on the shyness of adorned male birds. 456;
on the decoration of the bowers of bower- birds, 469; on the decora-
tion of their nests by humming birds, 469; on variation in the genus
Cynnnthns, 481; on the color of the thighs in a male paroquet, 481;
on Urodlcte Benjamini, 502 et seq.; on the nidification of the Orioles,
516, on obscurely colored birds building concealed nests, 516; on
trogons and kingfishers, 520; on Australian parrots, 521; on Austral-
ian pigeons, 522; on the moulting of the ptarmigan, 526; on the ini-
niature plumage of birds, 530 et seq.; on the Australian species of
Tarnix, 542; on the young of Aitharus polytmus, 555; on the colors
of the bills of toucans, 560; on the relative size of the sexes in the
marsupials of Australia. 588; on the colors of the marsupials, 609.

(joureaux, on the stridulation of Mutilla europcea, 332.

Gout, sexually transmitted, 268.

Graba, on the Pied Kaveus of the Feroe Islands, 482; variety of
the Guillemot, 4S2.

Gradation of secondary sexual characters in birds, 488.

Grallatores, absence of secondary sexual characters in, 248;
double moult in some, 443.

GndliiKi, nidification of, 517.

Grasshoppers, stridulation of the, 824.

Gratiolet, Prof., on the anthropomorphous apes, 175; on the evolu-
tion of the anthropomorphous apes, 202; on the difference in the de-
velopment of the brains of apes and man. 231.

Gray, Asa, on the gradation of species among the Compositae, 199;
Gray, J. PI, on the caudal vertebrae of monkeys, 65; on the i)ressnce
of rudiments of horns in the female of Cerxulus moschatus, 574; on
the horns of goats and sheep, 575; on crests of male antelopes, COG;
on the beard of the ibex, 607; on the Berbura goat, 608; on sexual
differences in the coloration of rodents, 609; ornaments of male sloth,
610; on the colors of the Elands, 611; on the sing-sing antelope, 612;
on the colors of goats, 612; on Lemur Macaco, 613; on the hog deer,
623.

"Greatest happiness principle," 135, 136.

Greeks, ancient. 159.

Green, A. H,, on beavers fighting, 570; on the voice of the
beaver, 602.

Cireenfinch, selected by a female canary, 472.

Greg, W. II., on the eifectsof natural selection on civilized natloni^
151; on the early marriages of the poor, 156; on the ancient Greeks^
159.

743 INDEX

Grenadiers, Prussian. 82.

Greyhounds, niinencal proportion of the sexes in, 244; nitmGrical
proportion of male and female births in, 278, 291.

Grouse, red, monoofamons, 248; ])ugnacity of younffmale, 414; pro-
dncinir a sound by beating their wings together, 416; duration of
courtsliip of, 460; colois and nidification of, 518.

Gruljer, Dr., on the occurrence of the supra condyloid foramen in
the humerus of man, 23; on division of malar bone, 44, stridulation
of locust, 322; ephipi)iger, 326.

Orus Amtncanax, age of mature plumage in, 551, breeding in im-
ffiature ])lumage, 652; yrus xiryo, trachea (jf, 425.

Gryllns campentris, 321; pugnacity of male, 327; gryllus domes-
tic us, 322

Grypus, sexual differences in the beak in, 408.

Guanacoes, battles of. 570; canine teeth of, 580.

Guanas, strife for women among the, 641; polyandry among the
677.

Guanche skeletons, occurrence of the supra-condyloid foramen in
the humerus (»f, 24.

Guaranys, ])rop()rtion of men and women among, 276; color of
new horn ciiildren of the, 636; beards of the, 639.

Guente, A., on the sexes of llyperythra, 283.

Guilding, L., on the stridulation of the locustidce, 820.

Guillemot, variety of the, 482.

Guinea, sheep of. with males only horned, 266.

Guinea-fowl, monogamous, 248; occasional polygamy of the, 249;
markings of the, 488.

Guinea-pigs, inheritance of tlie effects of operations by, 67.

Ciulls, .sea.sonal change of plumage in, 560; white, 560.

Giinther, Dr., on i)addle of Ceratodus, 42; on hermaphroditism in
Serraiius, 184: on male fishes hatching ova in their mouths. 185,
391, on mistaking infertile female fishes for males, 281; on the pre-
hensile organs of male Flagiostomous fishes, 37; spines and brushes
on fishes, 37; on the pugnacity of the male sahuon and trout, 377;
on the relative size of the sexes in fishes, 380; on sexual differences
in fishes, 381; et xeq.; on the genus CaUionymitfi, 381; on a i)rotec-
tive resemblance of pipe-fish, 390; on the genus f)f Soleiiostovut, 392;
on the coloration of frogs and toads, 396; combat of Testudo deyans,
898; on the sexual differences in the Ophidia, 399; on differences of
the sexes of li/urds, 402 tt seq.

Oynaiiim Lns, ocellated spots of, 486.

Gypsies, uniformity of. in various parts of the world. 220.

Habits, bad, facilitated by familiarity, 139; variability of the force
of, 142.

Hjickel, E., on the origin of man, 3; on rudimentary characters, 12;
on death caused by inHammation of the vermiform appendage, 23; on
the canire teetli in man, 45; on the steps by which man became a
biped, 58; on man as a member of the C'atarrhine group, 176; on the
]>osition of the Leinuridae. 178; <m the genealogy of the iMammalia,
179; on the lancelet. 181: on the transj)arency of pelagic animals,
295; on the musicrJ powers of women. 053.

Hagen, H., and Walsh, B. D., on American Nueroptera. 286.

Sair, development of, in man, 20j character of, bupposed to be.

INDEX. 749

determined by llglit and lieat, 33; distribution of, in man, 63, 685;
possibly removed for oruameutal purposes. (55: arrangement and direc-
tion of, 171; of tlie early ])rogenitors of man, U2: different texture
of, in distinct race:-, 190; and skin correlation of color of. 225: devel-
opment of, in maujuials, (506 ; management of. among different
peoples, 655; great length of, in some North Ameiican tribes. 662;
elongation of the, on the human head, 689; possible inherited etiect
of plucking out. 689.

Hairiness, difference of, in the sexes in man, 637: variation of, iu
races of men, 637.

Hairs and excretory pores, numerical relation of, in sheep, 225.

Hairy family, Siamese, 687.

Halbertsma, Prof., hermaphroditism in Serraiins, 184.

Haujadryas baboon, turning over stones, 114; mane of thema'.e. 594.

Hamiltou, C, <>n the cruelty of the Kaffirs to animals, 133; on the
engrossment of the women by the Kaffir chiefs, 680.

Hammering, difficulty of, 55.

Hancock, A., on the colors of nudibranch Mollusca, 296, 298.

Hands, larger at birth, in the children of laborers, 37. structure of,
in the quadrumana, 56; arms, freedom of, indirectly correlated with
dimunition of canines, 60.

Handwriting, inherited, 100.

Handyside, Dr., suj)ernumery mammae in men, 42.

Harcourt, E. Vernon, on Friiiyilla cannahiua, 447.

Hare, protective coloring of the, 619.

IJardda (/lacialiis, 478.

Hares, battles of male, 570.

Harlan, Dr., on the difference between field and Louse-slaves, 224.

Harris, J. M., on the relation of complexiini to climate, 222; Harris,
T. \V., on the Katy did locust, 321; on the stridulation of the gras.s-
Loppers, 324; on QCcaidhus nitalis, 328; on the coloring of Lepi*
doptera, 356; on the coloring of JSaturnia lo, 358.

Harting, spur of the Ornithorhynchus, 573.

Hartman, Dr., on the singing of Cicada iseptendecim, 319.

Hatred, persistence of, 127.

Haughton, S., on a variation of the fleyor pollicislongus, in man, 48.

Hawks, feeding or[)han nestling, 405.

Hayes, Dr.. on the diverging of sleclge-dogs on thin ice, 85.

llaymond, K., on the diumming of the male TttiaoumbtUus, 42C;
on the drunaning of birds, 427.

Head, altered position of, to suit the erect attitude of man, 62;
Lairine.^s of. in n.an, 64; processes of, in male beetles, 334; artificial
alterations of the form of the, 664.

hearue, on strife for women among the North American Indians,
640; on the N(jrth American Indians' notion of beauty, 659; repeated
elopements of a Ncuth American woman, 682.

heart, in the human emhiyo. 10.

Heat, supposed effects of, 36.

Ikctucotyk, 298.

Hedge-warbler. 589; young of the, 548.

Heel, small projection of, in the Aymara Indians, 89.

Pegt, M., on the development of the spurs in ])eacocks, 267.

Heiiconid^, 350; mimicry of, by other buttertiys, 86^.

750 INDEX.

JTeliopatlies, stridulation peculiar to tlie male, 345.

Hdiothrix auriculata, young of, 582, 538.

JJeliv poinatia, exanijjle of individual altacbraent in, 297.

Hellins, J., piopcitions of !?exes of, ]>epido[)tera reared by, 285.

Henilioltz, on pleasure derived from liaruionies, 104; on the LumaQ
eye, £01; on the vibration of the auditory hairs of Crustacea, 649:
the physiology of harmony, 649.

Hemiptera, 818.

J/emitragus, beardless in both sexes, 607.

Hemsbaclj. M. von, on medial mamma in man, 42.

Hen, clucking of, 418.

Hepburn, Mr., on the autumn song of the water-ouzel, 420.

Jlepialm humyli, sexual difference of color in the, 858.

Herbs, poisonous, avoided by animals, 75.

Hermaphroditism, of embryos, 188, in fishes, 184.

Jlerudias bvbulcus, veinal moult of, 445.

Heron, Sir H., on the habits of pea-fowl, 475, 477, 503.

Herons, love-gestures of, 381; decomposed feathers in, 437: breed-
ing plumage of, 448, 444; young of the, 648, 558, sometimes dimor-
phic, 552; continued growth of crest and plumes in the males of
some. 552; change of color in some, 562.

Jhaperomys coynatus, 648.

IJetiarina, proportion of the sexes in, 287; difference in the sexes
of, 828.

Utter ocerus, stridulation of, 342.

Hewitt, Mr., on a game cock killing a kite, 412; on the recognition
of dogs and cats by ducks, 468; on the pairing of a wild duck with a
pintail drake, 471; on the courtship of fowls, 473; on the coupling
of ])heasants with common hens. 477.

Hilgendorf, sounds produced by crustaceans* 309.

Hindoo, his horror of breaking his caste, 138, 140.

Hindoos, local differences of stature among, 85; difference of, from
Europeans, 218; color of the beard in, 637.

J/ipparchia Janira,4SS; instability of the ocellated spots of, 486.

Hippocampus, development of, 185; marsupial receptacles of the
male, 892; hippocampus minor, 227, 280.

Hippopotamus, nakedness of, 63.

Hips, proportions of, in soldiers and sailors, 30.

Hodgson, S., on the sense of duty, 111.

Hoff berg, on the horns of the reindeer, 574; on sexual preferences
shown by reindeer, 598.

Hoffman, Prof., protective colors, 318; fighting of frogs, 396.

Hog, wart, 592; river, 593.

Hog-deer, 623.

Holland, Sir H., on the effects of new diseases, 208.

Homologous structures, correlated variation of, 49.

Homoptera, 319; stridulation of the, and Orthoptera, discussed, 327.

Honduras, Quiscalus major in, 281.

Honey-buzzard of India, variation in the crest of, 481.

Honey-sucker, females and young of, 533.

Honey-suckers, moulting of the, 444; Australian, nidification of , 516.

Honor, law of, 187.

Hooker, Dr., forbearance of elephant to his keeper, 117; on the
color of the beard la man, 637. _^ ^

INDEX, 751

HooTtliam, Mr., on mental concepts in animals, 94.

Iloolock Gibbon, nose of, 171.

Hoopoe, 421: sounds produced by male. 427.

JJoplopterus armatuK, wing-spurs of, 414.

Hornbill, African, inflation of tlie neck- wattle of tlie mi.le during
courtship. 435.

Hornbills, sexual difference in the color of the ejes m, 483; nidfica-
tion and incubation of, 516.

Home, C, on the rejection of a brightly colored locust by lizards
and birds, 428.

Horns, sexual differences of, in sheep and goats, 260. loss of. ir
female merino sheep, 261 ; development of, in deer, 264 ; devel-
opment in antelopes, 265. from the head and thorax, in niale beetles,
386, of deer, 573, 577, 587; originally a masculine charscter in sheep,
576, and canine teeth, inversed development of, 586.

Horse, fossil, extinction oi the, in South America. 218; polygamous,
246; canine teeth of male, 572; winter change of color. 619.

Horses, rapid increase of, in South America, 53; diminution of
canine teeth in, 60 ; dreaming, 84 ; of the Falkland Islands and
Pampas. 206; numerical proportion of the sexes in, 244, 245: lighter
in winter in Siberia, 260; sexual preferences in, 598; pairing preferently
with those of the same color 617; numerical proportion of male and
female births in, 278; formerly striped, 626.

Hottentot women, peculiarities of, 198.

Hottentots, lice of, 192; readily become musicians, 650: notions ci
female beauty of the, 660; compression of nose by, 665.

Hough, Dr. S., men's temperature more variable than women's,
253, proportion of sexes in man, 274.

House slaves, difference of, from field-slaves, 224.

Houzeau, on the baying of the dog, 84; on reason in dogs, 84;
birds killed by telegraph wires, 90; on the cries of domestic fowls
and parrots, 96, 99; animals feel no pity, 116; suicide in the Aleutian
islands, 133.

Howorth, H. H., extinction of savages, 209.

Huber, P., on ants playing together, 77; on memory in ants, 83;
on the intercommunication of ants, 101; on the recognition of each
other by ants after separation, 331.

Hue, on Chinese opinions of the appearance of Europeans, 659.

Huia, the, of New Zealand, 238.

Human, man classed alone in a, kingdom, 167; sacrifices, 108.

Humanity, unknown among some savages, 133 ; deficiency of,
among savages, 139.

Humboldt, A. von, on the rationality of mules, 88; on a parrot
preserving the language of a lost tribe. 206; on the cosmetic arts of
savages, 654; on the exaggeration of natural characters by man, 664,
on the red painting of American Indians, 665.

Hume, D., on sympathetic feelings, 123.

Humming-bird, racket-shaped feathers in the tail of a, 436; dis-
play of plumage by the male, 447.

Humming-birds,* ornament their nests, 104, 469; polygamous, 248;
proportion of the sexes in, 231, 555; sexual differences in. 408, 503;
pugnacity of male, 409; modified primaries of male, 429; coloration
of the sexes of, 440; display by. 503; nidification of the, 516, 517;
color;i of female, 516; youn^ ot 555.

752 TKBEX,

Hamor, sense of, in dogs, 80.

Iluuiplireys, H. N , on the habits of the stickleback, 249, 376*

Hunger, insthici of, 127.

Huns, ancient, flattening of the nnse by the, 665.

Hunter, J..on the number of species of man, 199; on secondary sexual
characters, 234; on the general beliuvior of female animals during
courtship. 251; on the muscles of the larynx in song-birds, 421; on
strength of males, 588; on the curled frontal hair of the bull, 606; on
the r<?jection of an aas by a female zebra, 617.

Hunter, W. W., on the recent rapid increase of the Sautali, 51; on
the Santali, 218.

Huss, Dr Wax, on the mammary glands, 184.

Hnssey, Mr., on a partridge distinguishing i)ersons, 468.

Hutchinson, Col., example of reasoning in a retriever, 88.

Hutton. Cai)t., on the male wild goat falling on his horns, 579.

Huxley, T. 11., on the structural agreement of man with the apes,
2; on the agreement of the brain in man with that of lower animals,
0. on the adult age of the orang, 9. on the embryonic development
of uian, 10, on the origin of man, 3. 12; on variation in the skulls of
the nativesof Australia. 29. on the abductor of the fifth metatarsal in
apes. 47. on the nature of the reasoning power. 87: on the position
of man. 170: on the suborders of primates, 173: on the Lemuridae,
179. on the Dinosauria. 180; on the amphibian affinities of the Ich-
thyosauriaus, 180. on variability of the skull in certain races oi man,
198; on the races of man, 201; supplement on the brain, 227.

Hybrid birds, production of, 470.

Hydrophobia communicable between man and the lower animals, 7.

Hyclroporns, dimorphism of females of, 313.

Hyelaphi.is poreinus, 623.

Jlifgroguuus, 392,

Jlyld. singing species of, 397.

IJylohntes, absence of the thumb in, 57: upright progression of
some species of, 59; maternal affection in a. 79. direction of the hair
on the arms of species of, 172: females of. less hairy below than
males, o37; hylobalis nr/iUs, 57, hair on the arms of, 172; musical
voice of, 602, superciliary ridge of, 633; voice of, 647.

Ilylohdtes hodlock. .'^exnal difference of color in. 613: hylohatcs Inr,
57; hair on the arms of. 72. female less hairy. 637. hylobatcK leuns-
cuf, 57. song of, 647: hyl(;bnte6syn(iactylus,51: laryngeal sac of, 603.

Jlylifpliilti py/fd/Kiiift, 349.

Hymenoptera, 330; large size of the cerebral ganglia in, 437.;
classification of, 168: sex uj;v1 differences in the wings of, 314; aculeate,
relative size of the sexes of. 316.

Hymenopterftji. parasitic, with a sedentary male, 251.

JlyomosrJuis aqiiaticns, 624.

llypcrythra, proportion of the sexes in. 283.

Jlypoyywun dispnr, sexual difference of color in, 358.

Jlypopyiui. coloration of. 357.

Ihex, nuile. falling on his horns. 579; beard of the. 607.

Ibis, white, change of color of naked skin in, during the breeding
season, 442, scarlet, youn^ of the, 548: ibis tantolns, age oi maturo
plumaga in, 551; bre'eding in immature plumage, 55^.

Ibisis, decomposed featliers in, 437; wliite, 560; and black, 562.

Ichneuiuonidie, difference of the sexes in, 331.

Ichthyopterygia, 42.

Icbtbyosauriaus, 180.

Idiots, microcephalous, their characters and habits. 40: hairiness
and animal nature of their actions, 41; microcephalous imitative
faculties of, 98.

Iguana tuberculata, 403.

Iguanas, 402.

Illegitimate and legitimate children, proportion of the sexes in, 276.

Imagination, exii-tence of, in animals, 84.

Imitation, 77; of man by monkeys, 82; tendency to. in monkeys,
microcephalous idiots and savages, 98; influence of, 146.

Immature plumage of birds, 528, 531.

Implacentata, 179.

Implements, employed by monkeys. 91; fashioning of, peculiar to
man, 92.

