(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "The descent of man, and selection in relation to sex"



■^ 





:--.«^lc:r5lR5!St~ — 






ggMMMOMMaiaitnnaMnsaMMnMw^ .riimvxKmwsiivyt^y. 



Jffrnm tl|? ilibrarg of 

iJpqu^atl|p& by l|tm to 

tl|p SItbrary of 

JPnnrrton Ohmlogtral S>ntttnarg 



3:^54 



* J": 11 1922 *! 



THE 




DESCENT OF MAN 



AND 



SELECTION IN RELATION TO SEX. 



BT 



CHARLES DAR\\^N, M. A., F. R. S., Etc. 



Wirn ILLUSTRATJONS. 



IN TWO VOLUMES.— Vol. II. 



NEW YORK: 

D. APPLETON ANT) COMPANY, 

549 & 551 BROADWAY. 

1871. 



•1 



CONTENTS. 



PART IL 

SEXUAL SELECTION— contimwd. 

CHAPTER XII. 

SECONDARY SEX0AL CHARACTERS OF FISHES, AMminiAXS, AND REPTILES. 

Fishes : Courtship and Rattles of the Males. — Larf^or Size of tlie Females.^ 
Males, Briglit Colors and Ornamental Appendaf^es ; other Stran;,'e 
Cliaracters. — Colors and Appenda;;es acquired by the Males during tlie 
Breeding-season alone. — Fishes with both Sexes brilliantly colored. — 
Protective Colors. — Tiie less Conspicuous 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 : Dift'er- 
ences in Structure and Color between the Se.xes. — Vocal Oigans. Rep- 
tiles : Chelonians. — Crocodiles. — Snakes, Colors in some Cases pro- 
tective. — Lizards, Battles of. — Ornamental Appendages. — Strange Dif- 
ferences ill Structure between the Se-xes. — Colors. — Se.\ual Differences 
almost as great as with Birds . . . . . p. 1 

CHAPTER XIII. 

SECONDARY SEXUAL CHARACTERS OF BIRDS. 

Sexual Differences. — Law of Battle. — Special Weapons. — Vocal Organs. — 
Instrumental Music. — Love-Antics and Dances.— Decorations, Perma- 
nent an<l Seasonal. — Double and Single Annual Moults. — Display of 
Ornaments by the Males ...... 86 

CHAPTER XIV. 

BIRDS — contiunrd. 

Choice exerted by the Female. — Length of Courtship. — Unpaired Birds. — 
Mental Qualities and Taste for the Beautiful. — Preference or Antip- 
athy shown liy tiir Female for Particular Males. — Variability of 



iv CONTEXTS. 

Birds. — Variations sometimes abrupt. — Laws of Variation. — Formation 
of Ocelli. — Gradations of Character. — Case of Peacock, Argus Pheas- 
ant, and Urosticte . . . . . . . p. 95 

CHAPTER XV. 

BIRDS — contiimed. 

Discussion why the Males alone of some Species, and both Sexes of other 
Species, are brightly colored. — On Sexually-limited Inheritance, as ap- 
plied to Various Structures and to Brightly-colored Plumage. — Nidifi- 
cation in Relation to Color. — Loss of Nuptial Plumage during the 
Winter ........ 147 

CHAPTER XVI. 

B I R DS — 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 Color- 
ing. — Conspicuously-colored Birds. — Novelty appreciated. — Summary 
of the Four Chapters on Birds ..... 175 

CHAPTER XVII. 

SECONDARY SEXDAL CHARACTERS OF MAMMALS. 

The Law of Battle. — Special Weapons, confined to the Males. — Cause of 
Absence of Weapons in the Female. — Weapons common to both 
Sexes, yet primarily acquired by the Male. — Other Uses of such Weap- 
ons. — Their High Importance. — Greater Size of the Alale. — Means of 
Defence. — On the Preference shown by either Sex in the Pairing of 
Quadrupeds ....... 228 

CHAPTER XVIII. 

SECONDARY SEXUAL CHARACTERS OF MAMMALS Continued. 

Voice. — ^Remarkable Sexual Peculiarities in Seals. — Odor. — Development 
of the Hair. — Color of the Hair and Skin. — Anomalous Case of the 
Female being more ornamented than the Male. — Color and Ornaments 
due to Sexual Selection. — Color acquired for the Sake of Protection. — 
Color, though common to both Sexes, often due to Sexual Selection. — 



CONTENTS. V 

On the Disappearance of Spots and Stripes in Adult QuadrupedK. — 
On the Colors and Oruauients of the Quudrumanu. — Summary p. 261 

CHAPTER XIX. 

SECONDARY SEXUAL CHARACTERS OF MAN. 

Differences between Man and Woman. — Causes of such Differences and of 
Certain Churac-ters common to both Sexes. — Law of Buttle. — Differ- 
ences in Mental Powers — and Voice. — On the Influence of Beauty in 
detL'rmininj» the Marriufres of Mankind. — Attention paid by Savages 
to Ornaments. — Tliuir Iduas of Beauty in Woman. — The Tendency 
to CKaggerate each Natural Peculiarity .... 301 

CHAPTER XX. 

SECONDARY SEXCAL CHARACTERS OF MAN Continued. 

On tlio Effects of the Continued Selection of "Women according to a 
Difft-n-nt Standard of Beauty in each Race. — On the Causes which 
iiitcrfc-re 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 Hus- 
bands. — Absence of Hair on the Body, a^d Development of the Beard. 
— Color of the Skin. — Summary ..... 339 

CHAPTER XXI. 

GENERAL SUMMARY AND CONCLUSION. 

Main Conclusion that Man is descended from some Lower Form. — Man- 
ner of Dcvehipment. — Genealogy of Man. — Intellectual and Moral 
Faculties. — Sexual Selection. — Concluding Remarks . . 368 



ERRATA. 



Page line 

26 23 

30 15 

57, «o<<;^2 2 

11, note'' — 

114, «ofe28 — 
123, 7wte*^ 4 

199 20 
313 1 

815 25 

820 29 
325 6 

829 11 

366 30 
373 6 

384 23 

892 28 



VOL. I. 

For 
koato 

prostratica 
speech 
Browne 
Vol. I. 
Before vol. xiv 
prostratica 
Actineae 
land-shells 
Figs. 4 and 5 
Birgos 
attractions 
Typha»us 
tesselatum 
Hypopira 
AcroeidM 



read 
koala, 
prostatica. 
species. 
Brown. 
Vol. II. 
insert ' Proc. Rojal Soc' 
prostatica. 
Actinias 
land-snails. 
Figs. 4, 5, and 6. 
Birgus. 
attentions. 
Typhoeus. 
tcssellatum. 
Hypopyra. 
AcneidiE. 



POSTSCEIPT. 



Vol. T,, pp. 28'7-289. — I have fallen into a serious and 
nnfortunate error, in relation to tlie sexual differences of 
animals, in attempting to explain what seemed to me a 
singular coincidence in the late period of life at which 
the necessary variations have arisen in many cases, and 
the late period at which sexual selection acts. The ex- 
planation given is wholly erroneous, as I have discovered 
"by working out an illustration in figures. Moreover, the 
supposed coincidence of period is far from general, and 
is not remarkable ; for, as I have elsewhere attempted 
to show, variations arising early in life have often been, 
accumulated through sexual selection, being then com- 
monly transmitted to both sexes. On the other hand, 
variations arising late in life cannot fail to coincide ap- 
proximately in period with tliat of the process of sexual 
selection. 



SEXUAL SELECTIOIS'. 



CHAPTER XII. 

Secondaby Sexual Ciiaracteus of Fishes, Amphibi- 
ans, AND 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 tho 
Breeding-season alone. — Fishes with both Sexes brilliantly colored. — 
Protective Colors. — The less Conspicuous Colors of the Female cannot 
be accounted for on the Principle of Protection. — Male Fishes building 
Nests, and takingChargeof tlie Ovaand Young. Amphibians: Ditfer- 
ences in Structure and Color between the Sexes. — Vocal Organs. Rep- 
tiles : Chelonians. — Crocodiles. — Snakes, Colors in some Cases pro- 
tective. — Lizards, Battles of. — Ornamental Appendages. — Strange Dif- 
ferences in Structure between the Sexes. — Colors. — Sexual Ditfcrences 
almost as great as with Birds. 

"We have now arrived at the great svth-kingdom of the 
Yertebrata, and will eonimence with the lowest class, 
nanuly, Fishes. The males of Plagiostomous fishes 
(sharks, rays) and of Ciiimreroid fishes are provided with 
claspers which serve to retain the female, like the various 
stnu'tures possessed by so many of the lower animals. 
Besides the claspers, the males of many rays have clus- 
ters of strong sharp spines on their heads, and several 
rows along "the upper outer surface of their pectoral 
iius." These are present in the males of some species, 

wiruli have the other parts of their bodies smooth. They 
20 



2 SEXUAL SELECTION". [Part IL 

are only temporarily developed during the breeding-sea- 
son ; and Di-. Giintlier 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 remark- 
able fact that the females and not the males of some spe- 
cies, as of liaia clavata, have their backs studded with 
large hook-formed spines.' 

Owing to the element which fishes inhabit, little is 
known about their courtship, and not much about their 
battles. The male stickleback ( Gasterosteus leiurus) has 
been described as "mad Avith 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 
direction, then to his accumulated materials for the nest, 
then back again in an instant ; and as she does not ad- 
vance he endeavors to push her with his snout, and then 
tries to pull her by the tail and side-spine to the nest." ^ 
The males are said to be polygamists ; ' they are extraor- 
dinarily 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 sev- 
eral seconds, tumbling over and over again, until their 
strength appears completely exhausted." With the 
rough-tailed stickleback ( G. trachurus) the males while 
fitrhtincf swim round and round each other, biting and en- 
deavoring 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 lateral spines 

' Yarrcll, 'Hist, of British Fishes,' vol. ii. 1836, pp. 417, 425, 436. 
Dr. Giinther informs me that the spines in R. clavata are pecuHar to the 
female. 

' See Mr. R. Warington's interesting articles in ' Annals and Mag. of 
Nat. Hist.' Oct. 1852 and Nov. 1855. 

* Noel Humphreys, 'River Gardens,' 1857. 

* Loudon's ' Mag. of Natural History,' vol. iii. 1830, p. 331. 



Chap. XII.] FISHES. 3 

with such fotal effect, tliat I have seen one during a bat- 
tle absohitely rip his opponent quite open, so that he sank 
to the bottom and dieil." When a fish is conquered, "his 
galLant bearing forsakes him ; his gay colors fade away ; 
and he hides his disgrace among liis peaceable compan- 
ions, but is for some time the constant object of his con- 
queror's persecution." 

The male salmon is as pugnacious as the little stickle- 
back ; and so is the male trout, as I hear from Dr. Giin- 
ther. Mr. Shaw saw a violent contest between two male 
salmons which lasted the whole day ; and Mr. R. Buist, 
Superintendent of Fisheries, informs me that he has often 
watched from the bridge at Perth the males driving 
away their rivals while 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." ^ The keeper of the Stor- 
monttield breeding-ponds visited, as Mr. Buist informs me, 
in June, 1868, the northern Tyne, and found about 300 
dead salmon, all of which with one exception were males ; 
and he was convinced that they liad lost their lives by 
fighting. 

The most curious point about the male salmon is that 
during tlie breeding-season, besides a slight change in 
color, " the lower jaw elongates, and a cartilaginous pro- 
jection turns upward from the point, which, when the 
jaws are closed, occupies a deep cavity between " the in- 
termaxillary bones of the upper jaw." " (Figs. 26 and 

^ 'The Field,' June 29, 1807. For Mr. Shaw's statement, sec 'Edin- 
burgh Review,' 1813. Another experienced ob.^erver (Scrope's 'Days of 
Sahiion Fishintr,' p. 00) remarks that the male would, if he could, keep, 
like the stag, all other males away. 

* Yarrell, 'History of British Fishes,' vol. ii. ISSC, p. 10. 



SEXUAL SELECTIOX. 



[Part II. 



27.) In our salmon this change of structure lasts only 
during the breeding-season ; but in the Salmo lycaodon 
of Northwestern America the change, as Mr J. K. Lord ^ 




Fig. 2G.— Head of male of common palmon (Salmo ealar) during the brceding- 

eeason. 

[TluH drawing, as well ns all the others in the present chapter, have been ex- 
ecnted l)y the well-known artist, Mr. G. Ford, under the kind superintendence 
of Dr. Oflnther, from specimens in the British Museum]. 



'The Naturalist iu Vancouver's Island,' vol. 1. 1SG6, p. 54. 



Chap. XII.] FISUES. 5 

Lc'lifves, is })crmanent and best markol in tlic older males 
which have previously ascended the rivers. In these old 
males the jaws become developed into immense hook-like 




Fig. 27.— Iload of female salmon. 

])rojections, and the teeth <;row into regular fangs, often 
niore than half an inch in length. With the European 
salmon, according to Mr. Lloyd,' the temporary hook-like 
structure serves to strengthen and protect the jaws, when 

* 'Scandinavian Adventures,' vol. i. 1854, pp. 101, 101. 



6 SEXUAL SELECTION. [Part IL 

one male charges another with "wonderful violence ; but 
the greatly developed teeth of the male American salmon 
may be compared with the tusks of many male mammals, 
and they indicate an offensive rather than a ])rotective 
jiurpose. 

The salmon is not the only fish in which the teeth 
differ in the two sexes. This is the case with many rays. 
In the thornback [Raia clavata) the. adult male has sharp, 
pointed teeth, directed backward, while those of the fe- 
male are broad and flat, forming 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 fiat like those of 
the female. As so frequently occurs with secondary sex- 
ual characters, both sexes of some species of rays, for in- 
stance R. batis, possess, when adult, sharp, pointed teeth ; 
and here a character, proper to and primarily gained by 
the male, appears to have been transmitted to the off- 
spring of both sexes. The teeth are likewise pointed in 
both sexes of R. maculata, but only when completely 
adult ; the males acquiring them at an earlier age than the 
females. We shall hereafter meet with analogous cases 
with certain birds, in which the male acquires the plu- 
mage common to both adult sexes, at a somewhat earlier 
age than the female. With other species of rays the 
males even when old never possess sharp teeth, and con- 
sequently both sexes when adult are provided with broad, 
flat teeth, like those of the young, and of the mature fe- 
males of the above-mentioned species.' As the rays are 
bold, strong, and voracious fishes, we may suspect that the 
males require their sharp teeth for fighting with their 
rivals; but as they possess many parts modified and 

• See Yarrell's account of the Rays in his ' Hist, of British Fishes,' 
vol. ii. 1836, p. 416, with an excellent figure, and pp. 422, 432, 



Chap. XII.] FISHES. 7 

adapted for the prehension of the femak', it is possible 
that their teeth may be used for this purpose. 

In regard to size, M. Carbonnier " maintains tliat with 
almost all fishes the female is larger than the male ; and 
Dr. Giliitlier 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 the 
female. As with many kinds of fishes, tlie males habitu- 
ally fight together ; it is surprising that they have not 
generally become through the efiects of sexual selection 
larger and stronger than the females. The males suffer 
from their small size, for according to M. Carbonnier they 
are liable to be devoured by the females of their own spe- 
cies when carnivorous, and no doubt by other species. 
Increased size must be in some manner of more impor- 
tance 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 in the female. The male, also, is sometimes provided 
with apjieiidages 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 folloAving 
facts to the great kindness of Dr. Giinther. There is rea- 
son to suspect that many tropical fislies difier sexually in 
color and structure ; and there are some striking cases 
with our British fishes. The male Callionymus lyra has 
been called the gemmeous dragonet " from its brilliant, 
gem-like colors." When freshly taken from the sea the 
body is yellow of various shades, striped and spotted with 
vivid blue on the hca*! ; tlie dorsal fins are pale brown 
with dark longitudinal bands; the ventral, caudal, and 
anal fins being l)luish-l>lack. The female, or sordid drag- 

'0 As quoted in ' The Farmer,' 1808, p. 369. 



8 



SEXUAL SELECTIOX. 



[Part II. 



onct, was considered by Linnaeus and by many subse- 
quent naturalists as a distinct species; it is of a dingy 




Fig. 28.— Callionymns Ijra. Upper fifrurc, male ; lower figure, female. 

reddish-brown, with the dorsal fin brown and the other 
fins Avhite, The sexes difier also in the proportional size 
of the head and month, and in the position of the eyes ; " 
but the most striking diftcrcnce is the extraordinary elon- 
gation in the male (Fig. 28) of the dorsal fin. The young 
males resemble, in stiucture and color, the adult females. 
Throughout the genus Callionymus," the male is gcner- 

" I have drawn up this description from Yarrcll's 'British Fishes,' 
vol. i. 1836, pp. 261,266. 

" ' Catalogue of Acanth. Fishes in the British Museum,' by Dr. 
Gunther, 1861, pp. 138-151. 



Chap. XII.] FISHES. 9 

ally much more brightly spotted than tho fcnialc, and in 
several species, not only the dorsal, but the anal fin of the 
male, is much elongated. 

The male of the Cottus scorpius, or sea-scorpion, is 
more slender and smaller than the female. There is also 
a great dilference in color between them. It is difficult, 
as ]\Ir. Lloyd " remarks, " for any one, who has not seen 
this fish during the spawning-season, when its hues are 
brightest, 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 Lahrus tnixtus, al- 
though very ditlerent 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 Cyprinodontida^ — 
inhabitants of the fresh waters of foreign lands — the sexes 
sometimes diffi^r much in various characters. In the male 
of the Mollienesia jjetenefisis,^* the dorsal fin is greatly 
developed, and is marked with a row of large, round, ocel- 
lated, bright-colored spots; while the same fin in the fe- 
male is smaller, of a difierent shape, and marked only with 
irregularly-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 ^iphoj^/iorus 
Ilellerii (Fig. 29), the inferior margin of the anal fin is 
developed into a long filament, which is striped, as I hear 
from Dr. GUnther, with bright colors. This filament docs 
not contain any muscles, and appai'ently cannot be of any 
direct use to the fish. As in the case of the Callionymus, 
the males while young resemble in color and structure the 
adult females. Sexual difierences such as these may be 

" ' Came Birds of Sweden,' etc., 186T, p. 4G6. 

" 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. 



10 



SEXUAL SELECTION 



[Part IL 



strictly oomparccl with tliosc which aro so frequent with 
galhnaceous birds."" 




> 



/y 




Fig. 29. — Xiphophoras Hellerii. Upper figure, male; lower flgufe. female. 

In a sihiroid fish, inhabiting the fresh waters of South 
America, namely the Plecostomus harhatus " (Fig. 30), 
the male has its mouth and interopcrculum fringed with a 
beard of stiff hairs, of which the female shows hardly a 
trace. These 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 stiflf 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 probable, but we can hardly suppose 

" Dr. Giinthcr makes this remark: 'Catalogue of Fishes in the Brit- 
ish Museum,' vol. iii. 1861, p. 141. 

" See Dr. Giinthcr on this genus, in ' Proc. Zoolog. Soc.' 1 868, p. 232. 



Chap. XII.] 



FISUES. 



11 




Fio. 20.— Plccoetomus barMtns. Upptr lii^ui x, head of male ; lower flgnrc, female. 



12 SEXUAL SELECTION. [Part IL 

that stiff hairs and flexible filaments can be useful in any- 
ordinary way to the males alone. The Monacanthus 
scopas, which was shown to me in the British Museum by 
Dr. Gttnther, presents a nearly anah^gous case. The male 
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 an inch and a half in length ; the female 
lias on the same place a cluster of bristles, which may be 
compared with those of a tooth-brush. In another species, 
the M. peronii, the male has a brush like that possessed 
by the female of the last species, w^hile the sides of the 
tail in the female are smooth. In some other species the 
same part of the tail can be perceived to be a little rough- 
ened in the male and perfectly smooth in the female ; and 
lastly, in otliers, both sexes have smooth sides. In that 
strange monster, the Chhncera moy^strosa, the male has a 
hook-shaped bone on the top of the head, directed for- 
ward, with its rounded end covered with sharp spines ; in 
tlie female " this crown is altogether absent," but what its 
use may be is utterly unknown." 

The structures as yet referred to are permanent in the 
male after he has arrived at maturity; but with some 
Blennies and in another allied genus '^ a crest is developed 
on the head of the male only during the breeding-season, 
and their bodies at the same time become more brightly- 
colored. There can be little doubt that this crest serves 
as a temporary sexual ornament, for the fi-male 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 this case and in that of 
the INIonacanthus, we have good instances to how great 
an extent the sexual characters of closely-allied forms may 

" F. Buckland, in ' Land and Water,' July, 18f.8, p. Z11, with a 
figure. 

>8 Dr. Gunther, 'Catalogue of Fishes,' vol. iii. pp. 221, 240. 



Chap. XII.] FISHES. 13 

differ. In many <>1" tlic Chromida?, for instance, in Geo- 
phagus and esjK'cially in Cielila, the males, as I liear from 
Prof. Agassiz,'" have a eonspieuons protuberance on the 
forehead, which is wholly wanting in the females and in 
the young males. Prof Agassiz adds : " I have often 
observed these tislies 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 function, and 
the Indians on the Amazons know nothing about its use." 
These protuberances in their periodical appearance resem- 
ble the fleshy caruncles on the heads of certain birds ; 
but whether they serve as ornaments must reniain at 
present doubtful. 

The males of those fishes, which differ permanently in 
color from the females, often become more brilliant, as I 
hear from Prof. Agassiz and Dr. Gilnther, during the 
breeding-season. This is likewise the case with a multi- 
tude of fishes, the sexes of which at all other seasons of 
the year are identical in color. 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 gave it the a})i)earance of a Labrus, and 
the body jiartakes of a golden-orange tinge. The females 
arc (lark in color, and are commoidy called blackfish."" 
An analogous and even greater change takes place with 
the ^Sdlmo t'n'ojr^ or bull-trout ; the males of the char {S. 
umblti) are likewise at this season rather brighter in 
color than the females.^' The colors of the pike {Esox re- 

'» See also 'A .Tourney in Urazil,' by Prof. :in<l .Mrs. Agassiz, 1808, 
p. 220. 

'» Yarrell, ' Hriti.^h Fishes,' vol. ii. 1S3C, pp. 10, 12, S;"). 

" W. Thompson, in 'Annals and Mag. of Nat. Ilistory,' vol. vi. 1811, 
p. 440. 



14 SEXUAL SELECTION. [Part IL 

ticulatus), 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 alVordod by the male stickleback ( Gasterosteiis 
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 lustre 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 trans- 
lucent, 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. 

That with fishes there exists some close relation be- 
tween their colors and their sexual functions we can clearly 
see — firstly, from the adult males of certain species being 
differently colored from the females, and often much more 
brilliantly; secondly, from the same males, while im- 
mature, rcseml)ling the mature females ; and, lastly, from 
the males, even of those species which at all other times 
of the year are identical in color with the females, often 
acquiring brilliant tints during the spawning-season. We 
know that the males are ardent in their courtship, and 
sometimes fight desperately together. If we may assume 
that the females have the power of exerting a choice and 
of selecting the more highly-ornamented males, all the 
above facts become intelligible through the principle of 
sexual selection. On the other hand, if the females ha- 
bitually deposited and left their ova to be fertilized by the 
first male which chanced to appi'oach, this fact would be 

" 'The American Agriculturist,' 1868, p. 100. 
" ' Annals and Mag. of Nat. Hist.' Oct. 1852. 



Chap. XII.] FISHES. 15 

fatal to the efficiency of sexual selection; for tliere could 
be no choice of a partner. But, as far as is known, the 
female never willingly spawns except in the close presence 
of a male, and the male never fertilizes the ova except in 
the close presence of a female. It is obviously difficult to 
obtain direct evidence witli respect to female tislies select- 
ing their partners. An excellent observer," who carefully 
watched the spawning of minnows (C'/prhius phoxinus), 
remarks that owing to the males, which were ten times as 
numerous as the females, crowding closely round them, he 
could " speak only doubtfully on their operations. When 
a female came among a number of males they immediately 
pursued her ; if she was not ready for shedding her spawn, 
she made a precipitate retreat ; but if she was ready, she 
came boldly in among them, and was immediately pressed 
closely by a male on each side ; and when they had been 
in that situation a short time, were superseded by other 
two, who wedged themselves in between them and the 
female, who appeared to treat all her lovers with the same 
kindness." Notwithstanding this last statement, I can- 
not, from the several previous considerations, give up the 
belief that the males which are the most attractive to the 
females, from their brighter colors or other ornaments, 
are commonly preferred by them ; and that the males have 
thus been rendered more beautiful in the course of ages. 

We have next to inquire whether this view can be ex- 
tended, through the law of the equal transmission of char- 
acters to both sexes, to those groups in which the males 
and females are brilliant in the same or nearly the same 
degree and manner. In such a genus as Labrus, which 
includes some of the most splendid fishes in the world, for 
instance, the Peacock Labrus (X. pavo)y described," with 

»^ Loudon's 'Mag. of Nat. Hist.' vol. v. 1832, p. 681. 
'' Bory dc Saint-Vincent, in 'Diet. Class. d'Hist. Nat' torn. ix. 1826, 
p. 151. 



16 SEXUAL SELECTION. [Part H. 

pardonable exaggeration, as formed of jiolished scales of 
gold encrusting 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 ditt'er greatly in color. With some fishes, as with 
many of the lowest animals, sj)lendid colors may be the 
direct result of the nature of their tissues, and of the sur- 
rounding conditions, without any aid from selection. The 
golil-1\sh (Ct/prinus aurattis), judging from the analogy 
of the golden variety of the common carp, is, perhaps, a 
case in point, as it may owe its splendid colors to a single 
abruj)t variation, due to the conditions to which this fish 
has been subjected under confinement. It is, however, 
more probable that these colors have been intensified 
through artificial selection, as this species has been care- 
fully bred in China from a remote period." Under nat- 
ural conditions it does not seem probable that beings so 
highly organized as fishes, and which live under such com- 
plex relations, should become brilliantly colored without 
suttering some evil, or receiving some benefit, from so 
great a change, and consequently without the intervention 
of natural selection. 

AVhat, then, must we conclude in regard to the many 
fishes, both sexes of which are splendidly colored ? Mr. 
Wallace " believes that the species which frequent reefs, 

** Owing to some remarks on tliis 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 
encyclopaedias. He finds that gold-fish were first reared in confinement 
during the Sung Dynasty, which commenced a. d. 960. In the year 1129 
these fislies abounded. In another place it is said that since the year 
1548 there has been "produced at ILang-Chow a variety called the fire- 
fish, from its intensely red color. It is universally admired, and there Ls 
not a household where it is not cultivated, in rivalry as (o its color, and 
as a source of profit." 

" ' Westminster Review,' July, ISet, p. 7. 



Chap. XII.] FISHES. 17 

where corals and other brightly-colorcJ organisms ahound, 
■are In-iglitly colored in order to escape detection l)y tlieir 
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 or- 
ganisms for tlie fislies to resemble; yet many species in 
the Amazons are beautifully colored, and many of the car- 
nivorous Cyj)rinidaj in India are oi'namented with " bright 
longitudinal lines of various tints." "* Mr. McClelland, in 
descril)iiig 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 j^rey (as explained when treating of caterpillars) 
that they were unpalatable ; but it is not, I believe, 
known that any fish, at least any fresh-water fish, is re- 
jected from being distasteful to fisli-devouring animals. 
On the whole, the most probable view in regard to the 
fishes, of which both sexes are brilliantly colored, is that 
their colors have been acquired by the males as a sexual 
ornament, and have been transferred in an equal or nearly 
equal degree to the other sex. 

We have now to consider whether, when the male dif- 
fers in a marked manner from the female in color or in 
other ornaments, he alone has been modified, with the 
variations inherited only by his male oftspring; or whether 
tlie female has been specially modified and rendered incon- 
sjticuous for the sake of protection, such modifications be- 
ing inherited only by the females. It is iinj)Ossible to 

** " Indian Cyprinida?," by Mr. J. McClelland, * Asiatic Bcsearches,' 
vol. .\ix. part ii. 1839, p. 230. 



18 SEXUAL SELECTION. [Part IL 

doubt that color lias been acquired by many fishes as a 
protection : no one can behold the speckled upper surface 
of a flounder, and overlook its resemblance to the sandy 
bed of the sea on wliich it lives. One of the most striking 
instances ever recorded of an animal gaining protection 
by its color (as far as can be judged in preserved speci- 
mens) and by its form, is that given by Dr. Gilnther" of 
a pipe-iish, which, Avith its reddish streaming filaments, is 
hardly distinguishable from tlie sea-weed to which it 
clings with its prehensile tail. But the question now 
under consideration is, whether the females alone have 
been modified for this object. Fishes ofier valuable evi- 
dence on this head. We can see that one sex will not be 
modified through natural selection for the sake of protec- 
tion more than the other, supposing both to vary, unles^s 
one sex is exposed for a longer period to danger, or has 
less power of escaping from such danger than the other 
sex ; and it docs not appear that with fishes the sexes 
difler in these respects. As far as there is any difference, 
the males, from being generally of smaller size, 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 most conspicuously colored. 
The ova are fertilized immediately after being deposited, 
and when this process lasts for several days, as in the case 
of the salmoUj^" the female, during the whole time, is at- 
tended 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 concerned, 
are equally exposed to danger, and both are equally im- 
portant for the jjroduction of fertile ova ; consequently 
the more or less brightly-colored individuals of either sex 
would be equally liable to be destroyed or preserved, and 

S9 'Proc. Zoolog. Soc' 1865, p. 327, pis. xiv., xv. 
*" Yarrcll, 'British Fishes,' vol. il. p. 11. 



Chap. XI I.] FISHES. - 19 

botli would liiivc nil equal influence on the colors of their 
offspring or the race. 

Certain fishes, belonging to several families, make 
nests ; and some of these fishes take care of their young 
when hatched. Both sexes of the brightly-colored Creni- 
labi'us massa and rnclops work together in building their 
nests with sea-weed, shells, etc." But the males of cer- 
tain fishes do all the work, and afterward take exclusive 
charge of the young. This is the case Avith the dull-col- 
ored gobies," in wliich the sexes are not known to differ 
m color, and likewise with the stickleliacks (Gastcrosteus), 
in wliich the males become brilliantly colored during the 
spawning-season. The male of the smooth-tailed stickle- 
back ( G. leiurus) performs during a long time the duties 
of a nurse with exemplary care and vigilance, and is con- 
tinually 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 spe- 
cies. It would indeed be no small relief to the male if 
tlie female, after depositing her eggs, were immediately 
devoured by some enemy, for he is forced incessantly to 
drive her from the nest." 

The males of certain other fishes inhabiting South 
America and Ceylon, and belonging to two distinct or- 
ders, have the extraordinary habit of hatching the eggs 
laid by tlie females within their mouths or branchial cavi- 
ties." With the Amazonian species which follow this 
habit, the males, as I am informed by the kindness of 

" According to the observations of M. Gerbe ; see Giinther's ' Record 
of Zoolog. Litcniturc,' 1805, p. 194. 

a- Cuvicr, ' Regne Animal,' vol. ii. 1829, p. 242. 

"^ See Mr. Waiington's most interesting description of the habits of 
the Qasteroslcus Itlitrus, in 'Annals and Mag. of Nat. llist.' Nov. 1855. 

" Prof. Wyman, in ' Proc. Boston Soc. of Nat. Hist.' Sept. 15, 1857. 
Also, W. Turner, in 'Journal of Auatomy and Phys.' Nov. 1, 1866, p. 78. 
Dr. Gunther has likewise described other cases. 



20 SEXUAL SELECTION. [Pakt IL 

Prof. Agassiz, " not only are generally brighter than the 
females, but the difference is greater at the spawning-sea- 
son than at any otlier time." The species of Geopliagus 
act in the same manner ; and in this genus, a conspicuous 
protuberance becomes developed on the forehead of the 
males dui-ing the breeding-season. With the various spe- 
cies 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 Promotis does. It ought also to be 
observed that these sitters are among the brightest spe- 
cies in their respective families ; for instance, Hygrogonus 
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, 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 de- 
struction 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 these 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 hemispheri- 
cal depressions on the abdomen, in which the ova laid by 
the female are hatched. The males also show great at- 
tachment to their young." The sexes do not commonly 

«* Yarrell, ' Hist, of British Fishes,' vol. ii. 1836, pp. 329, 338. 



CiiAP. XII.] FISHES. 21 

differ miicli in color; but Dr. (Juntlier bclievos that the 
mule Hippocampi are rather brighter than the females. 
Tiie ijemis Solenostoma, however, otfers a very curious ex- 
ceptional case," for the female is much more vividly col- 
oreil and spotted than the male, and she alone has a mar- 
supial 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 
l»eing more brightly colored than the male. It is improb- 
able that this remarkable double inversion of character 
in till' female should be an accidental coincidence. As the 
males of several tishes which take exclusive cliarge of the 
eggs and young are more brightly colored than the fe- 
males, and as here the female Solenostoma takes the same 
charge and is brighter tlian the male, it might be argued 
that the conspicuous colors of the sex which is the most 
important of the two for the welfare of the offspring must 
serve, in some manner, as a protection. But from the 
multitude of fishes, the males of which are either perma- 
nently or periodically brighter than the females, but 
whose life is not at all more important than that of the 
female f(»r the welfare of the species, this view can hardly 
be maintained. When we treat of birds we shall meet 
with analogous cases in which there has been a complete 
inversion of the usual attributes of the two sexes, and we 
shall then give what appears to be the probable explana- 
tion, namely, that the males have selected the more at- 
tractive females, instead of the latter having selected, in 
accordance with the usual rule throughout the animal 
kingdom, tlie more attractive males. 