Impregnation, period of, influence of. upon sex. 277.

Imj^rovement, progressive, man alone suppposed to be capable
of, 89.

Incisor teeth, knocked out or filed by some savages, 656.

Increase, rate of, 50; necessity of checks in, 53.

Indecency, hatred of, a modern virtue, 135.

India, ditficulty of distinguishing the native races of, 190;
Cyprinidae of, 389; color of the beard in races of men of. 637

Indian, North American, honored for scalping a man of another
tribe. 132.

Individuality, in animals, 93.

Indolence of man, when free from a struggle for existence, 161.

Indopicus carlutta, colors of the sexf^s of, 52L

Infanticide, prevalence of, 52, 132, 289, 290; supposed cause of, 658;
prevalence and causes of, 675 et acq.

Inferiority, supposed ])hysical, of man, 72.

Inflammation of the bowels, occurrence of, in Cebus AzarcB, 7.

Inheritance, 31; of long and short sigbt, 37: of effects of u.-'e of
vocal and mental organs, 100; of moral tendencies, 139, 143; laws of
257; sexual, 262; sexually limited. 506.

Inquisition, influence of the, 159.

Insanity, hereditary, 31.

Insect, fossil, from'the Devonian, 327.

Insectivora, 610; absence of secondary s^nal characters in. 247

Insects, relative i-;ize of the cerebral gangli i in, GO: male, appear
ance of, before the females, 240; pursuit of leniale. ln*tbe males 250.
period of development of sexual cbaracters in. 268 : secondary
sexual characters of, 311; kept in cages, 319, 327; stridulation, 646.

Insessorec, vocal organs of, 421.

Instep, depth of, in soldiers and sailors, 36.

Instinct and intelligence, 75; migratory, vanquishing the maternal,
122, 128.

Instinctive actionrs, the result of inheritance. 119; impulses, dif-
ference of the force, 125 et seq ; and moral impulses, alliance of, 126.

Instincts, 74; complex origin of, through natural Hele(;ticr., 76;
possible origin of some, 76; acquired, of domestic animals, 118.

754 INDEX,

variability of fhe force of, 121; difference of force between tlio
social and other, 1?6, 143; utilized for new purposes, 651.

Instrumental music of birds, 425, 480.

Intellect, influence of, in natural selection in civilized society, 164.

Intellectual faculties, tbeir influence on natural selection in mani
144; probably perfected through natural selection, 14G.

Intelligence, Mr. H. Spencer on the dawn of, 75.

Intern i)erance, no reproach among savages, 135; its destructive
ness, 155.

Intoxication in monkeys, 7.

Iphias glaucippe, 354.

Iris, sexual difference in the color of the, in birds, 435, 488.

Ischio-pubic muscle, 46.

Ithnginis cruentas, number of spurs in. 413.

lulus, tarsal suckers of the males of, 310.

Jackals learning from dogs to I ark, 82.

Jack snipe, coloration of the, 557.

Jacquinot, on the number of species of man, 199.

Jaeger, Dr., length of bones increased from carrying weights. 36;
on the difficulty of approaching herds of wild animals. 114; male
silver jiheasant, rejected when his plumage was spoiled. 476.

Jaguars, black, 616.

Janson, E. W , on the proportions of the sexes in Tomicvs villosus,
286; on stridulant beetles, 342

Japan, encouragement of licentiousness in, 52.

Japanese, general beardlessness of the, 639; aversion of the, to
whiskers, 662.

Jardine. Sir W.. on the Argus pheasant, 436. 457.

Jarrold, Dr., on modifications of the skull induced by unnatural
position, 62.

Jarves, Mr., on infanticide in the Sandwich Islands. 290.

Javans. relative height of the sexes of, 638; notions of female
beauty, 661. •

Jaw, influence of the muscles of the, upon the physiognomy of
the apes. 60.

Jaws, smaller proportionately to the extremities. 37, influence of
food upon the size of, 37; diminution of, in man, 60; in man, re-
duced by correlation, 641.

Jay, young of the, 548; Canada, young of the, 549.

Jays,' new mates found by, 463; distinguishing persons. 468.

Jeffreys, J. iifwyn, on the form of the shell in tlie sexes of the
Gasteropoda, 297;' on the influence of light upon the colors of shells,
298.

Jelly-fish, bright colors of some. 295.

Jenner, Dr., on the voice of the rook, 426: on the finding of new
mates bv magpiess, 462; on retardation of the generative functions in
birds, 465.

Jenyns, L., on the desertion of their young by swallows, 122; on
male birds singing after the ])rf)per season. 465.

Jerdon, Dr., on birds dreaming, 84: on the juignarity of the male
bulbul, 409; on the pugnncity of the niiile Ortygornif* r/nlaris. 412;
on the spurs of Galloperdix, 413; on the habits of LobivaueUu», 414;

INDEX, 755

on tlie spoonbill. 425; on tlie drumming of the Kalij-pleasant, 426;
on Indian bustards, 429; on OtiH bengalensis, 432; on tiie ear tufts of
Sypheotides (luritus, 486; on tbe double moults of certain birds, 444;
on tbe moulting of the boneysuckers, 444; on tbe moulting of bustards,
plovers and drongos, 445, on the spring cbange of color in some
fincbes, 447; on display in male birds, M7; on tbe display of tbe
undertail coverts by tlie male bulbul, 456; on tbe Indian boney-
buzzurd, 481; on sexual differences in tbe color of tbe eyes of born-
bills, 483, on tbe markings of tbe Tragopan pbeasant,"487; on tbe
nidification of tbe Orioles, 516; on tbe niditication of tbe bornbills.
517; on tbe Sultan yellow-tit, 521; on Pakeornis javanicus, 525; on
tbe iuiuiature plumage of birds, 529. et seq.; on representative
species of birds, 533; on tbe babits of Turiiix, 542; on tbe continued
increase of beauty of tbe peacock, 552; on coloration in tbe genus
Palceornis, 562.

Jevons, VV. S., on tbe migrations of man, 53.

Jews, ancient use of Hint tools by tbe, 164; uniformity of, in
various parts of tbe world. 220; numerical proportion of male and
female birtbs among tbe, 275; ancient, tattooing practiced by, 655.

Johnstone, Lieut,, on tbe Indian elephant, 246.

Jollofs, fine appearance of the, 670.

Jones, Albert, proportion of sexes of Lepidoptera, reared by, 285.

Juan Fernandez, huunning-birds of, 555.

Janonia, sexual differences of coloring in species of, 351.

Jupiter, conn)arison with Assyrian effigies, 663,

Kaffir skull, occurrence of the diastema in a, 45.

Kaffirs, their cruelty to animals, 1.33; lice of tbe, 194; color of tbe,
661 ; engrossment of the handsomest womoa by the chiefs of the,680;
marriage-customs of the, 683,

Kalij -pheasant, drumming of the male, 426; young of, 533.

Kdllima, resemblance of, to a withered leaf, 353,

Kalmucks, general beardlessness of, 639; aversion of, to bairs on
tbe face, 662,

Kangaroo, great red, sexual difference in tbe color of, 60D.

Kant, Imm., on duty, 110; on self-restraint, 124; on the number of
species of man, 199.

Katy-did, stridulation of tbe, 321.

Keen, Dr., on the mental powers of snakes, 399.

Keller, Dr., on tbe difficulty of fashioning stone implements, 55.

Kent, W. S., elongation of dorsal fin of CalliouyinuH Ipra, 382;
courtship of Labras mUtas, 386; colors and courtship of Cantharus
lineatus, 386.

Kestrels, new mates found by, 463.

Kidney, one, doing double work in disease, 35.

King. VV. H., on the vocal organs of Tetmo cupido, 423; on tbe
drumming of grouse, 427; on tbe reindeer, 574; on tbe attraction of
male deer by the voice of tbe female, 601.

King and Fitzroy, on the marriage customs of tbe Fuegians, C84.

King-crows, nidification of, 516.

Kingfisher, 421; racket shaped feathers in the tail of a, 436.

King-fishers, colors and nidification of the, 5l8, 520, 522; imma-
ture plumage of the. 532, 533; young of the, 548.

King Lory, 521; immature plumagj of the, 532.

756 INDEX.

Kingsley, C, on tbe sounds produced hy Umbrina, 394.

Kirby and Spence, on sexual differences in tbe length of tli&
snout in Curculionidje, 236; on the courtship of insects, 250; on the
elytra of BytlacKs, 818; ou ])eculiarities in the legs of male insects,
313; on the relative size of the sexes in insects, 310; on tlie Fulgor-
idae, 319; on the habits of Termitefi, 330; on difference of color in the
sexes of beetles, 883; on the horns of the male iamelliccrn beetles,
33d; ou hornlike processes in male Curculionidre, 389; ou the pug-
nacity of the male stag-beetle, 339,

Kite, killed by a game-cock, 412.

Kuot, retention of winter i)luinage by the, 444.

Knox, K., ou the semilunar fold. 19; on the occurren^'e of the
supracondyloid foramen in the humerus of man, 23, on the features
of the young Memnon, 192.

Koala, length of the ccecum in, 23.

Kobax elUpaipryiniias, proportion of the sexes in, 230.

Kolreuter, on the sterility of hybrid plants, 196.

Koodoo, development of the horus of the, 265; markings of the, C21.

Koppen, F. T., on tbe migratory locust, 320.

Koraks, marriage customs of, 688.

Kordofan, protuberances artificially produced by natives of, 655.

Korte, ou the proportion of sexes in locusts, 287; Kussian locusts,
820.

Kovalevsky, A., on tbe affinity of the Ascidiatothe Vertebrata, 181.

Kovalevsky, W., on tbe pugnacity of the male capercailzie, 412;
on the pairing of the capercailzie, 416.

Krause. on a convoluted body at tbe extremity of tbe tail in a
Macncns and a cat. 25.

Kupffer, Prof., on the affinity of the Ascidia to the Vertebrata, 181.

Jjubidocera Dancinii, prehensile organs of the male, 301.

Lahruif, splendid colors of the species of, 382, lahrasmixtus, sexual
tifferences in, 382, 386; labrus paoo, 388.

Laceriilia, sexual differences of, 401.

Lafresnaye, M. de, on birds of paradise, 439.

Lamarck, on the origin of man, 3.

Lauiellibranchiata, 296.

Lauiellicorn beetles, horn-like processes from tbe bead and thorax
of, 384, 386; iniiuence of sexual selection on, 341.

Lainellicorniu, stridulatiou of, 348.

Lamont, Mr., on the tusks of the walrus, 572; on the use of its
tusks by the walrus, 585; on the bladder- nose seal. 603.

J.atnporuis porpht/rarus, colors of the female, 516.

Ijauipyridae, distasteful to mammals, 314.

Lancelet, 181, 187.

Landois, H., gnats attracted by sound. 318; on tbe production of
sound by the Cicadae, 319; on the stridulating organ of the crickets,
821; on Dectic as, 323; on the stridulating organs of the Acridiidae,
324; stridulating apparatus in Orthoptera, 326; on the stridulatiou of
NecrophoriLH, 342; on the stridulant orgaus of Cerambyx heros, 343;
on tbe stridulant organ of Ge-Arupes, 843; on the stridulating organs
in tbe Coleoptera, 344; on the ticking of Anobinm, 347.

Landor, Dr., on remorse for not obeying tribal custom, 130.

Language, an art, 97; articulate, origin of, 98; relation of the

INDEX. 757

progress of, to the development of the brain, 99; effects of inher-
itance in production of, 100; complex structure of. auiong barbar-
ous nations, 103. natural selection in, Vfd; gesture, 208; primeval,
204: of a lost tribe preserved by a ])avn't, 206.

Languages, presence of rudiments in, 102; classification of. 102;
variability of. 102; crossing or blending of, 102; complexity of. no test
of piM fection or ])roof of special creation, 103; resemblance of, evi-
dence of community of origin, 169; languages and species, identity
of evidence of their gradual development, 102.

Laniitu, 525; cliaiacters of young. 529; lanius rufus, anomalous
young of, 550.

LunUester, E, R., on comparative longevity, 151, 155; on the de-
structive effects of intemperance, 155.

Lanugo, ol the human fetus, 21. 685.

Lapponian language, highly artificial, 103.

Lark, proportion of tlie sexes in the, 281 ; female, singing of the, 420.

Larks, attracted by a mirror, 469.

Lartet, E., comparison of cranial capacities of skulls of recent and
tertiary mammals, 62; on the size of the brain in mammals, 91; on
Dryopithecfis, 177; on pre historic flutes, 650.

.Lams, seasonal change of plumage in, 561.

Larva, luminous, of a Brazilian beetle, 314.

Larnyx, muscles of the, in song birds, 421.

Lnsiocampa qaercus, attraction of males by the female, 284; sexual
difference of color in, 358.

Latham, H. U., on the migrations of man, 53.

Latooka, perforation of the lower lip by the women of. 656.

Laurillard, on the abnomal division of the malar bone in man, 44.

Lawrence, W., m the superiority of savages to Europeans in
power of sight, 38; on the color of negro infants, 636; on the fond-
ness of savages for ornaments, 654; on beardless races, 662; on the
beauty of the English aristocracy, 670.

Layard, E. L., on the instance of rationality in a cobra, 399; on
the i)ugnacity of Gallus Stanleyi, 412.

Lay cock. Dr., on vital ])eriodicity, 8; theroid nature of idiots, 41.

Leaves, autumn, tints, useless, 296.

Lecky, Mr., on the sense of duty. 111; on suicide, 132; on the
practice of celibacy, 135; his view of the crimes of savages, 135; on
the gradual rise of morality, 141.

Leconte, J. L., on the stridulant organ in the Coprini andDynas-
tini. 344.

L^e, H., on the numerical proportion of the sexes in the trout, 282.

Leg, calf of the, artifically modified, 655.

Legitimate and illegitiujate children, proportion of the sexes in, 276.

Legs, variation of the length of the, in man, 29; proporticms of. in
soltliers and sailors, 36; front, atrophied in some male butterflies,
314; i)eculiarities of, in male insects, 314.

Leguay, on the occurrence of the supra-condj'loid foramen in the
humerus of man, 24.

" Lek " of the black cock and capercailzie, 460.

Lemoine, Albert, on the origin of language, 98.

Lemur macnco, sexual difference of color in, 613.

Lemuridye, 173; ears of the, 17; variability of the muscles in the,
46; positiou and derivation of the, 17b; tkeix orijj;iu, 18$.

753 INDEX,

Lemurs, uterus in the, 43.

Lenguas, disfigurement of tlie ears of the, 656.

Leopards, black, 616.

Lepidoptera, 348; nuuierical proportions of tlie sexes in the, 282i
coloring of, 349; ocellated spots of, 486.

Lepidodren, 180, 187.

Leptalides, mimicry of, 368.
Leptovhynchns angustatus, pugnacity of male, 339.

Leptura testacea, difference of color in tbe sexes of, 833.

Leroy, on tbe wariness of young foxes in bunting districts, 90; on
tbe desertion of tbeir young by swallows. 122.

Leslie, D., marriage customs of Kaffirs, 683.

Lesse, valley of tbe, 24.

Lesson, on tbe birds of paradise, 248, 457; on the sea-elephant, 603.

Lessona, M., observations on Serranufi, 184.

Lethrus cephalotea, pugnacity of the males of, 337, 340.

Leuciscus phoxinvft, 282.

Leuckart, K., on tbe vesicula prostatica, 26; on the influence of the
age of parents on tbe sex of offspring, 277.

Levator claxiculce, muscle, 47.

Libellula depresm, color of tbe male, 329.

Libellulidae, relative size of tbe sexes of, 316; difference in the
sexes of, 329.

Lice of domestic animals and man, 193.

Licentiousness a check upon population, 52; prevalence of, among
savages, 134.

Lichenstein, on Chera progne, 476.

Life, inheritance at corresponding periods of, 259, 263.

Ligbt, effects on complexion, 36; influence of, upon the colors of
shells, 298.

Li 1 ford. Lord, the ruff attracted by bright objects, 469.

Limosa lapponica, 544.

LinaHfiy 525; ILiiaria montana, 281.

Lindsay, Dr. W. L., diseases communicated from animals to man,
8; madness in animals, 89; tbe dog considers bis master his God, 108.

Linnaeus, views of, as to tbe position of man, 170.

Linnet, numerical proportion of tbe sexes in the, 281; crimson
forebead and breast of tbe, 447; courtship of tbe, 455.

Lion, polygamous, 247; mane of the, defensive, 594; roaring of
the, 601.

Lions, stripes of young, 528.

Lips, piercing of tbe, by savages, 657.

Lithobius, prehensile ajjpendages of the female, 310.

Lithosia, coloration in, 356.

LittoHna littorea, 296.

Livingstone, Dr., manner of sitting of gorilla. 172: on the influence
of damjjness and dryness on tbe color of tbe skin, 220; on the
liability of negroes t«» tropical fevers after residence in a cold climate,
220; on tbe s]nir-winged goose, 414; on weaver-birds, 427; on an
African nigbt-jar, 436, 457; on tbe battle-scars of South African
male mammals, 570; on tbe removal of tbe upper incisors by tb«
Batokas, 656; on tbe ])erforation of the upper lip by the Makalolo,
657; on the Banyai, 661.

INDEX, 759

Livonia, numerical proportion of male and female births in, 243,
275.

Lizards, relative size of tlie sexes of, 401: gular pouches of, 403.

Lloyd. L., on the polygamy of the capercailzie and bustard, 248;
on the numeral proportion of the sexes in the capercailzie and black-
cock, 280; on the salmon, 378; on the colors of the sea-scorpion. 382;
on the pugnacity of male grouse, 415; on the capercailzie and
black-cock, 416, 420; on the call of the capercailzie, 425; on assem-
blages of grouse and snipes, 460; on the pairing of a shield drake
with a common duck, 471; on the battles oi seals, 571; on the elk,
571).

Lohimnellas, wing-spurs in, 414.

Local influences, elfec.t of, upon stature, 34.

Lockwood, Mr., on the development of Hippocampus, 185.

Lock wood, Hev. S., musical mouse, 048.

i^ocust, bright-colored, rejected by lizards and birds, 328.

Locust, migratory, 321; selection by female, 321.

Ijocustidae, siridulation of the 320, 322; descent of the, 323.

Locusts, proportion of sexes in, 287; stridulation of, 321.

Longicorn beetles, difference of the sexes of, in color, 333; stridula-
tion of, 343.

Lonsdale, Mr., on an example of personal attachment in Jlelix
pomaliii, 296.

Lophobranchii marsupial receptacles of the male, 392.

Lophophdrns, habits of, 477.

Jjttplioi-iiKi <itra, sexual difference in coloration of, 559.

Lophoriiiit oriuitUft, 439.

Lord, .J. K., on iSiilmo lycaodon, 377.

l^ory. King, 521; immature i)lumage of the, 532.

Lory, king, constancy of. 466.

Love-antios and dances of birds, 431.

Lowne, B, T., on Mnxat voviitoria, 61, 318.

Loxiii, characters of young of, 529.

Lubbock, Sir J., on the antiquity of man. 2; on the origin of man,
3; on the mental capacity of savages, 73; on the origin of imple-
ments, 93; on the simplification of languages, 104; on the absence of
the idea of God among certain races of men, 106; on the origin (*f the
belief in spiritual agencies, 107; on superstitions, 108; on the sense
of duty, 111; on the practice of burying the old and sick among the
Fijian.-<, 116; on the immorality of savages, 135; on Mr. Wallace's
claim to the origination of the idea of natural selection, 55; on the
former barbarism of civilized nations, 162; on improvements in the
arts among salvages, 164; on resemblances of the mental characters
in different races of men, 203; on the arts ])racticed by savages, 204;
on the power of counting in i)rimeval man, 204; on the ])rehensile
organs of the male Lubidocera Darmiiii, 301; on (J hloeoib, 311; on
Smyntluiruis luteins, 317; finding of new mates l)y jays, 463; on strife
for women among the North American Indians, 640; on music, 650;
on the ornamental practices of savages, 654; on the estimation of the
beard among the Anglo Saxons, 663; on artificial deformation of the
skull, 565; on "communal marriages," 671; on exogamy, 673, 676;
on the Veddahs, 675; on ])olyandry, 677.

Lucanidje, variability of the mandibles in the male, 339

7C0 IKDEX.

Lueanus, large size of males of, 316; lucanvs eervvs, numerical
proportion of sexes of, 286 ; weapons of tlie male. 389; lueanus
elnphns, use of mandibles of, 340; large jaws of male, 312.

Jjucas Prosper, on pigeons, 475; on sexual preference in horses and
bulls. 598.

Luminosity in insects, 314.

Lunar periods, 8, 187.

Lund, Dr., on skulls found in Brazilian caves, 193.

Lungs, enlargement of, in the Quichua and Aymara Indians, 38;
a modified swim-bladder, 183 ; different capacity of, in races of
man, 191.

Luschka, Prof., on the termination of the coccyx, 25.

Ijuxury, expectation of life uninfluenced by, 154.

Lf/coiiKC, sexual differences of color in species of, 351.

Lycaenap, colors of, 354.

Lyell, Sir C. on the antiquity of man, 2; on the origin of man, 3;
on the parallelism of the development of species and languages, 102;
on the extinction of languages 102; on the Inquisition, 160; on the
fossil remains of vertebrata, 178; on the fertility of mulattoes, 194.

Lynx, Canadian, throat-ruft' of the, 594.

Lyre-bird, assemblies of, 461.

M((cacus, ears of. 17; convoluted body in the extremity of the tail
of, 26; variability of the tail in species of, Go; whiskers of species of,
607; macacus branneus, 66; macacus cyuomolgvs, superciliary ridge
of, 63li; beard and whiskers of, becoming wLite with age, 637;
macacutf ecaudatns, 67; macacus ladotus, facial spots of, 629; maca-
cus uemenstriiius, 710; macacus radiatas, 171; macacus rhesus, sexual
difference in the color of, 616, 629.

Macalister, Prof., on variations of the palmaris accessorius muscle,
30; on muscular abnormalities in man, 47, 48; on the greater varia-
bility of the nmscles in men than in women, 253.

Macaws, Mr. Buxton's observations on, 115, 425.

McCann, J., on mental individuality, 95.

McClelland J., on the Indian Cyprinidae. 389.

Macculloch. Col., on an Indian village without any female
children, 676.

Macculloch, Dr., on tertian ague in a dog, 8.

Macgillivray, W., on the vocal organs of birds, 101; on the
Egyptian goose, 414; on the habits of woodpeckers, 427; on the
habits of tlie snipe, 428; on the whitethroat, 432; on the moulting
of the snipes, 444; on the moulting of the Anatidae, 446; on the
finding of new mates by magpies, 453; on the pairing of a blackbird
and thrush, 470; on ])ied ravens, 482 ; on the guillemots, 482; on
the colors of the tits, 521; on the immature plumage of birds, 530,
et seq.

Mcchetes, sexes and young of, 553, et seq.\ machetes pugnax, sup-
posed to be polygamous, 248; numerical proportion of the sexes in,
280; pugnacity of the male, 409; double moult in, 443.

Mcintosh, Dr., colors of the Nemertians, 299.

McKennan, marriage customs of Koraks, 684.

Mackintosh, on the moral sense, 110,

MacLachlan, R., on Apatania mulubris and Bore.us hycmalis, 2S7,
on the anal appendages of male insects, 311; on the pairing of

INDEX. 761

dragon flies, 316; on dragon flies, 829; on diraorpliism in Agrion,
329; on the want of pugnacity in male dragon flies, 330; color of
gbost-motli in the Shetland Islands. 359.

M'Lennan, Mr., on infanticide, 52, 675: on the origin of the belief
in spiritual agencies, 106; on the prevalence of licentiousness among
savages, 134, 671; on the primitive barbarism of civilized nations,
162; on traces of the custom of the forcible capture of wives, 163,
676; on polyandry, 677.

Macnamara, Mr., susceptibility of Andaman Islanders and Nepalese
to change, 214.

McNeill, Mr., on the use of the antlers of deer, 582; on the Scotch
deerhound. 589; on the long bairs on the throat of the stag, 595; on
tbe bellowing of stags, 600.

Macropus, courtship of, 387.

Macrorhiruis pTobot<cideu8, structure of the nose of, 603.

Magpie, power of speecb of, 101; vocal organs of the, 421; nuptial
assemblies of, 461; new mates found by, 462; stealing bright objects,
469; young of the, 548; coloration of the, 562.

Maillard, M., on the proportion of the sexes in a species of PapUio
from Bourbon, 283;

Maine, Sir Henry, on the absorption of one tribe by another, 145;
a desire for improvement not general, 150.

Major, Dr. C. Forsyth, on fossil Italian apes, 177; skull of Bos
etruscus, 576; tusks of miocene pigs, 593.

Makalolo, perforation of the upper lip by tbe, 657.

Malar bone, abnormal division of, in man, 44,

Malay, Archipelago, marriage -customs of tbe savages of tbe, 683.

Malays, line of separation between tbe Papuans and tbe, 192; gen-
eral beardlessness of tbe, 6'";9; staining of the teeth among, 655;
aversion of some, to bairs on tbe face, 662; and Papuans, contrasted
cbaracters of, 191.

Male animals, struggles of, for tbe possession of tbe females, 239,
241; eagerness of, in courtship, 250, 251; generally more modified
than female, 250, 252; differ in tbe same way from females and
young, 263; cbaracters, developed in females, 257; transfer of, to
female birds, 537; sedentary, of a bymenopterous parasite, 251,

Malefactors, 155.

Males, presence of rudimentary female organs in, 184; and females,
comparative numbers of, 241, 244 ; comparative mortality of, while
young, 244.

Malberbe, on tbe woodpeckers, 521.

Mnllotus Peronii,d76; villosus, 875.

Maltbus, T., on the rate of increase of population, 50, 51, 52.

Maluridae, nidification of tbe, 517.

Malurus, young of, 553.

Mammae, *285; rudimentary, in male mammals, 12, 26, 183, 184,
185; supernumerary, in women, 41; of male human subject, 42.

Mammalia, Prof.* Owen's classification of, 168; genealogy of the.
180.

Mammals, recent and tertiary, comparison of cranial cai>acity of,
62; nipples of, 184; pursuit of female, by tbe n-ales, 250; secondary
sexual cbaracters of, 570; weapons of, 571; relative size of tbe sexes
of, 588; parallelism of, with birds in secondary sexual cbaracters,
61@; Yoictis Qi, used especially during the breediiig season, 647.

763 INDEX,

Man, variability of, 29; erroneously regarded as more domesticated
tlian other animals, 31; migrations of, 58; wide distribution of, 53;
causes of the iialtefhiess of, 68; supposed physical inferiority of, 72;
a member of the C'atarrbine grouj), 176; early progenitors of, 182;
transition from ape indefinite, 205; numerical proportions of the
sexe.s in, 243; difference between tlie sexes, 252; proportion of sexes
among the illegitimate, 276; different com})lexion of male and
female negroes, 634 ; secondary sexual characters of, 634; primeval
condition of, 678.

Mandans, correlation of color and texture of hair in the, 225.

Mandible, left, enlarged in the male of TaphrodereH distortuis, 318.

Mandibles, use of the, in Ammophiln, 312; large, of Corydalia
c:n'iiiitihH, 312; large, of male Liicahus eUtplms, 312.

Mandrill, number of caudal vertebrae in the, 65; colors of the male,
614, 617, 629.

Mantegazza, Prof., on last molar teeth of man, 22; bright colors
in male animale, 254; on the ornaments of savages, 654 et seq.; on
the beardiessness of the Kew Zealanders, 663; on the exaggeration
of natural characters by man, 664.

Mantell, W., on the engrossment of pretty girls by the New Zear
land chiefs, 680.

MaiitU, pugnacity of species of, 710.

Maorips, mortality of, 210; infanticide and proportion of sexes,
289; distaste for hairiness among men, 663;

Marcus Aurelius, on the origin of the moral sense. 111; on the
influence of habitual thoughts, 139.

Marcca peiuUqie, 471.

Marks, letained throughout groups of birds, 485.

Marriage, restraints upon, among savages, 50; influence of, upon
morals, 184; influence of, on mortality, 157; development of, 673.

Marriages, early, 156 et seq.; commual, 670, 672.

Marshall, Dr. Vv., protuberances on birds' heads, 266, 435; on the
moulting of birds, 445; advantage to older birds of paradise, 552;
Marshall, Col, interbreeding among Todas, 215; infanticide and
])roportion of sexes with Todas, 288 ; choice of husbaid among
Todas, 677; Marshall, Mr., on the brain of aBushwoman, 191.

Marsupials, 179; development of the nictitating membrane in, 19;
uterus of, 43 ; possession of nipples by, 185 ; their origin from
Monotremata, 188; abdominal sacs of, 235; relative size of the sexes
of, 588; colors of, 609.

Marsupinm, rudimentary, in male marsupials, 183.

Martin, \V. C. L., on alarm manifested by an orang at the sight of
a turtle, 81; on the hair in Hylohates, 172; on a female American
deer, 586; on the voice of Hylohates acjilis, 602; on Semnopithecus
rtenxmts, 680; on the beards of the inhabitants of St. Kilda, 638.

Martins deserting their young, 122.

Martin, C, on death caused by inflammation of the vermiform
appendages, 23.

Mastoid ])rocesses in man and apes, 59.

Maudsley, Dr., on the influence of the sense of smell in man, 20;
on idiots smelling their food, 41; on Laura Bridgman, 99; on the
development of the vocal organs, 101; moral sense failing in
incipient madness, 140: change of mental faculties at puberty in man,
041

INDEX. 7G3

Mayers. W. F. , on the domestication of the goldfish in China, 389.

Maybew, E., on the affection between individuals of different sexes
in the dog, 596-

Maynard, C. J., on the sexes of C hrysemys picta, 397.

Meckel, on correlated variation of the muscles of the arm and
leg, 49.

Medicines, effect produced by, the same in man and in monkeys, 7.

Medusce, bright colors of some, 295,

Megalithic structures, prevalence of, 204.

Megajncus validus, sexual difference of color in, 521.

Mcf/asoma, large size of males of, 316.

Meigs, Dr. A., on variation in the skulls of the natives of
America, 29.

Meinecke, on the numerical proportion of the sexes in butter-
flies, 283.

Melanesians, decrease of, 211.

Meldola. Mr., colors and marriage flight of CoUas and Pieria, 362.

Meliphagidse, Australian nidification of, 517.

Mi'lita, secondary sexual characters of, 303.

Melo'e, difference of color in the sexes of a species of, 333.

Memnon, young, 192.

Memory, manifestations of, in animals. 83.

Mental characters, difference of, in different races of men, 191;
faculties, diversity of, in the same race of men. 30; inheritance of,
31; variation of, in the same s])ecies. 31, 74; similarity of the, in dif-
ferent races of man. 203; of birds, 466; powers, difference of, in the
two sexes in man, 643,

Meaum Alberti, 461; song of, 421; menura superha, 461; long
tails of both sexes of, 513.

Merganser, trachea of the male, 425; merganser serrator, male
plumage of, 446,

Mergus cucullatus, speculum of, 267; mergus merganser^ young
of, 532,

Metnllnra, splendid tail-feathers of, 503.

Methoca icJniemnonides, large male of. 316,
; Meves, M., on the drumming of the snipe, 428.

Mexicans, civilization of the, not foreign, 164.

Meyer, on a convoluted body at the extremity of the tail in a
Macacus and a cat, 25.

Meyer, Dr. A., on the copulation of Phryganidae of distinct
species, 313,

Meyer, Prof, L,, on development of helix of ear. 16 et seq.; men's
ears more variable than women's, 253; antennse serving as ears, 318.

Migrations of man, effects of, 53,

Migratory instinctof birds, 119; vanquishing the maternal. 122. 128.

Mil!. J. S.. on the origin of the moral sense, 111; on the "greatest
happiness principle," 135; on the difference of the mental powers in
the sexes of man, 644.

Millipedes. 310,

Milne-Edwards H,, on the use of enlarged chelae of the male
Gelnsi/nus, 303,

MlUago iencurus, sexes and young of, 546.

Mimicry, 366,

764 INDEX.

Mimus polyglottus, 467.

Mind, difference of, in man and tlie liigliest animals, 143; similarity
of the, in different races, 203.

Minnow, proportion of tlie sexes in the, 282.

Mirror, behavior of nionlceys before, 709.

Mirrors, larks attracted by, 469.

Mitchell, Dr , interbreeding in the Hebrides, 215.

Mitford, selection of children in Sparta, 32.

Mivart. St. George, on the reduction of organs, 13; on the ears of
the leniuroidea, 17; on variability of the muscles in lemuroidea, 46,
54; on the caudal vertebrae of monkeys, 65; on the classification of
the primates, 174; on the orang and on man, 175; on differences in
the lemuroidea, 176; on the crest of the male newt, 395.

Mobius, Prof., on reasoning powers in a pike, 85.

Mocking-thrush, partial migration of, 467; young of the, 554.

Modifications, unserviceable, 69.

Moggridge, J. T., on habits of spiders, 77; on habits of ants, 168.

Moles, numerical proportion of the sexes in, 279; battles of
male, 570.

Mollienesia petenensis, sexual difference in, 382.

Mollusca, beautiful colors and shapes of, 298; absence of secondary
sexual characters in the, 296.

Molluscoida, 181, 296.

Monacanthus scopas and M. Peronii, 376.

Monboddo, Lord, on music, 653.

Mongolians, perfection of the senses in, 38.

Monl?ey, protecting his keeper from a baboon, 117, 125; bonnet.
171; rhesus, sexual difference in color of the, 615, 629; mustache,
colors of the, 614.

Monkeys, liability of, to the same diseases as man. 7; male, recog-
nition of women by, 9; diversity of the mental faculties in, 31;
breaking hard fruits with stones, 56; hands of the, 56, 57; basal
caudal vertebrae of, imbedded in the body, 66; revenge taken by, 78;
maternal affection in, 79; variability of the faculty of attention in,
83; American, manifestation of reason in, 87 ; using stones and
sticks, 91; imitative faculties of, 98; signal-cries of, 98; mutual
kindnesses of, 115; sentinels posted by, 114; human characters of,
171; American, direction of the hair on the arms of some, 172; grada-
tion of species of, 199; beards of, 607; ornamental characters of,
626; analogy of sexual differences of, with those of man, 636;
different degrees of difference in the sexes of, 640; expression of
emotions by, 652; generally monogamous habits of. 674; polygamous
habits of some, 674; naked surfaces of, 686; courtship of, 709.

Monogamy, not primitive, 164.

Monogenists, 200.

Mononychus pseudacori, stridulation of, 345.

Monotremata, 179; development of the nictitating membrane
in, 19; lactiferous glands of, 184; connecting mammals with reptiles,
188.

Monstrocities, analogous in man and lower animals, 33; caused by
arrest of development, 40; correlation of, 49; transmission of, 197.

Montairu, G., on the habits of the black and red grouse, 248; on
rue pugnacity of the ruff, 401), 4i0; on the singing of birds, 418; on
tke doubl« moult ol the male jpiutail, HO*

INDEX, 765

Monteiro, Mr., on the Bucorax dbyssinicus, 435.

Montes de Oca, M., on the pugnacity of male humming-birds, 408.

Monticola cyanea, 519,

Monuments, as traces of extinct tribes, 206.

Moose, battles of, 571; horns of the, an incumberance, 587.

Moral and instinctive impulses, alliance of, 125; faculties, their in-
fluence on natural selection in man, 144; rules, distinction between
the higher and lower, 138; sense, so-called, derived from the social
instincts, 136; origin of the, 140; tendencies, inheritance of, 140.

Morality, supposed to be founded in selfishness, 135; test of, the
general warfare of the community, 137; gradual rise of, 141; in-
fluence of a high standard of, 149.

Morgan, L. H., on the beaver, 75; on the reasoning powers of the
beaver, 84; on the forcible capture of wives, 163; on the castoreum
of the beaver, 604; marriage unknown in primeval times, 671; on
polyandry, 677.

Morley, J ., on the appreciation of praise and fear of blame, 162.

Morris, b\ O., on hawks feeding an orphan nestling, 465.

Morse, Dr., colors of mollusca, 298.

Morselli, E., division of the malar bone, 44.

Mortality, comparative, of female and male, 244, 275.

Morton, on the number of species of man, 199.

Moschkau, Dr. A., on a speaking starling, 96.

Moschus moscJdferus, odoriferous organs of, 605.

Motaeilloi, Indian, young of, 534.

Moth, odoriferous, 349.

Moths, 355; absence of mouth in some males, 235: apterous female,
235; male, prehensile use of the tarsi by, 237; male, attracted by
females, 284; sound produced by, 349; coloration of, 357; sexual dif-
ferences of color in, 358.

Motmot, inheritance of mutilation of tail feathers, 67, 689; racket-
shaped feathers in the tail of a, 436.

Moult, double, 526; double annual, in birds, 442.

Moulting of birds, 551.

Moults, partial, 444.

Mouse, song of, 648.