On the whole, we may conclude thai, with most fishes, 
in which the sexes differ in color or in other ornamental 

** Dr. <}iintlicr, since piibli.-^hing an account of tliis .species in 'The 
Fishes of Zanzibar,' by Colonel I'layfair, 1800, p. 137, has reexamined 
the specimens, and has given me the above information. 



22 SEXUAL SELECTION. [Part IL 

characters, the males originally varied, with their varia- 
tions transmitted to the same sex, and accumulated 
through sexual selection by attracting or exciting the fe- 
males. In many cases, however, such characters have 
been transferred, either partially or completely, to the 
females. In other cases, again, both sexes have been col- 
ored alike for the sake of protection ; but in no instance 
does it appear that the female alone has had her colors or 
other characters specially modified for this purpose. 

The last point which need be noticed is that in many 
parts of the world fishes are known to make peculiar 
noises, which are described in some cases as being musi- 
cal. Very little has been ascertained with respect to the 
means by which such sounds are produced, and even less 
about their jjurpose. The drumming of the Umbrinas in 
the Europeain seas is said to be audible from a depth of 
twenty fathoms. The fishermen 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 with- 
out bait." " If this statement is trustworthy, we have an 
instance in this, the lowest class of the Vertcbrata, of 
what we shall find prevailing throughout the other verte- 
bi'ate classes, and which prevails, as we have already seen, 
with insects and spiders ; namely, that vocal and instru- 
mental sounds so commonly serve as a love-call or as a 
love-charm, that the power of producing them was proba- 
bly first developed in connection with liie propagation of 
the species. 

Amphibians. 

TIrodela. — First for the tailed amphibians. The sexes 
of salamanders or newts often difter much both in color 
and structure. In some species prehensile claws are de- 
veloped on the fore-legs of the males during the breeding- 
s'" Tlic Rev. C. Kingsley, in 'Nature,' Ma.v, ISVO, p. 40. 



Chap. XII.] 



AMPHIBIANS. 



23 



season ; and at this season in the male Triton palmipes 
the hind-feet are provided with a swimming web, which is 
almost comiiletely absorbed during the winter; so that 
their feet then resemble those of the female.'* This struct- 




FiG. 31.— Triton cristatiis (half natural eize, from Bell's 'British Eeptiles'). 
Upper figure, male during the breeding-season ; lower figure, female. 

ure no doubt aids the male in his eager search and pursuit 
of the female. With our common newts {Triton lyunc- 
tatus and cristatus) a deep, much indented crest is devel- 
oped along the back and tail of the male during the breed- 
ing-season, being absorbed during the winter. It is not 
furnished, as Mr. St. George Mivart informs me, with 
muscles, and therefore cannot be used for locomotion. 
As during the season of courtship it becomes edged with 
bright colors, it serves, there can hardly be a doubt, as a 
masculine ornament. In many species the body presents 
strongly-contrasted though lurid tints ; and these become 
more vivid during the breeding-season. The male, for 
instance, of our common little newt {Triton x>unctatus) is 
" brownish gray above, passing into yellow beneath, which 

33 Bell, "History of British Reptiles," 2d edit. 1849, pp. 156-159. 



24 SEXUAL SELECTION. [Part IL 

in tlic spring Lecomcs a I'icli bright orange, marked evcry- 
"wliere with round dark spots." The edge of the crest 
also is then tipped with V)riglit 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 
acquired their strongly-marked colors and ornamental ap- 
pendages through sexual selection ; these being trans- 
mitted either to the male oft'spring alone or to both sexes. 
A?mra or JBatrachia. — With many frogs and toads 
the colors evidently serve as a protection, such as the 
bright-green tints of tree-frogs and the obscure mot- 
tled shades of many terrestrial species. The most con- 
spicuously-colored toad which I ever saw, iiamely, the 
l^hryniscKS nigricans,*" had the whole upjior 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 may be 
beneficial by making this toad known to all birds of prey 
as a nauseous mouthful ; for it is familiar to every one 
that these animals emit a poisonous secretion, which 
causes the mouth of a dog to froth, as if attacked by hy- 
drophobia. I was the more struck with the conspicuous 
colors of this toad, as close by I found a lizard [Proctotre- 
tus multimaculatvs) which, Avhen frightened, flattened its 
body, closed its eyes, and then from its mottled tints 
could hardly be distinguishable fioiu the sun-ounding 
sand. 

3» Bell, ibid. pp. 14G, 151. 

*" ' Zoology of the Voyage of the " Beagle," ' 1843. " Reptiles," by 
Mr. Bell, p. 49. 



Chap. XII.] AMPHIBIANS. 35 

With respect to sexual differences of color, Dr. Giin- 
ther knows of no striking instance 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 Dr. Gtinther know of any striking difference in ex- 
ternal structure between tlie sexes, excepting the promi- 
nences which become developed during the breeding-sea- 
son on the front-legs of the male, by which he is enabled 
to hold the female. The Megalophrys montana'^^ (Fig. 
32) offers the best case of a certain amount of structural 
difference between the sexes ; for in the male the tip of the 
nose and the eyelids aro produced into triangular flaps of 
skin, and there is- a little black tubercle on the back — 
characters which are absent, or only feebly developed, in 
the females. It is surprising that frogs and toads should 
not have acquired more strongly-marked sexual differ- 
ences ; for, though cold blooded, their passions are strong. 
Dr. Gtinther informs me that he has several times found 
an unfortunate female toad dead and smothered from hav- 
ing been so closely embraced ly three or four males. 

These animals, however, offer one interesting sexual 
difference, namely, in the musical powers possessed by the 
males ; but to speak of music, when applied to the discord- 
ant and overwhelming sounds emitted by male bull-frogs 
and some other species, seems, according to our taste, a 
singularly inapprojjriate expression. Nevertheless certain 
frogs sing in a decidedly pleasing manner. Near Rio de 
Janeiro I used often to sit in the evening to listen to a 
number of little Hylse, which, perched on blades of grass 
close to the water, sent forth sweet chirping notes in har- 
mony. The various sounds are emitted chiefly by the 
males durmg the breeding-season, as in the case of the 
croaking of our common frog." In accordance with this 

41 'The Reptiles of India,' by Dr. A. Giinther, Ray Soc. 1864, p. 413. 

42 Bell, 'History of Britis.^ Reptile?,' 1849, p. 93. 

21 



26 



SRXUAL SELECTION. 



[Pakt II. 



fact the vocal organs of the males are more highly de- 
veloped than those of the females. In some genera the 
males alotoe are provided with sacs wliich open into the 
larynx." For instance, in the edible frog {Rana esculen- 
ta) " the sacs are peculiar to the male.^, and become, when 
filled with air in tlio act of croaking, large globular blad- 





Fio. .32.— Mcgalophrys TOontana. The two left-band flares, the male; the two 
right-hand figures, the female. 

ders, 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." The vocal organs differ 
considerably in structure in the several genera of the 
family ; and their development in all cases may be attrib- 
uted to sexual selection. 

Reptiles. 
Chelonia. — Tortoises and turtles do not ' offer well- 
marked sexual differences. In some species, the tail of 

*■> .1. Hishop, in ' Toild's Cyclop, of An;it. and Thys.' vol. iv. p. 1503. 
« Bell, ibid. pp. 112-114. 



Chap. XII.J REPTILES. 37 

tlie male is longer than that of the female. In some, the 
plastron or lower surface of the shell of the male is slight- 
ly 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 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.^° 

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 prodi 
gious display before the females. Bartram*^ describes the 
male alligator as striving to win the female by splashing 
and roaring in the midst of a lagoon, " swollen to an ex- 
tent ready to burst, with his head and tail lifted up, he 
spins or twirls round on the surface of the water, like an 
Indian chief rehearsing his feats of war." During the sea- 
son of love, a musky odor is emitted by the submaxillary 
glands of the crocodile, and pervades their haunts." 

Ophidia. — I have little to say about Snakes. Dr. 
Gtinther 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, Di-. Gilnther can almost al- 
ways distinguish the male from the female \)j his more 

*^ Mr. C. J. Maynard, ' The American Naturalist,' Dec. 1869, p. 555. 
*^ See my ' Journal of Researches during the Yoyage of the " Bea- 
gle," ' 1845, p. 384. 

« 'Travels through Carolina,' etc., 1Y91, p. 128. 

*^ Owen, ' Anatomy of Vertebrates,' vol. i. 1866, p. 615. 



28 SEXUAL SELECTION. [Part II. 

strongly-pronounced tints ; thus tlie black zigzag band on 
the back of the male English viper is more distinctly de- 
fined than in the female. The difference is much plainer 
in the Rattlesnakes of North America, the male of Avhich, 
as the kee2)er in the Zoological Gardens showed me, can 
instantly be distinguished from the female by having more 
lurid yellow about its whole body. In South Africa the 
Ut(cephalus capensis presents an analogous difference, for 
the female " is never so fully A-ariegated with yellow on 
the sides, as the male." " The male of the Indian Dtpsas 
cynodon^ 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 serve as a protection, 
as the green tints of tree-snakes and the various mottled 
shades of the species which live in sandy places ; biit it is 
doubtful whether the colors of many kinds, for instance 
of the common English snake or viper, serve to conceal 
them ; and this is still more doubtful with the many for- 
eign species which are colored with extreme elegance. 

During the breeding-season their anal scent-glands are 
in active function ; " 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 

« Sir Andrew Smith, ' Zoolog. of South Africa: Ileptilia,' 1849, pi. x. 

'0 Dr. A. Giiiither, 'Reptiles of British India,' Ray Soc. 18C4, pp. 304, 
308. 

" Owen, 'Anatomy of Vertebrates,' vol. i. 1806, p. 615. 

"Till" celebrated botanist Schleiden incidentally lemarks ('Uebei 
den Darwinismus : Insere Zeit,' I860, s. 269), that Rattlesnakes use 



Chap. XII.] REPTILES. 29 

appearing so sluggish, are amorous ; for many have been 
observed crowding round the same female, and even round 
the dead body of a female. They are not known to fight 
together from rivalry. Their intellectual powers are higli- 
er than might have been anticipated, ^n excellent ob- 
server in Ceylon, Mr, E. Layard,^^ saw a Cobra thrust its 
head through a narrow hole and swallow a toad. " With 
this encumbrance he could not witlidraw himself; finding 
this, he reluctantly disgorged the precious morsel, which 
began to move olF; this was too much for snake philoso- 
phy 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." 

It does not, however, follow because snakes have some 
reasoning power and strong passions, that they should 
likewise be endowed Avitli sufficient taste to admire bril- 
liant colors in their partners, so as to lead to the adorn- 
ment of the species through sexual selection. Neverthe- 
less, 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. Giinther," are found nowhere else in 

their rattles as a sexual call, by which the two sexes find each other. I 
do not know whether this suggestion rests on any direct observations. 
These snakes pair in the Zoological Gardens, but the keepers have never 
observed that they use their rattles at this season more than at any 
other. 

*^ " Rambles in Ceylon," ' Annals and Mag. of Nat. Hist.' 2d series 
vol. ix. 1852, p. 333. 

" ' Westminster Review,' July 1, 1867, p. 32. 



30 SEXUAL SELECTION. [Paut IL 

the world except in South America, and liere no less than 
four genera occur. One of these, Elaps, is venomous ; a 
second and widely-distinct genus is doubtfully venomous, 
and the two others are quite harmless. The species be- 
longing to these distinct genera inhabit tlie 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 Ijelieves, the innocuous kinds have 
probably acquired their colors as a protection, on the 
principle of imitation; for they would naturally be 
thought dangerous by their enemies. The cause, how- 
ever, of the bright colors of the venomous Elaps remains 
to be explained, and this may perhaps be sexual selection. 

Lacertilia. — The males of some, pi-obably of many 
kinds of lizards, fight together from rivalry. Thus the 
arboreal Anolis cristatellus of South America is extremely 
pugnacious : " 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, 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 
combatants 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. Gilnther has 
been able to ascertain, is the general rule with lizards of 
all kinds. 

The sexes often difter greatly in various external char- 
acters. The male of the above-mentioned Anolis is fur- 

" Mr. N. L. Austen kept these aniraals alive for a cousiderabic thue ; 
sec ' Liuid and Water,' July, 18G7, p. 9. 



Chap. XII.] 



REPTILES. 



31 



nishecl with a crest, which runs along tlie back and tail, 
and can be erected at pleasui'e ; but of this crest the female 
does not exhibit a trace. In the Indian Cophotis ceylanica, 
the female possesses a dorsal crest, though much less de- 
veloj)ed than in the male ; and so it is, as Dr. Giinther in- 
forms 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 tubercu- 
lata. In tlie genus Sitana, the males alone ai'e furnished 
with a large throat-pouch (Fig. 33), which can be folded 
up like a fan, and is colored blue, black, and red; but 
these splendid colors are exhibited only during the pair- 
ing-season. The female does not possess even a rudiment 
of this appendage. In the Anolls cristatellus, according 
to Mr. Austen, the throat-pouch, which is bright red mar- 
bled with yellow, is present, though in a rudimental con- 
dition, in the female. Again, in certain other lizards, both 
sexes are equally well provided with throat-pouches. Here, 
as in so many previous 
cases, we see, with species 
belonging to the same 
group, the same character 
confined to the males, or 
more largely developed in 
the males than in the fe- 
males, or 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 gallinaceous birds." These be- 
come erected when the animal is excited. They occur in 
both sexes, but are best developed in the male when ar- 




FiG. 33. — Sitana minor. Male, with tlie 
gular pouch expanded (from Gun- 
ther's 'Keptiles of India'). 



33 



SEXUAL SELECTION. 



[Part II. 



rived at maturity, at whicli age the middle appendage is 
Bometimes twice as long as the liead. ISIost of the species 
likewise have a low crest running along the neck ; and this 
is much more developed in the fuli-grown males than in 
the females or young male?." 

There are other and much more remarkable differences 
between the sexes of certain lizai'd^;. The male of Cerato- 
j)l(ora 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 terminal scale forms a minute 
horn on the summit of the flexible appendage ; and in a 
third species ( C. Stoddartif, Fig. 34), the whole api)cnd- 

age is converted into a horn, 
which is usually of a white color, 
but assumes apur])lish tint when 
the animal is excited. In the 
adult male of this latter species 
the horn is half an inch in length, 
but is of quite minute size in the 
female and in the young. These 
appendages, as Dr. Gunther has 
remarked to me, may be com- 
pared with the combs of galli- 
naceous birds, and apparently 
serve as ornaments. 

In the genus Chama^leon 
we come to the climax of dil- 
ference between the sexes. The v.]i])vt ]iart of the skull 
of the male C. hifurcus (Fig. 35), an inhabitant of ]Mada- 

'« All these statements and quotations, in regard to Cophotis, Fitana, 
and Draco, as well as the followinfi facts in regard to Ceratophora, arc 
taken from Dr. Gunther's magnificent work on the 'Rc^itiles of British 
India,' Ray Soc. 1864, pp. 122, 130, 135. 




Fig. 34.— Ccrntophora Stoddartii. 
Upper figure, male ; lower 
figure, female. 



Chap. XII.] 



REPTILES. 



33 



gascar, is produced into two great, solid, bony projec- 
tions, covered with scales like the rest of the head ; and 
of this wonderful modification of structure the female ex- 
hibits only a rudiment. Again, in Chamceleon Owenii 
(Fig. 36), from the West Coast of Africa, the male bears 




Fig. 35. — Chamseleon bifurcus. Upper figuie, male ; lower figure, female. 



on his snout and forehead three curious horns, of which 
the female has not a trace. These horns consist of an ex- 
crescence of bone covered with a smooth sheath, forming 
part of the general integuments of the body, so that they 
are identical in structure with those of a bull, goat, or 
other sheath-horned ruminant. Althouo;h the three horns 



34 



SEXUAL SELECTION. 



[Part IL 



differ so mucli in appearance from the two great prolon- 
gations of the skull in C. bifurcus^ 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; but Dr. GUnther, to whom I am in- 
debted for the foregoing details, does not believe that 
such peaceable creatures would ever become pugnacious. 

Hence we are 
driven to infer 
tliat these almost 
monstrous devia- 
tions of structure 
serve as mascu- 
line ornaments. 

With many 
kinds of lizards, 
the sexes differ 
slightly in color, 
the tints and 
stripes of the 
males being 

Fia. 36.— Chamaelcon Owenii. Upper figure, male ; brighter and 
lower figure, female. '^ -,• . 

more distinctly 
defined than in the females. This, for instance, is 
the case with the previously-mentioned Cophotis and 
"with the Acanthodactylus cajyensis of South Africa. 
In a Cordylus of the latter coimtry, the male is either 
much redder or greener than the female. In the Indian 
Calotes nigrilahris there is a greater difference in color 
between the sexes ; the lips also of the male are black, 
while those of the female are green. In our common little 
vivij>arous lizard [Zootoca tu'vipara), " the umlcr side of 
the body and base of the tail in the male are bright 
orange, spotted with black ; in the female these parts are 




Chap. XII.] REPTILES. 35 

pale grayish-green without spots." " We have seen that 
the males alone of Sitana possess a throat-pouch ; and this 
is splendidly tinted witli blue, black, and red. In the 
Proctotretus tenuis of Chili the male alone is mai'ked with 
spots of blue, green, and coppery-red.^^ I collected in 
South America fourteen species of this genus, and though 
I neglected to record the sexes, I observed that certain 
individuals alone were marked with emerald-like green 
spots, while others had orange-colored gorges ; and these 
in both cases no doubt were the males. 

In the foregoing species, the males are more brightly 
colored than the females, but with many lizards both 
sexes are colored in the same elegant or even magnificent 
manner; and there is no reason to suj^pose that such con- 
spicuous colors are protective. With some lizards, how- 
ever, the green tints no doubt serve for concealment ; and 
an instance has already been incidently given of one 
species of Proctotretus which closely resembles the sand 
on which it lives. On the whole we may conclude with 
tolerable safety that the beautiful colors of many lizards, 
as well as various appendages and other strange modi- 
fications of structure, have been gained by the males 
through sexual selection for the sake of ornament, and 
have been transmitted either to their male oft'spring alone 
or to both sexes. Sexual selection, indeed, seems to have 
played almost as important a part with reptiles as with 
birds. But the less conspicuous colors of the females in 
comparison with those of the males cannot be accounted 
for, as Mr. Wallace believes to be the case with birds, by 
the exposure of the females to danger during incubation. 

s'' Bell, 'History of British Reptiles,' 2d edit. 1849, p. 40. 

5S por Proctotretus see 'Zoology of the Voyage of the "Beagle:" 
Reptiles,' by Mr. Bell, p. 8. For the Lizards of South Africa, see ' Zool- 
ogy of South Africa : Reptiles,' by Sir Andrew Smith, pis. 25, 39. 
For the Indian Calotes, see ' Reptiles of British India,' by Dr. Giinther, 
p. 143. 



36 SEXUAL SELECTION. [Pakt U. 



CHAPTER XIII. 

Second AKY Sexual Characters of Birds. 

Sexual Differences. — Law of Battle. — Special Weapons. — Vocal Organs. — 
Instrumental Music. — Love-Antics and Dances.— Decorations, Penna- 
nent and Seasonal. — Double and Single Annual Moults. — Display of 
Ornaments by the Males. 

Secondary sexual characters are more divei-sified 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, pos- 
sess special weapons for fighting with each other. They 
charm the females by vocal or instrumental music of the 
most varied kinds. They are ornamented by all sorts of 
combs, wattles, protuberances, horns, air-distended sacs, 
topknots, naked shafts, plumes and lengthened feathers 
gracefully springing from all parts of the body. The 
beak and naked skin about the head and the feathers are 
often gorgeously colored. 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 observ- 
er, Mr. Kanisay,' says of the Australian musk-duck [Jiizi- 
ura lohata) that " the smell which the mule emits during 
the summer months is confined to that sex, and in some 
individuals is retained througliotit the year; I have never, 
even in the breeding-season, shot a female Avhich had any 

' ' Ibis,' vol. ill. (new series) 18G7, p. 414. 



Chap. XIIL] BIRDS. 37 

smell of musk." So powerful Is this odor during the pair- 
ing-season, that it can be detected long before the bird 
can be seen." On the whole, birds appear to be the most 
aesthetic of all animals, excepting of course man, and they 
have nearly the same taste for the beautiful as we have. 
This is shown by our 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. 

Before treating of the characters with which we are 
here more particulafly concerned, I may just allude to 
certain diiFei*ences between the sexes which apparently 
depend on differences in their habits of life ; for such 
cases, though conamon 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 sexes of the 
same species, and they differ slightly in the form of the 
beak. In another genus of humming-birds [Grt/piis), 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 curious Neomorpha of New Zealand, 
there is a still wider difference in the form of the beak ; 
and Mr. Gould has been informed that the male with his 
" straight and stout beak " tears off the bark of trees, in 
order that the female may feed on the uncovered larvfe 
with her weaker and more curved beak. Something of 
the same kind may be observed with our goldfinch ( Car- 
duelis elegmis), for I am assured by Mr. J. Jenner Weir 
that the bird-catchers can distinguish the males by their 
slightly longer beaks. The flocks of males, as an old and 
trustworthy bird-catcher asserted, are commonly found 

2 Gould, ' Hand-book to the Birds of Australia,' 18C5, vol. ii. p. 383. 



38 SEXUAL SELECTION: BIRDS. [Part I L 

feeding on tl)e seeds of the teazle (Dipsaciis) which they 
can reach with their elongated beaks, while the females 
more commonly feed on the seeds of the betony or 
Scrophularia. With a slight diiference of this nature as 
a foundation, we can see how the beaks of the two sexes 
might be made to difter greatly through natural selection. 
In all these cases, however, especially in that of the quar- 
relsome humming-birds, it is possible that the differences 
in the beaks may have been first acquired by the males in 
relation to their battles, and afterward led to slightly 
changed habits of life. 

Law of J^attle. — 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 
sparrows. The smallest of all birds, namely, the hum- 
ming-bird, is one of the most quarrelsome. Mr. Gosse ^ 
describes a battle, in which a pair of humming-birds 
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, says that two males 
rarely meet Avithout 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 feed." * With Waders, the males 
of the common water-hen [Gallinida chloropus) "when 
pairing, fight violently for the females : they stand nearly 
upright in the water and strike with their feet." Two 
were seen to be thus engaged for half an hour, imtil 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.^ The males of an allied 

3 Quoted l>y Mr. Gould, ' Introduction to the Trochilidae,' 1861, p. 29. 

* Gould, ibid. p. 52. 

' W. Thompson, ' Nat. Hist, of Ireland : Birds,' vol. ii. 1850, p. 327. 



Chap. XIII.J LAW OF BATTLE. 39 

bird {Gallicrex cristatus), as Mr. Blyth informs me, are 
one-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 same pur- 
pose, for instance, the Bulbuls [Pycnonotus hcBmorrhous) 
which " fight with great spirit." * 

The polygamous Ruif {^Machetes pugnax. Fig. 37) is 
notorious for his extreme pugnacity ; and in the spring, 
the males, which ai'e considerably larger than the females, 
congregate 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 bare. 
Here they fight very much like game-cocks, seizing each 
other with their beaks and striking with their wings. The 
great rufl^" of feathers round the neck is then erected, and 
according to Colonel 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 rufi" of feathers, how- 
ever, from its varied and rich colors pi-obably 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 Montagu observed that their 
pugnacity becomes greater during the sprmg, when the 
long feathers on their necks are fully developed ; and at 
this'period the least movement by any one bird provokes 
a general battle.' Of the pugnacity of web-footed birds, 
two instances will suffice : in Guiana " bloody fights occur 
during the breeding-season between the males of the wild 
musk-duck ( Gairina moschata) ; and where these fights 
have occurred the river is covered for some distance with 

* Jerdon, 'Birds of India,' 1863, vol. ii. p. 96 

' Macgillivray, ' Hist. Brit. Birds,' vol. iv. 1852, pp. I'Z'T-lSl. 



} 



40 



SEXUAL SELECTION: BIRDS. 



[Pakt II 



feathers." * Birds which seem ill-adapted for fighting en- 
gage in fierce conflicts ; thus with the pelican the stronger 




* Sir R. Schomburgk, in ' Journal of R. Geograph. Soc' vol. xiii. 
1843, p. 31. 



Chap. XIII.] LAW OF BATTLE. 41 

males drive away the weaker ones, snapping with their 
huge beaks and giving heavy blows with their wings. 
Male snipes fight together, "tugging and pushing each 
other with their bills in the most curious manner miagi- 
nable." Some few species are believed never to fight ; this 
is the case, according to Audubon, with one of the wood- 
peckers of the United States {Picus auratus), although 
" the hens are followed by even half a dozen of their gay 
suitors." ' 

The males of many birds are larger than the females, 
and this no doubt is an advantage to them in their bat- 
tles with their rivals, and has been gained through sexiial 
selection. The diiference 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 Cinclo- 
ramphus cruralis (allied to our pipits) are by measure- 
ment actually twice as large as their respective females.'" 
With many other bii'ds 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 ac- 
quired 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 
for fighting with their rivals, namely spurs, which can be 
used with fearful eifect. It has been recorded by a trust- 
worthy writer" that in Derbyshire a kite struck at a 

* ' Ornithological Biography,' vol. i. p. 191. For pelicans and snipes, 
see vol. iii. pp. 381, 4*77. 

"* Gould, ' Hand-book of Birds of Australia,' vol. i. p. 395 ; vol. ii. p. 
383. 

" Mr. Hewitt m the ' Poultry Book by Tegetmeier,' 1866, p. 137. 



42 SEXUAL SELECTION: BIHDS. [Part IL 

gamc-hcn accompanie<l by her cliickons, wlicn the cock 
rushed to the rescue and drove his spur right through the 
eye and skull of the aggressor. The spur -was with diffi- 
culty drawn from the skull, and as the kite though dead 
retained liis grasp, the two birds were firmly locked to- 
gether ; but the cock when disentangled was very little 
injured. The invincible courage of the game-cock is noto- 
rious : a gentleman who long ago witnessed the following 
brutal scene, told me that a bird had both its legs broken 
by some accident in the cockpit, and the owner laid a 
wager that if the legs could be spliced so that the bird 
could stand upright, he w^ould continue fighting. This 
w^as effected on the spot, and the bird fought with un- 
daunted courage until he received his death-stroke. In 
Ceylon a closely-allied and wild species, the Gallus Stan- 
leyi, is known to fight desperately "in defence of his 
seraglio," so that one of the combatants is frequently 
found dead." An Indian yiavtridge (Orfi/(/or}iis gidaris), 
the male of which is furnished with strong and sharp 
spurs, is so quarrelsome, " that the scars of former fights 
disfigure the breast of almost every bird you kill." " 

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 
Blackcock {Tetrao ^irogallvs and T. tetri.r), which are 
both polygamists, have regular ai)pointed places, where 
during many weeks they congregate in numbers to fight 
together and to display their charms before the females. 
M. W, Kowalevsky informs me that in Russia he has seen 
the snow all bloody on the arenas where the Capercailzie 
have fought ; and the Blackcocks "make the feathers fly 
in every direction," when several "engage in a battle 
royal." The elder Brehm gives a curious account of the 

'* Layard, 'Annals and Mag. of Nat. Hist.' vol. xiv. 1851, p. 63. 
'^ Jcrdon, ' Birds of hulia,' vol. iii. p. 574. 



Chap. XIII.] LAW OF BATTLE. 43 

Balz, as the love-dance and love-song of the Blackcock is 
called in Germany. The bird utters almost continuously 
the most strange noises : " He holds his tail up and spreads 
it out like a fan, he lifts up his head and neck with all the 
feathers erect, and stretches his wings from the body. 
Then he takes a few jumps in different directions, some- 
times in a circle, and presses the under part of his beak so 
hard against the ground that the chin-feathers are rubbed 
off. During these movements he beats his wings and 
turns round and round. The more ardent he grows the 
more lively he becomes, vintil at last the bird appears like 
a frantic creature." At such times the blackcocks 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 fight : 
and the same blackcock, in order to prove his strength 
over several antagonists, will visit in the course of one 
morning several Balz-places, which remain the same dur- 
ing 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. W. Darwin Fox informs me that two 
peacocks became so excited while fighting at some little 
distance from Chester, that they flew over the wliole city, 
still fighting, until they alighted on the top of St. John's 
tower. 

The spur, in those gallinaceous birds which are thus 
provided, is generally single ; but Polyplectron (see Fig. 51, 
p. 90) has two or more on each leg ; and one of the Blood 
pheasants {Ithaginis cruentus) has been seen with five 
spurs. The spurs are generally confined to the male, be- 

•* Brehm, 'Illust. Thierleben,' ISGY, B. iv. s. 351. Some of the fore- 
going statements are taken from L. Lloyd, 'The Game-Birds of Sweden,' 
etc., 1867, p. 79. 



44 SEXUAL SELECTION : BIRDS. [Part II. 

ing represented by mere knobs or rudiments in the female ; 
but the females of the Java peacock {Pavo rmiticiis) and, 
as I am informed by Mr. Blyth, of the small fire-backed 
j)hcasant {^Eiqolocainus erythrojjthahnns) possess spurs. 
In Gallopordix it is usual for the males to have two spurs, 
and for the females to have only one on each leg." Hence 
spurs may safely be considered as a masculine character, 
though occasionally transferred in a greater or less degree 
to the females. Like most other secondary sexual charac- 
ters, the spurs are highly variable both in number and de- 
velopment in the same species. 

Various birds have spurs on their wings. But the 
Egyptian goose ( Chenalopex ^gyptiacus) has only " bare 
obtuse knobs," and these jirobably show us the first steps 
by which true spurs have been developed in other allied 
birds. In the spur-winged goose {Plectropterus gamben- 
sis), the males have much larger spurs than the females ; 
and they use them, as I am informed by Mr. Bartlett, in 
fighting together, so that, in this case, the wing-spurs serve 
as sexual weapons ; but according to Livingstone, they are 
chiefly used in the defence of the young. The Palamedea 
(Fig. 38) is armed with a pair of spurs on each wing ; and 
these are such formidable weapons that a single blow has 
driven 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 cer- 
tain plovers, however, the wing- spurs must be considered 
as a sexual character. Thus in the male of om- common 
peewit ( Vatiellus cristatus) the tubercle on the shoulder 

'* Jerdon, 'Birds of India:' on Ithagini.^, vol. iii. p. 523; on Gallo- 
perdix, p. 541. 

'"For the Egyptian goose, see Macgillivray, 'British Birds,' vol. iv. 
p. 639. For Plectropterus, ' Livingstone's Travels,' p. 254. For Pala- 
medea, Brehm's ' Thierlcbcn,' B. iv. s. 740. See also on this bird Azara^ 
' Voyages dans I'Am^rique in6rid.' torn. iv. 1809, pp. 179, 263. 



Chap. XIII.] 



LAW OF BATTLE. 



45 



of the wing becomes more prominent during the breeding- 
season, and the males are known to fight together. In 







Fig. 38.— Palamedea cornuta (from Brehm), showing the dooble-wing-Bpiirs, 
and the filament on the head. 



46 SEXUAL SELECTION: BIRDS. [Part IL 

some species of Lol)ivanellus a similar tubercle becomes 
developed during the breeding-season " into a short horny 
spur." In the Australian L. lobatus both sexes have spurs, 
but these are much larger in the males than in the females. 
In an allied bird, the Iloplopterus armatus, the spurs do not 
increase in size during the breeding-season ; but these birds 
have been seen in Egypt to light together, in the same 
manner as our peewits, by turning suddenly in the air and 
striking sideways at each other, sometimes with a fatal 
result. Thus also they drive away other enemies." 

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," are ready 
to fight whenever they meet. The jiresence of the female 
is the teterrima belli causa. The Bengali baboos make the 
pretty little males of the amadavat [lUstrelda amandava) 
fight together by placing three small cages in a row, with 
a female in the middle ; after a little time the two males 
are turned loose, and immediately a desperate battle en- 
sues." When many males congregate at the same ap- 
pointed spot and fight together, as in the case of grouse 
and various other birds, they are generally attended by 
the females,"" which afterward pair with the victorious 

" See, on our peewit, Mr. R. Carr in ' Land and Water,' Aug. 8, 
1868, p. 46. In regard to Lobivanellus, see Jei"don's 'Birds of India,' 
vol. iii. p. 647, and Gould's ' Hand-book of Birds of Australia,' vol. ii. p. 
220. For the Iloplopterus, see Mr. Allen in the 'Ibis,' vol. v. 1863, 
p. 156. 

'* Audubon, 'Ornith. Biography,' vol. ii. p. 492; vol. i. pp. 4-13. 

'» Mr. Blyth, 'Land and Water,' 1867, p. 212. 

'" Richardson, on Tetrao umbellus, 'Fauna Bor. Amer. : Birds,' 1831, 
p. 343. L. Lloyd, 'Game-Birds of Sweden,' 1857, pp. 22, 7'.), on the 
capercailzie and blackcock. Brehm, however, asserts ('Tliierleben,* 
etc., B. iv. s. 352) that in Germany the gray-hens do not generally attend 
the Balzen of the blao'keocks, but this is an exception to the common 
rule ; possibly the hen^ »»ay lie hidden in the surrounding bushes, as is 



Chap. XIII.] LAW OF BATTLE. 47 

combatants. But in some cases the pairing precedes in- 
stead of succeeding the combat : thus, according to Audu- 
bon,^^ several males of the Virginian goat-sucker ( Caprl- 
mulgus Virginiayius) "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 with all their power to drive away or kill their 
rivals before they pair. It does not, however, appear that 
the females invariably prefer the victorious males. I have 
indeed been assured by M. W. Kowalevsky that the female 
capercailzie sometimes steals away with a young male who 
has not dared to enter the arena with the older cocks ; in 
the same manner as occasionally hajjpens with the does 
of the red-deer in Scotland. When two males contend in 
presence of a single female, the victor, no doubt,- common- 
ly gains his desire ; but some of these battles are caused 
by wandering males trying to distract the peace of an al- 
ready mated pair.^^ 

Even with the most pugnacious species it is probable 
that the pairing does not depend exclusively on the mere 
strength and coui'age of the male : for such males are gen- 
erally decorated with various ornaments, which often 
become more brilliant during the breeding-season, and 
which are sedulously displayed before the females. The 
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 prob- 
able that the females are indifferent to the charms of the 
opposite sex, or that they are invariably compelled to 

known to be the case with the gray-hens in Scandinavia, and with other 
species in North America. 