Mustache-monkey, colors of the, 614, 630.

Mustaches, in monkeys, 171.

Mud-turtle, long claws of the male, 397.

Mulattoes, persistent fertility of, 194; immunity of, from yellow
fever, 220.

Mule, sterility and strong vitality of the, 195.

Mules, rational, 88.

Miiller, Ferd., on the Mexicans and Peruvians, 164; Fritz: on asto-
matous males of 2anais, 235: on the disappearance of spots and
stripes in adult mammals, 625; on the proportions of tbe sexes in
some Crustacea, 287 : on secondary sexual characters in various
Crustaceans, 300, et seq.; musical contest between male Cicidce, 320;
mode of holding wings in Castina, 357; on birds showing a preference
for certain colors, 359; on the sexual maturity of young amphipod
Crustacea, 552.

Miiller, Hermann, emergence of bees, from pupa, 242; pollen-
gatheiing of bees, 258: proportion of sexes in bees, 286; courting of

768 INDEX,

Kristalis, 318; color and sexual selection witli bees, 331; J., on the
nictitating membrane and semilunar fold, 19: Max, on iht origin of
language, 98; language implies power of general conception^ 100;
struggle for life among the words, etc., of languages, 102; S., on the
banteng, 613; on the colors of tieitinopithecus chrysumelas, 613.

Muntjac-deer, Aveapons of the, 586.

Murie, J., on the reduction of organs, 13; on the ears of the Lemu-
roidea, 17; on variability of the muscles in the Lemuroidea, 46, 54;
basal caudal vertebrae of Macacus brurmeus imbedded in the body,
67; on the manner of sitting in short-tailed apes, 67: on differences
in the Lemuroidea, 176 : on the throat-pouch of the male bustard,
423; on the mane of Otarid juhata, 594; on the sub-oibital pits of
Ruminants, 605; on the colors of the seirces in (Jtaria iiigrescens, 610,

Murray, A., on the Pediculi of different races of men. 193; T. A,,
on the fertility of Australian women with white men. 194.

Mus coninga, 91: mimitus, sexual difference in the color of, 610.

Muscn vovntoria, 61.

Muscicapn grisola, 518; luctuosa^ 518; rw^iciWa, breeding in imma-
ture plumage, 551.

Muscle, ischic-pubic, 46.

Muscles, rudimentary, occurrence of, in man, 13 : variability of
the 30; effects of use ana disuse upon, 36: animal-like abnormalities
of, in man, 46; correlated variation of,in the arm and leg, 49; variability
of, in the hands and feet, 54; of the jaws, intiuence of, on the phy-
siognomy of the apes, 50; habitual spasms of, causing modifications of
the facial bones, 62; of the early progenitors of man, 182; greater
variability of the, in men than in women, 252.

Muculus sternal is. Prof. Turner, on the, 14.

Music, 203; of bird, 417, discordant, love of savages for, 431;
reason of power of perception of notes in animals, 648; power of dis-
tinguishing notes 649; its connection with primeval speech, 652; dif-
ferent appreciation of, by different peoples, 651; origin of, 650, 653;
effects of, 651.

Musical cadences, perception of, by animals, 649; powers of man,
645, et seq.

Musk-deer, canine teeth of male, 572, 586 ; male, odoriferous
organs of the, 604- av inter change of the, 619.

Musk-duck, Australian, 407; large size of male, 411; of Guiana,
pugnacity of the male, 411.

Musk-ox, horns of, 576.

Musk-rat, protective resemblance of the, to a clod of earth, 619.

Musophagif, colors and nidification of the, 513; both sexes of;
eqiMilly brilliant, 523.

Mussels opened by monkeys. 56.

Musteln, winter change of two species of, 619.

Musters, Capt., on lihea Dariciuii, 545, marriages among Pata-
gonians, 683.

Mutilations, healing of. 8; inheritance of, 67.

Mutilla europcea, strldulation of, 332.

Mutillidge, absence of ocelli in female. 311.

Mycctes carnya, ])olygamous, 245: vocal organs of, 002; beard of,
007; sexual differences of color in, 613; voice of, 647; mycetes seni'
cuius, sexual differences of color in, 613.

I

INDEX. 767

Myriapoda, 810.

]Skgeli, on tlie influence of natural selection on plants, 68; on the
gradation of species of plants, 199.

Nails, colored yellow or purple in part of Africa, 655.

Narwhal, tusks of the, 572. 578.

Nasal cavities, large size of, in American aborigines, 38.

Nascent organs, 12.

Nathusius, H. von, on the improved hreeds of pigs, 201 : male
domesticated animals more variable than females, 252 ; horns of
castrated sheep, 577; on the breeding of domestic animals, 680.

Natural selection, its effects on the early progenitors of man. 53-
influence of, on man, 67, 70 ; limitation of the principle, 68; in
fluence of. on social animals, 70; Mr. Wallace on the limitation of,
by the influence of the mental faculties in man, 144; influence of,
in the progress of the United States, 161: in relation to sex, 292.

Natural and sexual selection contrasted, 256.

Naulette, jaw from, large size of the canines in, 46.

Neanderthal skull, capacity of the, 61.

Neck, proportion of, in soldiers and sailors, 36.

Necrophorus, stridulation of, 342, 345.

Nectarinia, young of, 533.

Nectanniae, moulting of the, 444; nidification of, 517.

Negro, resemblance of a, to Europeans in mental characters, 203.

Negro-women, their kindness to Mungo Park, 133.

Negroes, Caucasian features in. 190; cliaracter of. 191; lice of, 193;
fertility of, Avhen crossed with other races, 194; blackness of, 194,
197, variability of, 198, 199; immunity of, from yellow fever, 220;
difference of, from Americans, 224; disfigurements of the, 617; color
of new-born children of, 635; comparative beardlessness of, 639;
readily become musicians, 650; appreciation of beauty of their women
by, 659, 661; idea of beauty among, 664; compression of the nose by-
some, 665.

Nemertians, colors of, 299.

Neolithic period, 164.

Neomorpha, sexual difference of the beak in, 408.

Nephiliiy size of male, 309.

Nests, made by fishes, 391; decoration of, by humming birds, 469.

Neumeister, on a change of color in pigeons after several moult-
ings, 269.

Neuration, difference of, in the two sexes of some butterflies and
hvmenoptera, 314.
'Neuroptera, 287, 327.

Neurothemis, dimorphism in, 329.

New Zealand, expectation by the natives of. of their extinction,
218; practice of tattooing in, 657; aversion of natives of, to hairs on
the face, 662; pretty girls engrossed by the chiefs in, 680.

Newton, A., on the throat-pouch of the male bustard, 423; on the
difference between the females of two species of Oxynotus, 536; on
the habits of the Fhalarope, dotterel and god wit, 544.

Newts. 394.

Nicholson, Dr., on the non-immunity of dark Europeans from
yellow fever, 222.

Nictitating membrane^ 19« 182.

7C8 INDEX,

Nidification, of fishes, 391; relation of, to color, 515, 519; of

British birds, 517.

Night-heron, cries of the, 417.

Nightinoale, arrival of the male before the female, 240; object of
the song of the, 418.

Nightingales, new mates found by, 463.

Nightjar, selection of a mate by the female, 473; Australian, sexes
of, 546; coloration of the 559.

Nightjars, noise made by some male, with their wings, 436; elon-
gated feathers in, 436, 457.

Nilghaii, sexual differences of color in the, 611.

Nillstni, Prof., on the resemblance of stone arrow-heads from
various places, 203; on the development of the horns in the rein-
deer, 265.

Nipples, absence of, in Monotremata, 184.

Nitsche, Dr., ear of fetal orang, 18.

Nitzsch, C. L., on the down of birds, 442.

Noctu£fi, brightly colored beneath, 357.

Noctuidae, coloration of, 355.

Nomadic habits, unfavorable to human progress, 150.

Nordmann, A., on Tetrao urogalloides, 460.

Norfolk Island, half-breeds on, 217.

Norway, numerical proportion of male and female births in, 275.

Nose, resemblance of, in man and the apes, 174; piercing and
ornamentation of the, 656; very flat, not admired in negroes, 664;
flattening of the, 665.

Nott and Gliddon, on the features of Ramesls II, 192; on the
features of Amunoph III, 192; on skulls from Brazilian caves, 192;
on the immunity of negroes and mulattoes from yellow fever,
220; on the deformation of the skull among American tribes, 665.

Nudibranch Mollusca, bright colors of, 296.

Numerals, Roman, 163.

Nunemaya, natives of, bearded, 639.

Nuthatch, of Japan, intelligence of, 466; Indian, 555.

Obedience, value of, 147.

Observation, powers of, possessed by birds, 467.

Occupations, sometimes a cause of diminished stature, 34; effect
of, upon the proportions of the body, 34.

Ocelli, absence of, in female Mutillid*, 311; of birds, formation
and variability of the, 486.

Ocelot, sexual differences in the coloring of the, 610.

Oci/phnps lophotesA^Q.

Odonata, 287.

Odonestis potatoria, sexual difference of color in, 358.

Odor, correlation of, with color of skin, 225; of moths, 349*
emitted by snakes in the breeding-season, 399; of mammals, 603.

QiJcnnthus nivalis, difference of color in the sexes of, 328; cecanthui
pellucidus, 328.

Ogle, Dr. W., relation between color and power of smell, 19.

Oidemia, 559.

Olivier, on sounds produced by Pimelia striata, 347.

OmalopUti hru7inea, stridulation of, 344.

Onitis furcifer, processes of anterior femora of the male, and on
the head and thorax of the female, 337, 338.

\

INDEX. 769

OntJiopJiaguSy 336; onthopJiagus rangifer, sexual differences of, 335;

variation in the liorns of the male, 386.
Opliidia, sexual differences of, 398.
Ophidium, 394.

Opossum, wide range of, in America, 193.

Oi)tic nerve, atrophy of the, caused by destruction of tbe eye, 36.
Orang outang-, 640; Bischott' on the agreement of the brain of the,
with that of n^an, 6; adult age of the, 9; ears of the, 15; vermiform
appendage of, 23; hands of the, 56; absence of mastoid processes in
the, 59; i)latfonus built by the, 75; alarmed at the sight of a turtle,
81; using a stick as a lever, 91; using missiles, 92; using the leaves
of the Pandnmis as a night covering, 93; direction of the hair on
the arms of the, 172; its aberrant characters, 175; supposed evolu-
tion of the, 202; voice of the, 602; monogamous habits of the, 674;
male, beard of the, 607.

Oranges, treatment of, by monkeys, 56.

Orange tip butterfly, 350, 354.

Orcheatia Darwinii, dimorphism of males of, 303 ; orchestia
tucurntinga, limbs of. 302, 307.

Ordeal, trial by, 108.

Oreas canna, colors of 612; oreas derhianus, colors of. 612. 621.

Organs, prehensile, 237: utilized for new purposes, 651.

Organic scale, von Baer's definition of progress in, 186.

Orioles, nidification of, 516.

Oriolus, species of, breeding in immature plumage, 552; oriolua
melanocephalus, coloration of the sexes in, 524.

Ornaments, prevalence of similar, 203; of male birds, 416; fond'
ness of savages for, 654.

Ornamental characters, equal transmission of, to both sexes, in
mammals, 619; of monkeys, 626.

Ornithoptera crcesus. 283.

Ornithorynchus, 178 ; reptilian tendency of, 180 ; spur of the
male, 573.

Orocetes erythrognstra, young of, 554.

Orrony, Grotto of, 24.

Orsoddcna atra, difference of color in the sexes of, 333; orsodacna
rufieoUis, 333.

Orthoptera, 320; metamorphosis of, 268; stridulating apparatus of,
321, 326; colors of, 327; rudimentary stridulating organs in female,
326; stridulation of the, and Homoptera, discussed, 327.

Ortygornis gularis, pugnacity of the male, 412.

Oryctes, stridulation of, 344; sexual differences in the stridulant
organs of, 345.

Oryx leucoryx, use of the horns of, 580, 585. 590.

Oitphranter rufas, sexual difference in the color of, 609.

Ostrich, African, sexes and incubation of the, 544.

Ostriches, stripes of young, 529.

Otana juhata, mane of the male, 594; otaria nigrescens, difference
in the coloration of the sexes of, 610.

Otis hengalensis, love -antics of the male, 432; otis tarda, throat-
pouch of the male, 423; polygamous, 248.

Ouzel, ring, colors and iiidification of the, 518; water, singing in
the autumn, 420; colors and nidification of the, 518.

770 INDEX.

Ovibos moschatus, liorns of, 576.

Ovipositor of iusects, 235.

0ms cydoceroat, mode of fighting of, 579, 585.

Ovule of mail, 9.

Owen, Prof., on the Corpora Wolffiana, 10; on tlie great toe in
man, 10; on tbe nictitating membrane and semilunar fold, 19; on the
development of the posterior molars in different races of man, 22;
on the length of the cacum in the Koala, 23; on tbe coccygeal verte-
brae, 25; on rudimentary structures belonging to the reproductive
system, 26; on abnormal conditions of the human uterus, 43; on the
number of digits in the Ichtbyopterygia, 42; on the canine teeth in
man, 45; on tbe walking of tbe chimpanzee and orang, 56; on the
mastoid processes in the higher apes, 59; on the hairiness of ele-
phants in elevated districts, 04; on the caudal vertebrae of monkeys,
65; classification of mammalia, 168; on the hair in monkeys, 171; on
the piscine affinities of the lchlbyo^^aurians, 180; on polygamy and
monogamy among the antelopes, 246; on the horns of Antilucapra
americana, 265; en the musky odor of tbe crocodiles during the
breeding season, 398; on the scent-glands of snakes, 399; on the
Dugong, Cachalot and Ondthorkyndvus, 572, 573; on the antlers of
the red deer. 582; on tbe dentition of the Camelidse, 586; on the
horns of the Irish elk, 587; on tbe voice of the giraffe, porcupine and
stag. 600; on the laryngeal sac of the gorilla and orang, 602; on the
odoriferous glands of mammals, 604, 605; on the effects of emascula-
tion on the vocal organs of men, 645; on the voice of Hylohatea
agilis, 647; on American monogamous monkeys, 674.

Owls, white, new mates found by, 463.

Oxynotus, difference of the females of two species of, 586.

Pachydermata, 247.

Pachytylus migratorius. 321.

Paget, on the abnormal development of hairs in man, 20; on the
thickness of tbe skin on the soles of the feet of infants, 87.

Pagurus, carrying the female, 303.

Painting, pleasure of savages in, 203.

Palcemcui, chelae of a species of, 302.

Pal(Bornis, sexual differences of color in, 562: pnlceoi'nis javantcuSt
color of beak of, 525; palcHornis roaa, young of, 532.

Pnlame.den cornutr, spurs on the wings, 414.

Paleolithic period, 164.

Palestine, habits of the chaffinch in, 281.

Pallas, on the perfection of the senses in the Mongolians, 88; on
the want of connection between climate and the color of the skin,
219; on the polygamous habits of Antilope Saiga. 246; on the lighter
color of horses and cattle in winter in Siberia, 260; on the tusks of
tbe musk-deer, 586; on tbe odoriferous glands of mammals, 604; on
the odoriferous glands of the musk-deer, 605: on winter cbanges
of color in mammals, 619; on the ideal of female beauty in Isorth
China. 659.

Pdlmaris ncccssorius. muscle variations of the, 30.

Pampas, horses of tbe, 206.

Pangenesis, hypothesis of, 258, 261.

Paiiiiiculus carnosus, 14.

Pansch, on the brain of a fcetal Cebus apclla, 233.

INDTHX. 771

Papilio, proportion ot the sexes m North American species of. 283;
sexual differeuces of coioriiig in species of, 351; coloration of the
wings in species of, 354.

Papilio nscanius, 251; papilio sesostris and childrencBy variability
of, 362. papilio tumus, 283.

Papilionidis, variability in tlie, 362.

Papuans, line of separation between the, and the Malays, 192;
beards of the, 639, hair of, 655; and Malays, contrast in characters
of, 191.

Paradise, birds of, 460, 526; supposed by Lesson to be polygamous,
248; rattling of their quills by. 426; racket-shaped feathers in, 437;
sexual diiferences in color of, 438; decomposed feathers in, 437, 457
display of plumage by the male, 449; sexual differences in color of
559.

Paradism apoda, barbless feathers in the tail of, 437; plumage of;
438; and P. papuaiia, 437, 438; divergence of the females of, 535;
increase of beauty with age, 552 ; paradisea papuana, plumage
of, 535.

Paraguay, Indians of, eradication of eyebrows and eyelashes
by, 662.

Parallelism of development of species and languages, 102.

Parasites, on man and animals, 8; as evidence of specific
identity or distinctness, 193; immunity from, correlated with color,
220.

Parental feeling in earwigs, star-fishes and spiders, 120; affection,
partly a result of natural selection, 119.

Parents, age of, influence upon sex of offspring, 277.

Parinse, sexual difference of color in, 521.

Park, Mungo, negro-women teaching their children to love th»
truth, 133; his treatment by the negro-women, 133, 642; on negro
opinions of the appearance of white men, 660.

Parker, Mr., no bird or reptile in line of mammalian descent, 179.

Paroquet, young of, 525, 549; Australian, variation in the color of
the thighs of a male, 481.

Parrot, racket-shaped feathers in the tail of a, 436; instance of
benevolence in a, 467.

Parrots, change of color in. 68; imitative faculties of, 82; living
in triplets. 464; affection of, 467; colors and nidifications of the, 518,
520, 521; immature plumage of the, 532; colors of, 557; sexual dif-
ferences of color in, 562, musical powers of, 651.

Parthenogenesis in the Tenthredinae, 286 ; in Cynipidap, 286; in
Crustacea, 287.

Partridge, monogamous, 248; proportion of the sexes in the, 280;
Indian. 412; female. 538; " dances." 431. 460.

Partridges, living in triplets, 464; spring coveys of male, 464; dis-
tinguishing persons, 467.

Par us cai'uleus. 521.

Passer, sexes and young of. 550; passer braehydactylus, 550; passer
domesticus, 518, 550; passer montanus, 518, 550.

Patagonians, self-sacrifice by. 126; marriages of, 683.

Fatterson, Mr., on the Agrionidae, 329.

Patteson, Bishop, decrease of Mehihesians, 211.

Pavo cristatus, 267, 489; ^)ai'(? muticus, 267 489; possession of
spurs by the female, 413, 511; p:ivo nigripennia, 470.

772 INDEX.

Payaguas Indians, thin legs and tliick arms of the, 37.

Payan, Mr., on the proportion of the sexes in sheep, 279.