^' ' Ornithological Biography,' vol. ii. p. 2*75. 

22 Brehm, ' Thierleben,' etc., B. iv. ISC'?, p. 990. Audubon, 'Ornith. 
Biography,' vol. ii. p. 492. 



48 SEXUAL SELECTION: BIRDS. [Part IL 

yield to the victorious males. It is more probable that 
tlic females are excited, either before or after the conflict, 
by certain males, and thus unconsciously prefer them. In 
the case of Tctrao umhellas, 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 who 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 
cupido of the United States, about a score of males assem- 
ble 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 {Stumella 
ludoviciana) the males engage in fierce conflicts, " but at 
the sight of a female they all fly after her as if mad." "* 

Vocal and Instniinental Music. — With birds the voice 
serves to express various emotions, such as distress, fear, 
anger, triumph, or mere happiness. It is a])parently 
sometimes used to excite terror, as with the hissing noise 
made by some nestling birds. Audubon '* relates that a 
night-heron {Ardea nycticorax, Linn.), which he kept 
tame, used to hide itself when a cat approached, and then 
" suddenly start \ip uttering one of the most frightful cries, 
apparently enjoying the cat's alarm and fliglit." The 

«3 ' Land and Water,' July 25, 1868, p. 14. 

'^^ Audubon's ' Ornitliolop. Biography ; ' on Tetrao cupido, vol. ii. p. 
492; on the Stumus, vol. ii. p. 219. 

** ' Oniitbological Biography,' vol. v. p. GOl. 



Chap. XIII.] VOCAL MUSIC. ' 49 

common domestic cock clucks to the hen, and the hen to 
her chickens, when a dainty morsel is 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 they flit from tree to tree, the flock is kept 
together by chirp answering chirp. During the noctur- 
nal migrations of geese and other water-fowl, sonorous 
clangs from the van may be heard in the darkness over- 
head, answered by clangs in the rear. Certain cries 
serve as danger-signals, which, as the sportsman knows to 
his cost, are well 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, 
however, 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 the " 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 knoAVS, and repairs to the spot to choose her mate." ^^ 
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." ^' There can be no doubt that 

2^ The Eon. Daines Barrington, 'Philosoph. Transact.' 1773, p. 252. 
^T 'Ornithological Dictionary,' 1833, p. 475. 

^* ' Naturgeschichte der Stubenvogel,' 1840, s. 4. Mr. Harrison Weir 
3 



50 SEXUAL SELECTION: BIRDS. [Part IL 

birds closely attend to each otlier's song. Mr. Weir lias 
told me of the ease 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 intro- 
duced into a room where other birds were kept and he 
began to sing, all the others, consisting of about twenty 
linnets and canaries, ranged themselves on the nearest 
side of their cages, and listened with the greatest interest 
to the new performer. Many naturalists believe that the 
singing of birds is almost exclusively " the effect of rival- 
ry 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 sinccinor. 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 Bech- 
stein,^" quite dead from rupturing a vessel in the lungs. 
Whatever the cause may be, male birds, as I hear from 
Mr. Weir, 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 dashing at its own image ; it likewise attacked 
with fury a female canary wiien put into the same cage. 

likewise writes to me : "I am informed that the best singing males gen- 
erally get a mate first when they are bred in the same room." 

*' 'Philosophical Transactions,' 1773, p. 263. White's 'Natural His- 
tory of Selborne,' vol. i. 1825, p. 246. 

«> ' Naturges. der Stubenvogel,' 1840, s. 252. 

s' Mr. Bold, 'Zoologist,' 1843-'44, p. 659. 



Chap. XIII.] VOCAL MUSIC. 51 

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, Avhile a stuiFed bird, sur- 
rounded by limed twigs, is exjjosed to view. In this man- 
ner a man, as Mr. Weir informs me, has caught, in the 
course of a single day, fifty, and in one instance seventy, 
male chaffinches. The power and inclination to sing difier 
so greatly with birds that although the price of an ordi- 
nary 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 owner's head. 

That birds should sing from emulation as well as for 
the sake of charming the female, is not at all incompatible ; 
and, indeed, might have been exj^ected to go together, 
like decoration and pugnacity. Some authors, however, 
argue that the song of the male cannot serve to charm the 
female, because the females of some few sjiecies, such as 
the canary, robin, lark, and bullfinch, esj^ecially, as Bech- 
stein remarks, when in a state of widowhood, pour forth 
fairly melodious strains. In some of these cases the habit 
of singing maybe in part attributed to the females having 
been highly fed and confined,^" for this disturbs all the 
usual functions connected with the reproduction of the 
species. Many instances have already been given of the 
jjartial transference of secondary masculine characters to 
the female, so that it is not at all surprising that the fe- 
males of some species should possess the power of song. 
It has also been argued, tliat 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.'^ But 

32 D. Barrington, 'Phil. Transact.' IIIS, p. 262. Bechstein, ' Stu- 
benvogel,' 1840, s. 4. 

^^ This is likewise the case with the watei'-ouzel, se« Mr. Hepburn in 
the 'Zoologist,' 1845-1846, p. 1068. 



52 SEXUAL SELECTION': BIRDS. [Part IL 

nothing is more common than for animals to take pleasure 
in practising whatever instinct they follow at other times 
for some real good. IIow 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 Aveaver-bird 
(Ploceus), when confined in a cage, amuses itself by neat- 
ly 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 halzens or leks at the 
usual place of assemblage during the autumn." Hence it 
is not at all surprising that male birds should continue 
singing for theii* own amusement after the season for 
courtship is over. 

Singing is to a certain extent, as shown in a previous 
chapter, an art, and is much improved by practice. Birds 
can be taught various tunes, and even the unmelodioiis 
sparrow has learned to sing like a linnet. They acquire 
the song of their foster-parents " and sometimes that of 
their neighbors." All the common songsters belong to 
the Order of Insessores, and their vocal organs are much 
more complex than those of most other birds ; yet it is a 
singular fact that some of the Insessores, such as ravens, 
crows, and magpies, possess the proper apparatus," though 
they never sing and do not naturally modulate their voices 
to any great extent. Hunter asserts^* that with the true 
songsters the muscles of the larynx are stronger in the 

" L. Lloyd, ' Game-Birds of Sweden,' 1867, p. 25. 

*' Barrington, ibid. p. 264. Bechstein, ibid. s. 5. 

** Durcau de la Malle gives a curious instance (' Annales des Sc. Nat.' 
3d scries, Zoolog. torn. x. p. 118) of some wild blackbirds in his garden 
in Paris which naturally learned from a caged bird a republican air. 

*' Bishop, in ' Todd's Cyclop, of Anat. and Phys.' vol. iv. p. 1496. 

*' As stated by Barrington Id ' Philosoph. Transact.' 1773, p. 262. 



Chap. XIIL] VOCAL MUSIC. . 53 

males than in the females ; but with this slight exception 
there is no difference in the vocal organs of the two sexes, 
although the males of most species sing so much better 
and more continuously than the females. 

It is remarkable that only small birds properly sing. 
The Australian genus Menura, however, must be ex- 
cepted; for the Menura Alberti, which is about the size of 
a half-grown turkey, not only mocks other birds, but " its 
own whistle is exceedingly beautiful and vai-ied." The 
males congregate and form " corrohorying places," where 
they sing, raising and spreading their tails like peacocks 
and drooping their wings. '° It is also remarkable that 
the birds which sing are rarely decorated with brilliant 
colors or other ornaments. Of our British birds, except- 
ing the bullfinch and goldfinch, the best songsters are 
plain-colored. The king-fisher, bee-eater, roller, hoopee, 
woodpeckers, etc., utter harsh ci'ies ; 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 have to be employed to charm 
the females; and the voice being rendered melodious 
would ofier one such means. 

In some birds the vocal organs differ greatly in the 
two sexes. In the Tetrao cupido (Fig. 39) the male has 
two bare, orange-colored sacs, one on each side of the 
neck ; and these are largely inflated when the male, dur- 
ing the breeding-season, makes a curious hollow sound, 
audible at a great distance. Audubon proved that the 
sound was intimately connected with this apparatus, 

39 Gould, 'Hand-book to the Birds of Australia,' vol. i. 1865, pp. 308- 
310. See also Mr. T. W. Wood in the 'Student,' April, 1870, p. 125. 

^^ See remarks to this eflfect in Gould's ' Introduction to the Trochi- 
lidae,' 1861, p. 22. 



54 



SEXUAL SELECTION: BIRDS. 



[Part II. 



wliich reminds \is of the air-sacs on each side of the 
mouth of certain male frogs, for he found that the sound 
was much diminished when one of tlie sacs of a tame 
bird was pricked, and wlien both were pricked it was 




Chap. XIII.] VOCAL MUSIC. 55 

altogether stopped. The female has " a somewhat similar, 
though smaller, naked space of skin on the neck ; hut this 
is not capable of inflation." " The male of another kind of 
grouse {Tetrao urophasianus), 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 liis neck-feath- 
ers erect, his wings lowered and buzzing on the ground, 
and his long pointed tail spread out like a fan, he displays 
a variety of grotesque attitudes. The oesophagus of the 
female is not in any way remarkable." 

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 serve, as was formerly 
supposed, to hold water, but is connected with the utter- 
ance, during the breeding-season, of a peculiar sound re- 
sembling "ock." The bird while uttering this sound 
throws himself into the most extraordinary attitudes. It 
is a singular fact that, with the males of the same species, 
the sac is not developed in all the individuals." A 
crow-like bird inhabiting South America {Gephalopterus 
ornatus, Fig. 40) is called the umbrella-bird, from its im- 
mense top-knot, formed of bare white quills surmounted 

*' ' The Sportsman and Naturalist in Canada,' by Major W. Ross 
King, 1866, pp. 144-146. Mr. T. W. Wood gives in the 'Student' 
(April, IS'/O, p. 116) an excellent account of the attitude and habits of 
this bird during its courtship. He states that the ear-tufts or neck- 
plumes are erected, so that they meet over the crown of the head. 

^'^ Richardson, 'Fauna Bor. Americana: Birds,' 1831, p. 359. Audu- 
bon, ibid. vol. iv. p. 507. 

^^ The following papers have been lately written on this subject : 
Prof. A. Newton, in the 'Ibis,' 1862, p. 107 ; Dr. CuUen, ibid. 1865, p. 
145; Mr. Flower, in ' Proc. Zool. 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 AustraUan Bustard in full display with the sac dis- 
tended. 



56 



SEXUAL SELECTION: BIRDS. 



[Part II. 



by dark-l)liic ]»1 nines, 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, cylin- 
drical, fleshy appendage, which is thickly clothed with 




Fig. 40.— The Umbrella-Bird, or Ceplmloptenis oruatus (male, from Brehm). 



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 de- 
velopment of the trachea and vocal organs." It is di- 
lated when the bird utters its singularly deep, loud, and 



Chap, XIII.] VOCAL MUSIC. 57 

long-sustained fluty note. The head-crest and neck-ap- 
pendage 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, like a French horn, and is deeply embedded 
in the sternum. In the wild-swan ( Cygnus ferus) it is 
more deeply embedded in the adult male than in the 
female or young male. In the male Merganser the en- 
larged portion of the trachea is furnished with an addi- 
tional pair of muscles." But the meaning of these differ- 
ences between the sexes of many Anatidae is not at all 
undei'stood; for the male is not always the more vo- 
ciferous ; thus with the common duck, the male hisses, 
while the female utters a loud quack." In both sexes of 
one of the cranes ( Grus virgo) the trachea penetrates the 
sternum, but pi'esents " certain sexual modifications." In 
the male of the black stork there is also a well-marked 
sexual difference in the length and curvature of the 
bronchi." So that highly-important structures have 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 

** Bates, ' The Naturalist on the Amazons,' 1863, vol. ii. p. 284 ; Wal- 
lace, in ' Proc. Zool. See' 1850, p. 206. A new species, with a stiU 
larger neck-appendage ( G. penduliger), has lately been discovered, see 
' Ibis,' vol. i. p. 457. 

■*^ Bishop, in Todd's 'Cyclop, of Anat. and Phys.' vol. iv. p. 1499. 

** 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 constant- 
ly present, so that perhaps they are now tending toward abortion. 

^'' 'Elements of Comp. Anat.' by K. Wagner, Eng. translat. 1845, p. 
111. With respect to the swan, as given above, Yarrell's 'Hist, of Brit- 
ish Birds,' 2d edit. 1845, vol. iii. p. 193. 



58 SEXUAL SELECTION: BIRDS. [Part IL 

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 hy a diiferent note from 
the gobbling noise which he makes, Avhen with erected 
feathers, rustling wings, and distended wattles, he puffs 
and struts before her." Tiie spcl of the blackcock cer- 
tainly 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 blackcock continues his 
spel for hours during successive days, and in the case of 
the capercailzie " with an agony of passion," we are led 
to suppose that the females which are ah*eady present are 
thus charmed." The voice of the common rook is known 
to alter during the breeding-season, and is therefoi*e 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 inharmonious 
contrast of their bright-yellow and blue plumage ? It is 
indeed possible that the loud voices of many male birds 
may be the result, without any advantage being thus 
gained, of the inherited effects of the coiitinued use of 
their vocal organs, when they are 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 practise, during their courtship, 
what may be called instrumental music. Peacocks and 
Bii-ds of Paradise rattle their quills together, and the 

*8 G. L. Bonaparte, quoted in the 'Naturalist Library: Birds,' voL 
xiv. p. 126. 

*9 L. Lloyd, 'The Ganic-Birds of Sweden,' etc., 18G7, pp. 22, 81. 
«• Jenner, ' Philosoph. Transactions,' 1824, p. 20. 



Chap. XIII.] INSTRUMENTAL MUSIC. 59 

vibratory movement apparently serves merely to" make a 
noise, for it can hardly add to the beauty of their plu- 
mage. Turkey-cocks scrape their wings against the 
ground, and some kinds of grouse thus produce a buzzing 
sound. Another North American grouse, the Tetrao um- 
helhcs^ when with his tail erect, his ruffs displayed, " he 
shows off his finery to the females, who lie hid in the 
neighborhood," drums rapidly with his " lowered wings 
on the trunk of a fallen tree," or, according to Audubon, 
against his own body ; the sound thus produced is com- 
pared 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." In 
the Himalayas the male of the Kalij-pheasant " often makes 
a singular 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 (Ploccus ?) 
congregate 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 per- 
forms for hours together, but only during the couiting- 
season. At this same season the males of certain night- 
jars (Caprimiilgus) make a most strange noise with their 
wings. The various sj^ecies of woodpeckers strike a 
sonorous branch with their beaks, with so rapid a vibrato- 
ry movement that " the head appears to be in two places 
at once." The sound thus prodixced is audible at a con- 
siderable distance, but cannot be described ; and I feel 
sure that its cause would never be conjectured by any one 
who heard it for the first timq. As this jarring sound is 
made chiefly during the breeding-season, it has been con- 
sidered as a love-song ; 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 



GO SEXUAL SELECTION: BIRDS. [Part IL 

same manner and soon appeared. Lastly, the male Hoopoe 
( Upupa epops) combines vocal and instrumental music ; 
for durin"- the breeding-season this bird, as Mr. Swinhoe 
savv^ first draws in air and then ta})S 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." When the male utters its 
cry without striking his beak, the sound is quite ditierent." 
In the foregoing cases sounds are made by the aid of 
structures already present and otherwise necessary ; but 
in tlie following cases certain feathers have been specially 
moditied for the express purpose of producing the sounds. 
The drumming, or bleating, or neighing, or thundering 
noise, as expressed by different observers, which is made 
by the common snipe {Scolopax galUnago) must have sur- 
prised every one who has ever heard it. This bird, during 




Fig. 41— Outer tail i i , i ,i m i'; /. , i. Soc. 1858). 

the pairing-season, flies to " perhaps a thousand feet in 
height," and, after zigzagging about for a time, descends 
in a curved line, with outsjaread tail and quivering pinions, 

*' For the forcfioing several facts see, on Birds of Paradise, Brehm, 
' Thierleben,' Band iii. .s. 325. On Grouse, Richardson, 'Fauna Bor. 
Americ. : Birds,' pp. 343, 359 ; Major W. Ross King, ' The Sports- 
man in Canada,' 1866, p. 156; Audubon, 'American Ornitholog. Biog- 
raph.' vol. i. p. 216. On the Kalij-pheasant, Jerdon, 'Birds of India,' 
vol. iii. p. 533. On the Weavers, ,' Livingstone's Expedition to the Zam- 
besi,' 1865, p. 425. On Woodpeckers, Macgillivray, 'Hist, of British 
Birds,' vol. iii. 1840, pp. 84, 88, 89, 95. On the Hoopoe, Mr Swin- 
hoe, in 'Proc. Zoolog. Soc.' June 23, 1863. On the Nisht-Jar, Audubon, 
ibid vol. ii. p. 255. The Enghsh Night-Jar likewise makes in the spring 
a curious noise during its rapid flight. 



Chap. XIII.] INSTRUMENTAL MUSIC. 61 

with surprising velocity to the earth. The sound is emit- 
ted 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 stiif, sabre-shaped shaft, with the ob- 
lique barbs of unusual length, the outer webs bemg strong- 
ly bound together. He found that, by blowing on these 
feathers, or by fastening them to a long thin stick and 
waving them raj^idly through the air, he could exactly re- 
produce the drumming noise made by the living bird. 
Both sexes are furnished with these feathers, but they are 
generally larger in 
the male than in the 



female, and emit a 

/^f.pi-,pi> note In ■^'*^' 42.— Outer tail-feather of Scolopax frenata. 

some species, as in 
S. frenata (Fig. 42), 
four feathers, and in 

& mvensis (Fv^. 43) Fig. 43.-Oiiter tail-feather of Scolopax javensis. 

no less than eight, on each side of the tail, are greatly 
modified. Different tones are emitted by the feathers of 
the different species when waved through the air; and the 
Seolopax Wilsonii of the United States makes a switching 
noise while descending rapidly to the earth. ^^ 

In the male of the Chaincepetes xmicolor (a large galli- 
naceous bird of America) the first primary wing-feather 
is arched toward the tip and is much more attenuated than 
in 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, 

^' See M. Meves's interesting paper in 'Proc. Zool. See.' 1858, p. 199. 
For the habits of the snipe, Macgillivray, ' Hist. British Birds,' vol. iv. p. 
371. For the American snipe, Captain Blakiston, 'Ibis,' vol. v. 1863, 
p. 131 



C2 SEXUAL SELECTION: BIRDS. [I'akt II. 

rushing noise," like the lulling of a tree." The male alone 
of one of the Indian bustards {ISypheotkles anritus) has its 
l)riinary wing-feathers greatly acuminated; and the male 
of an allied speeies is known to make a humming noise 
while courting the female." In a widely-different group 
of hirds, namely the Huniming-hirds, the males alone of 

certain kinds have either the 
shafts of their primary wing- 
feathers broadly dilated, or the 
webs abruptly excised toward 
the extremity. The male, for 
F.r n.-i',inu.r.y win^.A.uiu r of instance, of ^Selaspho7-us 2)l((fu- 

a Humnuug-bird, the Selaxplto- ■' I if 

rus i)iattjctrcm (from a sketch cercxs, when adult, has the 
by Mr. saivin). Upper flgurc, first primary winfj-foather (Fig. 

that of male ; lower lignre, cor- ..n .*,.,. \ o 

responding feather of female. '^'^) excised m this manner. 
While flying from flower to 
flower he makes "a shrill, almost.whistling noise;"" but 
it did not a])pear to Mr. tsalvin that the noise was inten- 
tionally made. 

Lastly, in several species of a sub-genus of Pipra or 
Manakin, the males have their secondare/ wung-feathers 
modified, as described by Mr. Sclater, in a still more re- 
markable manner. In the brilliantly-colored J*, deltciosa 
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 (?>, c) the 
shaft " is thickened to an extraordinary degree, forming a 
solid horny lump." Tlie barbs also are greatly changed, 
in shape, in comparison with the corresponding feathers 

"* Mr. Saivin, in ' Proc. Zool. Soc' 186Y, p. 160. I am much indebted 
to this distinguished ornithologist for sketches of the feathers of the 
Chamtcpetcs, and for other information. 

" Jerdon, 'Birds of India,' vol. iii. pp. 618, 621. 

** Gould, 'Introduction to the Trochilidae,' 18G1, p. 40. Saivin, 
'Proc. Zoolog. Soc.' 1867, p. 160. 



Chap. XIII.] 



INSTRUMENTAL MUSIC. 



G3 



{d, e, f) in the female. Even the bones of tlie 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." ^^ 







Fig. 45.— Secondary win^'-feathers of Pipra deliciosa (from Mr. Sclater, in Proc. 

Zool. Soc. 1800). The thieo upper feathers, a, b, e, from the male ; the three 

lower corresponding feathers, d,e,f, from the female. 
a and d. Fifth secondary wince-feather of male and female, upper surface, b 

and e. Sixth secondary, upper surface, c and /. Seventh secondary, lower 

surface. 



=8 Sclater, in 'Proc. Zool Soc' 1860, p. 90, and in 'Ibis,' vol. iv. 
1862, p. 1V5. Also Salvin, in 'Ibis,' 1860, p. 87. 



64 SEXUAL SELECTION: BIRDS. [Part II. 

The diver.'^ity of the sounds, both vocal and instrumen- 
tal, made by the males of many species during the breed- 
ing-season, and the diversity of the means for producing 
such sounds, are highly remarkal)le. We thus gain a 
high idea of their importance for sexual purposes, and are 
reminded of the same conclusion with respect 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 been improved into a melodious love- 
song. This is somewhat more difficult in the case of the 
modified feathers, by which the drumming, whistling, or 
roaring noises, are produced. But we have seen 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 whicli 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-like cry of certain water- 
fowl, the cooing of the turtle-dove, and the SQUg of the 
nightingale, should all be pleasing to the females of the 
several species. But we must not judge the tastes of dis- 
tinct 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 
tom-toms and the shrill notes of reeds, please the ears of 
savages. Sir S. Baker remarks," that "as the stomach of 
the Arab prefers the raw meat and reeking liver taken 

" -The Nile Tributaries of Abyssinia,' 1867, p. 203. 



Chap. XIII.] LOVE-ANTICS. Go 

hot from the animal, so does his ear prefer his equally 
coarse and discordant music to all other." 

Love-Antics and Dances. — The curious love-gestures 
of various birds, especially of the Gallinaceae, have already 
been incidentally noticed; so that little need here be 
added. In Northern America, lai'ge numbers of a grouse, 
the Tetrao phasianellus, meet every morning during the 
breeding-season on a selected level spot, and here they 
run round and round in a circle of about fifteen or twenty 
feet in diameter, 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 atti- 
tudes, and run round, some to the left and some to the 
right. Audiibon describes the males of a heron {Ardea 
herodias) as walking about on their long legs with great 
dignity before the females, bidding defiance to their rivals. 
With one of the disgusting carrion-vultures {CatJiartes 
jota) the same naturalist states that " the gesticulations 
and parade of the males at the beginning of the love-sea- 
son are extremely ludicrous." Certain birds perform 
their love-antics on the wing, as we have seen with the 
black African weaver, instead of on the ground. During 
the spring our little white-throat {Sylvia cinerea) often 
rises a few feet or yards in the air above some 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 Bengalensis) at such times 
" rises perpendicularly into the air with a hun-ied 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 manoeuvre several times successively, at 
the same time humming in a peculiar tone. Such females 



GG SEXUAL SELECTION: BIRDS. [Part IL 

as happen to be near " obey this saltatory summons," and 
wlien tliey approach be 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. 46), 
which, as we shall hereafter see, are highly decorated 
with feathers, shells, bones, and leaves, are built on the 
ground for the sole purpose of court sliip, 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 practised under confine- 
ment, and Mr. Strange has described '" the habits of some 
Satin Bower-birds, which he kept in his aviary in New 
South Wales. " At times the male wall chase the female 
all over the aviary, then go to the bower, pick up a gay 
feather or a large leaf, utter a curious kind of note, set all 
his fcatliers erect, run round the bower and become so 
excited that his eyes appear ready to start from his head ; 
he continues opening first one wing, and then the other, 
uttering a low, whistling note, and, like the domestic 
cock, seems to be picking up something from the groxmd, 
until at last the female goes gently toward him." Cap- 
tain Stokes has described the habits and " play-houses " 
of another species, the Great Bower-bird, which was seen 

*^ For Tctrao phasianollus, sec Richardson, 'Fauna Bor. America,' p. 
861, and for furtlicr particulars Captain Blakiston, ' Il>is,' 1863, p. 125. 
For the Cathartes and Ardca, Audubon, ' Ornitli. Bio<;raphy,' vol. ii. p. 
CI, and vol. iii. p. 89. On the White-throat, Mai-gillivrav, ' Hist. British 
Birds,' vol. ii. p. 354. On the Indian Bustard, Jerdon, ' Birds of India,' 
vol. iii. p. 618. 

'9 Gould, ' Hand-book to the Birda of Australia,' vol. i. pp. 444, 449, 
455. The bower of the Satin Bower-bird may always be seen in the 
Zoological Society's Gardens, Regent's Park. 



Chap. XIII.] 



LOVE-ANTICS. 



67 



" 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, 




68 SEXUAL SELECTION: BIRDS. LPart IL 

formed solely as halls of assemblages, where both sexes 
amuse themselves and pay their 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 wliich the 
males are ornamented either exclusively or in a much 
higher degree than the females; and in a succeeding 
chapter those in which both sexes are equally orna- 
mented, and finally the rare cases in which the female is 
somewhat more brightly colored than the male. As with 
the artificial ornaments nsed by savage and civilized men, 
80 with the natural ornaments of birds, the head is the 
chief seat of decoration.'^ The ornaments, as mentioned 
at the commencement of this chapter, are wonderfully di- 
versified. The plumes on the front or back of the head 
consist of variously-shaped feathers, sometimes capable of 
erection or expansion, by which their beautiful colors are 
fully displayed. Elegant ear-tufts (see Fig. 39 ante) are 
occasionally present. The head is sometimes covered 
witli velvety down like that of the pheasant ; or is naked 
and vividly colored; or supports fleshy appendages, fila- 
ments, and solid protuberances. The throat, also, is 
sometimes ornamented with a beard, or with wattles or 
caruncles. Such appendages are generally brightly col- 
ored, 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 more 
vivid tints, as in the case of the male turkey. At such 
times the fleshy appendages about the head of the male 
Tragopan pheasant ( Ceriornis temminckii) swell into a 

*" See remarks to this effect, on the " Feeling of Beauty among Ani- 
mals," by Mr. J. Shaw, in the ' Athenoeum,' Nov. 24, 1866, p. 081. 



Chap. XIII.] DECORATION. 69 

large lappet on the throat and into two horns, one on 
each side of the splendid top-knot ; and these are then 
colored of the most intense blue which I have ever be- 
held. The African hornbill {Bucorax Abyssinicus) inflates 
the scarlet bladder-like wattle on its neck, and with its 
wing drooping and tail expanded " makes quite a grand 
appearance." " 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 Suceros corrugatus, the 
whole beak and immense casque are colored more con- 
spicuously in the male than in the female ; and " the ob- 
lique grooves upon the sides of the lower mandible are 
peculiar to the male sex." " 

The males are often ornamented with elongated feath- 
ers or plumes, springing fi'om almost every part of the 
body. The feathers on the throat and breast are some- 
times developed into beautiful ruffs and collars. The tail- 
feathers are frequently increased in length, as we see in 
the tail-coverts of the peacock, and in the tail of the 
Argus pheasant. The body of this latter bird 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. °' The wing-feathers are not elongated 
nearly so often as the tail-feathers; for their elongation 
would impede the act of flight. Yet the beautifully ocel- 
lated secondary wing-feathers of the male Argus pheasant 
are nearly three feet in length ; and, in a small African 
night-jar [Cosmetornis vexillarius), one of the primary 
wing-feathers, during the breeding-season, attains a length 
of twenty-six inches, while the bii-d itself is only ten inches 
in length. In another closely-allied genus of night-jars, 

" Mr. Monteiro, 'Ibis,' vol. iv. 1862, p. 339. 

fi'' 'Land and Water,' 1868, p. 217. 

*-^ Jardine's 'Naturalist Library: Birds,' vol. xiv. p. 160. 



70 SEXUAL SELECTION; BIRDS. [Part IL 

the shafts of the eloiipjated wiiig-feathers are naked, ex- 
cept at the extremity, where there is a disk." Again, in 
another genus of niglit-jars, tlie tail-feathers are even 
still more prodigiously developed; so that we see the 
same kind of ornament gained by the males of closely- 
allied hirds, tlirough the development of Avidely-different 
feathers. 

It is a curious fact that the feathers of birds belonging 
to distinct groups have been modified in almost exactly 
the same peculiar mauner. Thus tlie 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 [Eumomota snpcrcillaris), 
of a king-fisher, finch, humming-bird, parrot, several 
Indian drongos {Dlcrurus and JEklolius, in one of which 
the disk stands vertically), and in the tail of certain Birds 
of Paradise. In these latter birds, similar feathers, beau- 
tifully ocellated, ornament the head, as is likewise the 
case with some gallinaceous birds. In an Indian bustard 
{SypJieotides auritus), the feathers forming the ear-tufts, 
which are about four inches in length, also terminate in 
disks." The barbs of the feathers in various widely-dis- 
tinct birds are filamentous or plumose, as with some 
Herons, Ibises, Birds of Paradise, and Gallinacea?. In 
other cases the barbs disa])pear, leaving the shafts bare; 
and these in the tail of the Paradisea apoda attain a 
length of thirty-four inches.*" Smaller feathers when thus 
denuded appear like bristles, as on the breast of the 
turkey-cock. As any fleeting fashion in dress comes to 

" Silater, in the 'Ibis,' vol. vi. 1864, p. 114. Livingstone, 'Expedi- 
tion to the Zambesi,' 1865, p. 66. 

«* Jeidon, ' Birds of India,' vol. iii. p. 620. 

«« Wiilhico, in 'Annals* and Mag. of Nat. Hist.' vol. xx. 1857, p. 416; 
and in his ' Malay Archipelago,' vol. ii. 1869, p. 390. 



"Chap. XIII.] DECORATION. 71 

be admired by man, so with birds a change of almost any 
kind in the structure or coloring of the feathers, in tlie 
male, appears to have been admired by the female. The 
fact of the feathers in widely-distinct groups having been 
modified in an analogous manner, no doubt depends pri- 
marily on all the feathers having nearly the same struct- 
ure and manner of development, and consequently tend- 
ing to vary in the same manner. We often see a ten- 
dency to analogous variability in the plumage of our 
domestic breeds belonging to distinct 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 tliey resembled, 
to a certain extent, the racket-shaped feathers above de- 
scribed. In certain breeds of the pigeon and fowl the 
feathers are plumose, with some tendency in the shafts to 
be naked. In the Sevastopol goose the scapular feathers 
are greatly elongated, curled, or even spirally twisted, 
with the margins plumose,*' 

In regard to color hardly any thing need here be said ; 
for every one knows how splendid are the tints of birds, 
and how harmoniously they are combined. The colors 
are often metallic and ii-idescent. Circular spots are 
sometimes surrounded by one or more diiferently-shaded 
zones, and are thus converted into ocelli. Nor need much 
be said on the wonderful difterences between the sexes, or 
of the extreme beauty of the males of many birds. The 
common peacock offers a striking instance. Female Birds 
of Paradise are obscurely colored and destitute of all orna- 
ments, while the males are probably the most highly 
decorated of all birds, and in so many ways, that they 
must be seen to be ajjpreciated. The elongated and 
golden-orange plumes which sj^ring from beneath the 

*' See my work on ' The Variation of Animals and Plants under Do- 
mestication,' vol. i. pp. 289, 293. 



72 



SEXUAL SELECTION: BIRDS. 



[Paut n. 



winfTs of the Paradisea apoda (see Fig. 47 of P. rubra, a 
much less beautiful species), when vertically erected and 
made to vibrate, are described as forming a sort of halo, 




Chap. XIII.] 



DECORATION. 



73 



in the centre of which the head " looks like a little eme- 
rald sun with its rays formed by the two plumes." *" In 
another most beautiful species the head is bald, " and of a 




Fig. 48.— Lophornis ornatus, male and female (from Brehm). 

8* Quoted from M. de Lafresnaye, in ' Annals and Mag. of Nat. Hist.' 
23 



n 



'SEXUAL SELECTION: BIRDS 



[Part IL 




Fio. 49.— Spatliura Underwood i, malenud IVmalo (from BroUni). 



vol. xiii. 1854, p. 157; see also Mr. Wallace's much fuller account in voL 
XX. 1857, p. 412, and in his Malay Archipelago. 