Peacoclc, polygamous, 248; sexual characters of, 267; pugnacity of
the, 413; Javan, possessing spurs, 413; rattling of the quills by, 426;
elongated tail-coverts of the, 435, 457; love of display of the,
447, 490; ocellated spots of the, 4S9; inconvenience of long tail of
the, to the female, 505. 513, 514; continued increase of beauty
of the, 552; butterfly, 354.

Peafowl, preference of females for a particular male, 475; first
advances made by the female, 477.

Pedicuh of domestic animals and man, 193.

Pedigree of man, 188.

Pedionomus torquatus, sexes of, 543.

Peel, J., on horned sheep, 576.

Peewit, wing-tubercles of the male, 414.

Pelagic animals, transparency of, 295.

Pelecanus erythrorhynchus, horny crest on the beak of the male,
during the breeding-season, 442 ; pelecanus 07iocrotalu8, spring
plumage of, 446.

Pelele, an African ornament, 657.

Pelican, blind, fed by his companions, 116; young, guided by old
birds, 116; pugnacity of the male, 411.

Pelicans, fishing in concert^ 114.

Pelohius Jlermanni, stridulation of, 343, 345.

Pelvis, alteration of, to suit the erect attitude of man, 59; differ-
ences of the, in the sexes of man, 635.

Penelope nigra, sound produced by the male, 429.

Pennant, on the battles of seals, 571; on the bladder-nose
seal, 603.

Penthe, antennal cushions of the male, 313.

Perch, brightness of the male, during breeding-season, 386.

Peregrine falcon, new mate found by, 463.

Period of variability, relation of, to sexual selection, 271.

Periodicity, vital. Dr. Lay cock on, 8.

Periods, lunar, followed by functions in man and animals, 8, 187;
of life, inheritance at corresponding, 258, 262.

Perisoreus canadensis, young of, 549.

Pentrichia, difference of color in the sexes of a species of, 333.

Periwinkle, 296.

Pernis cnstata, 481.

Perrier, M., on sexual selection, 237; on bees, 333.

Perseverance, a characteristic of man, 644.

Persians, said to be improved by intermixture with Georgians au^
Circassians, 669.

Personnat, M., on Bomhyx Tamamai, 283.

Peruvians, civilization of the, not foreign, 164.

Petrels, colors of, 562.

Petrocincla cyanea, young of, 554.

Petrocossyphus, 525.*

Petronia, 550.

Pfeiffer, Ida, on .Javaa ideas of beauty, 661.

Phacochoirus cethiopiciis, tusks and pads of, 593.

Phaianger, Vulpine, black varieties of the, 61d

INDEX. 773

Plialaropus fidicanus, 544: pTinlaropus hyperhm^eus, 544.

Phanoius, 338: phanceas carnifex, variation of the boms of tlie
male, 336: phanoius faunus,' sexual difference of, 335^ phanceus
lancifer, 336.

Phaseolarctus cinerens, taste for rum and tobacco, 7.

Phasgonura viridistdma, stridulatlon of, 322, 323.

Phasianus Scemmnrriiigii, 507; phasianus versicolor, 449; pTimianui
WallichiU 454, 538.

Pbeasant, polygamous, 248; and black grouse, hybrids of, 470;
production of hybrids with the common fowl, 477: immature
plumage of the, 532; Amberst, display of, 449; Argus 435, 526'
display of plumage l3y the male, 451; ocellated spots of the, 488,
493; gradation of characters in the, 493; blood, 413; cheer, 454;
eared. 267, 454, 538; lengtb of the tail in the, 513; sexes alike in
the, 524 : fire-backed, possessing spurs, 413 ; golden, display of
plumage by the male, 449; age of mature plumage in the, 551; sex
of young, ascertained by pulling out bead-feathers, 551; Kalij,
drumming of the male, 426, 533; Reeve's, lengtb of the tail in, 514;
silver, triumphant male, deposed on account of spoiled plumage,
476 , sexual coloration of the, 560 ; Scemmerring's, 507, 614 ;
Tragopan. 434; display of plumage by the male, 451; marking of iho
sexes of the, 487.

Pheasants, period of acquisition of male characters in the
family of the, 266; proportion of sexes in chicks of, 280; length of
the tail in, 507, 513, 514.

Philters, worn by women. 659.

Phoca grmnlandica, sexual difference in the coloration of, 611.

Plicenicura ruticilla, 464.

Phosphorescence of insects, 314.

Phryganidae, copulation of distinct species of, 313i

Phryniscus nigricans, 396.

Physical inferiority, supposed, of man, 67.

Pickering, on the number of species of man, 199.

Picton, J. A., on the soul of man, 700.

Picus auratus, 411; picus major, 456.

Pieris, 354, 361.

Pigeon, female, deserting a weakened mate. 242 ; carrier, late
development of the wattle in, 269; pouter, late development of the
crop in, 269; domestic, breeds and sub-breeds of, 523.

Pigeons, nestling, fed by the secretion of the crop of both parents,
185; changes of plumage in, 259; transmission of sexual peculiarities
in, 261 ; Belgian, with black-streaked males, 262, 269, 507; changing
color after several moultings, 269; numerical proportion of the sexes
in, 280; cooing of. 425; variations in plumage of, 438; display of
plumage by male, 456; local memory of, 467; antipathy of female,
to certain males, 475; pairing of, 475; profligate male and female,
475; wing-bars and tail-feathers of, 486; supposititious breed of, 506;
pouter and carrier, peculiarities of, predominant in males. 508; nidifi-
cation of, 516; Australian, 522; immature plumage of the, 632.

Pigs, origin of the improved breeds of. 202; numerical proportion
of the sexes in, 279; stripes of young, 529, 623; tusks of miocene,
693; sexual preference shown by, 598.

i*ike, American, brilliant colors of the male, during the breeding-

774 INDEX,

seasons, 056; reasoning powers of, 85; male, devoured by femaleSt
2«1.

Pike, L. O., on tlie psychical elements of religion, 108.

Pimelia striata, sounds produced by the female, 347.

Pinel, hairiness in idiots, 41.

Pintail, drake, plumage of, 446; pairing with a wild duck, 471;
duck. ])uiring with a widgeon, 471.

Fil)e-tish, tilanientous, b90; marsupial receptacles of the male, 392.

Pipits, moulting of the, 444.

Pipra, modified secondary wiusf-feathers of the male, 429: pipra
idicium, 429, 430.

Pirates stridulus, stridulation of, 819.

P.'tcuirn Island, half-breeds on, 217.

Pithecia leucocephala, sexual differences of color in, 613; pit7iecia
satauas. beard of, 607: resemblance of, to a negro. 690.

Pits, suborbital, of Ruminants, 604.

Pittidse, nidification of, 516.

Placentata, 179.

Piagiostomous fishes, 375.

Plain- wanderer, Australian, 542.

Plartai'ice, bright colors of some. 295.

Plantain-eaters, colors and nidification of the, 518; both sexes of,
equally brilliant, 523.

Plants, cultivated, more fertile than wild. 50: Nageli, on natural
selection in, 68; male flowers of, mature before the female, 240;
phenomena of fertilization in, 251.

Platalea. -125. change of plumage in, 525.

Platyblemnus, 328.

Platycercus, young of, 549.

Platyphylium concacum, 321, 324.

Piatyrrhine monkeys, 174.

Ptatysma myoides. 14.

Ple.costomus, head-tentacles of the males of a species of, 384;
plecostumus barbatus, peculiar beard of ihe male, 383.

Pkctropterus gambensis, spurred wings of, 414

Ploceus, 420, 426, 460.

Plovers, wing-spurs of, 414. double moult in, 442, 444.

Plumage, changes of, inheritance of, by fowls, 259: tendency Ut
analogous variation in, 438: display of, by male birds, 447. 455:
changes of, in relation to season, 526; immature, of birds, 529, 630;
color of, in relation to protection, 556.

Plumes on the head in birds, differences of, in the sexes, 513.

Piienmora, structure of, 325.

Podica, sexual difference in the color of the irides of, 483,

Poeppig, on the contact of civilized and savage races, 208.

Poison, avoidance of, by animals, 90.

Poisonous fruits and herbs avoided by animals, 75.

Poisons, immunity from, correlated with color. 220.

Polish fowls, origin of the crest in, 261.

Pollen and van Dam, on the colors of Lemvr macaco. 613.

Polyandry, 677; in certain Cyprinidae, 282; among the ElateridflB
286.

Polydactylism in man, 42.

INDEX. 775

Polygamy, influence of, upon sexual selection, 245; superinduced
by domestication, 249; supposed increase of female birtlis by, 277; iu
ibe stickleback, 376.

Polygenists, 200.

Polynesia, prevalence of infanticide in, 676.

Polynesians, wide geographical range of, 33; difference of stature
among the, 35; crosses of, 198; vrriability of, 198; heterogeneity of
the, 219; aversion of, to hairs on the face, 662.

Polyplecti on, number of spurs in, 411'; display of plumage by tht»
male, 450; gradation of characters in, 490, female of, 536; polyplect-
roil chiiiquis, 450, 491 ; pulyplectron hardmckii, 491 ; polypkctron
mnlnccense, 491, 492.

Pulyplectron Napoleonis, 490, 492.

Polv/oa. 296.

Pomotis, 391.

Pontoporeia affinis, 300.

Porcupine, mute, except in the rutting- season, 600.

Pores, excretory, numerical relation of, to the hairs in slieep. 225

Porpitm, bright colors of some, 295.

Portax picta, dorsal crest and throat-tuft of, 606; sexual differencwj
of color in, 611, 612, 621.

Poi'tunns puber, pugnacity of, 304.

Potamocharus peaicillatus, tusks and facial knobs of tlie, 593.

Pouchet G., the relation of instinct to intelligence, 75. on the
instincts of ants. 168; on the caves of AbouSimbel, 191; on the
immunity of negroes from yellow fever, 220; change of color in
fishes, 390.

Pouter- pigeon, late development of the large crop in, 269.

Powell. Dr., on stridulation, 319.

Power, Dr., on the different colors of the sexes in a species of
Squilla, 306.

Pcwys, Mr., on the habits of the chaffinch in Corfu, 281.

Pre eminence of man. 54.

Preference for males by female birds, 470, 477; shown by mammals,
in pairing, 595.

Prehensile organs, 237.

Preabytis entellus, fighting of the male, 641.

Preyer, Dr., on function of shell of ear, 15; on supernumerary
mammse in women, 41.

Prichard, on the difference of stature among the Polynesians, 35;
on the connection bf^tween the breadth of the skull in the Mongolians
and the perfection of their senses, 38; on the capacity of British
skulls of different ages, 61; on the flattened heads of the Colombian
savages, 655; on Siamese notions of beauty, 659; on the beardlessne.^s
of thi; Siamese, 663; on the deformation of the head among American
tribes and the natives of Arakhan, 665.

Primary sexnal organs, 234.

Primates, 170, 233; sexual differences of color in, 613.

Primogeniture, evils of, 153.

Prionidse, difference of the sexes in color. 333.

Proctotvctux viultimaculatus, 406; proctotntui tenuis, sexual differ-
ence in the color of, 406.

Profligacy, 155.

776 INDEX.

Progenitors, early, of man, 183.

Pioi^ress, not the normal rule in human society, 150: elements
of, 159.

Prong-hoVn antelope, horns of, 265.

Proportions, difference of, in distinct races, 190.

Protective coloring in butterflies, 353; in lizards, 406; in birds
539, 556; in mammals, 619; nature of the dull coloring of feuiaL
Lepidoptera, 363, 364, 367; resemblances in fishes, 390.

Protozoa, absence of secondary sexual characters in, 294.

Pruner-Bey, on the occurrence of the supra-condyloid foramen i
the humerus of man, 24; on the color of negro infants, 636.

Prussia, numerical proportion of male and female births in, 275.

Psociis, proportions of the sexes in, 287.

Ptarmigan, monogamous, 248; summer and winter plumage of the,
443, 444; nuptial assemblages of, 460; triple moult of the, 526; pro-
tective coloration of, 540.

Puff-birds, colors and nidification of the, 518.

Pugnacity of fine-plumaged male birds, 454.

Pumas, stripes of young, 528.

Puppies learning from cats to clean their faces, 82.

Pycnonotus hcemoiThous, pugnacity of the male, 409; display of
under tail coverts by the male, 456.

Pyraiiga wstica, male aiding in incubation, 515; male characters in
female of, 525.

Pyvodea, difference of the sexes in color, 333.

Quudrumana, hands of, 56; differences between man and the, 170;
sexual differences of color in, 612; ornamental characters of, 626;
analogy of sexual differences of, witli those of man, 634; fighting of
mnlf^s for the females, 641; monogamous habits of, 674; beards of
the, 688.

Quain, R., on the variation of the muscles in man, 30.

Quutrefages. A. de, on the occurrence of a rudimentary tail in man,
25; on variabi ity, 33; on the moral sense as a distinction between
man and anim: Is, 110; civilized men stronger than savages, 154; on
the fertility ol Australian women with white men, 194; on the
Paulistas of Brazil, 197; on the evolution of the breeds of cattle,
201; on the Jews, 220; on the liability of negroes to tropical fevers
after residence in a cold climate, 221; on the difference between
field and house slaves, 223; on the influence of climate on color, 223;
colors of annelids, 299; on the Ainos, 639; on the women of San
Giuliano, 670.

Quechua, see Quichua.

Querquedula acuta, 471.

Quetelet, proportion of sexes in man, 275; relative size in man and.
woman, 276.

Quichua Indians, 38; local variation of color in the, 223; no gray
hair among the, 637; hairlessness of the, 640; long hair of the, 662.

Quiscalas major, 255; proportion of the sexes of, in Florida and
Honduras, 281.

Rabbit, white tail of the, 619.
. Rabbits, domestic, elongation of the skull in, 63; modification of
the skull in, by the lopping of the ear, 63; danger-signals of, 114;
Bunierical proportiou of tlie sexes in. 279.

3»

1

INDEX. 777

Races, distinctive characters of, 190, 191; or species of iran, 191;
crossed, fertility or sterility of, 194; of man, variability of tbe. 198;
ot" man, resemblance of, in mental cbaracters, 203; formation of, 206;
of man, extinction of, 206; effects of tbe crossinjj: of, 218; of man,
formation of the, 218; of man, children of the, 635; beardless, aver-
sion of, to hairs on the face. 662.

Raffles, Sir S., on the banteug, 613.

Rafts, use of, 54, 205.

Rage, manifested by animals, 77.

Raia hatis, teeth of, 379: raia clavata, female spined on the back,
875; sexual difference in the teeth of, 379; raia maculata, teein of,
879.

Raili., spur- winged, 414.

Ram, mode of lighting of the, 579; African, mane of an, 608; fat'
tailed, 60S.

Rumeses IT, features of, 192.

Ramsay, Mr., on the Australian muck-duck, 407; on the regent-
bird, 470; on the incubation of Menura siiperba, 513.

liana esculenta, vocal sacs of, 397.

Rat, common, general dispersion of, a consequence of superior
cunning, 91: supplantation of the native, in New Zealand, by the
European rat, 218; common, said to be polygamous, 247; numerical
proportion of the sexes in, 279.

Rats, enticed by essential oils, 603.

Rationality of birds. 466.

Rattlesnakes, difference of the sexes in the, 898; rattles as a
call, 401.

Raven, vocal organs of the, 421; stealing bright objects, 469; pied,
of the Feroe Islands, 482.

Rays, prehensile organs of male, 375.

Razor bill, young of the, 553.

Reade. Winwood. suicide among savages in Africa. 133: mulattoes
not prolific, 195; effect of castration of horned sheep, 577; on the
Guinea sheep, 266; on the occurrence of a mane in an African ram,
608; on singing of negroes, 652; on the negroes appreciation of the
beauty of their women, 658: on the admiration of negroes for a
black'skin. 660; on the idea of beauty among negroes, 663; on the
Jollofs. 670: on the marriage customs of the negroes, 684.

Reason in animals, 84.

Redstart, American, breeding in immature plumage, 552.

Redstarts, new mates found by, 464.

Reduvidae, stridulation of, 319.

Reed-bunting, head feathers of the male, 455; attacked by a bull-
finch, 468.

Reefs, fishes frequenting, 389.

Reeks, H., retention of horns by breeding deer, 574; cow rejected
by a bull, 598; destruction of piebald rabbits by cats, 619.

Regeneration, partial, of lost parts in man, 8.

Regent-birds, 470-

Reindeer, horns of the. 264; battles of, 571; horns of the female,
574; antlers of. with numerous points, 582; winter change of the,
619; sexual preferences shown by, 598.

Kelatiouship, terms of, 675.

778 INDEX,

Religion, deficiency of among certain races, 106; psychical elements
of, 107.

Kemorse, 129; deficiency of, among savages, 149.

Hengger, on tbe diseases of Cehus Azarce, 7; on tLe diversity of
the mental faculties of monkeys. 81: on the Payaguas Indians,* 37;
on llie inferioiity of Europeans to savages in their senses. 38; revenge
taken l)y monkeys, 78; on maternal att'ection in a Cthus, "JQ; on the
reasoning powers of American monkeys, 87; on the use of stones by
monkeys for cracking liard nuts, 91; on tlie sounds uttered by Vthua
Azarce, 95; tm the signal-cries of monkeys, 98; on tbe polygamous
habits of Mycetes caraya, 246; on tlie voice of the bowling monkeys,
C02; on the odor of Cerxus can/pci-tris, C04; on the beards of Mycdcs
caraya and Pithecia Satanaa, CU7; on tbe colors of Felis mitin, 610;
en the colors of Cervus paludofius, 013; on sexual differences of color
in Mycetec, 613; on tbe color of tbe infant Ciuaranys, 636; on tbe
early maturity of tbe female of Cebes Azarce, 636; on tbe beards of tbe
Ouaranys, 639; on tbe emotional notes employed by monkeys, 652;
on American polygamous monkeys, 674.

Kepresentutive species, of birds, 533.

Reproduction, unity of phenomena of, throughout the mammalia,
8; period of, in birds, 551.

Reproductive uystem, rudimentary structures in the, 26; accessory
parts of, 183.

Reptiles, 397.

Reptiles and birds, alliance of, 188.

Resemblances, small, between man and the apes, 171.

Retrievers, exercise of reasoning faculties by, 88.

Revenge, manifested by aniirals, 78.

Reversion, 41 ; perbajjss tbe cause of some bad dispositions, 155.

Rfmgium, difference of color in the sexes of a Species of, 333.

Jfhamjyhnstos carinntus, 560.

Rhea Dariciiiii, 545.

Rhinoceros, nakedness of, 64; horns of, 576; horns of. used defens-
ively, 590; attacking white or gray horses, 617.

Rhynchmi, sexes and young of, 543 ; rhyncliCBa auatralis, 543;
r\yrichcea benynlensis, 543; rhyncha^a capenm, 543.

Rhythm, perception of, by animals, 649.

Jiicbard, M., on rudimentary muscles in man, 13.

Richard, Sir J., on tbe |)airing of Tttrao vmbellus, 416; on Tetrnc
UTophadanus, 423; on tbe drumming of grouse, 423, 427; on the
dances of Tetvao phasianellus, 431; on assemblages of grouse, 460;
on the battles of male deer, 571; on the reindeer, 574; on tbe horns
of the musk-ox, 576; on antlers of the reindeer with numerous
points, 582; on the moose, 587; on the Scotch deerhound, 589.

Richter, Jean Paul, on imaginaticm, 84.

Riedel, on profligate female pigeons, 475.

Riley, Mr., on nnmicry in butterflies. 367; bird's disgust at taste of
certain caterpillars. 370.

Ring-ouzel, colors and nidificalion of the. 513.

Ripa, Father, on the ditficulty of distinguishing the races of the
Chinese, 190.

Rivalry, in singing, between male birds, 419.

Eiver-'hog, African, tusks and knobs of the, 593b

INDEX, 779

Rivers, analogy of, to islands. 181.

Hoacli, bri^biuess of the male during brr^eding-season, 386.

Ki.'bbery. of .strangers, considered honorable. 133.

Kobert.son. Mr., remarks on the development of the horns in the
roebuck and red deer, 265.

".iobin, ])ngnacity of the male. 408; autumn song of i1k3. 420;
fe-.iiale singing of the, 420, attacking other birds with red iu their
plumage. 408; young of the, 547.

Kobiuet, on tbe difference of size of the male and female cocoons
of the silk-motb. 315.

Rodents, uterus in the, 43: absence of secondary sexual characters
in. 247; sexual differences in the colors of, 609.

Hoe, winter changes of the. 610.

Hohfs, L)r.,jtCauciisian features in negro. 190; fertility of mixed
races in Saliara, 195; colors of birds iu feiahara, 557; ideas of beauty
among the Bornuans, 663.

Holle, F., on the origin of man, 3; on a change in German families
settled in Georgia. 223.

Roller, hursli cry of, 421.

Honums, ancient, gladiatorial exhibitions of the, 139.

Hook, voice of the, 426.

Hossier. Dr.. on the resemblance of the lower surface of butterflies
to the l)ark of trees, 353.

Ro.struni, sexual difference in the length of, In some weevils, 235.

Rover, Madlle., mamnmls giving suck, 186.

Rudimentary organs, 12; origin of, 26.

Rudiments, presence of, in languages, 102.

Rudolphi, on the want of connection beiween climate and the color
of the skin. 219.

Ruff, supposed to he polygamous, 248; proportion of the sexes in
the, 280: pugnacity of the. 409; double moult in, 443. 445; duration
of dances of, 460: attracticm of the. to bright objects, 469.

Ruminants, male, disappearance of canine teeth in, 60, 641 ;
generally polygamous, 246; suborbital pits of, 604; sexual differences
of color in, 611.

liupicola crocea, display of jdumage by the male, 448.

Rii|>pell, on canine teeth in deer and antelope-, 586.

Ru.ssia, numerical proportion of male and female births in,
243, 275.

Unticilla, 525.

Rlituieyer, Prof., on the physiognomy of the apes, 60; on tusks of
miocene boar, 593; on the sexual differences of monkeys. 640.

Rutlandshire, numerical proportion of male and female births
in, 274.

Sacbs, Prof., on the behavior of the male and female elements in
fertilization, 252.

Sacrifices, human, 108.

Sagittal crest in male apes and Australians, 638.

Sahara, fertility of mixed races in, 195; birds of the, 519; animal
Inhabitants of tbe^ 557.

Sailors, growth of, delayed by conditions of life, 34 ; long-
sighted, 38.
"Sailors and soldiers, difference in the proportions of, 38.

780 INDEX,

8t. John, Mr., on the attachment of mated birds, 466.

St. Kilda, beards of the inhabitants of, 638.

Salino eriox and S. umbla, coloring of the male, during the breed-
ing-season, 886.

Salmo lycaodon, 378; salmo salar, 377.

Salmon, leaping out of fresh water, 122; male, ready to breed
before the female, 240; proportion of the sexes in, 282; male, pug-
nacity of the, 377; male, characters of, during the breeding-season,
377, 886; spawning of the, 390; breeding of immature male, 552.

Salvin, O., inheritance of mutilated feathers, 67, 436, 689; on the
humming-birds, 248, 516; on the numerical proportion of the sexes
in humming-birds, 281, 555; on Ohamcppetes and Penelope, 429; on
SelaspJiorus platycercus, 42d; Pipra deliciosa, A29; on Chasmorhyn-
chus, 442.

Samoa Islands, beardlessness of the natives of, 639f.663.

Sandhoppers, claspers of male, 307.

Sand-skipper, 805.

Sandwich Islands, variation in the skulls of the natives of the, 29;
decrease of native population, 211; population of, 290; superiority of
the nobles in the, 669; Islanders, lice of, 193.

San-Giuliano, women of, 670.

Santali, recent rapid increase of the, 51; Mr. Hunter on the, 213.

Saphirina, characters of the males of, 806.

Sarkidiornis melanonotits, characters of the young, 529.

Sars, 0., on Pontoporcin affiiiis, 800.

Sdtiirnia cnrpini, attraction of males by the female, 284; satitrnu
■7, difference of coloration in the sexes of, 858.

ISatiiriiiidcB, coloration of the, 856. 358.

Savage, Dr., on the fighting of the male gorillas, 641; on the habits
of the gorilla, 675. '

Savage and Wyman on the polygamous habits of the gorilla, 246

Savages, uniformity of. exaggerated. 82; long-sighted, 37; rate
increase among, usually small, 50; retention of the prehensile pow
of the feet by. 58; imitative faculties of. 98, 146; causes of lo
jnorality of, 135; tribes of, supplanting one another, 145; improve-
ments in the arts among, 164; arts o^ 203; fondness of. for rough
music. 431; on long-enduring fashions among, 563; attention paid
by, to personal appearance. 654; relation of the sexes among, 675,

Saviotti, Dr., division of malar bone, 44.

Saw fly, pugnacity of a male, 330.

Saw-flies, proportions of the sexes in, 286.

Saxicola ritbicola, young of, 555.

Scalp, motion of the. 14.

Scent-glands in snakes, 399.

Schaaffhausen, Prof., on the development of the posterior mola:
in different races of man, 22; on the jaw from La Naulette, 46; o:
the correlation between muscularity and prominent supraorbit
ridges, 49; on the mastoid processes of man, 59; on modifications o:
the cranial bones, 62; on human sacrifices, 163; on the probabl
speedy extermination of the anthropomorphous apes, 178; on the
ancient inhabitants of Europe, 207; on the effects of use and disuse,
of parts, 225, on the superciliary ridge in man, 684; on the absence
of race-differences in the infant skull in man, 635; on ugliness, 666,

4

its

y

INDEX. 781

Scliaum, H., on the elytra of JDytiscus and Hydroporus, 313.

Scherzer and Schwarz, measurements of savages, 638.

Scbelver, on dragon-tlies, 329.

Scbiodte, on the stridulatiou of Heterocerus, 343.

Schlegel, b\ von, on the complexity of the languages of uncivilized
peoples, 103.

Schlegel, Prof., on Tanysiptera. 533.

Schleicher, Prof., on the origin of language, 98.

Schomburgk, Sir R., on the puj;nacit>' of the male musk-duck of
Guiana, 411; on the courtship of Rupicola erocea, 448.

Schoolcraft, Mr., on the difficulty of fashioning stone imple-
ments, 55.

Schopenhauer, on importance of courtship to mankind, 669.

Schweinfurth, complexion of negroes, 634.

Sciama aquila, 394.

Sclater, P. L. , on modified secondary wing-feathers in the males of
Pipra, 429, 430 ; on elongated feathers in nightjars, 436 ; on the
species of G hasmorhynchns, 442; on the plumage of Pelecanua
ouocrotdlus, 446; on the plantain-eaters, 523; on the sexes and young
of 'ladorna variegata, 546; on the colors of Lemur macaco, 613; on
the stripes in asses, 626.

Scolecida, absence of secondary sexual characters in, 294.

Scolopax frenata, tail - feathers of, 428; scolopax gallinago,
drumming of, 427; scolopax javensis, tail-feathers of, 428; scolopax
major, assemblies of, 460; scolopax wilsonii, sound produced by, 428.

IScolytus, stridulatiou of, 342.

Scoter-duck, black, sexual difference in coloration of the, 559;
bright beak of male, 559.

Scott, Dr., on idiots smelling their food, 41.

Scott, J., on the color of the beard in man, 637.

Scrope, on the pugnacity of the male saltoon, 377; on the hattles
of stags, 571.

Scudder, S. H., imitation of the stridulation of the Orthoptera,
321; on the stridulation of the Acridiidae, 324; on a Devonian insect,
327; on stridulatiou, 646.

Sculpture, expression of the ideal of beauty by, 663.

Sea-anemones, bright colors of, 294.

Sea-bear, polygamous, 247.

Sea-elephant* male, structure jf the nose of the, 603; polygamous,
247.

Sea-lion, polygamous, 247.

Seal, bladder-nose, 603.

Seals, their sentinels generally females, 114; evidence furnished
bv, on classification, 170; polygamous habits of. 247; battles of male,
570; canine teeth of male. 572; sexual differences, 588 ; pairing of,
696. sexual peculiarities of, 603; in the coloration of, 610; apprecia-
tion of music ly, 649.

Sea -scorpion, sexual differences in, 381.

Season, changes of color in birds, in accordance with the, 442;
changes of plumage of birds in relation to, 526.

Seasons, inheritance at corresponding, 259.

Sebituani, African chief, trying to alter a fashion, 656.

?»ebright Bantam, 370»

7S^ INDEX.

Secondary sexual characters, 234; relations of polygamy to, 245;
transmitted through both sexes, 255; gradation of, in birds, 488.

Sedgwick, W,, on hereditary tendency to produce twins, 51.

Seeniann, Dr., on the different ai)y)ret:iation of music by different
peoples, 650; on the effects of music, 651.

Seidlit/, on horns of reindeer, 577.

JSelasphorvs platycercus, acuminate first primary of the male, 429.

Selby, P. J., on the habits of the black and red grouse. 248.

Selection, as applied to primeval man, 32; double. 255; injurious
forms of, in civilized nations, 152; of male by female birds, 459, 477;
methodical, of Prussian grenadiers, 32; sexual, explanation of, 230,
241, 249; influence of, on the coloring of Lepidoptera, 363; sexual
and natural, contrasted, 256.

Self-command, habit of, inherited, 131; estimation of, 134.

Self -consciousness, in animals. 93.

Self-preservation, instinct of, VZ1.

Self sacrifice, by savages, 126; estimation of, 134

Semilunar fold, 19.

iSemnopithecus, 175; long hair on the heads of species of, 171,
689; semnopithecus chrysomelas, sexual differences of color in, 614;
semnopithecus cornatus, ornamental hair on the head of, 627; semnopi'
tlu'cuts frontatus, beard, etc., of. 629; semnopithecus nnsica, nose of,
171; semnopithecus nemaus. coloring of. 629; semnopithecus ruhicuii-
dus, ornamental hair on the head of, 625.

Senses, inferiority of Europeans to savages in the, 38.

Sentinels, among animals, 114, 121.

Serpents, instinctively dreaded by apes and monkeys, 75, 80.

i>erranus. hermaphroditism in, 184.

Setina. noise produced by, 349.

Sex. inheritance limited by, 260.

Sexes, relative proportions of, in man, 274, 636; proportions of,
sometimes influenced by selection, 288; probable reiaiiou of the, in
primeval man, 674.

Sexual and natural selection, contrasted, 256; characters, effects of
the loss of, 261; limitation of, 262; characters, secondary, 234; rela-
tions of polygamy to, 245; transmitted through both sexes, 255;
gradation of. in birds. 488.

Sexual differences in man, 8; selection, explanation of. 236, 241,
249; influence of. on the coloring of Lepidoptera, 363; objections to,
663; action of, in mankind, 679; selection in spiders, 30?; Bclection,
supplemental note on, 709; similarity, 288.

Shaler. Prof., sizes of sexes in whales, 583.

Shame, 129.

Sharks, prehensile organs of male. 375.

Sharpe, Dr., Europeans in the tropics, 223.

Sharpe, R. B., on Tanysiptera syhin, 514: on Ceryle, 520; on the
young male of Dacelo Gaudichnvdi, 532.

Shaw. Mr., on the pugnacity of the male salmon, 377.

Shaw, J., on the decorations of birds. 434.

Sheep, danger-signals of. 114; sexual differences in the horns of,
260; horns of, 266, 576; domestic, sexual differences of. late devel-
oped, 269; numerical proportion of the sexes in, 279; inheritance of
liorns by one sex, 570, effect of castraiion, 577; mode of fighting of,

INDEX. 783

579; arched forelieads of some, COS; merino, loss of liorns in females
of, 2G1; liorns of, 266.

Shells, difference in form of, in male and female Gasteropoda. 297;
beautiful colors and shapes of. 298.

Shield drake, pairing with a common duck, 471; New Zealand,
sexes and young of, 546.

Shooter, J., on the Kaffirs, 661; on the marriage-customs of the
Kaffirs, 661. ,

Shrew-mice, odor of, 604.

Shrike, Drongo, .524.

Shrikes, characters of young, 520.

Shuckard, W. E., on sexual differences m the wings of Ilyraenop^
tera, 314.

Shyness of adorned male birds, 457.

Siaf/oaium, proportions of the sexes in, 286; dimorphism in males
of, 339.

Siatu, proportion of male and female births in, 277.

Siamese, general beardiessness of the, 639; notions of beauty of
the, 660. hairy family of. 687.

Sidgwick, H., on morality in hypothetical bee community, 113; our
actions not entirely directed by pain and pleasure, 136.

Siebold, C. T. von, on the proportion of sexes in the Ajms, 287; on
the auditory apparatus of the stridulant Orthoptera, 321.

Sight, inheritance of long and short, 38.

Signal -cries of monkeys, 98.

Silk-moth, proportion of the sexes in. 282, 284; AVnntJius, Prof.
Canestrini, on the destruction of its larvae by wasps, 284; difference
of size of the male and female cocoons of the, 315; pairing of
the, 360.

Simladae, 173; their origin and divisions, 188.

Similarity, sexual. 254.

Singing, "of the Clcadte and Fulgoridae, 319; of tree-frogs, 397; of
birds, object of the, 417.

Sirenia, nakedness of, 63.

Sirex juMnciiH, 331.

Siricidae, difference of the sexes in, 331.

Siskin, 446; pairing with a canary, 472.

Sitfifia, throat-p.')uch of the males of, 403, 406.

Size, relative, of the sexes of insects, 315.

Skin, dark color of, a protection against heat, 223.

Skin, movement of the, 14; nakedness of, in man, 63; color of
the, 219; and hair, correlation of color of, 225.

Skull, variation of, in man, 29; cubic contents of, no absolute test
of intellect, 61; Neanderthal, capacity of the, 61; causes of modifica
tion of the, 62; difference of, in form and capacity, in different race.^
of men. 192; variability of the shape of the, 198; diflFerences of, in
the sexes in man, 635; artificial modification of the shape of. 655.

Skunk, odor emitted by the. 603; white tall of, protective, 621.

Slavery, i)revalence of. 133; of women. 677.

Slaves, difference between field and house-slaves, 224.

Sloth, ornaments of male, 610.

Smell, sense of, in man and animals, 19.

Smith, Adam, on the basis of sympathy, 120.

784 INDEX.

Smith, Sir A., on the recognition of women by male CynocepMU,
9; on revenge by a baboon, 78; on an instance of memory in a
baboon, 83; on the retention of their color by the Dutch in South
Africa, 219; on the polygamy of the South African antelopes, 246;
on the polygamy of the lion, 247; on the proportion of the sexes in,
Kobus ellipdijrymmis. 279; on Biicephdas capensis, 398; on Soutli
African lizards, 406; on fighting gnus. 571; on the horns of rhinoce-
roses, 576; on the fighting of lions, 594; on the colors of the Cape
eland, 612; on the colors of the gnu, 612; on the Hottentot notions
of beauty, 660; disbelief in communistic marriages, 671.

Smith, F., on the Gynipidae and Tenthredinidae, 286; on the rela-
tive size of the sexes of Aculeate Hymenopetra, 316; on the difference
between the sexes of ants and bees, 331; on the stridulation of I'rox
sahulosus, 343: on the stridulation of Moiionychus pseudacori, 345.

SmyntJuirus liiteus, courtship of, 317.

Snakes, sexual differences of, 398; mental powers of, 399; male,
ardency of, 399.

•* Snarling muscles," 46.

Snipe, drumming of the, 427; coloration of the, 558; painted,
sexes and young of, 542; solitary, assemblies of, 461.

Snipes, arrival of male before the female, 240; pugnacity of male,
411; double moult in, 442.

Snow-goose, whiteness of the, 560.

Sociability, the sense of duty connected with. 111; impnlse to, in
animals, 119, manifestations of, in man, 123; instinct of, in ani-
mals, 124.

Social animals, affection of, for each other, 115, defense of, by the
males, 121.

Sociality, probable, of primeval men, 70; influence of, on the de-
velopment of the intellectual faculties, 146; origin of, in man, 147.

Soldiers, American, measurements of, 34; and sailors, difference in
the proportions of, 36.

Soknostoma, bright colors and marsupial sac of the females
of, 393.

Song, of male birds appreciated by their females, 104; want of, in
brilliant plumaged birds, 454; of birds, 512.

Bar ex. odor of, 603.

Sounds, admired alike by man and animals, 104; produced by
fishes, 393; ])roduced by male frogs and toads, 397; instrumeutally
produced by birds, 426 H seq.

Si)ain decadence of, 160.

ISpardisHUs Hinaragdulaa, difference of color in the sexes of, 307.

Sparrow, pugnacity of the male, 409; acquisition of the linnet'a
song by a, 420; coloration of the, 539; immature plumage of the,
532: white-crowned, young of the. 553.

Sparrows, house and tree, 518. 550; new mates found by, 463:
sexes and young of, 550; learning to sing, 651.

JSpathura Undericoodi, 440.

Spawning nf fishes, 387, 391.
-Spear, used before dispersion of man, 204.