Chap. XIII.] DECORATION. 75 

rich cobalt blue, crossed by several lines of black velvety- 
feathers." '' 

Male humming-birds (Figs. 48 and 49) almost vie with 
Birds of Paradise in their beauty, as every one will admit 
who has seen Mr. Gould's splendid volumes or his rich 
collection. It is very remarkable in how many different 
ways these birds are ornamented. Almost every part of 
the 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 be- 
longing to nearly every sub-group. Such cases are curi- 
ously 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 
belonging to the same species in other characters ; and 
these have been seized on by man and augmented to an 
extreme point — as the tail of the fantail-pigeon, the hood 
of the jacobin, the beak and wattle of the carrier, etc. 
The sole difference 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 Paradise, etc., it 
is due to sexual selection — that is, 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 sexes, namely, 
fhe famous Bell-bird ( ChasmorhyncJms niveus) of South 
America, the note of which can be distinguished at the 
distance of nearly three miles, and astonishes every one 
who first hears it. The male is pure white, while the fe- 
male is dusky-green; and the former color with terres- 
trial species of moderate size and inoffensive habits is very 
rare. 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 

*9 "Wallace, 'The Malay Archipelago,' vol. ii. 1869, p. 405. 



76 SEXUAL SELECTION: BIRDS. [Part H. 

minute downy feathers. This tiil)e can be inflated with 
air, tlirough a communication with the palate ; and when 
not inflated liangs down on one side. The genus consists 
of four species, the males of which are very distinct, while 
the females, as described by Mr. Sclater in a most inter- 
esting paper, closely resemble each other, thus oflTering an 
excellent instance of the common rule that within the 
same group the males differ much more from each other 
than do the females. In a second species {(J. niidicollis) 
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 breeding-season is of a tine green 
color. In a third species (6^. tricarunculatus) the head 
and neck alone of the male are white, the rest of the body 
being chestnut-brown, and the male of this species is pro- 
vided with three filamentous projections half as long as 
the body — one rising from the base of the beak and the 
two others from the corners of the mouth." 

The colored plumage and certain other ornaments of 
the males when adult are either retained for life or are 
periodically renewed during the summer and breeding-sea- 
son. At this season the beak and naked skin about the 
head frequently 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." In one 
of the rails, Gallicrex cristatus, a large red caruncle is de- 
veloped during this same period on the head of the male. 
So it is with a thin horny crest on the beak of one of the 
pelicans, P. erythrorliynchKS ; for, after the breeding-sea- 
son, these horny crests are shed, like horns from the heads 

■"• Mr. Sclater, 'Intellectual Observer,' Jan. 1867. ' Waterton's Wan- 
derings,' p. 118. See also Mr. Salvin's interesting paper, with a plate, in 
the 'Ibis,' 1866, p. 90. 

" ' Land and Water,' 18G7, p. 394. 



Chap. XIIL] DOUBLE ANNUAL MOULT. 77 

of stags, and the 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 sea- 
son 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 by very young birds of their down ; 
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 (Glareolse) 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, 
which seems, when there is no change of color, the most 
probable cause of a double moult. Secondly, there are 
birds, for instance, certain species of Totanus and other 
grallatores, the sexes of wliich resemble each other, but 
have a slightly diflferent summer and winter plumage. 
Tlie difference, however, in color in these cases is so 
slight that it can hardly be an advantage to them ; and it 
may, perhaps, be attributed to' the direct action of the 
diffei'ent 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 difler from each other in color ; 
but the females, though moulting twice, retain the same 
colors throughout the year, while the males undergo a 

" Mr. D. G. Elliot, in 'Proc. ZooL Soc' 1869, p. 589. 
'^ ' Nitzsch's Pterylography,' edited by P. L. Sclater. Ray Soc. 
1867, p. 14. 



78 SEXUAL SELECTION : BIRDS. [Paut II. 

change, sometimes, as witli certain bustards, a great 
cliange of color. Fifthly and lastly, there are hirds the 
sexes of which difter from each other in both their sum- 
mer and winter plumage, but the male undergoes a 
greater amount of change at each recurrent season than 
the female — of Avhich the iluif [Madietes 2^^tOnax) offers 
a good instance. 

With respect to the cause or pur2)ose of the differences 
in color between the summer and winter plumage, this 
may in some instances, as with the ])tarmigan,'* serve 
during both seasons as a pi'otection. When the difference 
between the two plumages is slight it may perhaps be at- 
tributed, 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 tliey 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 highly devel- 
0])ed 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, frequent- 
ly checks the development of their secondary sexual char- 
acters, but has no immediate influence on any other char- 
acters ; and I am informed by Mr. Bartlett that eight or 
nine specimens of the Knot {Triiiga canutus) retained 
their unadorned winter plumage in the Zoological Gar- 

"'• 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 disappeared, this t)ird 
is known to suflTer greatly from birds of prey, before it has acquired its 
summer dress : see Wilhelm von Wright, in Lloyd, ' Game-Birds of 
Sweden,' 18C7, p. 125. 



Chap. XIII.] DOUBLE ANNUAL MOULT. 79 

dens throughout the year, from which fact we may infer 
that the summer phimage, though common to both sexes, 
partakes of the nature of the exclusively masculine plu- 
mage 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 colors 
throughout the year, we may conclude that the habit of 
moulting twice in the year has not been acquired in order 
that the male should assume during the breeding-season 
an ornamental character ; but that the double moult, hav- 
ing been originally acquired for some distinct purpose, 
has subsequently been taken advantage of in certain cases 
for gaining a nuptial ])lumage. 

It appears at first sight a surprising circumstance that, 
with closely-allied birds, some 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 blackcock only once : some of 
the splendidly-colored honey-suckers (Nectarinije) of In- 
dia and some sub-genera of obscurely-colored pipits (An- 
thus) have a double, while others have only a single an- 
nual moult." But the gradations in the manner of moult- 
ing, which are known to occur with various birds, show 
us how species, or whole groups of species, might have 

'* Li regard to the previous statements on moulting, see, on snipes, 
etc., Macgillivray, ' Hist. Brit. Birds,' vol. iv. p. 371 ; on Glareolas, cur- 
lews, and bustards, Jerdon, 'Birds of India,' vol. iii. pp. 615, 630, 683 ; 
on Tetanus, ibid. p. TOO ; on the plumes of herons, ibid. p. 738, and Mac- 
gillivray, vol. iv. pp. 435, 444, and Mr. Stafford Allen, in the ' Ibis,' vol. 
V. 1863, p. 33. 

'^ 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. 32. 



80 SEXUAL SELECTION : BIRDS. [Paut II. 

originally acquired tlu-ir doiil>k' iiiinual moult, or, having 
once gained the habit, liave again lost it. With certain 
bustards and i)lovers the vernal moult is far from com- 
plete, some feathers being renewed, and some changed in 
color. There is also reason to believe that with certain 
bustards and rail-like birds, which properly imdergo a 
double moult, some of the older males retain their nup- 
tial plumage throughout the year. A few liighly-modified 
feathers may alone be added during the spring to the 
phunage, as occurs with the disk-fox-raed tail-feathers of 
certain drongos {Bhringa) in India, and ^^dth the elon- 
gated feathers on the back, neck, and crest, of certain 
herons. By such steps as these, the vernal moult might 
be rendered more and more complete, until a perfect 
double moult was acquired. A gradation can also be 
shown to exist in the length of time during which either 
annual plumage is retained ; so that the one might come 
to be retained for the whole year, the other being com- 
pletely lost. Thus the Machetes pugnax retains his ruff 
in the spring for barely tAvo months. Tlie male widow- 
bird {Chera progm') acquires in Natal his tine plumage 
and long tail-feathers in December or January, and loses 
them in March ; so that they are retained during only 
about three months. Most species which undergo a 
double moult keep their ornamental feathers for abmit 
six months. The male, however, of the Avild Gallus 
haJikiva 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 tlie do- 
mesticated descendant of this species, the neck-liackles of 
the male are immediately replaced by new ones ; so that 
we here see, with respect to part of the j^lumage, a double 
moult changed under domestication into a single moult." 

" For the forcgoinf^ stiitcracnts in regard to partial moults, and on 
old males retaining their nuptial plumage, sec Jerdon, on bustards and 



Chap. XIII.J DOUBLE ANNUAL MOULT. 81 

The common drake (Anas hoschas) is well known after 
the breeding-season to lose his male plumage for a period 
of thi'ee months, during which time he assumes that of 
the female. The male pintail-duck (Anas acuta) 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 circum- 
stance, that seems to bid defiance to all human reasoning. 
But he who believes in the gradual modification of spe- 
cies will be far from feeling surprised at finding grada- 
tions of all kinds. If the male pintail were to acquire his 
new plumage within a still shorter period, the nfiw male 
feathers would almost necessarily be mingled with the old, 
and both with some proper to the female ; and this ap- 
parently 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 
completely lost.'* 

Some male birds, as before stated, become more bright- 
ly 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. 
With the Pelecanus onocrotalus a beautiful rosy tint, with 

plovers, in 'Birds of India,' vol. iii. pp. 617, 637, 709, 711. Also Blyth 
in 'Land and Water,' 1867, p. 84. 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 bwbulcus, 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 ' Variation of Animals 
under Domestication,' vol. i. p. 236. 

■'8 See Macgillivray, 'Hist. British Birds' (vol. v. pp. 34,70,223), 
on the moulting of the Anatidae, with quotations from Waterton and 
Montagu. Also Yarrell, ' Hist, of British Birds,' voL iii. p. 243. 



82 SEXUAL SELECTION: BIRDS. [Part II. 

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 liave been attained." 
Certain tinclies shed the margins of their feathers in the 
spring, and then become bright-colored, while other finches 
undergo no such change. Thus the Frhiffilla tristis of the 
Ignited States (as well as many other American 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 close- 
ly in structure, undergo no such annual change. But a 
difference of this kind in the jjlumage of allied species 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 
Madeii'a these colors are retained throughout the year." 

Dispknj by Male Birds of tJieir Plumage. — Ornaments 
of all kinds, whether permanently or temporarily gained, 
are sedulously displayed by the males, and apparently 
serve to excite, or attract, or charm, 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 will show off his finery, 
as I have often seen, before poultry or even pigs.*" All 
naturalists who have closely attended to the habits of 

"On the pelican, see Sclater, in 'Proe. Zool. Soe.' 1868, p. 2C5. 
On the Aracricau finches, see Audubon, ' Ornith. Biography,' vol. i. pp. 
174, 221, and .lerdon, 'Birds of India,' vol. ii. p. 383. On the Frinffilla 
cannahina of Ma<k'ira, Mr. E. Vernon Ilurcourt, 'Ibis,' vol. v. 1863, 
p. 230. 

^ See also ' Ornamental r.)ultrv,' bv Ilev. E. S. Dixon, 1848, p. 8. 



Cbap. XIII.] DISPLAY BY THE MALE. 83 

birds, whether in a state of nature or under confinement, 
are unanimously of opinion that the males delight to dis- 
play 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 eflect. 

It must be a grand sight in the forest of India " to 
come suddenly on twenty or thirty pea-fowl, the males 
displaying their gorgeous trains, and strutting about in 
all the pomp of pride before the gratified females." The 
wild-turkey-cock erects his glittering plumage, expands 
his finely-zoned tail and barred wing-feathers, and alto- 
gether, with his gorged crimson and blue 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 plumose. The fe- 
male is brownish-green, shaded with red, and has a much 
smaller crest. Sir R. 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 tn 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 apparent 
delight of several others. Kow spreading its wings, 

*^ ' Birds of India,' Introduct. vol. i. p. xxiv. ; on the peacock, vol. 
iii. p. 507. See Gould's ' Introduction to the Trochilidaj,' 1861, pp. 15, 
111. 



84 



SEXUAL SELECTION: BIRD& 



[Part IL 



throwing uj) its head, or opi'iiing its tail like a Ian; now 
strutting about with a hopping gait until tired, when it 
gal)hled some kind of note, and was relieved by another. 




Fig. 50.— Rupicola crocea, male (from Brelim). 

Thus three of them successively took the field, an<i then, 
with self-api)r<)bation, withdrew to rest." The Indians, in 
order to obtain their skins, wait at one of the Jiieeting- 
places till the birds are eagerly engaged in dancing, and 



Chap. XIII.] DISPLAY BY THE MALE. 85 

then are able to kill, with their poisoned arrows, four or 
five males, one after the other. ^'^ With Birds of Paradise 
a dozen or more fuU-plumaged males congregate in a tree 
to hold a dancing-party, as it is called by the natives ; 
and here flying about, raising their wings, elevating their 
exquisite plumes, and making them vibrate, the whole tree 
seems, as Mr. Wallace remarks, to be filled with waving 
plumes. When thus engaged, they become so absorbed 
that a skilful archer may shoot nearly the whole party. 
These birds, when kept in confinement in the Malay Archi- 
pelago, are said to take much care in keeping their feathers 
clean ; often spreading them out, examining them, and re- 
moving 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 -pheasant {^Thaumalea picta^ during his 
courtship not only expands and raises his splendid frill, 
but turns it, 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.** Mr. Bartlett has observed a male Polyplectron 
(Fig. 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 beau- 
tiful ocelli, like those on the peacock's train. Now, when 
the peacock displays himself, he expands and erects his 
tail transversely to his body, for he stands in front of the 
female, and has to show off, at the same time, his rich 

83 'Journal of R. Geograph. Soc' vol. x. 1840, p. 236. 

^ 'Annals and Mag. of Nat. Hist.' vol. xiii. 1854, p. 15*7; also Wal- 
lace, ibid. vol. XX. 185*7, p. 412, and ' The Malay Archipelago,' vol. ii. 
1869, p. 252. Also Dr. Bennett, as quoted by Brehm, ' Thierleben,' B. 
iii. s. 326. 

84 Mr. T. W. Wood has given ('The Student,' April, 18*70, p. 115) a 
full account of this manner of display, which he calls the lateral or one- 
sided, by the gold-pheasant and by the Japanese pheasant, Ph. versicolor. 



86 



SEXUAL SELECTION: BIRDS. 



[Part II. 



blue throat :ui<l l»roast. Jiut the breast of the Polyplec- 
tron is obscurely colored, and the ocelli are not confined 
to the tail-feathers. Consequently the Polyplectron does 










Chap. XIIL] DISPLAY BY THE MALE. 87 

not stand in front of the female ; but he erects and ex- 
pands 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 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 Tragopan 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 feath- 
ers are exhibited at the same time. 

The case of the Argus pheasant is still more striking. 
The immensely-developed secondary wing-feathers, which 
are confined to the male, are ornamented with a row of 
from twenty to twenty-three ocelli, each above an inch in 
diameter. The feathers are also elegantly marked with 
obliqixe dark stripes and rows of spots, like those on the 
skin of a tiger and leopard combined. The ocelli are so 
beautifully shaded that, as the Duke of Argyll remarks," 
they stand out like a ball lying loosely within a socket. 
But when I looked at the specimen in the British Museum, 
which is mounted with the wings expanded and trailing 
downward, I was greatly disappointed, for the ocelli ap- 
peared flat or even concave. Mr, Gould, however, soon 
made the case clear to me, for he had made a drawing of 
a male while he was displaying himself. At such times 
the long secondary feathers in both wings are vertically 
erected and expanded ; and these, together with the enor- 
mously-elongated tail-feathers, make a grand semicircular 
upright fan. Now as soon as the wing-feathers are held 
in this position, and the light shines on them from above, 
the full effect of the shading comes out, and each ocellus 
85 ' The Reign of Law,' ISeV, p. 203. 



88 SP:X1:aL selection: birds. [Part II. 

at once rcsonibles 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 orna- 
ments have been formed by means of sexual selection ? 
But it will be convenient to defer giving an answer to 
this question until we treat in the next cliapter of the 
principle of gradation. 

The primary wing-feathers, which in most gallinaceous 
birds are uniformly colored, are in the Argus pheasant 
not less wonderful objects than the secondary wing-feath- 
ers. They are of a soft brown tint with numerous dark 
spots, each of which 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 feather lying within the true feath- 
er. This inner part is colored of a lighter chestnut, and 
is thickly dotted with minute white points. I have shown 
this feather to several persons, and many have admired it 
even more than the ball-and-socket feathers, and have de- 
clared that it was more like a work of art than of Xature, 
Now these feathei's are quite hidden on all ordinary occa- 
sions, but are fully displayed when the long secondary 
feathers are erected, though in a widely-different manner ; 
for they arc expanded in front like two little fans or 
shields, one on each side of the breast near the ground. 

The case of the male Argus pheasant is eminently in- 
teresting, because it affords good evidence that the most 
refined beauty may serve as a charm for the female, and 
for no other purpose. We must conclude that this is the 
case, as the primary wing-feathers are never displayed, 
and the ball-and-socket ornaments are not exhibitt'd in full 
perfection, except when the male assumes the attitude of 
courtship. The Argus pheasant does not possess brilliant 
colors, so that his success in courtship appears to have 



Chap. XIII.] DISPLAY BY THE MALE. 89 

depended on the great size of his plumes, and on the elab- 
oration of the most elegant patterns. Many will declare 
that it is utterly incredible that a female bird should be 
able to appreciate fine shading and exquisite patterns. It 
is undoubtedly a marvellous fact that she should possess 
this almost human degree of taste, though perhaps she 
admires the general eifect rather than each separate de- 
tail. He who thinks that he can safely gauge the discrimi- 
nation and taste of the lower animals, may deny that the 
female Argus pheasant can appreciate such refined beau- 
ty ; but he will then be compelled to admit that the ex- 
traordinary attitudes assumed by the male during the act 
of courtship, by which the wonderful beauty of his plu- 
mage is fully displayed, are purposeless ; and this is a con- 
clusion which I for one will never admit. 

Although so many pheasants and allied gallinaceous 
birds carefully display their beautiful 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 I*hasianus Walli- 
chii) • 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-character- 
ized 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 orna- 
mented. 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 



yO SEXUAL SELECTION: BIUDS. [Part IL 

l)riglit colors to the males of any species, it has also very 
often given a strong tendency to pugnacity. We shall 
meet with nearly analogous cases when we treat of mara- 
niuls. On the other hand, with birds the power of song 
and brilliant colors have rarely been both ac([uired by the 
males of the same sjjeiies ; but in this case, the advantage 
gained would have been identically the same, namely, suc- 
cess in charming the female. Nevertheless, it must be 
owned that the males of several brilliantly-colored birds 
have had their feathei-s si)ecially 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 orna- 
mented in any very high degiee, but which nevertheless 
display, during their courtship, whatever attractions they 
may possess. These cases are in some respects more 
curious than the foregoing, and have been but little no- 
ticed. I owe the following facts, selected from a large 
body of valuable notes, sent to me by Mr. Jenner Weir, 
who has long kept birds of many kinds, including all the 
British P'ringillidai and P2mberizida?. The bullfinch makes 
his advances in front of the female, and then puffs out his 
breast, so that many more of the crimson 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 showing his red breast, and 
" blue-bell," as the fanciers call his head ; the wings at the 
same time being slightly expanded, with the pure white 
hands on the shoulders thus rendered conspicuous. The 
common linnet distends his rosy breast, slightly expands 
his brown whigs and tail, so as to make the best of them 
by exhibiting their white edgings. We must, however, 
be cautious in concluding that the wings are sjjread out 



Chap. XIII.] DISPLAY BY THE MALE. 91 

solely for display, as some birds act thus 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 goldfinch 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. No other 
British finch, as Mi". Weir informs me, turns during his 
courtship from side to side in this manner ; 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 {Emberiza schoenicxdus) 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 latter being marked with three large conspicuous oval 
spots of white." This species, when courting the female, 
slightly spreads out and vibrates these party-colored tail- 
coverts in a very peculiar manner. The male Amadina 
Lathami behaves very diffei'ently, exhibiting before the 
female his brilliantly-spotted breast and scarlet nxmp, and 
scarlet upper tail-coverts. I may here add from Dr. 
Jerdon, that the Indian Bulbul {Pycnonotus hmmorrhous) 
has crimson binder tail-coverts, and the beauty of these 
feathers, it might be thought, could never be well exhib- 

^ For the description of these birds, see Gould's ' Hand-book to the 
Bii-ds of Australia,' vol i. 1865, p. 41*7. 



92 SEXUAL SELECTION: BIRDS. [Part II. 

ited ; but tlic ])ir(l " when excited often spreads them out 
hiterally, " so that they can be seen even from above." " 
The common j>igeon has iridescent featliers on the breast, 
and every one must have seen how the male inflates his 
breast while courting the female, thus showing off these 
feathers to the best advantage. One of the beautiful 
bronze-winged pigeons of Australia ( Ocyphaps lophotes) 
behaves, as described to me by Mr. Weir, very differently : 
the male, Avhile standing before the female, lowers his head 
almost to the ground, spreads out and raises perpendicu- 
larly his tail, and half expands his wings. He then alter- 
nately and slowly raises and depresses his body, so that 
the iridescent metallic feathers are all seen at once, and 
glitter in the sun. 

Sufticient 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 tlie same manner, it appears that 
actions, at first perhaps intentional, have become instinc- 
tive. If so, we ought not to accuse birds of conscious 
vanity ; yet when we see a peacock strutting about, with 
exj^anded 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 they have 
been acquired in some cases at the expense of greatly-im- 
peded powers of flight or of running. The African night- 
jar i^Cosmetornis), which during the pairing-season has 
one of its primary wing-feathers developed into a streamer 
of extreme length, is thus much retarded in its flight, !»1- 
though at other times remarkable for its swiftness. Tlie 

" ' Birds of India,' vol. ii. p. 96. 



Chap. XIII.] DISPLAY BY THE MALE. 93 

" unwieldly size " of the secondary wing-feathers of the 
male Argus pheasant are said " almost entirely to deprive 
the bird of flight." The fine plumes of male Birds of 
Paradise trouble them during a high wind. The ex- 
tremely long tail-feathers of the male widow-birds (Vidua) 
of Southern 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 a more easy 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 it probably is, as Mr, 
Gould has remarked, that such birds are generally of a 
shy disposition, as if conscious that their beauty was a 
source of danger, and are much more diflicult to discover 
or approach, than the sombre-colored and comparatively 
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- 

** On the Cosmetornis, see Livingstone's ' Expedition to the Zambesi,' 
1865, p. 66. On the Argus pheasant, Jardine's 'Nat. Hist. Lib. : Birds,' 
vol. xiv. p. 167. On Birds of Paradise, Lesson, quoted by Brehm, 
' Thierleben,' B. iii. s. 325. On the widow-bird, Barrow'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 to Birds of Australia,' vol i. 1865, 
pp. 210, 457. 



94 SEXUAL SELECTION: BIRDS. [Part IL 

iiK'iits. Cock-liglitt'rs trim the liackles and cut off the 
comb and gills of their cocks ; and the birds are then said 
to be dubbed. An undubbed bird, as Mr, Tegctmeier in- 
sists, "is at a fearful disadvantage: the comb and gills 
otter 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 sutt"ered l»y 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 
))resume that the old birds tight in the same manner. It 
may perhaps be objected that the comb and wattles are 
not ornamental, and cannot be of service to the birds in 
this way ; but even to our eyes, the beauty of the glossy 
black h>panish cock is much enhanced by his white face 
and crimson comb; and no one who has ever seen the 
splendid blue wattles of the male Tragopan pheasant, 
when distended during the act of courtship, can for a mo- 
ment doubt that beauty is the object gained. From the 
foregoing facts we clearly see that the plumes and other 
ornaments of the male must be of the highest importance 
to him; and Ave further see that beauty in some cases is 
even more important than success in battle, 

8' Tegetmeier, 'The Poultry-Book,' 1800, p. 13<.». 



Chap. XIV.l SEXUAL SELECTION : BIRDS. 95 



CHAPTER XIV. 

BiEDS — continued. 

Choice exerted by the Female. — Length of Courtship. — Unpaired Birds. — 
Mental Qualities and Taste for the Beautiful.— Preference or Antip- 
athy 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 Pheas- 
ant, and Urosticte. 

Whex the sexes differ in beauty, in the power of singl- 
ing, or in producing what I have called instii;mental mu- 
sic, it is almost invariably the male whicli excels the fe- 
male. These qualities, as we have just seen, are evidently 
of high importance to the male. Wlien they are gained 
for only a part of the year, this is always shortly before 
the breeding-season. It is the male alone who elaborate- 
ly 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 
all 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 bear- 
ing on sexual selection, namely. Does every male of the 
same species equally excite and attract the female? or 
does she exert a choice, and prefer certain males ? This 
question can be answered in the affirmative by much di- 



96 SEXUAL SELECTION: BIRDS. [Part XL 

rect and iiulircct evidence. It is much more ditlicult to 
decide wliat 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, courage, and other men- 
tal (lualitics, come into play. "We will begin with the in- 
ilirect evidence. 

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 court- 
ship being a prolonged atlair, and partly on the reitera- 
tion of the act of pairing. Thus in Germany and Scandi- 
navia the balzens or leks of the Blackcocks last from the 
middle of March, all through April into May. As many 
as forty or fifty, or even more, birds congregate at the 
k'ks ; and the same place is often frequented during suc- 
cessive 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 
phasianelltcs " last for a month or more." Other kinds of 
grouse both in North America and Eastern Siberia' fol- 
low 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 full-])lu- 
maged male Birds of Paradise congregate. In this latter 

' Nordraann describes (' Bull. Soc. Imp. des Xat. Moscow,' 18(51, tome 
xxxiv. p. 264) the balzen of Tetrao urogalloidcs iu Amur Land. He esti- 
mated the number of assembled males at above a hundred, the females, 
which lie hid in the surrounding bushes, not being counted. The noises 
uttered differ from those of the T. urogaJhis or the capercailzie. 



Chap. XIV.] LENGTH OF COURTSHIP. 97 

case it is not expressly stated that the females meet on 
the same trees, but the hunters, if not specially asked, 
would not probably mention their presence, as their skins 
are valueless. Small parties of an African weaver [Plo- 
ceus) congregate, during the breeding-season, and perform 
for hours their graceful evolutions. Large numbers of 
the Solitary snipe {Scolopax major) assemble during the 
dusk in a morass ; and the same j^lace is frequented for 
the same purpose during successive years ; here they may 
be seen running about " like so many large rats," puffing 
out their feathers, flapping their wings, and uttering the 
strangest cries." 

Some of the above-mentioned birds, namely, the black- 
cock, capercailzie, pheasant-grouse, the ruff, the Solitary 
snipe, and perhaps some otliers, are, as it is believed, po- 
lygamists. With such birds it might have been thought 
that the 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 indispensable for 
the male to excite or please the female, we can understand 
the length of the courtship and the congregation of so 
many individuals of both sexes at the same spot. Certain 
species which are strictly monogamous likewise hold nup- 
tial 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-bird or Menura superba iorms "small round hillocks," 
and the 3£. Alberti scratches for itself shallow holes, or, as 
they are called by the natives, coirohorying-places, where 

' With respect to the assemblages of the above-named grouse, see 
Brehm, ' Thierleben,' B. iv. s. 350; also L. Lloyd, 'Game-Birds of Swe- 
den,' 1867, pp. 19, 78. Richardson, 'Fauna Bor. Americana,' Birds, p. 
362. References in regard to the assemblages of other birds have pre- 
Tiously been given. On Paradisea, see Wallace, in 'Annals and Mag. of 
Nat. Hist.' vol. xx. 1857, p. 412. On the snipe, Lloyd, ibid. p. 221. 
24 



98 SEXUAL SELECTION: BIRDS. [Part H. 

it is boliL'ved both sexes assemble. The meetings of the 
M. superha are sometimes very large ; and an account has 
lately been published' by a traveller, who heard in a val- 
ley beneath him, thickly covered with scrub, " a din which 
completely astonished " him ; on crawling onward he be- 
held to his amazement about one hundred and fifty of the 
magnificent lyre-cocks, " ranged in order of battle, and 
fighting with indescribable fury," The bowers of the 
Bower-birds are the resort of both sexes during the 
breeding-season ; and " here 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.* 

The common magpie {Corvus pica, Linn.), as I have 
been informed by the Rev. W. Darwin Fox, used to as- 
semble 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. 
While they were so numerous, they had the habit very 
early in the spring of assembling at particular spots, where 
they could be seen in flocks, chattering, sometimes fight- 
ing, bustling and flying about the trees. The whole afiair 
was evidently considered by the birds as 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 which a species 
does not exist in large numbers, great assemblages cannot, 
of course, be held, and the same species may have differ- 
ent habits in different countries. For instance, I have 

* Quoted by Mr. T. W, Wood iu the 'Student,' April, 1870, p. 126. 

* Gould, 'Hand-book of Birds of Australia,' vol. i. pp. 300, 308, 448 
451. On the ptarmigan, above alluded to, see Lloyd, ibid. p. 129. 



Chap. XIV.] UNPAIRED BIRDS. 99 

never met with any account of regular assemblages of 
black game in Scotland, yet these assemblages are so well 
known in Germany and Scandinavia that they have spe- 
cial names. 

Unpaired Birds. — From the facts now given, we may 
conclude that with birds belonging to widely-different 
groups their courtship is often a prolonged, delicate, and 
troublesome affair. There is even reason to suspect, im- 
probable 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 in consequence 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 fre- 
quently 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 purpose, 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. Thompson 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 th"an the fe- 
males ; and that in the above cases, as well as in many oth- 
ers which could be given, the males alone had been killed. 
This apparently holds good in some instances, for the 

* On magpies, Jenner, in 'Phil. Transact.' 1824, p. 21. Macgillivray, 
' Hist. British Birds,' vol. i. p. 570. Thompson, in ' Amials and Mag. of 
Nat. Hist.' vol. viii. 1842, p. 494. 



100 SEXUAL SELECTION: BIRDS. [Part IL 

gamc-kecpcrs 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 be- 
ing easily killed while bringing food to the sitting females. 
Macgillivray, however, gives, on the authority of an ex- 
cellent observer, an instance of three magpies successively 
killed on the same nest, which were all females ; and an- 
other case of six magpies successively killed while sitting 
on the same eggs, which renders it probable that most of 
them were females, though the male will sit on the eggs, 
as I hear from Mr. Fox, when the female is killed. 

Sir J. Lubbock's game-keeper has repeatedly shot, but 
how many times he could not say, one of a pair of jays 
{Garrulus fflandarius), and has never failed shortly after- 
ward to find the survivor rematched. The Rev. W. D. 
Fox, Mr. F. Bond, and others, have shot one of a pair of 
carrion-crows (Corvus corone), but the nest was soon 
again tenanted Isy a pair. These birds are rather com- 
mon; but the peregrine falcon [Falco peregriynis) is rare, 
yet Mr. Thom])8on 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 
very few days, so that the eyries, notwithstanding such 
casualties, are sure to turn out their complement of young." 
Mr. Jenner Weir has known the same tiling to occur with 
the peregrine falcons at Beachy Head. The same observer 
informs me that three kestrels, all males [Falco tinnuncu- 
lus), were killed one after the otlur while attending the 
same nest ; two of these were in mature plumage, and the 
third in the plumage of the previous year. Even with the 
rare golden eagle (Aguila chrysa'etos), Mr. Birkbeck was 
assured by a trustworthy gamc>-keoper in Scotland, that if 
one is killed, another is soon found. So with the white 
)wl (Strixjlainmea), it has been observed that " the sur- 



Chap. XIV.] UNPAIRED BIRDS. 101 

vivor readily found a mate, and the mischief went 
on." 

White of Selborne, who gives the case of the owl, 
adds that he knew a man who, from believing that par- 
tridges when paired were disturbed by the males fighting, 
used to shoot them ; and, though he had widowed the 
same female several times, she was always soon provided 
with a fresh pai'tner. This same naturalist ordered the 
sparrows, which deprived the house-martins of their nests, 
to be shot: but the one which 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 ( Phmnicura ruticilla), the writer remarks that 
it was by no means common in the neighborhood, and he 
expresses much surprise how the sitting female could so 
soon give effectual notice that she was a widow. 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 
far from loud. I will give only one other fact, on the 
authority of this same observer ; one of a pair of starlings 
[Sturnus 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 dur- 
ing 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 : 



102 SEXUAL SELECTIOX : BIRDS. [Part II. 

nevertheless after all this destruction, a brood was 
reared." 

These facts are certainly remarkahle. How is it that 
so many birds are ready immediately to replace a lost 
mate ? Magpies, jays, carrion-crows, partridges, and 
some other birds, are never seen during the spring by 
themselves, and these oflfer at first sight the most perplex- 
ing case. But birds of the same sex, although of course 
not truly paired, sometimes live in pairs or in small par- 
ties, as is known to be the case with pigeons and par- 
tridges. Birds also sometimes live in triplets, as has been 
observed with starlings, carrion-crows, parrots, and par- 
tridges. With partridges two females have been known 
to live with one male, and two males with one female. 
In all such cases it is probable that the union would be 
easily broken. The males of certain birds may occasion- 
ally be heard jiouring forth their love-song long after the 
proper time, showing that they have either lost or never 
gained a mate. Death from accident or disease of either 
one of a pair, would leave ^he other bird 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 in- 
duced to desert their mates, and would probably be glad 
to take what sliare they could of the pleasures and duties 
of rearing offspring, although not their own.' Such con- 

' On the Peregrine falcon see Thompson, ' N'at. 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 Pha?nicura, 
see Loudon's 'Mag. of Nat. Hist.' vol. vii. 1834, p. 245. Brehni ('Thier- 
leben,' B. iv. s. 991) also alludes to cases of birds thrice mated during 
same day. 

"> See White ('Nat. Ili.-^t. of Selborne,' 1825, vol. i. p. 140) on the ex- 
istence, carl}- in the season, of small coveys of male partridges, of which 
fact 1 have heard other instances. See Jeimer, on the retarded state of 



Chap. XIV.] MENTAL QUALITIES. 103 

tingencies as these probably explain most of the foregoing 
cases.* 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 Weir, that inasmuch as the act of courtship 
appears to be with many birds a prolonged and tedious 
affair, so it occasionally happens that certain males and 
females do not succeed, during the proper season, in ex- 
citing each other's love, and consequently do not pair? 
This suspicion will appear somewhat less improbable after 
we have seen what strong antipathies and preferences fe- 
male birds occasionally evince toward particular males. 