Species, causes of the advancement of, 156; distinctive characters
of, 190; or races of man, 191; sterility and fertility of, when
crossed, 194: supposed, of man, 198: gradation of j 198; difficulty at

INDEX. 786

defining, 199; representative, of birds, 533; of birds, comparative
differences between the sexes of distinct, 534.

Spectrum femoratum, difference of color in tbe sexes of, 328.

Speech, connection between the brain and- the faculty of, 99; con
nection of intonation with music, 653.

•' Spel " of the black-cock, 425.

Spencer, Herbert, on the influence of food on the size of the jaws,
37; on the dawn of intelligence, 75; on the origin of the belief in
spiritual agencies, 106; on the origin of the moral sense, 139; on
music, 652, 653.

Spengel, disagrees with explanation of man's hairlessness, 687.

Sperm-whales, battles of male, 570.

Sphingidae, coloration of the, 356.

Sphinx, humming-bird, 359; Mr. Bates on the caterpillar of a, 369.

Sphinx moth, musky odor of, 349.

Spiders, 307; parental feeling in, 120; male, more active than
female, 250; proportion of the sexes in, 287; secondary sexual char-
acters of, 308; courtship of male, 308; attracted by music, 309; male,
small size of, 308.

Spilosoma menthastri, rejected by turkeys, 358.

Spine, alteration of, to suit the erect attitude of man, 59.

Spirits, fondness of monkeys for, 7.

Spiritual agencies, belief in, almost universal, 106.

Spiza cyanea and ciris, 468.

Spoonbill, 425; Chinese, change of plumage in, 525.

Spots, retained throughout groups of birds, 485; disappearance of,
in adult mammals, 623.

Sprengel, C. K., on the sexuality of plants, 240.

Spring- boc, horns of the, 580.

Sproat, Mr., on the extinction of savages in Vancouver Island, 208;
on the eradication of facial hair by the natives of Vancouver Island,
662; on the eradication of the beard by the Indians of Vancouver
Island, 689.

Spurs, occurrence of, in female fowls, 257, 261; development of,
in various species of Phasianidae, 267; of Gallinaceous birds, 412,
413; development of, in female Gallinacese, 511.

Squilla, different colors of the sexes of a species of, 306.

Squirrels, battles of male, 570; African, sexual differences in the
coloring of, 609; black, 616.

Stag, long hairs of the throat of, 595; horns of the, 257, 260;
battles of, 571; horns of the, with numerous branches, 581; bellow,
ing of the, 601; crest of the, 606; beetle, numerical proportion of
sexes of, 286; use of jaws, 312; large size of male, 316; weapons of
the male, 339.

Stainton, H. T., on the numerical proportion of the sexes in the
smaller moths, 283; habits of Klacldsta rvfocinerea, 284 ; on tie
coloration of moths, 357; on the rejection of Spilosoma menthastn by
turkeys, 358; on the sexes of AgrotU exclamdtioniSy 358.

Staiey, Bishop, mortality of infant Maories, 213.

Stallion, mane of the, 594.

Stallions, two, attacking a third, 115; fighting. 571; small canin<d
teeth of. 586.

Stausbury, Capt., observations on pelicans, 116.

786 INDEX,

StapLylinidap, Lornlike processes in male, 338.

Starfishes, parental feeling in, 120; bright colors of some, 295.

Stark. Dr., on the death-rate in towns and rural districts, 157; on
the influence of marriage on mortality, 158; on the higher mortality
of males in Scotland, 275.

Starling. American field, pugnacity of male, 417 ; red-winged,
selection of a mate by the female, 472.

Starlings, three, frequenting the same nest, 248, 464; new mates
found by, 464.

Statutes, Ciireek, Egyptian, Assyrian, etc., contrasted, 663.

Stature, dependence of, upon local influences. 34.

Staudinger, Dr., on breeding Lepidoptera, 284; his list of Lepidop-
tera. 284.

Staunton, Sir G.. hatred of indecency a modern virtue, 135.

Stealing of bright objects by birds, 469.

Stebbing, T. K.. on the nakedness of the liuman body, 685.

Stemmato^niH, 603.

Stendhal, nee Bonibet.

Steriohothrus piatorum, stridulation, 324.

Stejihen, Mr. L., on the difference in tlie minds of men and
animals. 88; on general concepts in animals, 100; distinction between
material and formal morality, 125.

Sterility, general, of sole daughters, 153; when crossed, a dis-
tinctive character of species, 189 ; under changed conditions
215. 217.

Sterna, seasonal change of plumage in, 561.

Stickleback, polygamous, 249; male, courtship of the, 376; male,
brilliant coloring of, during the breeding-season, 386. nidification of
the, 391.

Sticks used as implements and weapons by monkeys, 91.

Sting in bees, 235.

Stokes, Capt., on the habits of the great bower-bird, 434.

Stolic/ka, Dr., on colors in snakes, 399.

Stoliczka, on the pre-anal pores of lizards, 402.

Stonechat, young of the, 555.

Stone implements, difficulty of making, 55; as traces of extinct
tribes, 206.

Stcmes, used by monkeys for breaking hard fruits and as missiles,
66; piles of. 204.

Stork, black, sexual differences in the bronchi of the, 425; red
beak of the, 559.

Storks, 559, 562; sexual difference in the color of the eyes of, 483.

Strange, Mr., on the t-atin bower-bird, 434.

StrepidceroH kvdu, horns of, 583; markings of, 621.

Stretch, Mr., on the numerical proportions in the sexes of
chickens, 280.

Stridulation, by males of Theridion, 309; of Homiptera. 319; of
the Orthoptera and Honioptera discussed, 327: of beetles, 341.

Stripes, retained throughout groups of birds, 485: disappearance
of. in adult mammals, 624.

Strix flnmmen, 463.

Structure, existence of unserviceable modifications of, 68.

Struggle for existence, in man, 161. 160.

I

IITDEX. 787

Strutliers, Dr., on the occurrence of the supra-condyloid foramen
in the humerus of man, 23,

Sturnella ladoviciana, pugnacity of the male, 417.

Sturnus vulgaris, 464.

Sub-species, 199.

Suffering, in strangers, indifference of savages to, 133.

Suicide, 155; formerly not regarded as a crime, 132; rarely prac-
ticed among tlie lowest savages, 133.

Suidse, stripes of young, 529.

Siilivan, Sir B. J., on spealdng of parrots, 96; on two stallions
attacliing a third, 571.

Suuuitra, compression of the nose by the Malays of, 665.

Sumner, Archb., man alone capable of progressive improve-
ment, 89.

Sun-birds, nidification of, 517.

Superciliary ridge in man, 634, 636.

Supernumerary digits, more frequent in men than in women, 253;
inheritance of, 262; early development of, 268.

Superstitions, 164; prevalence of, 138.

Superstitious customs, 108.

Supra-condyloid foramen in the early progenitors of man, 183.

Suspicion, prevalence of, among animals, 78.

Swallow-tail butterfly, 354.

Swallows deserting their young, 122, 128.

Swan, black, wild, trachea of the, 424; white, young of, 550; red
beak of the, 559; black-necked, 562.

Swans, 559, 562; young. 548.

Swnysland, Mr., on the arrival of migratory birds, 240.

Swifts, migration of, 122.

Swinhoe, li., on the common rat in Formosa and China, 91;
behavior of lizards when caught, 403; on the sounds produced by
the male lioopoe, 427; on Dicrurus macrocercus and the spoonbill,
5.24; on the young of Ardeola, 534; on the habits of Turnix, 542; on
the habits of Rhynclma bengalensis, 543; on Orioles breeding in
immature plumage, 552.

Sylcia atricapilla, young of, 554; syhia cinerea, aerial love-dance
of the male, 432.

Sympathy, 152; among animals, 115; its supposed basis, 120.

Sympathies, gradual widening of, 139.

S.\ ngnathous tisbes, abdominal pouch in male, 185.

Sypheotides auritus, acuminated primaries of the male, 429; ear-
tufts of, 430.

Tabunidse, habits of, 235.

'J'adorna variegata, sexes and young of, 546; tadorna vulpan-
eei\ 471.

Tahitians, 164; compression of the nose by the, 665.

Tail, rudimentary, occurrence of, in man, 25; convoluted body in
the exliemity of tlie, 25; absence of, in man and the higher apes, 65;
variability of, in species of Miicacua and in baboons, 65; presence of,
in the early i)rogenitors of man, 182; length of, in pheasants, 507,
513, 514; difference of length of the, in the two sexes of birds, 513.

Tait, Lawson, on the effects of natural selection on civilized
nations, 151.

788 INDEX,

Tanager, scarlet, variation in the male, 481.

Tanagra cestica, age of mature plumage in, 551.

Tanagra rubra, 481 ; young of, 555,

Taiiais, absence of mouth in tlie males of some species of. 235; rela
iions of the sexes in, 287; dimorpbic males of a species of, 300.

Tankerville, Earl, on the battles of wild bulls, 571.

Tanysiptera, races of, determined from adult males, 533; tanp-
itpte?'(t Sylvia, long-tailed feathers of, 513.

Taphroderes distortus, enlarged left mandible of the male, 313.

Tapirs, longitudinal stripes of young, 529, 623.

Tarsi, dilatation of front, in male beetles, 312.

Tarsias, 178.

Tasmania, half-castes killed by the natives of, 194.

Tasmanians, extinction of, 209.

Taste, in the Quadrumana, 618.

Tattooing, 203; universality of, 655.

Taylor, (i., on Qaiscalus major, 281.

Taylor, Rev. R. , on tattooing in New Zealand, 657.

Tea, fondness of monkeys for, 7.

Teal, constancy of, 466.

Tear-sacs, of Ruminants, 604.

Teebay, Mr., on changes of plumage in spangled Hamburg
fowls, 259.

Teeth, rudimentary incisor, in Ruminants, 12; posterior molar in
man, 22; wisdom, 22; diversity of, 30; canine, in the early pro-
genitors of man, 182; canine, of male mammals, 572; in man, re-
duced by correlation, 641; staining of the, 655; front, knocked out
or filed by some savages, 656.

Tegetmeier, Mr., on the transmission of colors in pigeons by one
sex alone, 262; numerical proportion of male and female births in
dogs, 278; on the abundance of male pigeons, 280; on the wattles of
game-cocks, 458; on the courtship of fowls, 473; on the loves of
pigeons, 474; on dyed pigeons, 474; blue dragon pigeons, 508.

Tembeta, S., American ornament, 656.

Temper, in dogs and horses, inherited, 78.

Tench, proportion of the sexes in the, 282; brightness of male,
during breeding season, 386.

Tenebrionidse, stridulation of, 342.

Tennent, Sir J. E., on the tusks of the Ceylon elephant, 578, 587;
on the frequent absence of beard in the natives of Ceylon, 638; on
the Chinese opinion of the aspect of the Cingalese, 659.

Tennyson, A., on the control of thought, 139.

Tenthredinidae, proportions of the sexes in, 286; fighting habits of
male, 330; difference of the sexes in, 331.

Tephrodornis, young of, 533.

Terai, in India, 207.

2'ermites, habits of, 330.

Terns, white, 560; and black, 561; seasonal change of plumage
in, 560.

Terror, common action of, upon the lower animals and man, 77.

Testiido elegans, 398; testudo nigra, 397.

Tetrao cupido, battles of, 417; sexual difference in the vocal
organs of, 422; ieti'ao phasianellus, dances of, 431; duration of

INDEX, 789

iances of, 460; tetrao scoticus, 518, 530, 537; tetrao tetrix, 518, 530,
537; pugnacity of the male, 413; tetrao mnbellus, pairing of, 417;
battles of, 417; drumiiiing of the male. 426; tetrao urogalloides,
dances of, 460; tetrao urogaUus, pugnacity of the male, 412; tetrao
urophasiaiLUS, inflation of the oesophagus in the male, 423.

'Jhamiwhia, young of, 533.

Thecla, sexual differences of coloring in species of, 351; theclarubi,
protective coloring of, 353.

Thecophora fovea, 349.

Theognis, selection in mankind, 33.

Theridion, stridulation of males of, 309; theridion lineatum, 308.

Tiiomisas citizens, and 2\ iloricolens, difference of color in the sexes
of, 307.

Thompson, J. H., on the battles of sperm-whales, 571.

Thompson, W,, on the coloring of the male char during the
breeding-season, 386; on the pugnacity of the males of Gallinula
chloropus, 409; on the finding of new mates by magpies, 462; on the
finding of new mates by Peregrine falcons, 463.

Thorax, processes of, in male beetles, 334.

Thorell, T., on the proportion of the sexes in spiders, 287.

Thornback, difference in the teeth of the two sexes of the, 379.

Thoughts, control of, 139.

Thrush, i^airing with a blackbird, 470; colors and nidification of
the. 518.

Thrushes, characters of young, 518, 529.

Thug, remorse of a, 133.

Thumb, absence of, in Ateles and Hylolates, 57.

Thury, M., on the numerical proportion of male and female births
among the Jews, 275.

Ihylacinus, possession of the marsupial sac by the male, 183.

Thysanura, 317.

Tibia, dilated, of the male Crdbro cribrarius, 313; and femur, pro-
portions of, in the Aymara Indians, 39.

Tierra del Fuego, marriage-customs of, 683.

Tiger, colors and markings of the, 622.

Tigers, depopulation of districts by, in India, 52.

Tillus elongatus, difference of color in the sexes of, 333.

Timidity, variability of, in the same species, 78.

Tima tiulgaris, 282.

Tipula, pugnacity of male, 317.

Tits, sexual difference of color in, 521.

Toads, 895; male, treatment of ova by some, 185; male, ready to
breed before the female, 240.

Todas, infanticide and proportion of sexes, 288; practice polyandry,
677; choice of husbands among, 677.

Toe, great, condition of, in the human embryo, 12.

Tomicus villosiis, proportion of the sexes in, 286.

Tomtit, blue, sexual difference of color in the, 521.

Tonga Islands, beardlesoness of the natives of, 639, 663.

Tooke, llorno, on language, 97.

Tools, flint, 164; used by monkeys, 91; use of, 54.

Topuots in birds, 438.

Tortoise, voice of the male, 646.

790 INDEX,

Tortures, submitted to by American savages, 134.

'Jotanus, double moult in, 442.

Toucans, colors and i>>diiicatioii of tlic, 518; beaks and ceres of
iLe. 5(50.

Towns, residence in, a cause cf diminished stature, 35.

Toynbee, J., on tbe external sbell of the ear in man, 15.

Tracbea, convoluted and imbedded in the sternum, in some birds,
425; structure of tbe, in Rhynchmt, 542.

Trades, affecting the form of tbe skull, G2.

Tragelaphua, sexual differences of color in, Gil; tragelaplius
scripina, dorsal crest of, 606; markings of, C21.

Tragopau, 249; swelling of tbe wattles of tbe male, during court-
sbip, 434; display of plumage by tbe male, 451; marking of tbe
sexes of tbe, 487.

Trngops dispar, sexual difference in tbe color of, 399.

Training, effect of, on tbe mental difference between tbe sexes of
man, 645.

Transfer of male characters to female birds, 536.

Transmission, equal, of ornamental characters, to botb sexes in
mammals, 618.

Traps, avoidance of, by animals, 90; use of, 54.

1'reachery, to comrades, avoidance of, by savages, 126.

Tremex columbce, 331.

Tribes, extinct. 145; extinction of, 207.

Trichius, difference of color in the sexes of a species of, 333.

Trigla, 394.

Trigonoce[)halus, noise made by tail of, 401.

Trimen, R., on tbe proportion of the sexes in South African but-
terflies. 283; on the attraction of males by tbe female Lasiocnmpa
querciis, 284 • on Pnevmora, 826 ; on difference of color in the
sexes of beetles, 333; on moths brilliantly colored beneath, 357; on
mimicry in butterflies, 367, 368; on Gyiianim his, and on the ocel-
lated spots of Lepidoptera, 486; on Cyllo Leda, 486.

Tringa, sexes and young of, 553; tringa cornuta, 444.

Triphcena, coloration of the species of, 355.

Tristram, H. B., on unhealthy districts in North Africa, 221; on the
habits of the chaffinch in Palestine, 281; on tbe birds of tbe Sahara,
519; on the animals inhabiting the Sahara, 557.

Iriton cristatas, 394; triton palmipes, 394; triton punctatus, 394,
395.

Troglodyte skulls, greater than those of modern Frenchmen, 62.

Troglodytes vulgaris, 539.

Trogons, colors and nidification of the, 518.

Tropic- birds, white only when mature, 560.

Tropics, freshwater fishes of the, 389.

Tiout, proportion of tbe sexes in, 281; male, pugnacity of
the, 377.

Trox sabnlosus. stridulation of, 343.

'J'ruth, not rare between members of the same tribe, 123; more
highly appreciated by certain tribes, 138.

Tuilocl:. Major, on the immunity of the negro from certain
fevers, 220.

Tumbler, almond, change of plumage in the, 269.

INDEX, 791

Tardus merula, 518; young of, 554; turdus migrntorivi, 529;
tnrdiLH niudcus, 518; tardus pulyglottan, young of, 554; turdus tor-
quatus, 518.

Turkey, wild, pugnacity of young male. 414; wild, notes of the,
425; swelling of tlie wattles of the male, 434; variety of, with a top-
knot, 488; recognition of a dog by a, 468; male, wild, acce])table to
donjesticated females, 475; wild, first advances niado by older
females, 477; wild, breast-tuft of bristles of tbe, 525.

Turkey-cock, scraping of the wings of, upon the ground, 426:
wild, display of plumage by, 447; fighting habits of, 458.

Turner, Prof. W., on muscular fasciculi in man referable to thr.
])anniculus carnosus, 14; on the occurrence of the supra-coi.dyiold
foramen in the human humerus, 24; on muscles attached tt) the
coccyx in man, 25; on the jilam termiaale in mm, 25; on the varia-
bility of the muscles, 30; on abnormal conditions of the human
nterus. 43; on the development of the mamn.ary glands, 184; on
male fishes hatching ova in their mouths, 185, 391; on the external
perpendicular fissure of the brain, 228; on the bridging convolutions
in the brain of a chimpanzee, 228.

2\trnix, sexes of some species of, 542, 547.

Turtle-dove, cooing of the, 425.

Tuttle, H., on the number of species of man, 199.

Tylor, E. 13., on emotional cries, gestures, etc., of man, 96: on the
origin of the belief in sjiiritual agencies, 106; remorse for violation
of tribal usage in marrying, 130; on the priujitive barbarism of
civilized nations, 162; on the origin of counting, 162; inventions
of savages, 164 ; on re.semblances, of the mental characters in
different races of man, 203.

Type of structure, prevalence of, 186.