Mental Qualities of Birds and their Taste for the 
^Beautiful. — Before we discuss any further the question 
whether the females select the more attractive males, or 

the generative organs in certain birds, in 'Phil. Transact.' 1824. In re- 
gard to birds living in triplets, I owe to Mr. Jemier Weir the cases of 
the starling 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, ' Observations in Natural History,' 
1846, p. 87. 

* The following case has been given (' The Times,' Aug. 6, 1868) by 
the Rev. F. 0. Morris, on the authority of the Hon. and Rev. 0. W. For- 
ester. " The game-keeper here found a hawk's nest this year, with five 
young ones in it. He took four and killed them, 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 af- 
terward- 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 
fiiid. No more came on the like fruitless errand." 



104 SEXUAL SELECTION: BIRDS. [Part IL 

accept the first whom they may encounter, it will be ad- 
visal)le briefly to consider the mental powers of birds. 
Their reason is jrenerally, and perhaps justly, ranked as 
low; yet some facts could be given" leading to an oppo- 
site conclusion. Low powers of reasoning, however, are 
compatible, as we see with mankind, with strong affec- 
tions, 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 at- 
tached to each other tliat when one dies the other for a 
long time pines ; but ]Mr. Jenner Weir thinks that Avith 
most birds the strength of their affection has been much 
exaggerated. Nevertheless 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 proving the attachment of mated 
birds. Starlings, however, as we have seen, may be con- 
soled thrice in the same day for the loss of their mates. 
In the Zoological Gardens parrots have clearly recognized 
their former masters after an interval of some months. 
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 would naturally remain mated for 
life be separated for a few weeks during the winter and 
matched with other birds, the two, when brouglit together 
again, rarely, if ever, recognize each other. 

Birds sometimes exhibit benevolent feelings ; they will 

' For instance, Mr. Yarrell states (' Hist. British Birds,' vol. iii. 1845, 
p. 585) that a gull was not able to swallow a small bird which had been 
given to it. The gull " paused for a moment, and then, as if suddenly 
recollecting himself, ran off at full speed to a pan of water, shook the 
bird about in it until well soaked, and immediately gulped it down. 
Since that time he invariably has had recourse to the same expedient in 
similar cases." 

'<• 'Tour in Sutherlandshire,' vol. i. 1849, p. 185. 



Chap. XIV.] MENTAL QUALITIES. , 105 

feed the deserted young even of distinct species, but this 
perhaps ought to be considered as a mistaken instinct. 
They will also 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 tne same species." These parrots, also, evinced un- 
bounded curiosity, and clearly had " the idea of property 
and possession." '^ 

Birds possess acute powers of observation. Every 
mated bird, of course, recognizes its fellow. Audubon 
states that with the mocking-thrushes of the United States 
[Jifiinus polyglottus) a certain number remain all the year 
round in Louisiana, while the others migrate to the East- 
ern States ; these latter, on their return, are instantly 
recognized, and always attacked, by their Southern breth- 
ren. Bii'ds under confinement distinguish different per- 
sons, as is proved by the strong and permanent antipathy 
or alFection which they show, without any apparent cause, 
toward certain individuals. I have heard of numerous 
instances with jays, partridges, canaries, and especially 
bullfinches. Mr. Hussy has described in how extraordi- 
nary a manner a tame partridge recognized everybody ; 
and its likes and dislikes were very strong. This bird 
seemed " fond of gay colors, and no new gown or cap 

" Acclimatization of Parrots,' by C. Buxton, M. P. ' Annals and 
Mag. of Nat. Hist.' Nov. 1868, p. 381. 



106 SEXUAL SELECTION : BIRDS. [Part IL 

could be put on without catchinj^ his attention." " Mr. 
Hewitt has carefully described the habits of some ducks 
(recently descended from wild birds), which, at the ap- 
proach of a strange dog or cat, would rush headlong into 
the water, and exhaust themselves in their attempts to es- 
cape ; but they knew so well Mr. Hewitt's own dogs and 
cats 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 who attended them if 
she made any great change iu 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 mutu- 
ally recognized each other as old friends.'^ 

Mr. Jenner Weir is convinced that birds pay particu- 
lar attention to the colors of other birds, sometimes out of 
jealousy, and sometimes as a sign of kinship. Thus he 
turned a reed-bunting [Ember iza schcenlculus)^ which had 
acquired its black head, 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 had never before quarrelled with any of its com- 
rades, including another reed-bunting, which had not as 
yet become black-headed: but the reed-bunting with a 
black head was so iininercifuUy treated, that it had to be 
removed. Mr. Weir was also obliged to turn out a robin, 
as it fiercely attacked all bii-ds with any red in their plu- 
mage, but no other kinds; it actually killed a red-breasted 

>2 'The Zoologist,' 1 847-1848, p. 1602. 

" Hewitt on wild ducks, 'Journal of Horticulture,' Jan. 13, 1863, p. 
39. Audubon on the wild-turkey, 'Ornith. Biography,' vol. i. p. 14. On 
the mocking thrush, ibid. vol. i. p. 110. 



Chap. XIV.] TASTE FOR THE BEAUTIFUL. 107 

crossbill, and nearly killed a goldfinch. On the other 
hand, he has observed that some birds, when first intro- 
duced into his aviary, fly toward the species which re- 
semble them most in color, and settle by their sides. 

As male birds display with so much care their fine 
plumage and other ornaments in the presence of the fe- 
males, it is obviously probable that tliese appreciate the 
beauty of their suitors. It is, howevei", difticult 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 at a supposed rival, 
though this is not the conclusion of some observers. In 
other cases it is difficult to distinguish between mere curi- 
osity and admiration. It is perhaps the former feeling 
which, as stated by Lord Lilford,^* attracts the Ruff 
strongly toward any bright object, so that, in the Ionian 
Islands, it "will dart down to a bright-colored handker- 
chief, 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 outside 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. 
" The ' Ibis,' vol. ii. 1860, p. 344. 



108 SEXUAL SELECTION': BIRDS. [Part IL 

46, p. GV), where the sexes congregate and play strange 
antics, are differently constructed, bnt what most concerns 
us is, that tliey are decorated in a different manner by the 
several species. The Sntin l)ower-bird collects gayly-col- 
ored articles, such as the blue tail-feathers of parrakeets, 
bleached 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 
bowei*-bii"d " is beautifully lined with tall grasses, so dis- 
posed 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 
brouglit from a great distance. The Regent-bird, as de- 
scribed by Mr. Ramsay, 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 " these 
highly-decorated halls of assembly must be regarded as 
the most wonderful instances of bird-architecture yet dis- 
covered ; " and the taste, as we see, of the several species 
certainly difiers." 

Preference for Particulnr Males by the Females. — 
Having made these preliminary remarks on the discrimi- 

"■ On the ornamented nests of hizmminfr-liirds, Gould, ' Introduction 
to the Trochilidre, 1861, p. 19. On the bower-birds, Gould, 'Hand-book 
to the Birds of Australia,' 1865, vol. i. pp. 444-401. Mr. Ramsay in the 
'Ibis,' 1867, p. 456. 



Chap. XIV.] PREFERENCE BY THE FEMALE. 109 

nation 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 occasionally pair in a state of nature and produce 
hybrids. Many instances could be given : thus Macgil- 
livray relates how a male blackbird and female thrush 
"fell in love with each othei'," and produced offspring." 
Several years ago eighteen cases had been recorded of 
the occurrence in 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 believe, hybrids ai-e some- 
times the result of the casual intercourse of birds building 
in close proximity. But these remarks do not apply to the 
many recorded instances of tamed or domestic birds, be- 
longing 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 Wig- 
eon {Mareca penelope), living with females of the same 
species, has been known to pair with a Pintail duck, ^wer- 
qtcedula acuta. Lloyd describes the remarkable attach- 
ment between a shield-drake (Tadorna vulpanser) and a 
common duck. Many additional instances could be given ; 
and the Rev. E. S. Dixon remarks that " those who have 

" ' Hist, of British Birds,' vol. ii. p. 92. 

" 'Zoologist,' 1853-1854, p. 3946. 

'8 Waterton, 'Essays on Nat. Hist.' 2d series, pp. 42, 11 7. For tbe 
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; Bechstein, ' Stubenvogel,' 1840, 
s. 230. 



110 SEXUAL SELECTION: BIRDS. [Part IL 

kept many different species of gccsc together, well know 
what unaccountable attachments they are frequently form- 
ing, 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 cygnokles), 
and a coinmon gander with three geese. The two lots 
kept quite separate, until the Chinese gander seduced one 
of the common geese to live with him. Moreover, 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 Pin- 
tail 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 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 her blandishments, 
for thej' nested and produced seven or eight young ones." 

What the charm may have been in these several cases, 
beyond mere novelty, we cannot even conjecture. Color, 
however, sometimes comes into play ; for in order to raise 
hybrids from the siskin {Prinf/iUa sphms) 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, chatfinches, and 
other birds, in order to see which she would choose ; but 
there never was any doubt, and the greenfinch carried the 
day. They ^laired and produced hybrid offspring. 



Chap. XIV.] PREFEREXCE BY THE FEMALE. m 

With the members of the same species the fact of the 
female preferring to pair with one male rather than with 
another is not so likely to excite attention, as when this 
occurs between distinct species. Such 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 lat- 
ter fact I could give sufficient proofs with pigeons, and 
especially with fowls, but they cannot be here related. 
Vitiated instincts may also account for some of the hybrid 
unions above referred to ; 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 high 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 phmnice- 
us) is likewise pursued by several males, " until, becoming 
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 as- 
tonishing 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 {Cathartes aura) of the United States, 



112 SEXUAL SELECTION: BIRDS. [Part IL 

parties of eight or ten or more males and females assem- 
ble on ftiUen logs, "exhibiting the strongest desire to 
please mutually," and after many caresses, each male 
leads oft" his partner on tl)e wLng. Audubon likewise care- 
fully 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 j^re- 
viously mated " renewed their courtship as early as the 
month of January, while the others would be contend- 
ing or coquetting for hours every day, until all seemed 
satisfied with the choice they had made, after which, al- 
though 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 ob- 
server. 

Turning now to domesticated and confined birds, I 
will commence by giving what little I have learned re- 
specting the courtship of fowls. I have received long let- 
ters on this subject from Messrs. Hewitt and Tegetmeier, 
and almost an essay from the late ]\[r. Brent. It will be 
admitted by every one that these gentlemen, so well 
known from their published works, are careful and expe- 
rienced observers. Tliey do not believe that the females 
]nTfer certain males on account of the beauty of their plu- 
mage ; but some allowance must be made for the artificial 
state under which they have long been kept. Mr. Teget- 
meier is convinced that a game-cock, though disfigured 
by being dubbed with his hackles trimmed, would be ac- 

'• Audubon, ' Ornitholog. Biography,' vol. i. pp. 101, 349; vol. ii. pp. 
42, 275 ; vol. iii. p. 2. 



Chap. XIV.] PREFERENCE BY THE FEMALE. II3 

cepted as readily as a male retaining all his natural orna- 
ments. Mr. Brent, however, admits that the beauty 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 fe- 
male almost invariably prefers the most vigorous, defiant, 
and mettlesome male ; hence it is almost useless, as he re- 
marks, " to attempt true breeding if a game-cock in good 
health and condition runs the locality, for almost every 
hen on leaving the roosting-place will resort to the game- 
cock, even though that bird may not actually drive away 
the male of her own variety." Under ordinary circum- 
stances the males and females of the fowl seem to come to 
a mutual understanding by means of certain 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 disposition, as the same writer in- 
forms me, dislike strange males, and will not yield xxntil 
well beaten into compliance. Ferguson, however, de- 
scribes how a quarrelsome hen was subdued by the gentle 
courtship of a Shanghai cock.^" 

There is reason to believe tliat pigeons of both sexes 
prefer pairing with birds of the same breed ; and dove- 
cot-pigeons dislike all the highly improved breeds.^' Mr. 
Harrison Weir has lately heard from a trustworthy ob- 
server, 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 be matched, after repeated trials, with a black 
male, but immediately paired with a dun. Generally col- 
or alone appears to have little influence on the pairing of 
pigeons. Mr. Tegetmeier, at my request, stained some 

20 ' Rare and Prize Poultry,' 1854, p. 27. 

^^ ' The Variation of Animals and Plants under Domestication,' vol. ii. 
p. 103. 



114 SEXUAL SELECTION : BIRDS. [Part IL 

of his Inrils witli magenta, but they were not much no- 
ticed by the others. 

Female pigeons occasionally feel a strong antipathy 
toward certain males, without any assignable cause. 
Thus MM. Boitard and Corbie, whose experience ex- 
tended over forty-five years, state : " Quand une feraelle 
<iprouve de I'antipathie pour un male avec lequel on veut 
I'accoupler, malgre tous les feux de I'amour, malgre I'al- 
piste et le ch^nevis dont on la nourrit pour augmenter son 
ardeur, malgre un em])iisonnement de six mois et m6me 
d'un an, elle refuse constamment ses caresses ; les avances 
empi-essees, les agaceries, les tournoiemens, les tendres 
roucoulemens, rien ne peut lui plaire ni I'emouvoir ; gonflee, 
boudense, blottie dans un coin de sa prison, elle n'en sort 
que pour boire et manger, ou pour repousser avec une 
esp^cc de rage des caresses devenues trop pressantes." " 
On the other hand, Mr. Harrison Weir has himself ob- 
served, and has heard from several breeders, that a female 
pigeon will occasionally take a strong fancy for a particu- 
lar male, and will desert her own mate for him. Some 
females, according to anotlier experienced observer, Rie- 
del,^' are of a profligate disposition, and ])refer almost any 
stranger to their own mate. Some amorous males, called 
by our Englisli fanciers " gay birds," are so successful in 
their gallantries, that, as Mr. II. "Weir informs me, they 
must be shut up, on account of the mischief which they 
cause. 

Wild-turkeys in the United States, according to Au- 
dubon, " sometimes pay their addresses to the domesti- 
cated females, and are generally received by them with 

22 Boitard and Corbie, 'Les Pigeons,' 1824, p. 12. Prosper Lucas 
('Trait6 de I'llered. Nat.' tome ii. 1850, p. 29»)) lias hirasell" observed 
nearly similar facts with pigeons. 

" 'Die Taubenzucht,' 1824, s. 86. 



Chap. XIV.] PREFERENCE BY THE FEMALE. US 

great pleasure." So that these females apparently prefer 
the wild to their own males." 

Here is a more curious case. Sir R. Heron during 
many years kept an account of the habits of the peafowl, 
which he bred in large numbers. He states that " the 
hens have frequently great preference to a particular pea- 
cock. They were all so fond of an old pied cock, that one 
year, Avhen he was confined though still in view, they 
were constantly assembled close to the trellis-walls of his 
prison, and would 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, which to our eyes is a 
more beautiful bird than the common kind. 

Lichtenstein, who was a good observer and had excel- 
lent opportunities of observation at the Cape of Good 
Hope, assured Rudolphi that the female widow-bird 
{Ghera 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."' Here is 
another striking case ; Dr. Jaeger," director of the Zoo- 
logical Gardens of Vienna, states that a male silver-pheas- 
ant, who had been triumphant over the other males and 
was the accepted lover of the females, had his ornamental 
plumage spoiled. He was then immediately superseded 

2* ' Ornithological Biography,' vol. i. p. 1 3. 

2* ' Proc. Zool. Soc' 1835, p. 54. The japanned peacock is consid- 
ered by Mr. Sclater as a distinct species, and has been named Pavo ni' 
gripennis. 

^^ Rudolphi, ' Beytrage znr Anthropologie,' 1812, s. 184. 

*' ' Die Darwin'sche Theorie, und ihre Stellung zu Moral und Religion,' 
1869, s. 59. 



IIG SEXUAL SELECTION: BIRDS. [Part IL 

by a rival, who got the upper hand and afterward led the 
flock. 

Not only docs the female exert a choice, but in some 
few cases she courts the male, or even fights for his pos- 
session. 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 caper- 
cailzie, the females flit round the male, while he is parad- 
ing at one of the places of assemblage, and solicit his 
attention."* We have seen that a tame wild-duck seduced 
after a long courtship an unwilling Pintail drake. Mr. 
Bartlett believes that the Lophophorus, 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 ot 
rivalry is more surprising 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 immedi- 
ately 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 re- 
tribution, for, ceasing to be pugnacious, Mr. Weir replaced 
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 exceptions to this rule, as we 
siiall hereafter see, apparently occur in some few groups. 
W^ith domesticated birds, I have heard of only one case in 

'8 In regard to peafowl, see Sir R. Heron, 'Proc. Zoolog. Soc' 1835, 
p. 54, and the Rev. E. S. Dixon, ' Ornamentdl Poultry,' 1848, p. 8. For 
tlie turkey, Audubon, ibid. p. 4. For the capercailzie, Lloyd, 'Game- 
Birds of Sweden,' 1867, p. 23. 



Chap. XIV.] PREFERENCE BY THE FEMALE. H^ 

which the males show any preference for particular fe- 
males, namely, that of the domestic cock, who, according 
to the high authoi'ity of Mi'. 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." ^' From some inexplicable cause he shows 
the most determined aversion to certain hens, which no 
care on the part of the breeder can overcome. Some hens, 
as Mr. Hewitt informs me, are quite unattractive even to 
the males of their own species, so that they may be kept 
with several cocks during a wliole season, and not one egg 
out of forty or fifty will prove fertile. On the other hand, 
with the Long-tailed duck (ITarelda glacialls), "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 
stuff them as decoys.^" 

With respect to female birds feeling a preference for 
particular males, we must bear in mind that we can judge 
of choice being exerted, only by placing ourselves in 
imagination in the same position. If an inhabitant of 
another planet were to behold a number of young rustics 
at a fail', coui-ting and quarrelling over a pretty girl, like 
birds at one of their places of assemblage, he woidd be 
able to infer that she had the power of choice only by ob- 
serving the eagerness of the wooers to please her, and to 
display their fineiy. Now with birds, the evidence stands 
thus ; they have acute powers of observation, and they 

'' Mr. Hewitt, quoted in ' Tegetmeier's Poultry-Book,' 1866, p. 165. 
^ Quoted in Lloyd's ' Game-Birds of Sweden,' p. 345. 



118 SEXUAL SELECTION: BIRDS. [Part IL 

seem to have some taste for the beautiful both in color 
and sound. It is certain that the females occasionally ex- 
hibit, from unknown causes, the strongest antipathies and 
preferences for particular males. When the sexes differ 
in color or in other ornaments, the males with rare excep- 
tions are the most highly decorated, either permanently 
or temporarily during the breeding-season. They sedu- 
lously display their various ornaments, exert their voices, 
and perform strange antics in the presence of the females. 
Even well-armed males, who, it might have been thought, 
would have altogether depended 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 con- 
gregate at the same spot, and their courtship is a pro- 
longed afiair. There is even reason to suspect that the 
males and females within the same district do not always 
succeed in pleasing each other and pairing. 

What, then, are we to conclude from these facts and 
considerations ? Does the male parade his charms with 
so much pomp and rivalry for no purpose ? Are we not 
justified 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 delib- 
erates; 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 proliably 
struck only by the general effect. Nevertheless, after hear- 
ing how carefully the male Argus pheasant displays his 
elegant primary wing-feathers, and erects his ocellated 
plumes in the right position for their full effect; or again. 



Chap. XIV.] VARIABILITY. 119 

how the male goldfinch alternately displays his gold-be- 
spangled 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 the analogy of our own minds ; and the mental 
powers of birds, if reason be excluded, do not fundamen- 
tally differ 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 individual 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 at- 
tractive males would almost certainly lead to their modi- 
fication ; and such modifications might in the course of 
time be augmented to almost any extent, compatible with 
the existence of the species. 

VarlahlUty of Birds, and especially of their Secondary 
Sexual Characters. — Variability and inheritance are the 
foundations for the work of selection. That domesticated 
birds have varied greatly, ther variations being inherited, 
is certain. That birds in a state of nature present indi- 
vidual differences is admitted by every one ; and that 
they have sometimes been modified into distinct races, is 
generally admitted." Variations are of two kinds, which 

51 According to Dr. Blasius ('Ibis,' vol. ii. 1860, p. 29'7), there are 
425 indubitable species of birds which breed in Europe, besides 60 
forms, which are frequently regarded as distinct species. Of the latter, 
Blasius thinks that only 10 are really doubtful, and that the other 50 
ought to be united with their nearest allies ; but this shows that there 
must be a considerable amount of variation with some of our European 



120 SEXUAL SELECTION: BIRDS. [Part IL 

insensibly graduate into each other, namely, slight difter- 
ences between all the members of the same species, and 
more strongly-marked deviations which occur only occa- 
sionally. These latter are rare witli birds in a state of 
nature, and it is very doubtful whether they have often 
been preserved through selection, and then transmitted to 
succeeding generations." Nevertheless, it may be worth 
while to give the few cases relating chiefly to color (sim- 
ple albinism and melanism being excluded), which I have 
been able to collect. 

Mr. Gould is well known rarely to admit the existence 
of varieties, for he esteems very slight ditt'erences as spe- 
cific ; now he states " that near Bogota certain humming- 
birds belonging to the genus Cynanthus are divided into 
two or three races or varieties, which difier 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 

birds. It is also an unsettled point with naturalists, whether several 
Korth American birds ought to be ranked as specifically distinct from 
the corresponding European species. 

»2 'Origin of Species,' fifth edit. 18G9, p. 104. I had always per- 
ceived that rare and strongly-marked deviations of structure, deserving 
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 appre- 
ciated 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 individ- 
uals of each breed, without any intention on his part to modify the char- 
acters of the breed. But until I read an able article in the 'North Brit- 
ish Review' (March, 18G7, p. 289, et seq.\ which has been of more use to 
me than any other Review, I did not see how great the chances were 
against the preservation of variations, whether slight or strongly pro- 
nounced, occurring only in single individuals. 

33 ' Introduct. to the Trochilidae,' p. 102. 



Chap. XIV.] VARIABILITY. 121 

or the following cases. In the males alone of one of the 
Australian parrakeets " the thighs in some are scarlet, in 
others grass-green." In another parrakeet 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." °* In the United States some few of the 
males of the Scarlet Tanager ( Tanagra rubra) have " a 
beautiful transverse 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 circum- 
stances. In Bengal the Honey buzzard {Pernis cristata) 
has either a small rudimental crest on its head, or none at 
all ; so slight a difference, 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 interest- 
ing : A pied variety of the raven, with the head, breast, 
abdomen, and parts of the wings and tail-feathers white, 
is confined to the Feroe Islands. It is not very rare there, 
for Graba saw during his visit from eight to ten living 
specimens. Although the characters of this variety are 
not quite constant, yet it has been named by several dis- 
tinguished 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 Brtinnich to conclude that it was 
specifically distinct ; but this is now known to be an 
error. ^' 

34 Gould, ' Hand-book of Birds of Australia,' vol. ii. pp. 32, 68. 

3^ Audubon, 'Ornitholog. BiograpLy,' 1838, vol. iv. p. 389. 

3^ Jerdon, 'Birds of India,' vol. i. p. 108; and Mr. Blyth, in 'Land 
and Water,' 1868, p. 381. 

3' Graba, 'Tagebuch, Reise nach Faro,' 1830, s. 51-54. Macgillivray 
'Hist. British Birds,' vol. iii. p. 745. 'Ibis,' vol. v. 1863, p. 469. 

35 



122 SEXUAL SELECTION : I5IRDS [Part IL 

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 
Graba's estimation, consists of this variety. It is charac- 
terized " 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 dis- 
tinct species under the name of U. lacrt/mans, 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 ap- 
pear suddenly are often, as I have elsewhere shoAvn," 
transmitted either unaltered or not at all. We thus see 
that two distinct forms of the same species may coexist in 
the same district, and we cannot doubt that if the one had 
possessed any great advantage 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 and driven away by their comrades, had been 
highly attractive, like the pied peacock before mentioned, 
to the common black females, their numbers would have 
rapidly increased. And this would have been a case of 
sexual selection. 

With respect to the slight individixal dittl-rences which 
are common, in a greater or less degree, to all the members 
of the same species, we have every reason to believe that 
they are by far the most impcn-tant for the work of selec- 
tion. 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 

^* Graba, ibid. s. 54. Macgillivray, ibid. vol. v. p. 327. 

^^ 'Variation of Animals and I'lant.-^ under Domestication,' vol. ii. 
p. 02. 

*° On these points sec also ' Variation of Animals and Plants under 
Domestication,' vol. i. p. 253 ; vol. ii. pp. 73, 75. 



Chap. XIV.] VARIABILITY. 123 

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 selection. 
Whether characters thus acquired are transmitted to one 
sex or to both sexes, depends exclusively in most cases, as 
I hope to show in the following chapter, on the form of 
inheritance which prevails in the groups in question. 

It is sometimes difficult to form any opinion whether 
certain slight differences between the sexes of birds are 
simply the result of variability with sexually-limited in- 
heritance, without tlie aid of sexual selection, or whether 
they have been augmented through this latter process. I 
do not here refer to the innumerable instances in which 
the male displays splendid colors or other ornaments, of 
which the female partakes only to a slight degree ; for 
these cases are almost certainly due to characters primarily 
acquired by the male, having been transferred, in a greater 
or less degree, to the female. But what are we to con- 
clude with respect to certain birds in which, for instance, 
the eyes differ slightly in color in the two sexes ? " In 
some cases the eyes differ conspicuously ; thus Avith the 
storks of the genus Xenorhytichus those of the male are 
blackish-hazel, while those of the females are gamboge- 
yellow ; with many hornbills (Buceros), as I hear from 
Mr. Blyth," the males have intense crimson, and the fe- 
males white eyes. In the Suceros bieomis, the hind mar- 
gin 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 sex- 
ual selection in the males ? Tliis is very doubtful ; for 
Mr. Bartlett showed me in the Zoological Gardens that 

*^ See, for instance, on the ii-ides of a Podica and Gallicres. in ' Ibis,' 
vol. ii. 1860, p. 206 ; and vol. v. 1863, p. 426. 

42 See also Jerdon, ' Birds of India,' vol. i. pp. 243-245. 



124 SEXUAL SELECTION: BIRDS. [Part II. 

the inside of the mouth of this Buceros is black in the 
male and flesh-colored in the female ; and their external 
appearance of beauty would not be thus affected. I ob- 
served in Chili" that the iris in the condor, vhen about a 
year old, is dark-brown, but changes at maturity into yel- 
lowish-brown in the male, and into bright red in the female. 
The male has also a small, longitudinal, leaden-colored, 
fleshy crest or comb. With many gallinaceous birds the 
comb is highly ornamental, and assumes vivid colors dur- 
ing 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 fe- 
male. No certain answer can be given to these questions ; 
but we ought to be cautious in assuming that knobs and 
various fleshy appendages cannot be attractive to the fe- 
male, when we remember that with savage races of man 
various hideous deformities — deejD scars on the face with 
the flesh raised into jirotuberances, the septum of the nose 
pierced by sticks or bones, holes in the ears and lips 
stretched widely 0})en — are all admired as ornamental. 

Whether or not unimportant difterences between the 
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 j)lumage 
often varies on diflerent parts of the body, or over the 
whole body, in the same manner. We see this well illus- 
trated in 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 feath- 

« 'Zoology of the Voyage of H. M. S. Beagle,' 1841, p. C. 



Chap. XIV.] VARIABILITY. 125 

ers on the head of the male become hackle-shapied, evi- 
dently on the principle of correlation; while those on 
the head of the female are of the ordinary shape. The 
color also of the hackles forming the top-knot of the male, 
is often correlated 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 Iloudans, and 
Creve-coeur breeds. In some natural species we may ob- 
serve exactly the same correlation in the colors of these 
same feathers, as in the males of the splendid Golden 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 pencilled breeds 
of the fowl ; and on the principle of correlation the feathers 
over the whole body are often modified in the same man- 
ner. We are thus enabled without much trouble to rear 
breeds with their plumage marked and colored almost as 
symmetrically as in natural species. In laced and spangled 
fowls the colored margins of the feathers are abruptly de- 
fined ; 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 ex- 
tremities, 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 dis- 
tribution 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 sur- 
rounded by a regular zone of dark-brown, edged with 
brownish-white. In these cases we see feathers becoming 
symmetrically shaded, like those which give so much ele- 
gance to tlie plumage of many natural species. I have 



126 SEXUAL SELECTION : BIRDS. [Part II. 

ulso noticed a variuty of the common pigeon with the 
wing-Lars symmetrically zoned with three bright shades, 
instead of being simply black on a slaty-blue ground, as in 
the parent-species. 

In many large groups of birds it may be observed 
that the ])lumage is difterently colored in each species, 
yet that certain spots, marks, or stripes, though likewise 
difterently colored, are retained by all the species. Anal- 
ogous 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 different tint. Here is a 
more curious case, in which certain marks are retained, 
though colored in almost an exactly reversed manner to 
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 hav- 
ing a white instead of a blue tail, with precisely that 
small part black which is white in the parent-species." 

Formation and VariahilUy of the Ocelli or Eye-like 
Spots on the Plumage of Hii'ds. — 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 the 
wings of many Le])idoptera and other insects, they de- 
serve to l)e especially noticed. An ocellus consists of a 
spot within a ring of another color, like the puj)il within 
the iris, but the central spot is often surrounded by addi- 
tional concentric zones. The ocelli on the tail-coverts of 
the peacock ofter a familiar example, as well as those on 
the wings of the peacock-butterfly (Vanessa). Mr. Tri- 
men has given me a description of a South African moth 

** Bcclistoin, ' Naturgcschichte Deutschlands,' B. iv. 1705, s. 31, ou a 
Bub-varicty of the Monck pigeon. 



Chap. XIV.] OCELLI. 127 

{Gynaiiisa Isis), allied to our Empei'or moth, in which a 
magnificent ocellus occupies nearly the whole surface of 
each hinder wing ; it consists of a black centre, including 
a semitransparent crescent-shaped mark, surrounded by 
successive ochre-yellow, black, ochre-yellow, pink, white, 
pink, brown, and whitish zones. Although we do not 
know the steps by which these wonderfully-beautiful and 
complex ornaments have been developed, the process at 
least with insects has probably been a simple one ; 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 {Hip- 
parchia Janira) exhibiting numerous gradations from a 
simple minute black spot to an elegantly-shaded ocellus. 
In a South African butterfly ( Cyllo Leda^ Linn.) belong- 
ing to the same family, the ocelli are even still more vari- 
able. In some specimens (A, Fig. 52) large spaces on 
the upper surface of the wings are colored black, and in- 
clude irregular white marks ; and from this state a com- 
plete gradation can be traced into a tolerably perfect (A') 
ocellus, and this results from the contraction of the irreg- 
ular 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 (B), into 
perfectly symmetrical andlai-ge ocelli (B')." In cases like 
these, the development of a perfect ocellus does not re- 
quire a long course of variation and selection. 

•*' This woodcut has been engraved from a beautiful drawing, most 
kindly made for me by Mr. Trimen ; see also his description of the won- 
derful amount of variation in the coloration and shape of the wings of 
this butterfly, in his 'Rhopalocera Africae Australis,' p. 186. See also 
an interesting paper by the Rev. H. H. Higgins, on the origin of the 
ocelli in the Lepidoptera in the ' Quarterly Journal of Science,' July. 
1868, p. 326. 



128 



SEXUAL SELECTION: BIRDS. 



[I'art II. 



With birtls ami many other animals it seems, from the 
comparison of allied species, to follow, that circular spots 
are often generated by the breaking up and contraction 
of stripes. In the Tragopan pheasant faint white lines in 
the female represent the beautiful white spots in the 
male • " and something of the same kind may be observed 

A A' 




Fig. 52. — Cyllo leda, Liun., from a flrawinij liy Mr. Trimen, ehowing the extreme 
range of variation in tlie ocelli. 
A. Specimen, from Mauritins, upper B. Specimen, from Java, npper surface 

piirface of fore-wing. of hind-wing. 

A'. Specimen, from Natal, ditto. B'. Specimen, from Mauritius, ditto. 

in the two sexes of the Argus pheasant. However this 
may be, ajipearances strongly favor the belief that, on the 
one liand, a dark spot is often formed by the coloring 
matter being drawn toward a central point from a sur- 
rounding zone, Avhich 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 seems to be 
a nearly constant quantity, but is redistributed, cither 

*' Jcrdon, 'Birds of India,' vol. iii. p. 517. 



Chap. XIV.] GRADATION OF CHARACTERS. 129 

centripetally or centrifugally. The feathers of the com- 
mon guinea-fowl offer a good instance of white spots sur- 
rounded by darker zones ; and whenever the white spots 
ai'e 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 for- 
mation of an ocellus in its simplest 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 bearing in mind the zoned feathers of the mongrel 
offspring from differently-colored fowls, and the extraor- 
dinary variability of the ocelli in many Lepidoptera, the 
formation of these beautiful ornaments can hardly be a 
highly-complex process, and probably depends on some 
slight and graduated change in the nature of the tissues. 

Gradation of Secondary Sexual Characters. — Cases 
of gradation are important for us, as they show that it is 
at least possible that highly-complex ornaments may have 
been acquired by small successive steps. In order to dis- 
cover the actual steps by which the male of any existing 
bird has acquired his magnificent colors or other orna- 
ments, we ought to behold the long line of his ancient and 
extinct progenitors ; but this is obviously impossible. 
"We may, however, generally gain a clew by comparing all 
the species of a group, if it be a large one ; for some of 
them will probably retain, at least in a partial manner, 
traces of their former characters. Instead of entering on 
tedious details respecting various groups, in which strik- 
ing instances of gradation could be given, it seems the 
best plan to take some one or two strongly-characterized 
cases, for instance that of the peacock, in order to dis- 
cover if any light can thus be thrown on the steps by 



130 SEXUAL SELECTION: BIRDS. [P^vrt IL 

which this bird lias 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 Avith the feathers of many species, and with 
some varieties of the domestic fowl and pigeon. The 
barbs coalesce toward the extremity of the shaft to form 
the oval disk or ocellus, which is certainly one of the most 
beautiful objects in the world. This consists of an irides- 
cent, intensely blue, indented centre, surrounded by a 
rich green zone, and 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 per- 
haps deserves notice ; the barbs, for a space along one of 
the concentric zones are destitute, to a greater or less de- 
gree, of their bai-bules, so that a part* of the disk is sur- 
rounded by an almost transparent zone, which gives to it 
a highly - finished aspect. But I have elsewhere de- 
scribed " an exactly analogous variation in the hackles of 
a sub-variety of the game-cock, in which the ti])s, having 
a metallic lustre, " 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 centre of the ocellus is 
deeply indented on the line of the shaft. The surround- 
ing zones likewise show traces, as may be seen in the 
drawing (Fig. 53), of indentations, or rather breaks. 
These indentations are common to the Indian and Javan 
peacocks (Pavo cristatics and J*, miiticus) ; and they 
seemed to me to deserve particular attention, as jtroliably 
connected with the development of the ocellus; but for a 
long time I could not conjecture their meaning. 

If we admit the principle of gradual evolution, there 

*' ' \^ariationof Animals and Plants under Domestication,' vol. i. p. 254. 



Chap. XIV.] 



GRADATION OF CHARACTERiS. 



131 



must formerly have existed many sjDecies 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 
of the former, and the simpler ocelli or mere colored spots 




Fig. 53.— Feather of Peacock, about two-thirds of natural size, carefully drawn 
by Mr. Ford. The transparent zone is represented by the outermost white 
zone confined to the upper end of the disk. 

of other birds ; and so with all the other characters of the 
peacock. Let us look to the allied Gallinacea? for any 
still-existing gradations. The species and sub-species of 
Polyplectron inhabit countries adjacent to the native land 
of the peacock ; and they so far resemble this bird that 



132 SEXUAL SELECTION: BIRDS. [Part II. 

they arc soinetinics called peacock-pheasants. I am also 
informed 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 be- 
fore the comparatively plain-colored females, expanding 
and erecting their tail and wing feathers, which are orna- 
mented with numerous ocelli. I re(iuest the reader to 
turn back to the drawing (Fig. 51, p. 86) of a Polyplec- 
tron. In P. jyapoleonis the ocelli are confined to the tail, 
and the back is of a rich metallic blue, in which respects 
this species approaches the Java peacock. P. Ilardwickii 
possesses a peculiar top-knot, somewhat like that of this 
same kind of peacock. The ocelli on the wings and tail 
of the several species of Polyplectron 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. chinquis shades into brown which is edged 
with cream-color, so that the ocellus is here surrounded 
with differently, though not brightly, shaded concentric 
zones. The imusual length of the tail-coverts is another 
highly-remarkable character in Polyplectron; for in some 
of the species they are half as long, and in others two- 
thirds of the length of the true tail-feathers. The tail-cov- 
erts are ocellated, as in the peacock. Thus the several 
species of Polyjilectron manifestly make a graduated ap- 
proach in the length of their tail-coverts, in the zoning of 
the ocelli, and in some other characters, to the peacock. 

Notwithstanding this approach, the first species of 
Polyplectron which I hapj)eued to examine almost made 
me give up the search ; for I found not only that the true 
tail-feathers, which in the peacock are quite plain, Avere 
ornamented with ocelli, but that the ocelli on all the 
feathers differed fundamentallj^ from those of the peacock, 
in there being two on the same feather (Fig. 54), one on 
each side of the shaft. Hence I concluded that the early 



Chap. XIV.] GRADATION OF CHARACTERS. 



133 




progenitors of the peacock could not have resembled 
in any degree a Polyplectron. 
But on continuing my search, 
I observed that in some of the 
species the two ocelli stood 
very near each other ; that in 
the tail-feathers of P. liard- 
wickii they touched each 
other ; and, finally, that in the 
tail-coverts of this same spe- 
cies as well as of P. malaccense 
(Fig, 55) they were actually 
confluent. As the central part 
alone is confluent, an indenta- 
tion is left at both the ui^per 
and lower ends ; and the sur- 
rounding colored zones are 
likewise indented. A single 
ocellus is thus formed on each Fi«- 54.-Pait of a taii-covert of 

Poly plectron ehinquis, with 

tail-covert, though still plainly 
betraying its double origin. 
These confluent ocelli difler 
from the single ocelli of the 
peacock in having an indenta- 
tion at both ends, instead of at 
the lower or basal end alone. 
The explanation, however, of 
this difierence is not diflacult ; 
in some species of Polyplec- 
ti'on the two oval ocelli on the 
same feather stand parallel to 
each other ; in other species 
(as in P. chinquis) they con- Ym. 55. -Part of a tuii-coveit of 

verge toward one end; now Polyplectron malaccense, with 
° ' the two ocelli, partially conflu- 

the partial confluence of two ent, of natural size. 



the two ocelli of natural size. 




134 SEXUAL SELECTION : BIRDS. [Part II. 

convcrixeiit ocelli 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 be quite obliterated. 

The tail-feathers in both species of peacock are entire- 
ly destitute of ocelli, and this apparently is related to 
their being covered u}) and concealed by the long tail-cov- 
erts. In this respect they differ remarkably from the 
tail-feathers of Polyi>lectron, 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 of Polyplectron, in order to 
discover whether the ocelli in any of them showed any 
tendency to disappear, and, to my great satisfaction, I was 
successful. The central tail-feathers of P. N'apoleonis 
have the two ocelli on each side of the shaft perfectly de- 
veloped ; but the inner ocellus becomes less and less con- 
spicuous on the more exterior tail-feathers, until a mere 
shadow or rudimentary vestige is left on the inner side of 
the outermost feather. Again, in P. malaccense, the 
ocelli on the tail-coverts are, as we have seen, confluent ; 
and these feathers are of unusual length, being two-thirds 
of the length of the tail-feathers, so that in both these 
respects they resemble the tail-coverts of the peacock. 
Now in this species the two central tail-feathers alone are 
ornamented, each with two brightly-colored ocelli, the 
ocelli having completely disappeared from the inner sides 
of all the other tail-feathers. Consequently the tail-cov- 
erts 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 the principle of gradation throws light 
on the steps by which the magniflcent train of the pea- 
cock has been acquired, hardly any thing more is needed. 



Chap. XIV.] GRADATION OF CHARACTERS. 135 

We may picture to ourselves a progenitor of the peacock 
in an almost exactly intermediate condition between the 
existing peacock, with his enormously elongated tail-cov- 
erts, ornamented with single ocelli, and an ordinary gal- 
linaceous bird with short tail-coverts, merely spotted with 
some color; and we shall then see in our mind's eye a 
bird possessing tail-coverts, capable of erection and ex- 
pansion, ornamented with two partially confluent ocelli, 
and long enough almost to conceal the tail-feathers — the 
latter having already partially lost their ocelli ; we shall 
see, in short, a Polyplectron. The indentation of the cen- 
tral disk and surrounding zones of the ocellus in both sjie- 
cies of peacock, seems to me to speak plainly in favor of 
this view ; and this structure is otherwise inexplicable. 
The males of Polyplectron are no doubt very beautiful 
birds, but their beauty, when viewed from a little dis- 
tance, cannot be compared, as I formerly saw in the Zoo- 
logical Gardens, with that of the peacock. Many female 
progenitors of the peacock must, during a long line of de- 
scent, 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 investi- 
gation is ofiered by the ocelli on the wing-feathers of the 
Argus pheasant, which are shaded in so wonderful a man- 
ner as to resemble balls lying within sockets, and which 
consequently differ from ordinary ocelli. No one, I pre- 
sume, will attribute the shading, which has excited the ad- 
miration of many experienced artists, to chance — to the 
fortuitous concourse of atoms of coloring matter. That 
these ornaments should have been foi*med thi-ough the 
selection of many successive variations, not one of which 
was ox'iginally intended to produce the ball-and-socket 



13G SEXUAL SELECTION: BIRDS. [Part IL 

eftcct, seems as incredible, as that one of Raphael's Ma- 
donnas sliould have been formed by the selection of 
chance daubs of paint made by a lonor succession of young 
artists, not one of whom intended at first to draw the 
human figure. In order to discover how the ocelli have 
been develo])ed, we cannot look to a long line of progeni- 
tors, nor to various 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 demonstration that a gradation is at least pos- 
sible from a mere spot to a finished ball-and-socket ocel- 
lus. 

The wing-feathers, bearing the ocelli, are covered with 
dark stripes or rows of dark spots, each stripe or row run- 
ning obliquely down the outer side of the shaft to an ocel- 
lus. The spots are generally elongated in a transverse 
line to the row in which they stand. They often be- 
come 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, and then they 
form transverse stripes. A spot sometimes 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 admi- 
rably drawn by Mr. P^'ord, and engraved, but a w^oodcut 
cannot exhibit the exquisite shading of the original. The 
ring is almost always slightly broken or interrupted (see 
Fig. 56) at a point in the upper half, a little to the right 
of and above the white shade on the enclosed ball 5 it is 
also sometimes broken toward the base on the right hand. 
These little breaks have an im]>()rtant meaning. The ring 
is always much thickened, with the edges ill-defined 



Chap. XIV.] GRADATION OF CHARACTER, 



137 



toward the left-Land upper corner, the feather being held 
erect, in the position a b c 

in which it is here 
drawn. Beneath this 
thickened part there is 
on the surface of the 
ball an oblique almost 
pure-white mark whicli 
shades ofi downward 
into a pale-leaden hue, 
and this into yellow- 
ish and brown tints, 
which insensibly be- 
come darker and dark- 
er toward the 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 loAver 
part is of a browner 

lint oiirl i<j inrli«tinr>flxr Fig. 56.— Part of Secondary winsr-reather of 
imt ana is maiSlinctiy ^^.^^^ pheasanf, showing two. « anrl b, per- 

HPnfiTntpfl \\\r o piir-eprl feet ocelli. A, B, C, etc.. dark stripes run- 

Sepai area Oy a CUrveCl ^^^^^ obliquely down, each to an ocellus. 

oblique line from the [Much of the web on both sides, especially to 
. the left of the shaft, has been cut off]- 

upper part, which is 

yellower and more leaden ; this oblique line runs at right 
angles to the longer axis of the wliite patch of light, and 
indeed of all the shading ; but this difference in the tints, 
which cannot of course be shown in the woodcut, does not 
in the least interfere with the perfect shading of the ball.^^ 

*s When the Argus pheasant displays his wing-feathers hke a great 
fan, those nearest to the body stand more upright than the outer ones, 




138 



SEXUAL SELECTION: BIRDS. 



[Pakt II. 



It shoukl be i)articiilarly observed that each ocellus stands 
in obvious connection with a dark stripe, or row of dark 
spots, lor both occur indiflerently on the same feather. 
Thus ill ViiT. 50 stripe A runs to ocellus a ; B inins to ocellus 
h ; stripe C is broken in the upper part and runs do^\^l to 
the next succeeding ocellus, not rejiresented 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 oth- 
er by a pale sui-f:ice 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. 57), nearest 
to the body, is marked, 
like the other feathers, 
Avith oblique, longitudi- 
\ --■' nal, rather irregular, rows 

of sjtots. The lowest spot, 
or that nearest the shaft, 
in the five lower rows (ex- 
\ I eluding the basal row) is 

a little larger than the 

Fig. ."JT.— Baenl part of the Secondary , "^ . , 

winsi-fcatlicr, nearest to the body. OtiKT SpotS in the Same 

SO that the shading of the ball-and-socket ocelli ought to be slightly 
different on the different feathers, in order to bring out their full effect, 
relatively to the incidence of the light. Mr. T. W. Wood, who has the 
c.Kperienced eye of an artist, asserts ('Field,' newspaper. May 28, 1870, 
p. 4r)7) that this is the case ; but after carefully examining two mounted 
specimens (the proper feathers from one having been given to me by Mr. 
(Jould for more accurate comparison) I cannot perceive that this acme 
of l)erfcction in the shading has been attained ; nor can others to whom 
I have shown these feathers recognize the fact. 




Chap. XIV.] GRADATION OF CHARACTERS. 139 

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 
plumage of many birds, and might easily be quite over- 
looked. The next higher spot in each row does not diifer 
at all from the upper ones in the same row, although in 
the following series it becomes, as we shall see, greatly 
modified. The larger spots occupy exactly the same rela- 
tive position on this feather as those occupied by the per- 
fect ocelli on the longer wing-feathers. 

By looking to the next two or three succeeding sec- 
ondary wing-feathers, an absolutely insensible gradation 
can be traced from one of the above-described lower 
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 accompany- 
ing figure (Fig. 58). We here see several oblique rows, 
A, B, C, D (see the lettered diagram), etc., of dark spots 
of the usual character. Each row of spots runs down to 
and is connected with one of the elliptic ornaments, in ex- 
actly the same manner as each stripe in Fig. 56 runs down 
to, and is connected with, one of the ball-and-socket ocelli. 
Looking to any one row, for instance, B, the lowest spot 
or mark (b) 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 
upper side by a rather broad space of richly-shaded tints, 
beginning with a narrow brown zone, which passes into 
orange, and this into a pale leaden tint, with the end 
toward the shaft much paler. This mark corresponds in 
every respect with the larger, shaded spot, described in 
the last pai'agraph (Fig 57), but is more highly developed 
and more brightly colored. To the right and above this 



1-iO 



SEXUAL SELECTION: BIRDS. 



[Part II. 



spot (b), with its bright shading, there is a long, narrow, 
black mark (c), belonging to the same row, and which is 
arclied ;i little downward so as to face (b). 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 



A B c 




Fig. 58.— Portion of one of the Secondary winj-fenthera near to the bodr ; show 
ing the so-called elliptic ornaments. The ri.;ht-hand flgiire is eiven merely 
as a diagram for the sake of the letters of reference. 



A, B, C, etc. Rows of spots ruii'iincr 
down to and formin;; the elliptic 
ornaments. 

b. Lowest spot or mark in row B. 



c. The next sncceeding spot or mark 

in the same row. 

d. Apparently a broken prolonsrsition 

of the spot c in the same row B. 



always more or less distinct from it, there is another black 
mark (d). This mark is generally sub-triangular and ir- 
regular in shape, but in the one lettered in the diagram is 
unusually narrow, elongated, and regular. It apparently 
consists of a lateral and broken prolongation of the mark 
(c), as I infer from traces of similar prolongations from 
the succeeding upper spots ; but I do not feel sure of this. 



Chap. XIV.] GRADATION OF CHARACTERS. 141 

These three marks, 5, c, and d, with the intervening bright 
shades, form together the so-called elliptic ornament. 
These oi-naments stand in a line parallel to the shaft, and 
manifestly correspond in position with the ball-and-socket 
ocelli. Their extremely elegant appearance cannot be ap- 
preciated 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. I regret that I have not given an additional 
drawing, besides Fig. 58, which stands about half-way in 
the series between one of the simple spots and a perfect 
ocellus. The passage from the elliptic ornament into an 
ocellus is eifected by the elongation and greater curvature 
in opposed directions of the lower black mark [b), and 
more especially of the upper one (c), together with the 
contraction of the irregular sub-triangular or narrow mark 
(c?), 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, at the same 
time increasing in diameter. Traces of the junction of all 
three elongated spots or marks, especially of the two upper 
ones, can still be observed in many of the most perfect 
ocelli. The broken state of the black ring on the upper 
side of the ocellus in Fig. 56 was pointed out. The ir- 
regular sub-triangular or narrow mark (c?) manifestly 
forms, by its contraction and equalization, the thickened 
portion of the ring on the left upper side of the perfect 
ball-and-socket ocellus. The lower part of the ring is in- 
variably a little thicker than the other parts (see Fig. 56), 
and this follows from the lower black mark of the elliptic 
ornament {b) having been originally thicker than the 
upper mark (c). Every step can be followed in the pro- 



142 SEXUAL SELECTION: BIRDS. [Paht IT. 

coss of confluoiu'o and niodiiioation ; and the black ring 
which surrounds the ball of the ocellus is unquestionably 
formed by the union and modification of the three black 
marks, b, c, d, of the elliptic ornament. The irregular 
zigzag l)lack marks between the successive ocelli (see 
again Fig. 5G) 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-leaden narrow zones which 
border the lower black mark of the elliptic ornament can 
be seen gradually to become more and more softened and 
shaded into each other, with the upper lighter part toward 
the left-hand corner rendered still lighter, so as to become 
almost white. But even in the most perfect ball-and- 
socket ocelli a slight diftVrence in the tints, though not in 
the shading, between the upper and lower parts of the 
ball can be perceived (as w^as before especially noticed), 
the line of separation being oblique, in tlie same direction 
with 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 orna-ments; and the de- 
velopment of the latter can be traced by equally small 
steps from the imion of two almost simple spots, the lower 
one (Fig. 57) having some dull fulvous shading on the 
upper side. 

The extremities of the longer secondary feathers which 
bear the perfect ball-and-socket ocelli are peculiarly orna- 
mented. (Fig. 59.) The oblique longitudinal stripes 
suddenly cease upward and become confused, and above 
this limit the wdiole upper end of the feather (a) is covered 
with white dots, surrounded by little black rings, stand- 
ing on a dark ground. Even the oblique stripe belonging 



Chap. XIV.] GRADATION OF CHARACTERS. 



143 



to the uppermost ocellus (b) is represented only by a very 
short irregular black mark with the usual, curved, trans- 
verse base. As this stripe is thus abruptly cut off above, 
we can understand, from what has gone before, how it is 
that the upper thickened part 
of the ring is absent in the 
uppermost ocellus ; for, as 
before stated, this thickened 
part is apparently formed 
by a broken prolongation of 
the next higher spot in the 
same row. From the absence 
of the upper and thickened 
part of the ring, the upper- 
most ocellus, though perfect 
in all other respects, appears 
as if its top had been ob- 
liquely sliced off. It would, I 
think, perplex any one, who 
believes that the plumage of 
the Argus pheasant was cre- 
ated as we now see it, to ac- 
count for the imperfect condi- 
tion of the uppermost ocelli. 
I should add that in the sec- 
ondary wing-feather farthest 
from the body all the ocelli 

are smaller and less perfect Fio.sa— Portion near summit of oue 

, ^ , of the Secondary wine-feathers, 

than on the other feathers, bearing perfect ball-and-socliet 

with the upper parts of the „ Omamented upper part. 

external black rings deficient, '■ YPJlT^ocdilr'S 'silldS 

as in the case just mentioned. l^^^^^,,^ .lI^'^LCis Tere'l 

The imperfection here seems ^ perfec\°ocenus? 

to be connected with the fact 

that the spots on tins feather show less tendency than 




144 SEXUAL SELECTION : BIRD^. [Part 1L 

usual to become confluent into stripes; on the contrary, 
they are often broken up into smaller spots, so that two 
or three rows run down to each ocellus. 

We have now seen that a perfect series can be 
followed, from two almost simple spots, at first quite 
distinct from each other, to one of the wonderful 
ball-and-socket ornaments. 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 in devcloimient exhibited by the feathers 
on the same bird do not at all necessarily show us the 
steps which have been passed through by the extinct pro- 
genitors of the species ; but they probaldy give us the 
clew to the actual steps, and they at least prove to demon- 
stration that a gradation is possible. Bearing in mind 
how carefully the male Argus pheasant displays his 
plumes before the female, as well as the many facts ren- 
dering it probable that female birds prefer the more at- 
tractive males, no one who admits the agency of sexual 
selection will deny that a simple dark spot with some 
fulvous shading might be converted through the approxi- 
mation and modification of the adjoining spots, together 
with some slight increase of color, into one of the so-called 
elliptic ornaments. These latter ornaments have been 
shown to many persons, and all have admitted that they 
are extremely pretty, some tliinking them even more 
beautiful than the ball-and-socket ocelli. As the second- 
ary plumes became lengthened through sexual selection, 
and as the elliptic ornaments increased in diameter, their 
colors apparently became less bright ; and then the orna- 
mentation of the plumes had to be gained by imjn-ove- 
ments in the pattern and shading ; and this process has 
been carried on until the wonderful ball-and-socket ocelli 
have been finally developed. Thus we can miderstand — 
and in no other way, as it seems to me — the present con- 



Chap. XIV.] GRADATION OF CHARACTERS. 145 

dition and origin of the ornaments on the wing-feathers 
of the Argus pheasant. 

From the light reflected 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 more clearly see) 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 dark- 
ness. Mr. Gould several years ago pointed out to me a 
humming-bird, the JJrosticte henjaynini, remarkable from 
the curious differences presented by the two sexes. The 
male, besides a splendid gorget, has greenish-black tail- 
feathers, with the four central ones tipped with white ; in 
tlie female, as with most of the allied species, the three 
outer tail-feathers on each side are tipped with white, so 
that the male has the four central, while the female has the 
six exterior feathers ornamented with white tips. What 
makes the case curious is that, although the coloring of 
the tail differs remarkably in both sexes of many kinds 
of humming-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 va- 
rieties 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, 

« 'The Reign of Law,' 1867, p. 247. 
26 



146 SEXUAL SELECTION: BIRDS. [Part IL 

SO as to have aqcuired white tips? The variations may 
have bt'cn gradual, or somewhat abrupt as in the case re- 
cently 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 Uros- 
ticte 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-featliers of the male varying in white- 
ness, there is nothing strange in such variations having 
been sexually selected. The white tips, together with 
the stnall white ear-tufts, certainly add, as the Duke of 
Argyll admits, to the beauty of the male ; and whiteness 
is ajjparently appreciated by other birds, as may be in- 
ferred from such cases as the snow-white male of the Bell- 
bird. The statement made by Sir R. Heron should not 
be forgotten, namely, that his peahens, when debaiTcd 
from access to the 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. ^Ir. Gould, after describing the peculiar plu- 
mage of the Urosticte, adds, " that ornament and vai-iety 
is the sole object, I have myself but little doubt." '" If this 
be admitted, we can perceive tliat the males which 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 consequently 
have left a larger number of offspring to inherit their 
newly-acquired beauty. 

*» 'Introduction to the Trochilid.ne' 1861, p. 110. 



Chap. XV.] SEXFALLY-LIMITED INHERITANCE. I47 



CHAPTER XV. 

BiRBa— continued. 

Discussion why the Males alone of some Species, and both Sexes of other 
Species, are brightly colored. — On Sexually-limited Inheritance, as ap- 
plied to Various Structures and to Brightly-colored Plumage. — Nidifi- 
catiou in Relation to Color. — Loss of Nuptial Plumage during the 
Winter. 

We have in this chapter to consider, why with many- 
kinds of birds the female has not received the same orna- 
ments as the male; and why, with many others, both 
sexes are equally, or almost equally, ornamented ? In the 
following chapter we shall consider why in some few rare 
cases 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 dan- 
gerous, to the female during the period of incubation ; and 
consequently 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 tliat when the sexes differ, 
the successive variations have generally been from the 
first limited in their transmission to the same sex in which 

1 Fourth edition, 1866, p. 241. 



148 SEXUAL SELECTION: BIRDS. [Part IL 

they first appearcrl. Since my remarks appeared, the sub- 
ject 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 transmitted equally to both sexes ; but that the female 
was saved, 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 diffi- 
cult point, namely, whether the transmission of a charac- 
ter, which is at first inherited by both sexes, can be subse- 
quently limited in its transmission, by means of selection, 
to one sex alone. We must bear in mind, as shown in the 
preliminary chapter on sexual selection, that characters 
which are limited in their development to one sex are 
always latent in the other. An imaginary illustration will 
best aid us in seeing the difficulty of the case : we may 
suppose 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 would have to try to con- 
vert this latter form of inheritance into sexually-limited 
transmission. 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 pro- 
cess, if steadily carried on for a long time, and if the pale 
variations 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 af^er gen- 
eration, 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 

* ' Westminster Review,'' July, 1867. 'Journal of Travel,' vol. i. 
1868, p. 73. 



Chap. XV.] SEXUALLY-LIMITED INHERITANCE. I49 

more probably the speedy and complete loss of the pale- 
blue color, for the primordial slaty tint would be trans- 
mitted with prepotent force. Supposing, however, that 
some pale-blue males and slaty females were produced 
during each successive generation, and were always crossed 
together ; then the slaty females would have, if I may use 
the expression, much blue blood in their veins, for their 
fathers, grandfathers, etc., will all have been blue birds. 
Under these circiimstances it is conceivable (though I 
know of no distinct facts 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 theii' 
male oiFspring, their female offspring still inheriting the 
slaty tint. If so, the desired end of making a breed with 
the two sexes permanently different in color might be 
gained. 

The extreme importance, or rather necessity, of the de- 
sired character in the above case, namely, pale-blueness, 
being 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 inclies ; the tail of the male common 
pheasant is about twenty inches and that of the female 
twelve inches long. Now if the female Soemmerring pheas- 
ant with her short tail were crossed with the male com- 
mon pheasant, there can be no doubt that the male hybrid 
offspring would have a much longer tail than that of the 
pure offspring of the common pheasant. On the other 
hand, if the female common pheasant, with her tail nearly 
twice as long as 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 Scemmerring's pheasant.' 

3 Temminck says that the tail of the female Phasianus Sammerringii 



150 SEXUAL SELECTION: BIRDS. [Part II. 

Our fancier, in order to make liis new breed with the 
males of a decided pale-hUie tint, and the femak'S un- 
changed, 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 fe- 
males. The task would be an extremely difficult one, and 
has never been tried, but might possibly succeed. The 
chief obstacle would be the early and complete loss of the 
pale-blue tint, from the necessity of reiterated crosses with 
tlie slaty female, the latter not having at first any latent 
tendency to produce pale-blue ofispring. 

On the other hand, if one or two males were to vary 
ever so slightly in })aleness, 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 
striae. In the case of the fowl, variations of color limited 
in their transmission to the male sex habitually occur. 
Even when this form of inheritance prevails, it might 
Avell happen that some of the successive steps in the 
process of variation might be transferred to the female, 
who would then come to resemble in a slight degree the 
male, as occurs in some breeds of the fowl. 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 

is only six iiu-hes long. 'Planches colorizes,' vol. v. 1838, pp. 478, 408: 
the measurements above given were made for me by Mr. Sclater. Por 
the common pheasant, see Slacgillivray, 'Hist. British Birds,' vol. i. pp. 
118-121. 

* Dr. Chapuis, 'Le Pigeon Voyageur Beige,' 1865, p. 87. 



Chap. XV.] SEXUALLY-LIMITED INHERITANCE. 151 

somewhat larger crop, and of the male carrier-pigeon 
having somewhat larger wattles, than their respective fe- 
males ; for fanciers have not selected one sex more than the 
other, and have had no wish that these characters should 
be more strongly displayed in the male than in the female, 
yet this is the case with both breeds. 

The same process would have to be followed, and the 
same difficulties Avould be 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 diifering from each other, and both from the 
parent-species. Here the difficulty would be extreme, un- 
less the successive variations were from the first sexually 
limited on both sides, and then there would be no diffi- 
culty. We see this with the fowl ; thus the two sexes of 
the pencilled Hamburgs 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 ; tlie male has an immense comb, but some of the succes- 
sive variations, by the accumulation of which it was ac- 
quired, 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 



152 SEXUAL SELECTION: BIRDS. [Part IL 

be a scxiuvlly-liinitc'd 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 woxdd be an ex- 
tremely difficult and complex process, though perhaps not 
impossible, to change through selection one form of trans- 
mission into the other. Therefore, without distinct evi- 
dence in each case, I am unwilling to admit that this has of- 
ten been effected with 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 differ- 
ent 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. If 
all the successive variations w^cre transmitted equally to 
both sexes, the females would be undistinguishable from the 
males ; and this likewise occurs with many birds. If, how- 
ever, dull colors Avcre 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. But the 
tendency in the males to continue for an indefinite period 
transmitting to their female offspring their own bright- 
ness, would have to be eliminated by a change in the form 
of inheritance ; and this, as shown by our previous illus- 
tration, would be extremely difficult. The more probable 
result of the lonij-continued destruction of the more bright- 



Chap. XV.] SEXUALLY-LIMITED INHERITANCE. I53 

ly-colored females, supposing the equal form of trans- 
mission to prevail, would be the lessening or annihila- 
tion of the bright colors of the males, owing to their 
continually crossing with the duller females. It would 
be tedious to follow out all the other possible results ; but 
I may remind the reader, as shown in the eighth chapter, 
that if sexually-limited variations in brightness occurred 
in the females, even if they were not in the least injurious 
to them and consequently were not eliminated, yet they 
would not be favored or selected, for the male usually 
accepts any female, and does not select the more attrac- 
tive individuals ; consequently 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 less brightly colored than 
the males. 

In the chapter just referred to, instances were given, 
and any number might have been added, of variations 
occurring at diflerent ages, and inherited at the same 
age. It was also shown that variations which occur late 
in life are commonly transmitted to the same sex in 
which they first appeared; while variations occuri'ing 
early in life are apt to be transmitted to both sexes ; not 
that all the cases of sexually-limited transmission can thus 
be accounted for. It was further shown that if a male 
bii'd varied by becoming brighter while young. Such varia- 
tions would be of no service until the age for reproduction 
had arrived, and there was competition between rival 
males. But in the case of birds which live on the ground 
and which commonly need the protection of dull colors, 
bright tints would be far more dangerous to the young 
and inexperienced than to the adult males. Consequently 
the males which varied in brightness while young would 
suffer much destruction and be eliminated through nat- 
ural selection ; on the other hand the males which varied 



154 SEXUAL SELECTION: BIRDS. [Part IL 

in this manner when nearly mature, notwitlistanding 
tliat they were exposed to some additional danger, 
might survive, and, from being favored through sexual 
selection, would procreate their kind. The hrightly-col- 
ored young males being destroyed and the mature ones 
being successful in their courtship may account, on the 
principle of a relation existing between the period of 
variation and the form of transmission, for the males 
alone of many birds having acquired and transmitted 
brilliant colors to their male oflfspring alone. But I by 
no means wish to maintain that the influence of age 
on the form of transmission is indirectly the sole cause 
of the great difierence in brilliancy between the sexes of 
many birds. 

As with all birds in which the sexes difier in color, 
it is an interesting question whether the males alone 
have been modified through sexual selection, the fe- 
males being left, as far as this agency is concerned, 
unchanged or only partially changed ; or whether the 
females have been specially . modified through natural 
selection for the sake of protection, I will discuss this 
question at considerable length, even at greater length 
than its intrinsic importance deserves ; for various cu- 
rious collateral points may thus be conveniently consid- 
ered. 

Before we enter on the subject of color, more espe- 
cially in reference to Mr. Wallace's conclusions, it may be 
useful to discuss under a similar point of view some other 
differences between the sexes. A breed of fowls foimerly 
existed in Germany* 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 

* Bechsteiu, ' Natuigesch. Doutschlands,' 1793, B. iii. s. 339. 



Chap. XV.] DEVELOPMENT OF SPURS. 155 

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 the 
wing-spurs, which could not be injurious during nidification, 
are often as well developed in the female as in the male ; 
though in not a 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 
rudiments sometimes consisting of a mere scale, as with the 
species of Gallus. Hence it might be argued that the fe- 
males had aboriginally been furnished with well-developed 
spurs, but that these had subsequently been lost either 
through "disuse or natural selection. But if this view be 
admitted, it would have to be extended to innumerable 
other cases ; and it implies that the female progenitors of 
the existing spur-bearing species were once encumbered 
with an injurious appendage. 

In some few genera and species, as in Galloperdix, 
Acomus, and the Javan peacock [Pavo muticus), the fe- 
males as well as the males possess well-developed spurs. 
Are we to infer from this fact that they construct a differ- 
ent sort of nest, not liable to be injured by their spurs, 
from that made by their nearest allies, so that there has 
been no need for the removal of their spurs ? Or are we 
to suppose that these females especially require sj)urs for 
their defence ? 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, indepen- 
dently of natural selection. With the many females in 
which spurs appear as rudiments, we may conclude that some 
few of the successive variations, through which they were 
developed in the males, occurred very early in life, and 
were as a consequence transferred to the females. In the 
other and much rai-er cases, in which the females possess 



156 SEXUAL SELECTION: lilKUS. [Part IL 

fully-dcvelopcd spurs, we may conclude that all the succes- 
sive variations were transferred to them ; and that they 
gradually acquired the inherited habit of not disturbing 
their nests. 

The vocal organs and the variously-modified feathers 
for producing sound, as well as the proper instincts for 
using them, often difler 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 inheriluig 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 the 
country with their voices during the spring." It is a safer 
conclusion that as vocal and instrumental organs are of spe- 
cial service only to the males during their courtship, these 
organs were developed through sexual selection and con- 
tinued use in this sex alone — the successive variations and 
the effects of use having been from the first limited in their 
transmission in a greater or less degree to the male off- 
spring. 

Many analogous cases could be advanced ; for instance, 
the plumes on the head, which are 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 sometimes occurring in the same group of birds. It 
would be difficult to account for a difference of this kind 
between the sexes on the principle of the female having 
been benefited by possessing a slightly shorter crest than 

* Daines Barrington, however, thought it probable (' Phil. Transact.' 
1773, p. 164) that few female birds sing, because the talent would have 
been dangerous to them during incubation. lie adds, that a similar 
view may jjossibly account for the inferiority of the female to the male 
in plumage. 