TyphcRUS, stridulating organs of, 341; stridnlation of, 343.

Twins, tendency to produce, hereditary, 51.

Twite, proportion of the sexes in the, 281.

Ugliness, said to consist in an approach to the lower animals, 6C6.

Umbrella bird, 423.

Uiiibrina, sounds produced by, 394.

United States, rate of increase in, 50; influence of natural selec-
tion on the progress of, 161 ; change undergone by Europeans in
the. 223.

Upapn, epops, sounds produced hy the male, 427.

Uraniidae. coloration of the, 356.

Urid troile, variety of (= U. iacrymans), 483.

Vroddn, 394.

Uro/iticte Benjnmitn. sexual differences in, 502.

Use and disuse of parts, effects of, 36; influence of, on the races
of man, 224.

Uterus, reversion in the. 43; more or less divided, in the human
.subject, 43, 48; double, in the early ^progenitors of man, 183.

Vaccination, influence of, ]51.

Vancouver Island, Mr. Sjjroat on the savages of, 208; natives of,
eradication of facial hair by the, 662.

Vnaellus cHiitatus, wing'tubercies of the male, 414.

Vanessw, 350 ; lesemblance of lower surface of, to hark of
trees, 353.

792 INDEX.

Variability, causes of , 31; in man, analogous to that in the lower
animals, 33; of the races of man, 198 ; greater in men than in
women, 252; period of, relation of the, to sexual selection, 272; of
birds, 479, of secondary sexual characters in man, 638.

Variation, laws of, 33; correlated, 48; in man, 166; analogous, 173;
analogous, in plumage of birds, 438.

Variations, spontaneous, 49.

Varieties, absence of, between two species, evidence of their dis-
tinctness. 189.

Variety, an object in nature, 561.

Variola, communicable between man and the lower animals, 7.

Vaureal, human bones from, 24.

Veddahs, monogamous habits of, 675.

Veitch, Mr., on the aversion of Japanese ladies to whiskers, 663-

Vengeance, instinct of, 127.

Venus Erycina, priestesses of, 670.

Vermes, 299.

Vermiform appendage, 23.

Verreaux, M., on the attraction of numerous males by the female
of an Australian Bombyx, 284.

Vertebrae, caudal, number of, in macaques and baboons, 65; of
monkeys, partly imbedded in the body, 66.

Vertebrata, 375; common origin of the, 180; most ancient progeni-
tors of, 183; origin of the voice in air breathing, 646.

Vesicula prostatica, the homologue of the uterus, 26, 183.

Vibrissse, represented by long hairs in the eyebrows, 20.

Vidua, 457, 526; vidua axillaris, 248.

Villerme, M., on the influence of plenty upon stature, 35.

Vinson, Aug., courtship of male spider, 308; on the male of
Epeira nic/ra, 309.

Viper, difference of the sexes in the, 398.

Virey, on the number of species of man, 199.

Virtues, originally social only, 132; gradual appreciation of, 148
Viscera, variability of, in man, 30.

Vlacovich, Prof., on the ischio-pubic muscle, 46.

Vocal music of birds, 417; vocal organs of man, 98; of birds, 96,
512; of frogs, 397; of the Insessores, 421; difference of, in the sexes
of birds, 421; primarily used in relation to the propagation of the
species, 646.

Vogt, Karl, on the origin of species, 1; on the origin of man, 3;
on the semilunar fold in man, 19; on microcephalous idiots, 40; on
the imitative faculties of microcephalous idiots, 98; on skulls from
Brazilian caves, 192, on the evolution of the races of man, 201; on
the formation of the skull in women, 635;- on the Ainos and negroes,
639; on the increased cranial difference of the sexes in man with
race development, 645; on the obliquity of the eye in the Chines^e
and Japanese, 659. *

Voice in mammals, 600; in monkeys and man, 636; in man, 645;
origin of, in air-breathing vertebrates, 646.

Von Baer, see Baer.

Vulpian, Prof., on the resemblance between the brains of man and
the higher apes, 6.

Vultures, selection of a mate by the female, 473; colors of, 561.

INDEX. 798

Waders, young of, 653.

Wagi-er, K., on the occurrence of tlie diastema in a Kaffir skull,
45; on the bronclii of the black stork, 485.

Wagtail, Ray's, arrival of the male before the female, 240.

Wagtails, Indian, young of, 534.

Waist, proportions of, in soldiers and sailors, 87.

Waitz, Prof., on the number of species of man, 199; on tbe liabil-
ity of negroes to tropical fevers after residence in a cold climate, 221;
on tbe color of Australian infants, 636; on the beardlessness of
negroes, 639; on tlie fondness of mankind for ornaments, 654; on
negro ideas of female beauty, 660; on Javan and Cochin Chineses
ideas of beauty, 661.

Waldeyer, M., on the hermaphroditism of the vertebrate em
bryo, 183.

NVales, North, numerical proportions of male and female births
in, 274.

Walkenaer and Qervais, spider attracted by music, 309; on the
Myriapoda, 310.

Walker, Alex., on the large size of the hands of laborers' chil-
dren, 37.

Walker, F., on sexual differences in the diptera, 317.

Wallace, Dr. A,, on the prehensile use of the tarsi in male moths,
237; on the rearing of the A'ilanthua silkmoth, 284; on breeding
Lepidoptera, 284; proportion of sexes of Bomhyr cynthia, B. yama-
mai, and B. Pernyi reared by, 285; on the development of Bombyx
cynthia and B. yamamai, 315; on the pairing of Btmibyx cynthia, 360.

Wallace, A. R., on the origin of man, 3; on the power of imita-
tion in man, 77; on the use of missiles by the orang, 92; on the
vary appreciation of truth among different tribes, 138; on the limits
of natural fielection in man, 144; on tbe occurrence of remorse among
savages, 149; on the effects of natural selection on civilized nations,
151; on the use of the convergence of the hair at the elbow in the
orang, 172; on the contrast in the characters of the Malays and
Papuans, 191; on the line of separation between the Papuans and
Malays, 192; on the birds of paradise, 248; on the sexes of Orni-
thoptcra C'rasus, 283; on protective resemblances, 295; on the rela-
tive sizes of the sexes of insects, 315; on KlnpJwmyia, 317; on the
pugnacity of the males of Leptorhynchus angustatus, 339; on sounds
produced by Kuchirus longimanus, 344; on the colors of Diadema,
850; on Kallima, 353; on the protective coloring of moths, 355; on
bright coloration as protective in butterflies, 356; on variability in
the Papilionidae, 363; on male and female butterflies inhabiting dif-
ferent stations, 364; on the protective nature of the dull coloring of
female butterflies, 864, 365, 367; on mimicry in butterflies, 367; on
the bright colors of caterpillars, 369; on brightly colored fishes fre-
ouenting reefs, 389; on the coral snakes, 400; on Paradisea apoda,
438; on the display of plumage by male birds of paradise, 449; on
assemblies of birds of paradise, 460; on the instability of the ocel-
lated spots in Hippavchia Janira, 486; on sexually limited inherit-
ance, 505; on the sexual coloration of birds, 514, 538, 539, 541. 546;
on the relation between the colors and nidification of birds. 515, 518;
on the coloration of the Cotingidae, 523; on the females of Paradises
apoda and papuana, 535; on the incubation of the cassowary, 545}

794 INDEX,

on protective coloration in birds, 556; on the Babirusa, 592; on the
markings of the tiger, 622; on the beards of the Papuans, 639; on
the hair of the Papuans, 656; on the distribution of hair on the
human body, 685.

Walrus, development of the nictitatitig membrane in the, 19;
tusks of the, 572, 578; use of the tusks by the, 585.

Walsh, B. D., on the proportion of the sexes in Papilio Tumus,
283; on the Cynipidse and Cecidomyidse, 286; on the jaws of Am-
mophila, 312; on Corydalis cornutus, 312; on the prehensile organs
of male insects, 312; on the antennae of Peiithe, 313; on the caudal
appendages of dragon tiies, 313; on Platyphyllum concavum, 324; on
the sexes of the Ephemeridae, 328; on the difference of color in the
sexes oi Spectrum femoratum, 328; on sexes of dragon flies, 328; on
the difference of the sexes in the Ichneumonidee, 331; on the sexes
of Orsodacna atra, 333; on the variation of the horns of the male
Phanceas carnifex, 336; on the coloration of the species of Antho-
chaiis, 354.

Wapiti, battles of, 571 ; traces of horns in the female, 574; attack-
ing a man, 582; crest of the male, 606; sexual difference in the color
of the, 612.

Warbler, hedge, 539; young of the, 548.

Warblers, superb, nidification of, 517.

Wariness, acquired by animals, 91.

Warington, R., on the habits of the stickleback, 376, 891; on the
brilliant colors of the male stickleback during the breeding-
season, 386.

Wart-hog, tusks and pads of the, 593.

Watchmakers, short-sighted, 37.

Water-hen, 409.

Waterhouse, C. O., on blind beetles, 333; on difference of color in
the sexes of beetles, 333.

Waterhouse, G. R., on the voice of Hyldbates agilis, 647.

Water-ouzel, 518; autumn song of the, 420.

Waterton, C, on the Bell-bird, 441; on the pairing of a Canada
goose with a Bernicle gander, 471 ; on hares fighting, 570.

Wattles, disadvantageous to male birds in fighting, 458.

Weale, J. Mansel, on a South African caterpillar, 869,

Wealth, influence of, 152.

Weapons, used by man, 54; employed by monkeys, 91; offensive,
of males, 238; of mammals, 571; et seq.

Weaver-bird, 420.

Weaver-birds, rattling of the wings of, 426; assemblies of, 460.

Webb, Dr., on the wisdom teeth, 22.

Wedderburn, Mr. , assembly of black game, 462.

Wedgwood, Hensleigh, on the origin of language, 98.

Weevils, sexual difference in length of snout in some, 285.

Weir, Harrison, on the numerical proportion of the sexes in pigs
and rabbits, 279; on the sexes of young pigeons, 280; on the songs of
birds, 418; on pigeons. 467; on the dislike of blue pigeons to other
colored varieties, 474; on the desertion of their mates by female
pigeons, 475.

Weir, J. Jenner, on the nightingale and blackcap, 240; on the
relative sexual maturity of male birds, 241; on female pigee«ns

J

INDEX. 795

deserting a feeble mate, 243; on three starlings frequenting the same
nest, 248; on the proportion of the sexes in Machetes pugnax and
other birds, 280; on the coloration of the Triphcence, 355; on the
rejection of certain catapillars by birds, 369; on sexual differences of
the beak in the goldfinch, 408; on a piping bullfinch, 418; on the object
of the nightingale's song, 418; on song-birds, 419; on the pugnacity
of male fine-plumaged birds, 454; on the courtship of birds, 455; on
the finding of new mates by Peregrine-falcons and Kestrels, 463; on
the bullfinch and starling, 464; on the cause of birds remaining un-
paired, 465; on starling and parrots living in triplets, 466; on recog-
nition of color by birds, 468; on hybrid birds, 470; on the selection
of a greenfinch by a female canary, 472; on a case of rivalry of
female bullfinches, 477; on the maturity of the golden-pheasant, 551.

Weisbach, Dr. , measurement of men of different races, 191 ; on the
greater variability of men than of women, 252; on the relative pro-
portions of the body in the sexes of different races of man, 638.

Weismann, Prof., colors of Lyccence, 354.

Welcker, M., on brachycephaly and dolichocephaly, 63; on sexual
differences in the skull in man, 635.

Wells, Dr., on the immunity of colored races from certain
poisons, 220.

Westring, on the stridulation of males of T/ieridion, 309; on the
stTidnl&tion of Reduvius personatus, dl9; on the stridulation of bee-
tles, 343; on the stridulation of Omaloplia brunnea, 844; on the
stridulating organs of the Coleoptera, 345; on sounds produced by
Cychrus, 344.

Westropp, H. M., on reason in a bear, 86; on the prevalence of
certain forms of ornamentation, 203.

Westwood, J. O., on the classification of the Hymenoptera, 168; on
the Culicidse and Tabanidse, 235; on a Hymenopterous parasite with
a sedentary male, 251; on the proportions of the sexes in Lucaniis
cervus and Siagonium, 286; on the absence of ocelli in female Mut-
lllidae, 311; on the jaws of AmmophUa, 312; on the copulation of
insects of distinct species, 312; on the male of Grc^ro cribrarius, 312;
on the pugnacity of male Tipuloe, 317; on the stridulation of Pirates
stridulus, 319; on the Cicadae, 319; on the stridulating organs of the
cricket, 322; on EpJdppiger vitium, 323; on Pneumora, 325; on the
pugnacity of the Mantides, 327; on PlatyUemnus, 327; on difference
in the sexes of the Agrionidae, 328; on the pugnacity of the males of
a species of Tenthredinae, 330; on the pugnacity of the male stag-
beetle, 339; on Bledius taurus and Siagonium, 338; on lamellicom
beetles, 341 ; on the coloration of Lithosia, 356.

Whale, Sperm, battles of male, 570, 588.

Whales, nakedness of, 63.

Whateley, Arch., language not peculiar to man, 96; on the primi-
tive civilization of man, 162.

Whewell, Prof., on maternal affection, 78.

Whiskers, in monkeys, 171.

White, F. B., noise produced by Hylophila, 349.

Whf<te, Gilbert, on the proportion of the sexes in the partridge, 280;
on the house- cricket, 321; on the object of the song of birds, 419; on
the finding of new mates by white owls, 468; on spring conveys of
male partridge^ 460, 464.

796 INDEX.

Wliiteness, a sexual ornament in some birds, 668; of mammals In
habiting snowy countries, 619.

White-tliroat, aerial love-dance of the male, 482.

Whitney, Frof., on the development of language, 97; language
not indispensable for thought, 100.

Widgeon, pairing with a pintail duck, 471.

Widow-bird, polygamous, 248; breeding plumage of the male, 445,
457; female, rejecting the unadorned male, 476.

Widows and widowers, mortality of, 158.

Wilckens, Dr., on the modification of domestic animals in mount-
ainous regions, 40; on a numerical relation between the hairs and
excretory pores in sheep, 225.

Wilder, Dr. Burt, on the greater frequency of supernumerary
digits in men than in women, 253.

Williams, on the marriage-customs of the Fijians, 684.

Wilson, Dr., on the conical heads of the natives of Northwestern
Africa, 665; on the Fijians, 665; on the persistence of the fashion of
compressing the skull, 666.

Wing-spurs, 413, 511.

Wings, differences of, in the two sexes of butterflies and Hymen-
optera, 314; play of, in the courtship of birds, 455.

Winter, change of color of mammals in, 619.

Witchcraft, 108.

Wives, traces of the forcible capture of, 163.

Wolf, winter change of the, 619.

Wolff, on the variability of the viscera in man, 80.

Wollaston, T, V., on Kurygnathiis, 314; on musical Curculionidae,
841; on the stridulation of Acalles, 346.

Wolves learning to bark from dogs, 82; hunting in packs, 114;
black, 616.

Wombat, black varieties of the, 616.

Women distinguished from men by male monkeys, 9; preponder-
ance of, in numbers, 276; selection of, for beauty, 682; effects of
selection of, in accordance with different standards of beauty, 666;
practice of capturing 673, 676; early beth rot hals and slavery of, 677;
fieedom of selection by, in savage tribes, 683.

Wonder, manifestations of, by animals, 80.

Wonfor, Mr., on sexual peculiarities in the wingsof butterflies, 814;
Wood. J., on muscular variations in man, 29, 46, 47; on the greater
variability of the muscles in men than in women, 253; Wood, T. W.,
on the coloring of the orange-tip butterfly, 355; on the habits of the
Saturniidae, 358; quarrels of chamaeleoiis, 405; on the habits of
Meiiura Alherti, 421 ; on Tetrao cvpido, 422 ; on the display of
l)lumage by male pheasants, 449, 451; on the ocellated spots of the
Argus pheasant, 501; on fighting of Menura aupevba, 461; on the
habits of the female cassowary, 545.

Woodcock, coloration of the, 559.

Woodpecker, sylection of a mate by the female, 472.

Woodpeckers, 421; tapping of, 426; colors and nidification of the,
518. 521, 529; characters of young, 540, 548. 557.

Woolner, Mr., observations (m the ear in man, 16.

Wormald, Mr., on the coloration of llypopyra, 357.

Wounds, healing of, 8.

INDEX. 797

Wren,539; young of tlie. 539. 548.

Wright. C. A., oa the young of Orocetes and Petrocincla, 554;
Wright, Chauucey. great brain-power requi:S!te for language 54; on
correlative acquisition, (jol ; on the enlargement of the brain in
man, 097; Wright, Mr., on the Scotch deerhound, 689; on saexnal
preference in dogs, 597; on the rejection of a hor.se by a mure, 598;
Wright, W., von, on the protective plumage of the Ptarmigan, 443.

Writing, 163.

Wyman, Prof., on the prolongation of the coccyx in the human
embryo, 10; on the conditicm of the great toe in the human
embryo, 13; on the occurrence of the supra-condyloid foramen in the
humerus of man. 24; on variation in the skulls of the natives of the
Sandwich Islands, 29; on the hatching of the eggs in the mouths
and branchial cavities of male fishes, 185, 391.

Xenarchus, on the Cicadae, 319.

Xenophon, selection in mankind advocated by, 32.

Xenorhynchus, sexual difference in the color of the eyes in, 483.

Xiphophorus Hellerii, peculiar analfin of the male, 382.

Xylucopa, difference of the sexes in, 331.

Yarrell, W., on the habits of the Cyprinidae, 282; on Raindnvnta,
375; on the characters of the male salmon during the breeding-
season, 377, 386; on the characters of the ray.s 380; on tbegenimeous
dragonet, 381; on colors of the salmon, 386; on the s])awning of the
salmon, 390; on the incubation of the Lophobranchii. 392; on rivalry
in song-birds, 419; on the trachea of the swan. 425; on the moulting
of the Anatidae, 446; on the young of the waders, 553.

Yellow fever, immunity of negroes and mulattoes from, 220.

Youatt, Mr., on the development of the horns in cattle, 266.

Yura-caras, their notions of beauty, 661.

Zebra, rejection of an ass by a female, 617; stripes of the, 623.

Zebus, humps of, 608.

Zigzags, prevalence of, as ornaments, 204.

Zincke, Mr., on European emigration to America, 161.

Zoatoca mvipara, sexual difference in the color of, 405.

Zouteveen, Dr., poly dactyl ism, 42; proportion of sexes at Cape of
Good Hope, 275; spiders attracted by music, 309; on sounds pro-
duced by fish, 394.

Zygsenido), coloration of the, 856.

THB SNIX

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