Chap. XV.] LENGTH OF TAIL IN FEMALE. 157 

the male, and its consequent diminution or complete sup- 
pression through natural selection. But 1 will take a 
more favoi'able case, namely, the length of the tail. The 
long train of the peacock would have been not only incon- 
venient but dangerous to the peahen during the period of 
incubation and while accompanying her young. Hence 
there is not the least a priori improbability in the develop- 
ment of her tail having been checked through natural 
selection. But the females of various pheasants, which 
apparently are exposed on their open nests to as much 
danger as the peahen, have tails of considerable length. 
The females as well as the males of the Menura superba 
have long tails, and they build a domed nest which is a 
great anomaly in so large a bird. Naturalists have won- 
dered how the female Menura could manage her tail during 
incubation ; but it is now known ' 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 toler- 
able guide to the length of time the bird has been sit- 
ting." Both sexes of an Australian kingfisher ( Tanysiptera 
Sylvia) have the middle tail-feathers greatly lengthened; 
and, as the female makes her nest in a hole, these feathers 
become, as I am informed by Mr. R. B. Sharpe, much 
crumpled dui'ing nidification. 

In these two cases the great length of the tail-feathers 
must be in some degree inconvenient to the female ; and, 
as in both species the tail-feathers of the female are some- 
what shorter than those of the male, it might be argued 
that their full development had been prevented through 
natural selection. Judging from these cases, if, with the 
peahen, the development of the tail had been checked only 
when it became inconveniently or dangerously long, she 
would have acquired a much longer tail than she actually 

^ Mr. Ramsay, in Proc. Zoolog. Soc' 1868, p. 50. 



158 SEXUAL SELECTION: BIRDS. [Pabt H. 

possesses ; for Ler tail is not nearly so long, relatively to 
the size of l)er 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 consequently checked, she would 
have continually reacted on her male jjrogeny, and thus 
have pi-evented the peacock from acquiring his present 
magnificent train. We may therefore infer that the length 
of the tail in the peacock and its shortness in the jteahen 
are the result of the requisite variations in the male having 
been from the first transmitted 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 pheas- 
ants. In the Eared pheasant ( Crossoptiloii auritum) 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 Strminorring's pheasant, thirty-seven inches in the male, 
and only eight in the female ; and lastly in Reeve's pheas- 
ant it is sometimes actually seventy-two inches long in the 
male and sixteen in the female. Thus in the several spe- 
cies, the tail of the female differs much in length, irrespec- 
tively 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, owing to the length of tail having 
been injurious in a greater or less degree to the females of 
the several species. 

We may now consider Mr. Wallace's arguments in re- 
gard to the sexual coloration of birds. He believes that 



Chap. XV.] COLOR AND NIDIFICATION. 159 

the bright tints, originally acquired through sexual selec- 
tion by the males, would in all or almost all cases have 
been transmitted to the females, unless the transference 
had been checked through natural selection. I may here 
remind the reader that various facts bearing on 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 following statement,* that when both sexes 
are colored in a strikingly-conspicuous manner the nest is 
of such a natiire as to conceal the sitting bird ; but when 
there is a marked contrast 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 coinci- 
dence, as far as it goes, certainly supports the belief that 
the females which sit on open nests have been specially 
modified for the sake of pi-otection. Mr. Wallace admits 
that there are, as might have been expected, some excep- 
tions to his two rules, but it is a question whether the 
exceptions are not so numerous as seriously to invalidate 
them. 

There is in the first place much truth in the Duke of 
Argyll's remark," that a large-domed nest is more con- 
spicuous to an enemy, especially to all tree-haunting car- 
nivorous animals, than a smaller open nest. Nor must 
we forget that with many birds which build open nests 
the males sit on the eggs and aid in feeding the young as 
well as the females : this is the case, for instance, with 
Pyranga oestiva^'^ 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 

8 ' Journal of Travel,' edited by A. Murray, vol. i. 1868, p. '78. 

9 Ibid. p. 281. 

'" Audubon, ' Ornithological Biography,' vol. i. p. 233. 



160 SEXUAL SELECTION: BIRDS. [Part IL 

nests, the nuiles in these cases would have suffered greatly. 
It might, however, be of such paramount importance to 
the male to be brilliantly colored, in order to beat his 
rivals, that this would more than compensate for some ad- 
ditional danger. 

Mr. Wallace admits that with the King-crows (Dicru- 
rus), Orioles, and Pittida?, the females are conspicuously 
colored, yet they 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 concealing 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 the whole great 
family of pigeons, which are sometimes brightly and 
almost always conspicuously colored, and which are noto- 
riously liable to the attacks of birds of prey, offers a seri- 
ous exception to the rule, for pigeons 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 bril- 
liant than the males, are very brightly colored. Nor 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.'* 

" Jerdon, 'Birds of India,' vol. ii. p. 108. Gould's 'Hand-book of 
the Birds of Australia,' vol. i. p. 463. 

" For instance, the female Eupetomena macroura has the head and 
tail dark blue with reddish loins; the female Lampornis porphyrurvs is 
blackish-green on the upper surface, with the lores and sides of the 
throat crimson ; the female Eulampis juffuhiris has the top of the head 
and back green, but the loins and the tail are crimson. Many other in- 
stances of highly-conspicuous females could be given. See Mr. Gould's 
magnificent work on this family. 



Chap. XV.] COLOR AND NIDIFICATION. 161 

In regard to birds which huild 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 rays of the sun ; " so that it is no valid objection 
to his view that many birds having both sexes obscurely 
coloi'ed build concealed nests.'* The female Horn-bills 
[JBuceros), for instance, of India and Africa are protected, 
during nidification, with extraordinary care, for the male 
plasters up the hole in which the female sits on her eggs, 
and leaves only a small orifice through which he feeds 
her ; she is thus kept a close prisoner during the whole 
period of incubation; '^ yet female hornbills 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 fe- 
males obscure, and yet the latter hatch their eggs in 
domed nests. This is the case with the Grallinte of Aus- 
tralia, the Superb Warblers (Maluridfe) of the same conn- 
try, the Sun-birds (Nectarinije), and with several of the 
Australian Honey-suckers or Meliphagidse." 

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 constructed by 

" 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, than during cool, 
cloudy, or rainy weather. 

'* I may specify, as instances of obscurely- colored birds building 
concealed nests, the species belonging to eight Australian genera, de- 
scribed in Gould's ' Hand-book of the Birds of Australia,' vol. i. pp. 340, 
362, 365, 383, 387, 389, 391, 414. 

'^ Jerdon, 'Birds of India,' vol. i. p. 244. 

'^ On the nidification and colors of these latter species, see Gould's 
' Hand-book,' etc., vol. i. pp. 504, 527. 



162 SEXUAL SELECTION: BIRDS. [Pakt IL 

her. 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 tlie colors of the female goldfinch, bullfinch, or 
blackbird, as a standard of the degree of conspicuousness, 
which is not highly dangerous to the sitting female, then, 
out of the above forty birds, the females of only twelve 
can be considered as conspicuous to a dangerous degree, 
the remaining twenty-eight being inconspicuous." Nor 
is there any close relation between a well-pronounced dif- 
ference in color between the two 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. montmms) differs hardly at all, and 
yet both build well-concealed nests. The two sexes of the 
common fly-catcher (Muscicapa grisola) can hardly be 
distinguished, while the sexes of the ])icd fly-catcher 
{M. luctNosa) differ considerably, and both build in holes. 
The female blackbird [Turdus mernla) differs much, the 
fcmate ring-ouzel {T. torqtiatvs) differs less, and the female 
common thrush {T. irmsiciis) hardly at all, from their re- 
8j)ective males ; yet all build open nests. On the other 
hand, the not very distantly-allied water-ouzel {Cinclus 

" I have consulted, on this subject, Macgillivray's ' British Birds,' 
and though doubts may be entertained in some cases in regard to the 
degree of conceahuent ot' the nest, and of the degree of conspicuousness 
of the female, yet the following birds, which all lay their eggs in holes or 
in domed nests, can hardly be considered, according to the above stand- 
ard, as conspicuous : Passer, 2 species ; Sturaus, of which the female is 
considerably less brilliant than the male ; Cinclus; Motacilla boarula(?): 
Erithacus (V) ; Fruticola, 2 sp. ; Saxicola ; Ruticilla, 2 sp. ; Sylvia, 8 sp. ; 
Parus, 3 sp. ; Mecistura; Anorthura; Certhia; Sitta; Yunx ; Muscicapa, 
2 sp. ; Hirundo, 3 sp. ; and Cypselus. The females of the following 1 2 
birds may be considered as conspicuous according to the same standard, 
viz.. Pastor, Motacilla alba, Parus major and P. cicrulcus, Upupa, Picus, 
4 sj)., Coracias, Alcedo, and Merops. 



Chap. XV.] COLOR AND NIDIFICATION. 163 

aquaticus) builds a domed nest, and the sexes diifer about 
as much as in the case of the ring-ouzel. The black and 
red grouse {Tetrao tetrix and T. Scoticus) build open 
nests, in equally well-concealed spots, but in the one spe- 
cies the sexes diifer 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 equal- 
ly conspicuous) build concealed nests for the sake of pro- 
tection, Mr. Wallace enumerates " a long series of grouj^s 
in which this rule holds good ; but it will suffice here to 
give, as instances, the more familiar groups of kingfishers, 
toucans, trogons, puff-birds (Capitonidse), plantain-eaters 
(Musophagfe), woodpeckers, and parrots. Mr. Wallace 
believes that in these groups, as the males gi-adually 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 enjoyed from their manner of nidification. Ac- 
cording to this 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 theii* instincts (supposing that they origi- 
nally built open nests), and to seek protection by building 
domed or concealed nests. No one, who studies, for in- 
stance, 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) 

1^ ' Journal of Travel,' edited by A. Murray, vol. i. p. 78. 

^^ See many statements in the ' Ornithological Biography.' See, also, 



164 SEXUAL SELECTION: BIRDS. [Part XL 

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. 

Tliis 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 
analogous cases occurring in the Sahara Desert. Here, as 
in most other deserts, various birds, and many other ani- 
mals, have had their colors adapted in a wonderful man- 
ner to the tints of the surrounding surface. Nevertheless 
there are, as I am informed by the Rev. Mr. Ti-istram, 
some curious exceptions to the rule ; thus the male of the 
Monticola cyanea is conspicuous from his bright-blue col- 
or, and the female almost equally consjjicuous from her 
mottled brown and white plumage; both sexes of two 
species of Dromoltea are of a lustrous black ; so that these 
three birds are far from receiving protection from their 
colors, yet they are able to survive, for tliey have acquired 
the habit, when in danger, of taking refuge in holes or 
crevices in the rocks. 

With respect to the above-specified groups of birds, 
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 modi- 
fied ; but only that tlie 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. This 
conclusion, as far as it can be trusted, is interesting, 
namely, that sexual selection, together with equal or 
nearly equal inheritance by both sexes, has indirectly 
determined the manner of nidification of whole groups of 
birds. 

some curious observations on the nests of Italian Birds by Engenio Bet- 
toni, in the ' Atti della Society Italiana,' vol. xi. 1869, p. 487. 



Chap. XV.] COLOR AND NIDIFICATION. 165 

Even in the groups in which, according to Mr. Wal- 
lace, the females, from being protected during nidification, 
have not had their hright colors eliminated through natu- 
ral selection, the males often differ in a slight, and occa- 
sionally in a considerable degree, from the females. This 
is a significant fact, for such differences in color must be 
accounted for on the principle of some of the variations 
in the males having been from the first limited in their 
transmission to the same sex ; as it can hardly be main- 
tained that these differences, especially when very slight, 
serve as a protection to the female. Thus all the species 
in the splendid group of the Trogous build in holes ; and 
Mr. Gould givesfigures ^^ of both sexes of twenty-five spe- 
cies, in all of which, with one partial exception, the sexes 
differ sometimes slightly, sometimes conspicuously in col- 
or — the males being always more beautiful than the 
females, though the latter are likewise beautiful. All the 
species of kingfisher build in holes, and with most of the 
species the sexes are equally brilliant, and thus far Mr, 
Wallace'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.^* Mr. R. B. Sharpe, who has es- 
pecially studied this group, has shown me some American 
species (Ceryle) 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 part- 
ly fawn-colored, and there is much red about the head ; in 
the female the upper surface is reddish-brown banded 
with black, and the loAver surface white with black 

5" See his ' Monograph of the Trogonidae,' first edition. 
^' Namely Cyanalcyon. Gould's ' Hand-book of the Birds of Austra- 
lia,' vol. i. p. 133; see, also, pp. 130, 136. 



166 SEXUAL SELECTION: BIRDS. [Part IL 

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 dif- 
fers from the female only in the tail heing dull-l>lue 
banded with black, while that of the female is brown with 
blackish bars ; so that here the tail differs in color in the 
two sexes in exactly the same manner as the whole upper 
surface in the sexes of Carcineutcs. 

With parrots, which likewise build in holes, we find 
analogous cases : in most of the species both sexes are 
brilliantly colored and undistinguisliable, but in not a few 
species the males are colored rather more vividly than the 
females, or even very differently from them. Thus, be- 
sides other strongly-marked differences, the whole under 
surface of tlie male King Lory [Apros/nlctus scapulatus), is 
scarlet, while the throat and chest of the female are green 
tinged with red: in the Eupheyna splendida there is a 
similar difference, the face and wing-coverts, moreover, of 
the female being of a paler blue than in the male."' In 
the family of the Tits {ParinoB)^ which build concealed 
nests, the female of our common blue tomtit [Parus cmru- 
leus) is " much less brightly colored " than the male ; and 
in the magnificent Sultan yellow tit of India the differ- 
ence is greater." 

Again, in the great group of the woodpeckers,"* 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 fe- 

'* Every gradation of difference between the sexes may be followed in 
the parrots of Australia. See Gould's 'Hand-book,' etc., vol. ii. pp. 14- 
102. 

" Macgillivray's ' British Birds,' vol. ii. p. 433. Jerdon,. ' Birds of 
India,' vol. ii. p. 282. 

** All the following facts are taken from 51. Malherbe's magnificent 
' Monographic des Picid6es,' 1861. 



Chap. XV.] COLOR AND NIDIFICATION. 167 

male. As in several woodpeckers the head of the male is 
bright crimson, while that of the female is plain, it oc- 
curred 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 consequent- 
ly 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 intensified in 
the adult male. Nevertheless, the following considera- 
tions render this view extremely doubtful : the male takes 
a fiiir share in incubation,^* and would be thus far almost 
equally exposed to danger; both sexes of many species 
have their heads of an equally bright crimson ; in other 
species the difierence between the sexes in the amount of 
scarlet is so slight that it can hardly make any appre- 
ciable 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 Australian pigeons.''* It 
deseiwes especial notice that in all these cases the slight 
differences in plumage between the sexes are of the same 

^^ Audubon's ' Ornithological Biography,' vol. ii. p. '75 ; see also the 
'Ibis,' vol. I p. 268. 

^^ Gould's 'Hand-book of the Birds of Australia,' vol. ii. pp. 109-149. 



168 SEXUAL SELECTION: BIRDS. [Part IL 

general nature as the oceasionally greater difFerences. A 
good illustration of this fact has already been afforded by 
those kingfisliers in which either the tail alone or the 
whole upjier 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 be- 
tween 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 diffbrs consid- 
erably from the female, he is not colored in a quite rrtw 
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 slightly or even 
considerably from the female, have in most cases been 
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. Assum- 
ing, 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 under- 
going 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. Even if we consider somewhat 
more marked sexual differences, is it probable, for in- 
stance, 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 pro- 
cess of selection for the sake of protection ? I cannot 
think so; and still less Avith the slight differences between 
the sexes of those birds which build concealed nests. On 



Chap. XV.] COLOR AND NIDIFICATION. 169 

the other hand, the differences in color between the sexes, 
whether great or small, may to a large extent be ex- 
plained 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 transmis- 
sion to the females. That the degree of limitation should 
differ in different species of the same group will not sur- 
prise 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 action." 

As far as I can discover, there are very few groups 
of birds, containing a considerable number of species, in 
which all have both sexes brilliantly colored and alike ; 
but this appears to be the case, as I hear from Mr. Sclater, 
with the Musophagae or plantain-eaters. Nor do I be- 
lieve 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 {Cotin- 
gidm) offer one of the best instances ; but with some of 
the species, in which the male has a splendid red breast, 
the female exhibits some red on her breast ; and the fe- 
males of other species show traces of the gi*een and other 
colors of the males. Nevertheless, we have a near ap- 
proach to close sexual similarity or dissimilarity tbrougli- 
out several groups : and this, from what has just been 
said of the fluctuating nature of inheritance, is a some- 
what surprising circumstance. But that the same laws 
should largely prevail with allied animals is not surpris- 
ing. 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 a re- 
markable circumstance when in certain sub-breeds they 
resemble each other. On the other hand, the domestic 

^^ See remarks to this efiFect in my work on ' Variation under Domes- 
tication,' vol. ii. chap. xii. 

27 



170 SEXUAL SELECTION: BIRDS. [Part IL 

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 va- 
ried, it would not be rash to predict that the same general 
rules of sexual similarity and dissimilarity, depending on 
the form of transmission, would, in both cases, hold good. 
In a similar manner the same form of transmission has 
generally prevailed throughout the same natural groups, 
although marked exceptions to this rule occur. Within 
the same family, or even genus, the sexes may be identi- 
cally alike or very diiferent in color. Instances have 
already been given relating to the same genus, as with 
sparrows, fly-catchers, thrushes, and grouse. In the fam- 
ily of pheasants the males and females of abnost all the 
species are wonderfully dissimilar, but are quite similar 
in the eared pheasant or Crossojytilon auritum. In two 
species of Chloehaga, a genus of geese, the males 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, by acquiring at a late 
period of life certain characters proper to the male, ulti- 
mately comes to resemble him in a more or less complete 
manner. Here protection can hardly have come int6 play. 
Mr. Blyth informs me tliat the females of Oriolus melan- 
ocephahis and of some allied species, when sufficiently 
mature to breed, differ considei'ably 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 'Ibis,' vol. vi. 1864, p. 122. 



Chap. XV.] COLOR AND NIDIFICATION. 171 

the mean while she presents 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, Swin- 
hoe states that, with one of the Drongo shrikes (Dicnirtis 
macroeercus), the male, while almost a nestling, moults his 
soft brown plumage and becomes of a uniform glossy 
greenish-black ; but the female retains for a long time the 
white strise and spots on the axillary feathers, and does 
not completely assume the uniform black color of the 
male for the first three years. The same excellent ob- 
server remarks that in the spring of the second year the 
female spoonbill (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 JBomhycilla Carolinensis diifers 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. The upper mandible 
in the male of an Indian parrakeet {JPalceornis Javanicus) 
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.''* 

^' On Ardetta, Translation of Cuvier's ' Regne Animal,' by Mr. Blytb, 
foot-note, p. 159. On the Peregrine Falcon, Mr. Blyth, in Charlesworth's 
'Mag. of Nat. Hist.' vol. i. IBS'/, p. 304. On Dicrurus, 'Ibis,' 1863, p. 
44. On the Platalea, 'Ibis,' vol. vi. 1864, p. 366. On the Bombyeilla, 



172 SEXUAL SELECTION: BIRDS. [Part IL 

In these cases, the females follow a normal course of 
development in ultimately becoming like the males ; and 
sufh cases must not be confounded with those in which 
diseased or old females assume masculine characters, or 
with those in which perfectly fertile females, while young, 
acquire, through variation or some unknown cause, the 
characters of the male.'" But all these cases have so much 
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 elec- 
tive affinities of her constituent tissues. 

A few words must be added on changes of plumage in 
relation to the season of the year. Fi-om 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 exclusively for ornamental or 
nuj^tial purposes, though common to both sexes. The fe- 
male is thus rendered 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 tAvice in the year may have been 
gradually acquired through natural selection for the sake 
of casting oflf inconvenient oi'naments during the winter. 

Audubon's ' Omitholog. Biography,' vol. i. p. 229. On the Palaeomis, 
see, also, Jerdon, ' Birds of India,' vol. i. p. 263. On the wild-turkey, 
Audubon, ibid. vol. i. p. 15 : I hear from Judge Caton that in Illinois the 
female very rarely acquires a tuft. 

^ Mr. Blyth has recorded (Translation of Cuvier's ' R6gne Animal,' p. 
158) various instances with Lanius, Rutieilla, Linaria, and Anas. Audu- 
bon has also recorded a similar case ('Ornith. Biog.' vol. v. p. KIO) with 
Ti/ranga wstiva. 



Chap. XV.] SUMMER PLUMAGE. I73 

But this view cannot be extended to the many waders, 
in which the summer and winter phimages differ very 
little in color. With defenceless species, in which either 
both sexes or the males alone become extremely conspicu- 
ous during the breeding-season — or when the males ac- 
quire 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 purpose of throwing 
off these ornaments. We must, however, remember that 
many birds, such as Birds of Paradise, the Argus pheasant, 
and peacock, do not cast their plumes during the winter ; 
and it can hardly be maintained that there is something 
in the constitution of these birds, at least of the Gallina- 
ceae, rendering a double moult impossible, for the ptarmi- 
gan moults thrice in the year." Hence it must be con- 
sidered 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 in- 
convenience or danger which they would otherwise have 
suffered. 

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 occurring 
during the summer were accumulated thi-ough sexual se- 
lection, and transmitted to the offspring at the same season 
of the year ; such variations being inherited either by both 
sexes or by the males alone, according to the form of in- 
heritance which prevailed. This appears more probable 
than that these species in all cases originally tended to 
retain their ornamental plumage during the winter, but 
were saved from this through natural selection, owing to 
the inconvenience or danger thus caused. 

31 See Gould's ' Birds of Great Britain.' 



174 SEXUAL SELECTION: BIRDS. [Part IL 

I have endeavored in this chapter to show that the 
arguments are not trustworthy in favor of the view that 
weapons, bright colors, and various ornaments, are now 
confined to the males owing to the conversion, by means 
of natural selection, of a tendency to the equal transmis- 
sion 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 limit- 
ed 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 following chapter, on the ditiereuces in 
plumage between the young and old. 



Chap. XVI.] INHERITANCE, LIMITED BY AGE. 175 



CHAPTER XVI. 

Birds — concluded. 

The Immature Plumage in Eelation to the Character of the Humage in 
both Sexes when Adult. — Six Classes of Cases. — Sexual Differences 
between the Males of Closely-allied or Eepresentative Species. — The 
Female assuming the Characters of the Male. — Plumage of the Young 
in Eelation to the Summer and Winter Plumage of the Adults. — On 
the Increase of Beauty in the Birds of the World. — Protective Color- 
ing. — Conspicuously-colored Birds. — Novelty appreciated. — Summary 
of the Pour 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 
corresponding 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 all the differences in plumage between the young 
and the old, as far as known to me, may be included, it 
will be well to make a few preliminary remarks. 

With animals of all kinds, when the young differ in 
color from the adults, and the colors of the former are 
not, as far as we can see, of any special service, they may 
generally be attributed, like various embryological struct- 
ures, to the retention by the young of the character of an 
early progenitor. But this view can be maintained with 
confidence only when the young of several species closely 
resemble each other, and likewise resemble other adiilt 
species belonging to the same group ; for the latter are 
the living proofs that such a state of things was formerly 



176 SEXUAL SELECTION: BIRDS. [Part IL 

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 naturalist, who 
believes in the gradual evolution of species, will doubt 
that the progenitor of tlie lion and puma was a striped 
animal, the young having retained vestiges of the stripes, 
like the kittens of black cats, which when grown up are 
not in the least striped. Many species of deer, which 
when mature are not spotted, are while young covered 
with white spots, as are likewise some few species in their 
adult state. So, again, tlie young in the whole family 
of pigs (Suidiie), and in certain rather distantly-allied ani- 
mals, 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 effect- 
ed 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 Gallinacese, and of 
some distftntly-allied bii'ds such as ostriches, are, while 
covered with down, longitudinally striped ; but this charac- 
ter points back to a state of things so remote that it hard- 
ly concerns us. Young cross-bills (Loxia) have at first 
straight beaks like those of other finches, and in their im- 
mature 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 each other, 
and likewise the adult state of the connnon bunting, IJ. 
miliaria. In almost the wliole large group of thrushes 



Chap. XVI.] INHERITANCE, LIMITED BY AGE. 177 

the young have their breasts spotted — a character which 
is retained by many species throughout life, but is quite 
lost by others, as by the Tiirdus migratorius. So, again, 
with many thrushes, the feathers on the back are mottled 
before they are moulted for the first time, and this charac- 
ter is retained for life by certain Eastern species. The 
young of many species of shrikes (Lanius), of some wood- 
peckers, and of an Indian pigeon {Chalcophaps Indicus), 
are transversely striped on the under surface ; and certain 
allied species or genera when adult are similarly marked. 
In some closely-allied and resplendent Indian cuckoos 
(Chrysococcyx), the species when mature differ consider- 
ably from each other in color, but the young cannot be 
distinguished. The young of an Indian goose {Sarkidior- 
nis melanonotus) closely resemble in plumage an allied 
genus, Dendrocygna, when mature.' Similar facts will 
hereafter be given in regard to certain herons. Young 
black grouse {Tetrao tetrix) resemble the young as well as 
the old of certain other species, for instance, the red grouse 
or T. Scoticus. Finally, as Mr. Blytb, who has attended 
closely to this subject, has well remarked, the natural 
affinities of many species are best exhibited in their im- 
mature plumage ; and, as the true affinities of all organic 
beings depend on their descent from a common progenitor, 
this remark strongly confirms the belief that the immature 
plumage approximately shows us the former or ancestral 
condition of the species. 

Although many young birds belonging to various or- 

1 In regard to thrushes, shrikes, and woodpeckers, see Mr. Blyth, in 
Charlesworth's 'Mag. of Nat. Hist.' vol. i. 1837, p. 304; also foot-note to 
his translation of Cuvier's 'R^gne Animal,' p. 159. I give the case of 
Loxia from Mr. Blyth's information. On thrushes, see, also, Audubon, 
' Ornith. Biography,' vol. ii. p. 195. On Chrysococcyx and Chalcophaps, 
Blyth, as quoted in Jerdon's ' Birds of India,' vol. iii. p. 485. On Sar- 
kidiornis, Blyth, in 'Ibis,' ISO'J, p. 1*75. 



178 SEXUAL SELECTION: BIRDS. [Paut IL 

ders thus give us a glimpse of the plumage of their remote 
progenitors, yet they are many other birds, both dull- 
colored and bright-colored, in which the young closely re- 
seniblc tlieir parents. With such species the young of the 
different species cannot resemble each other more closely 
than do the parents ; nor can they present striking resem- 
blances to allied forms in their adult state. They give us 
but little insight into the plumage of their progenitors, ex- 
cepting in so far that, when the young and the old are 
colored in the same general manner throughout a whole 
group of species, it is probable that their progenitors were 
similarly colored. 

We may now consider the classes of cases or rules 
under which the differences and resemblances, between the 
plumage of the young and the old, of both sexes or of one 
sex alone, may be grouped. Rules of this kind were first 
enounced by Cuvier ; but with the progress of knowledge 
they require some modification and amplification. This I 
have attempted to do, as far as the extreme complexity 
of the subject permits, from information derived from 
various sources ; but a full essay on this subject by some 
competent ornithologist is much needed. In order to 
ascertain to Avhat extent each rule prevails, I have tabu- 
lated the facts given in four great works, namely, INIacgilli- 
vray on the birds of Britain, Audubon on tliose of North 
America, Jerdon on those of India, and Gould on those 
of Australia. I may here premise, firstly, that the several 
cases or rules graduate into each other ; and, secondly, 
that, when the young are said to resemble their parents, it 
is not meant that they are identically alike, for their 
colors are almost always rather less vivid, and the feathers 
are softer and often of a different shape. 



Chap. XVI.] CLASSES OF CASES. 179 

RULES OR CLASSES OF CASES. 

L When the adult male is more beautiful or conspicu- 
ous than the adult female, the young of both sexes in 
their first plumage closely resemble the adult female, as 
with the common fowl and peacock ; or, as occasionally 
occurs, they resemble her much more closely than they do 
the adult male. 

II. When the adult female is more conspicuous than 
the adult male, as sometimes though rarely occurs, the 
young of both sexes in their first plumage resemble the 
adult male. 

III. When the adult male resembles the adult female, 
the young of both sexes have a peculiar first plumage of 
their own, as with the robin. 

IV. When the adult male resembles the adult female, 
the young of both sexes in their first plumage resemble 
the adults, as with the kingfisher, many parrots, crows, 
hedge-warblers. 

Y. When the adults of both sexes have a distinct 
winter and summer plumage, whether or not the male 
difiers 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 the females alone ; 
or the young may have an intermediate character ; or, 
again, they may difier greatly from the adults in both 
their seasonal plumages. 

YI. In some few cases the young in their first plumage 
difier 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. 

Class L — In this class, the young of both sexes re- 
semble, more or less closely, the adult female, while the 
adult male difiers, often in the most conspicuous manner, 
from the adult female. Innumerable instances in all Or- 



180 SEXUAL SELECTION : BIRDS. [Part IL 

ders could be given ; it will suffice to call to mind tlie 
common pheasant, duck, and house-sparrow. The cases 
under this class graduate into others. Thus the two sexes 
when adult may diifer so 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 both sexes, in- 
stead of being quite alike, may difter in a slight degree 
from each other, as in our sixth class. These transitional 
cases, however, are few in lumibcr, 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 the male in these groups 
does diifer from the female, as with certain parrots, king- 
fishers, 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 IleUothrlx auriculata (one of the humming-birds) diflers 
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 

* See, for instance, Mr. Gould's account (' Hand-book of the Birds of 
Australia,' vol.i. 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. 2G0) on tha Palaornis 
rosa, in which the young are more like the female than the male. See 
Audubon ('Omith. Biograph.' vol. ii. p. 475) on the two sexes and the 
young of Columba passerina. 



Chap. XVI.] THE YOUNG LIKE THE ADULT FEMALES. 181 

being spotted with bronze) the adult female in all 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.' Again, the plumage of 
the male goosander [Mergus merganser) is more conspicu- 
ously colored, Avith the scapular and secondary wing- 
feathers much longer than in the female, but 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 resemble 
in all respects 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 male, the most obvious 
conclusion is that the male alone has 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 charactei'S having since 
been partially lost by the adult males from some unex- 
plained cause, and transmitted in their diminished state to 
their male offspring alone, when arrived at the correspond- 
ing age of maturity. The belief that in the present class 
the male alone 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 

^ I owe this information to Mr. Gould, who showed me the specimens : 
see also his 'Introduction to the Trochilidae,' 1861, p. 120. 

* Macgillivray, ' Hist. Brit. Birds,' vol. v. pp. 20*7-214. 

^ See his admirable paper in the ' Journal of the Asiatic Soc. of Ben- 
gal,' vol. xix. 1850, p. 223 ; see also Jerdon, 'Birds of India,' vol. i. in- 



182 SEXUAL SELECTION: BIRDS. [Part IL 

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 tlie young being imdis- 
tinguishable, and therefore absolutely imchanged. This 
is the case with certain Indian chats (Thamnobia), with 
certain honeysuckers (Nectarinia), shrikes (Tephrodornis), 
certain kingfishers (Tanysiptera), Kallij pheasants (Gal- 
lophasis), and tree-partridges (Arboricola). 

In some analogous cases, namely, with birds having 
a distinct summer and winter plumage, but with the two 
sexes nearly alike, certain closely-allied species can easily 
be distinguished in their summer or nuptial plumage, yet 
are undistinguishable in their winter as well as in their 
immature plumage. This is the case with some of the 
closely-allied Indian wag-tails or Motacilla. Mr. Swinhoe * 
informs me that three species of Ardeola, a genus of her- 
ons, which represent each other on separate continents, 
are " most strikingly different " when ornamented with 
their summer plumes, but are hardly, if at all, distinguish- 
able during tlie winter. The young also of these three 
species in their immature jilumage 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 first three 
species diiring 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 

troduction, p. xxix. In regard to Tanysiptera, Prof. Sehlegel told Mr. 
Blyth that he could distinguish several distinct races, solely by compar- 
ing the adult males. 

' See also Mr. Swinhoe, in 'Ibis,' July, 1863, p. 131 ; and a previous 
paper, with an extract from a note by Mr. Blyth, in 'Ibis,' Jan. 1861, 
p. 52. 



Chap. XVI.] THE YOUNG LIKE THE ADULT FEMALES. 183 

how the progenitor of the genus was colored. In all these 
cases, the nuptial plumage, which we may assume was 
originally acquired by the adult males during the breed- 
ing-season, and transmitted to the adults of both sexes 
at the corresponding 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 ia 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 dis- 
tinct countries will almost always have been exposed to 
somewhat different conditions, but we can hardly attrib- 
ute the modification of the plumage in the males alone to 
this- action, seeing that the females and the young, though 
similarly exposed, have not been affected. Hardly any 
fact in Nature 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 variations, than the surprising difference be- 
tween the sexes of many birds ; for both sexes must 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 time new conditions may 
produce some direct effect ; we see only that this is sub- 
ordinate in importance to the accumulated results of se- 
lection. When, however, a species migrates into a new 
country, and this must precede the formation of represent- 
ative species, the changed conditions to which they will 
almost always have been exposed will cause them to 
undergo, judging from a widely-spread analogy, a certain 
amount of flixctuating variability. In this case sexual 
selection, which depends on an element eminently liable 
to change — namely, the taste or admiration of the female 
— will have had new shades of color or other differences 



184 SEXUAL SELECTION: BIRDS. [Part IL 

to act on and accumulate; and, as sexual selection is 
always at work, it would (judging from what we know 
of the results on domestic animals of man's unintentional 
selection) be a surprising fact if animals inhabiting sepa- 
rate districts, which can never cross and thus blend tlu-ir 
newly-acquired characters, were not, after a sufficient 
lapse of time, diflferently modiiied. These remarks like- 
wise apply to the nuptial or simimer plumage, whether 
confined to the males or common to both sexes. 

Although the females of the above closely-allied spe- 
cies, together with their young, differ hardly at all from 
each other, so that the males alone can be distinguished, 
yet in most cases the females of the species within the 
same genus obviously differ from each other. The differ- 
ences, however, are rarely as great as between the males. 
We see this clearly in the whole family of the Gallinaceaj : 
the females, for instance, of the common and Japan pheas- 
ant, and especially of the gold and Amherst pheasant, 
of the silver pheasant and the wild-fowl, resemble each 
other very closely in color, while the males differ to an 
extraordinary degree. So it is with the females of most 
of the Cotiiigidte, Fringillida^ and many other families. 
There can indeed be no doubt that, as a general rule, the 
females have been modified to a less extent than the 
males. Some few birds, however, offer a singular and 
inexplicable exception ; thus the females of Paradisca 
apoda and P. Papuana differ from each other more than 
do their respective males ; ' the female of the latter spe- 
cies having the under surface pure white, while the female 
P. apoda is deep brown l)eneath. So, again, as I hear 
from Prof. Newton, the males of two species of Oxy- 
notus (shrikes), which represent each other in the islands 
of Mauritius and Bourbon,* differ but little in color, while 

' WiiUaco, 'The Malay Archipelago,' vol. ii. 1869, p. 30 1. 
* These species are described, with colored figures, liy M. F. Polleu, 
ill 'Ibis,' 1866, p. 275. 



Chap. XVI.] THE YOUNG LIKE THE ADULT FEMALES. 185 

the females diiFer much. In the Bourbon species the 
female appears to have partially I'etained 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 which occui*, 
independently of selection by man, and which we cannot 
explain, in certain sub-breeds of the game-fowl, in which 
the females ^are very different, while the males can hardly 
be distinguished.^ 

As I account so largely by sexual selection for the dif- 
ferences 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; fox-, with these, adapta- 
tion to different habits of life, and other agencies, will 
have come into play. In regard to the differences be- 
tween the females within the same genus, it appears to 
me almost certain, after looking through various large 
groups, that the chief agent has been the transference, in 
a greater or less degree, 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, chafiinch, goldfinch, bullfinch, crossbill, 
sparrow, etc., we shall see that they differ from each other 
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 gallina- 
ceous 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 transfer- 
ence of character from the male to the female. The fe- 
males of the several species of Polyplectron exhibit in a 
dim condition, and chiefly on the tail, the splendid ocelli 

^ 'Variation of Animals, etc., under Domestication,' vol. i. p. 251. 



186 SEXUAL SELECTION: BIRDS. [Part H. 

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 much duller. 
In the guinea-fowl the two sexes are undistinguishablc. 
There is no improbability in the plain, though peculiar 
spotted plumage of this latter bird having been acquired 
through sexual selection by the males, and then trans- 
mitted to both sexes ; for it is not essentially different 
from the much more beautifully-spotted plumage, charac- 
teristic of the males alone of the Tragopan pheasants. 

It should be observed that, in 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 transfer- 
ring to the female any of his later-gained characters. For 
instance, the female and the young of the black-grouse 
{Tetrao tetrix) 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 plainly barred during the 
breeding-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 that 
his plumage has been, at least to a certain extent, influ- 
enced by sexual selection. If so, we may further infer 
that the nearly similar plumage of the lemale black-grouse 
was similarly produced at some fonner 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 characters there has hardly been 
any transference to the female, excepting that she shows 
in her tail a trace of the ciu-ved fork. 

'• MacgUlivray, 'Hist. British Birds,' vol. i. pp. 172-1V4. 



Chap. XVI.] THE YOUNG LIKE THE ADULT FEMALES. 187 

We may therefore conclude that the females of dis- 
tinct though allied species have often had their plumage ren- 
dered more or less different by the transference, in various 
degrees, of characters acquired, both during former and 
recent times, by the males through sexual selection. But 
it deserves especial attention that brilliant colors have 
been transferred much more i*arely than other tints. For 
instance, the male of the red-throated bluebreast ( Cya- 
necula suecica) has a rich blue breast, including a sub-tri- 
angular red mark ; now, marks of approximately the same 
shape have been transferred to the female, but the central 
space is fulvous instead of red, and is surrounded by mot- 
tled instead of blue feathers. The Gallinaceae offer many 
analogous cases ; for none of the species, such as partridges, 
quails, guinea-fowls, etc., in which the colors of the plu- 
mage have been largely transferred from the male to the fe- 
male, 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 {Grossoptilon auritum and Phasianus Wal- 
lichii) the two sexes closely resemble 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 pheas- 
ants had been brilliantly colored, this 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 nidification, the transference 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 ex- 
posed to much danger, and wotild generally have been 
destroyed; the older and more cautious males, on the 
other hand, if they varied in a like manner, would not only 



188 SEXUAL SELECTION: BIRDS. [Part IL 

have been able to survive, but would have been favored in 
their rivalrywith 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 Avould not 
have been transmitted to the females. On the other hand, 
ornaments of a less conspicuous kind, such as those pos- 
sessed 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 
chai'acters from the males to the females, some of the dif- 
ferences between the females of closely-allied species may 
be attributed to the direct or definite action of the condi- 
tions of life." With the males any such action would 
generally have been masked by the brilliant colors gained 
through sexual selection ; but, not so with the females. 
Each of the endless diversities in plumage, which we see 
in our domesticated birds, is, of course, the result of some 
definite cause ; and, under natural and more uniform con- 
ditions, some one tint, assuming that it was in no way in- 
jurious, would almost certainly sooner or later prevail. 
The free intercrossing of 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 
Dossible that the females alone of some species may have 
been thus modified. Although it woulcLbe a difficult, per- 
haps an impossible process, as shown in the last chapter, 
to convert through selection one form of transmission into 
another, 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 accimiulation 

" See, on this subject, chap, x.viii. in the ' Variation of Animals and 
Plants under Domestication.' 



Chap. XVI.] THE YOUNG LIKE THE ADULT FEMALES. 189 

of variations which were from the first limited in their 
transmission to the female sex. If the variations Avere not 
thus limited, the bright tints of the male would be deteri- 
orated or destroyed. 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 difiicul- 
ties. 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 intercrossing, or from being eliminated when trans- 
ferred to the male and in any way injurious to him. Thus 
the plumage of the female would be kej^t constant in char- 
acter. 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), with respect to 
which we have no sufiicient evidence of the action of sex- 
ual selection. We ought, however, to be cautious in 
concluding that colors, which appear to us dull, are not 
attractive to the females of certain species; we should 
bear in mind such cases as that of the common house-spar- 
row, in which the male differs much from the female, but 
does not exhibit any bright tints. No one probably will 
dispute that many gallinaceous birds which live on the 
open ground have acquired their present colors, at least 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 and 
red grouse serve as a protection ? Are partridges, as they 
are now colored, better protected than if they had re- 



190 SEXUAL SELECTION: BIRDS. [Paut H. 

sembled quails? Do the slight differences between the 
females of the common pheasant, the Japan and golden 
pheasants, serve as a protection, or might not their plu- 
mages have been interchanged with impunity ? From what 
Mr. Wallace has observed of the habits of certain gallina- 
ceous birds in the East, he thinks that such slight differ- 
ences are beneficial. For myself, I will only say that I 
am not convinced. 

Formerly, when I was inclined to lay much stress on 
the principle of protection, as accounting for the less 
bright colors of female birds, it occurred to me that pos- 
sibly both sexes and the young might aboriginally have 
been brightly colored in an equal degree ; but that, subse- 
quently, the females, from the danger incurred during 
incubation, and the young, from 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 subsequently 
been necessary to shield their modified descendants. We 
have, also, to reduce, through a gradual process of selec- 
tion, the females and the young to almost exactly the 
same tints and markings, and to transmit them to the cor- 
responding sex and period of life. It is also a somewhat 
strange fact, 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, 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 discov- 
er, of species with the females dull-colored and the young 
bright-colored. A partial exception, however, is offered 
by the young of certain woodpeckers, for they have "the 
whole upper part of the head tinged with red," which 
afterward either decreases into a mere circular red line in 



Chap. XVI.] THE YOUNG LIKE THE ADULT MALES. 191 

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 varia- 
tions 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 varia- 
tions, owing to the late period of life at which they ap- 
peared, have been from the first transmitted only to the 
adult male ofispring. Any variations in brightness which 
occurred in the females or in the young would have been 
of no service to them, and would not have been selected ; 
moreover, if dangerous, would have been eliminated. Thus 
the females and the young will either have been left un- 
modified, or, and this has much more commonly occurred, 
will have been partially modified, by receiving, through 
transference from the males, some of the successive varia- 
tions. Both sexes have perhaps been directly acted on 
by the conditions of life to which they have long been ex- 
posed ; but the females, from not being otherwise much 
modified, will best exhibit any such efiects. These changes 
and all others will have been kept uniform by the free in- 
tercrossing of many individuals. In some cases, especially 
with ground-birds, the females and the young may possi- 
bly have been modified, independently of the males, for 
the sake of protection, so as to have acquired the same 
dull-colored plumage. 

Class II. When the adult female is more conspicuous 
than the adult male^ the young of both sexes in their first 
plumage resemble the adxdt male. — This class is exactly the 
reverse of the last, for the females are here more brightly 

"^ Audubon, ' Ornith. Biography,' vol. i. p. 193. Macgillivray, 'Hist. 
Brit. Birds,' vol. iii. p. 85. See also the case before given of Indopicus 
carlotta. 



192 SEXUAL SELECTION: BIRDS. [Part IL 

colored or more conspicuous than tlie males ; and the 
young, as far as they are known, resemble the adult males 
instead of the adult females. But the difference between 
the sexes is never nearly so great as occurs with many 
birds in the first class, and the cases are comparatively 
rare. Mr. "Wallace, who first called attention to the singu- 
lar relation which exists between the less bright colors of 
the males and their performing the duties of incubation, 
lays great stress on this point,'' as a crucial test that ob- 
scure colors have been acquired for the sake of protection 
during the period of nesting. A different view seems to 
me more probable. As the cases are curious, and not 
numerous, I will briefly give all that I have been able to 
find. 

In one section of the genus Tumix, 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 Gallinacea?. In most 
of the species the female is more distinctly colored and 
brighter than the male," but in some few species the sexes 
are alike. In Ttimix taigoor of India the male " wants 
the black on the throat and neck, and the whole tone of 
the plumage is lighter and less jjronounced than that of 
the female." The female appears to be more vociferous, 
and is certainly much more jiugiiacious, than the male ; 
so that the females and not the males are often kept by 
the natives for fighting, like game-cocks. 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 ri- 

" ' Westmrnster Review, July, 1807, and A. Murray, 'Journal of 
Travel,' 1868, p. 83. 

" For the Australian species, see Gould's ' Iland-book,' etc., vol. ii 
pp. 178, 180, 186, 188. In the British Museum specimens of the Aus- 
tralian Plain-wanderer {Pedionotnus torquatns) may be seen, showing 
similar se.\ual ditt'crcnces. 



Chap. XVI.] THE YOUNG LIKE THE ADULT MALES. 193 

valry, so the females of this Turnix are employed in India. 
When thus exposed the females soon begin their " loud, 
purring call, which can be heard a long way oiF, and any 
females within ear-shot run rapidly to the spot, and com- 
mence 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. The 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 supported by 
some observations made in China by Mr. Swinhoe." Mr. 
Blyth believes that the young of both sexes resemble the 
adult male. 

The females of the three species of Painted Snipes 
(Rhynchsea) " are not only larger, but much more richly 
colored than the males." " With all other birds, in 
which the trachea diifers in structure in the two sexes, 
it is more developed and complex in the male than in the 
female ; but in the MhynchcBa Australis it is simple in 
the male, while in the female it makes four distinct con- 
volutions before entering the lungs." The female, there- 
fore, of this species has acquired an eminently masculine 
character. Mr. Blyth ascertained, by examining many 
specimens, that the trachea is not convoluted in either sex 
of It. Sengalensis^ which species so closely resembles R. 
Australis that it can hardly be distinguished except by 
its shorter toes. This fact is another striking instance of 
the law that secondary sexual characters are often widely 
different in closely-allied forms ; though it is a very rare 
circumstance when such differences relate to the female 
sex. The young of both sexes of M. Bengalensis in their 

>' Jerdon, ' Birds of India,' vol. iii. p. 596. Mr. Swinhoe, in ' Ibis,' 
1865, p. 542; 1866, pp. 131, 405. 

'* Jerdon, ' Birds of India.' vol. iii. p. eYY. 
" Gould's ' Hand-book of the Birds of Australia,' vol. ii. p. 275. 
28 



194 



SEXUAL SELECTION: BIRDS. 



[Part 11. 



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 '" found the fe- 




FiG. 60.— Rhynchaea capcnsis (from Brehm). 

males before the close of the summer associated in flocks, 
as occurs with the females of the Turnix, 

The females of Phalaropus fidlcariiis and P. hyperho- 
reics are larger, and in their summer plumage " more gayly 

'8 'The Indian Field,' Sept. 1858, p. 3. 
'9 ' Ibis,' 1 8G6, p. 298. 



Chap. XVI.] THE YOUNG LIKE THE ADULT MALES. 195 

attired than the males." But the diiFerence in color be- 
tween the sexes is far from conspicuous. The male alone 
of P. fulicarms undertakes, according to Prof. Steenstrup, 
the duty of incubation, as 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 surface, 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 likewise attends to the young. *"• I have not 
been able to discover whether with these species the 
young resemble the adult males more closely than the 
adult females ; for the comparison is somewhat difficult to 
make on account of the double moult. 

Turning now to the Ostrich order: the male of the 
common cassowary {Casiiarivs galeatus) would be 
thought 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 in- 
formed by Mr. Bartlett that in the Zoological Gardens it 
is certainly the male alone who sits on the eggs and takes 
care of the young.^' The female is said by Mr. T. W. 
Wood ^"^ to exhibit during the breeding-season a most 

*" For these several statements, see Mr. Gould's ' Birds of Great Brit- 
ain.' 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 species take either the whole or a large share of the duties 
of incubation, and that they " show much greater devotion toward their 
young, when in danger, than do the females." So it is, as he informs me, 
with Limosa lapponica and some few other Waders, in which the females 
are larger and have more strongly-contrasted coloi's than the males. 

=*' The natives of Ceram (Wallace, 'Malay Archipelago,' vol. ii. p. 150) 
assert that the male and female sit alternately on the eggs ; but this as- 
sertion, as Mr. Bartlett thinks, may be accounted for by the female visit- 
ing the nest to lay her eggs. 

5-^ ' The Student,' April, 1870, p. 124. 

/ - 



196 SEXUAL SELECTION: BIRDS. [Part XL 

pugnacious disposition ; and her wattles then become en- 
larged 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 undistinguishable in plumage. She ap 
pears, 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 
jronsf. 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 incuba- 
tion, but 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 par- 
ents 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 sav- 
age, quarrelsome, and noisy, tlie males gentle and good. 
The case is very different with the African ostrich, for the 
male is somewhat larger than the female and has finer 
plumes with more strongly-contrasted colors ; neverthe- 
less, he undertakes the whole duty of incubation." 

I will specify the few other cases. known to me, in 
which the female is more coTispicuously colored than tlie 
male, although nothing is known about their manner of 

** See the excellent account of the lial)its of this bird under confine- 
ment, by Mr. A. W. Bennett, in ' Land and Water,' May, 1868, p. 233. 

'* Mr. Sclater, on the incubation of the Struthioncs, ' Proc. Zool. Soc.,' 
June 9, 1863. 



Chap. XVI.] THE YOUNG LIKE THE ADULT MALES. 197 

incubation. With the carrion-hawk of the Falkland Isl- 
ands {Milvago leucurus) I was much sm-prised to find by 
dissection that the individuals, which had all their tints 
strongly pronounced, with the cere and legs orange-col- 
ored, were the adult females; while those with duller 
plumage and gray legs were the males or the young. In 
an Australian tree-creeper ( Cllmacteris erythrops) the fe- 
male differs from the male in " being adorned with beauti- 
ful, radiated, rufous markings on the throat, the male hav- 
ing 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 than 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 

^^ For the Milvago, see ' Zoology of the Voyage of the Beagle,' 
Birds, 1841, p. 16. For the Climacteris and night-jar (Eurostopodus), 
see Gould's ' Hand-book of 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 the male ; the head of the male is of a rich dark bronzed color, 
and his back is clothed with finely-pencilled slate-colored feathers, so 
that he may altogether 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 aU 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, resembled 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. 



198 SEXUAL SELECTION: BIRDS. [Part IL 

the last class ; so that the cause of the difference, what- 
ever it may have been, has acted on the females in the 
present class cither less energetically or less persistently 
than on the males in the last class. Mr. Wallace believes 
that the males have had their colors rendered less conspic- 
uous for the sake of protection during the period of incu- 
bation ; 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 of less size, and have less strength. 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 or- 
gans. Thus an almost complete transposition 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 w^hich is usual to their 
sex, so that 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 im- 
probable 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 
** Jerdon, * Birds of India,' vol. iii. p. 598. 



Chap. XVI.] THE YOUNG LIKE BOTH ADULTS. 199 

birds, the greater size and strength and the extraordinary 
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 brighter colors, other 
ornaments, or vocal powers. Sexual selection would then 
soon 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 male resembles the adult 
female^ the young of both sexes have a peculiar first plu- 
mage of their own. — In this class both 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 plumage. The male and female of the splen- 
did scarlet Ibis are alike, while the young are brown ; and 
the scarlet color though common to both sexes, is appar- 
ently a sexual character, for it is not well developed with 
birds under confinement, in the same manner as often oc- 
curs in the case of brilliantly-colored male birds. With 
many species of herons the young differ greatly from the 
adults, and their summer plumage, though common to both 
sexes, clearly has a nuptial character. Young swans are 
slate-colored, while the mature birds are pure whit'- but it 
would be superfluous to give additional instancet,. These 
differences between the young and the old apparently de- 
pend, as in the last two classes, on the young having 
retained a former or ancient state of plumage, which has 
been exchanged for a new plumage by the old of both 
sexes. When the adults are brightly colored, we may 
conclude from the remarks just made in relation to the 



300 SEXUAL SELECTION: BIRDS. [Part II. 

scarlet ibis and to many licnins, and from the analogy of 
the species in the first class, that such colors have been 
acquired through sexual selection by the nearly mature 
males; but that, ditierently from what occurs in the first 
two classes, tlie transmission, though limited to the same 
age, has not been liuiited to the same sex. Consequently 
both sexes, when mature, resemble each other and differ 
from the young. 

Class IV. When the adult male resembles the adult 
female, the young of both sexes in their first plumage 
resemble the adults. — In this class the young and the 
adults of both sexes, whether brilliantly or obscurely 
colored, resemble each other. Such cases are, I think, 
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 simi- 
larity in plumage between the young and the old is never 
absolutely complete, and graduates away into dissimilari- 
ty. Thus the young of some members of the kingfisher 
family are not only less 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 in the same group of birds, even 
within the same genus, for instance in an Australian genus 
of parrokeets (Platycercus), the young of some species 
closely resemble, while the young of other species differ 
considerably from their parents of both sexes, which are 
alike."* Both sexes and the young of the common jay are 
closely similar; but in the Canada jay {Perisoreus Cana- 
densis) the young differ so much from their parents that 
they were formerly described as distinct species.** 

" Jcrdon, ' Birds of India,' vol. i. pp. 222, 228. Gould's ' Hand-book 
of the Birds of Australia,' vol. i. pp. 124, 130. 
»8 Gould, Ibid. vol. ii. pp. 37, 46, 56. 
" Audubon, ' Ornith. Biography,' vol. ii. p. 66. 



Chap. XVI.] THE YOUNG LIKE BOTH ADULTS. 201 

Before proceeding, I may remark that under the pres- 
ent and two next 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. 

The brilliant or conspicuous colors which characterize 
many birds in the present class, can rarely or never be of 
service to them as a i3rotection ; so that they have prob- 
ably 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 
characters to their offspring of both sexes, the same re- 
sults would follow as from the selection of the more at- 
tractive males by the females. But there is some evidence 
that this 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 exceeded to a slight degree 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 
whether 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 elEcient than 
selection on one side alone. It is, therefore, the most 
probable view that sexual selection has acted, in the pres- 
ent class, as far as ornamental characters are concerned, in 
accordance with the general rule throughout the animal 
kingdom, that is, on the males; and that these have 



202 SEXUAL SELECTION: BIRDS. [Pakt H. 

transmitted their gradually-acquired colors, either equally 
or almost equally, to their oifspring of hoth sexes. 

Another poiut is more doubtful, namely, whether the 
successive 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 corre- 
sponding 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 
Colymbus glacialis which had assumed while young, in a 
quite anomalous manner, the adult plumage of their 
parents." Again, the young of the common swan {Cyg- 
ni(s olor) do not cast off their dark feathers and become 
white until eigliteen 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 boi'n pure white. 
These young birds were not albinoes, as shown by the 
color of their beaks and legs, which nearly resembled the 
same parts in the adults. '" 

^ ' Variation of Animals and Plants under Domestication,' vol. ii. 
p. 79. 

3' Charlesworth, 'Mag. of Nat. Hist.' vol. i. 1837, pp. 805, 306. 

35 'Bulletin de la Soc. Vaudoise des Sc. Nat.' vol. x. 1869, p. 132. 
The young of the Polish swan, Cygmis immutabilis of Yarrell, are always 
white; but this species, as Mr. Sclater informs me, is believed to be 
nothing more than a variety of the Domestic Swan ( Cygnus olor). 



CiiAP. XVI.] THE YOUNG LIKE BOTH ADULTS. 203 

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 genus Passer/^ In the house-spar- 
row (P. domesticus) the male differs much from the fe- 
male and from the young. These resemble each other, 
and likewise to a large extent both sexes and the young 
of the 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. montanus) 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- 
genitor. This may have been effected by a male ancestor 
of the tree-sparrow having varied, firstly, when nearly ma- 
ture, or, secondly, while quite young, 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 correspondiag 
ages, at some subsequent period to his young. 

It is impossible to decide which of these three modes 
has generally prevailed throughout the present class of 
cases. The belief that the males varied while young, and 
transmitted their variations to their offspring of both 
sexes, is perhaps the most probable. I may here add that 
I have endeavored, with little success, by consulting vari- 
ous works, to decide how far with birds the period of vari- 
ation has generally determined the transmission of charac- 
ters to one sex or to both. The two rules, often referred 
to (namely, that variations occurring late in life are 

2* I am indebted to Mr. Blyth for infonnation in regard to this genus. 
The sparrow of Palestine belongs to the sub-genus Petronia. 



204 SEXUAL SELECTION: BIRDS. [Part IL 

transmitted to one and the same sex, while those which 
occur early in life are transmitted to both sexes), ap- 
parently hold good in the first," second, and fourth classes 
of cases ; but they fail in an equal number, namely, in the 
third, often in the fifth," and in the sixth small class. 
They hold good, however, as far as I can judge, with a 
considerable majority of the species of birds. Whether 
or not this be so, we may conclude from the facts given 
in the eighth chapter that the period of variation has 
been 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 du- 
ration of life, or to the power of reproduction, or to the 
number of moults through which the species passes. The 
raoulting of birds, even within the same family, sometimes 
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 were first 
developed would falsely appear to us to have been earlier 

•^ For instance, the males of Tanagra cestiva and FringiUa cyanea re- 
quire three years, the male of FrmgiUa ciris four years, to complete their 
beautiful plumage. (See Audubon, ' Ornith. Biography,' vol. i. pp. 233, 
280, 378.) The Harlequin duck takes three years (ibid. vol. iii. p. 614). 
The male of the Gold pheasant, as I hear from Mr. J. Jenner Weir, can 
be distinguished from the female when about three months old, but he 
docs not acquire his full splendor until the end of the September in the 
following year. 

^ Thus the Ibis taiilahis and Grus Amcricanus 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. 221 ; vol. 
iii. pp. 133, 139, 211. 



Chap. XVI.] THE YOUNG LIKE BOTH ADULTS. 205' 

than it really was. This may be illustrated by the practice 
followed by some bird-fanciers, who pull out a few feathers 
from the breasts 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 re- 
placed 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 powers of reproduction are gained, it is a remarkable 
fact that various birds occasionally breed while retaining 
their immature plumage." 

The fact of birds breeding in their immature plumage 
seems opposed to the belief that sexual selection has played 
as important a part as I believe it has in giving ornament- 
al colors, plumes, etc., to the males, and, by means of 
equal transmission, to the females of many species. The 
objection would be a valid one, if the younger and less 
ornamented males were as successful in winning females 
and propagating their kind, as the older and more beauti- 
ful males. But we have no reason to suppose that this is 

36 Mr. Blyth, in Charlesworth's 'Mag. of Nat. Hist.' vol. i. ISST, p. 
300. Mr. Bartlett has informed me in regard to gold-pheasants. 

*'' I have noticed the following cases in Audubon's ' Omith. Biogra- 
phy. The Redstart of America' {Micscicapa ruticilla, vol. i. p. 203). 
The Ibis tantalus takes four years to come to full maturity, but sometimes 
breeds in the second year (vol. iii. p. 138). The Grus Americanus takes 
the same time, but breeds before acquiring its full plumage (vol. iii. p. 
211). The adults of Ardea ccerulea are blue and the young white; and 
white, mottled, and mature blue birds may all be seen breeding together 
(vol. iv. p. 58) : but Mr. Blyth informs me that certain herons apparently 
are dimorphic, for white and colored individuals of the same age may be 
observed. The Harlequin duck (Anas histrionica, Linn.) takes three 
years to acquire its full plumage, though many birds breed La the second 
year (vol. iii. p. 614). The Whiteheaded Eagle {Falco leucocephalus, vol. 
iii. p. 210) is likewise known to breed in its immature state. Some spe- 
cies of Oriolus (according to Mr. Blyth and Mr. Swinhoe, in ' Ibis,' July, 
1863, p. 68) likewise breed before they attain their full plumage. 



206 SEXUAL SELECTION: BIRDS. [Part IL 

the case. Audubon speaks of the breeding of the imma- 
ture males of Ibis tantalus as a rare event, as does Mr. 
Swinboe, in regard to the immature males of Oriolus." K 
the young of any species in their immature plumage were 
more successful in winning partners than the adults, the 
adult plumage would probably soon be lost, as the males 
which retained their immature dress for the longest period 
would prevail, and thus the character of the species would 
ultimately be modified." If, on the other hand, the young 
never succeeded in obtaining a female, the habit of early 
reproduction would perhaps be sooner or later quite elim- 
inated, from being superfluous and entailing waste of 
power. 

Tlie plumage of certain birds goes on increasing in 
beauty during many years after they are fully mature ; 
this is the case with the train of the peacock, and with 
the crest and plumes of certain herons ; for instance, the 
Ardea lAidovicana ;*" but it is very doubtful whether 
the continued development of such feathers is the result of 

^ See the last foot-note. 

*' Other animals, belonging to quite distinct classes, are either habit- 
ually 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 Miiller has shown (' Facts and Arguments 
for Darwin,' Eng. Trans. 1869, 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 claspcrs. All such facts are highly interesting, as 
bearing on one means by which species may undergo great modifications 
of character, in accordance with Mr. Cope's views, expressed under the 
terras of the " retardation and acceleration of generic characters ; " but 
I cannot follow the views of this eminent naturalist to their full extent. 
See Mr. Cope, " On the Origin of Genera," from the ' Proc. of Acad. Nat. 
Sc. of Philadelphia,' Oct. 1868. 

*> Jerdon, ' Birds of India,' vol. iii. p. 507, on the peacock. Audu- 
bon, ibid. Tol. iiL p. 1S9, on the Ardea. 



Chap. XVI.] SEASONAL CHANGES OF PLUMAGE. 207 

the selection of successive beneficial variations, or merely 
of continuous growth. Most fishes continue increasing 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 both sexes have a dis- 
tinct winter and summer plumage, whether or not the male 
diners 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 the females alone / 
or the young may have an intermediate character ; or, 
again, they may differ greatly from the adults in both 
their seasonal plmnages. — The cases in this class are 
singularly complex ; nor is this surprising, as they depend 
on inheritance, limited in a greater or less degree in three 
difierent 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 Amer- 
ica, and apparently with the splendid Maluri of Aus- 
tralia." With the species, the sexes of which are alike 
during both the summer and winter, the young may re- 
semble the adults, firstly, in their winter dress ; secondly, 
which occurs much more rarely, in their summer dress ; 
thirdly, they may be intermediate between these two 
states; and, fourthly, they may differ greatly from the 

•*' For illustrative cases see vol. iv. of Macgillivray's ' Hist. Brit. 
Birds;' on Tringa, etc., pp. 229, 271; on the Machetes, p. 1*72; on the 
Charadriits hiaticula, p. 118; on the Charadrius pluvialis, p. 94. 

*' For the goldfinch of North America, Fringilla tristis, Linn., see Au- 
dubon, ' Omith. Biography,' vol. i. p. 172. For the Maluri, Gould's ' Hand- 
book of the Birds of Australia,' vol. i. p. 318. 



208 SEXUAL SELECTION: BIRDS. [Part IL 

adulta at all seasons. We have an instance of the first of 
these four cases in one of the egrets of India {Buphus 
coromandus), in which the young and tlie adults of both 
sexes arc white during the winter, the adults becoming 
golden-buff during the summer. With the Gaper {Anas- 
tomits 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 be- 
coming 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 during the summer ; and the young of the white- 
crowned sparrow of North America {Fringilla leuco- 
phri/s), as soon as fledged, have elegant white stripes on 
their heads, which are lost by the young and the old dur- 
ing the winter.''* With respect to the third case, namely, 
that of the young having an intermediate character be- 
tween the summer and winter adult plumages, Yarrell " 
insists that this occurs with many waders. Lastly, in re- 
gard to the young differing greatly from both sexes in 
their adult summer and winter plumages, this occurs with 
some herons and egrets of North America and India — the 
young alone being white. 

I will make only a few remarks on these complicated 
cases. When the young resemble the female in her sum- 
mer dress, or the adults of both sexes in their winter 
dress, the cases differ from those given under Classes L 
and III. only in the characters originally acquired by the 

■•* I am indebted to Mr. Blyth for information in regard to the 
Buphus : see also Jerdon, ' Birds of India,' vol. iiL p. 749. On the 
Anastomus, see Blyth, in 'Ibis,' 1867, p. 173. 

■"On the Alca, see Macgillivray, 'Hist. Brit. Birds,' vol v. p. 347. 
On the FringUla Icucophrys, Audubon, ibid. vol. iL p. 89. I shall have 
hereafter to refer to the young of certain herons and egrets being white. 

« 'ffistory of British Birds,' vol. i. 1839, p. 159. 



Chap. XVI.] THE YOUNG LIKE ADULTS OF SAME SEX. 209 

males during the breeding-season having been limited in 
their transmission to the corresponding season. When 
the adults have a distinct summer and winter plumage, 
and the young difier 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 can 
account through sexual selection for the summer or nup- 
tial plumage of the adults, but how are we to account for 
their distinct winter plumage ? K we could admit that 
this plumage serves in all cases as a protection, its ac- 
quirement 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 plu- 
mage ; this may have had some effect, but I have not 
much confidence in so great a difference, as we 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 characters from the summer plumage, has been re- 
tained by the adults during the winter. Finally, all the 
cases in our present class apparently depend on charac- 
ters 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 fol- 
low out these complex relations. 

Class VI. The young in their first plumage differ 
from each other according to sex / the young males re- 
sembling more or less closely the adult males, and the 
young females more or less closely the adult fem,ales. — 
The cases in the present class, though occurring in vari- 
ous groups, are not numerous ; yet, if experience had not 
taught us to the contrary, it seems the most natural thing 
that the young should at first always resemble to a cer- 
tain extent, and gradually become more and more like, the 



210 SEXUAL SELECTION : BIRDS. [Part IL 

adults of the same sex. 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 similar cases have been noticed ; the 
male blackbird {Turdus menila) can be distinguished in 
the nest from the female, as the main wing-feathers, which 
are not moulted so soon as the body-feathers, retain a 
brownish tint until the second general moult." The two 
sexes of the mocking-bird [Turchis 2^oly(/lottus, Linn.) dif- 
fer 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 (viz., Orocetes erythrogastra and Pe- 
trocincla 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." So that the very same feathers which in the 
young blackbird assume their mature character and be- 
come black after the others, in these two species assume 
this character and become blue before the others. The 
most probable view with reference to these cases is that 
the males, differently from what occurs in Class I., have 
transmitted their colors to their male offspring at an ear- 
lier age than that at which they themselves first acquired 
them; for if they had varied while quite young, they 
would probably have transmitted all their characters to 
their offspring of both sexes." 

<« Blyth, in Charlesworth's 'Mag. of Nat. Hist.' vol. i. 1837, p. 362; 
and from information given to me by liim. 

*' Audubon, 'Ornith. Biography,' vol. i. p. 113. 

« Mr. C. A. Wright, in 'Ibis,' voL vi. 1864, p. 65. Jerdon, 'Birds 
of India,' vol. i. p. 515. 

*' The following additional cases may be mentioned : the young males 



Chap. XVI.] THE YOUNG LIKE ADULTS OF SAME SEX. 211 

In Aithuriis polytmus (one of the humming-birds) 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-feath- 
ers 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 be- 
longing to the genus Eustephanus, both beautifully col- 
ored, inhabit the small island of Juan Fernandez, and 
have always been i-anked as specifically distinct. But it 
has lately been ascertained that the one, which is of a rich 
chesnut-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 resemble to a certain extent the 
adults of the corresponding sex, the resemblance gradu- 
ally 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 independently rendered beautiful ; 
and not that the one sex has partially transferred its 
beauty to the other. The male apparently has acquired 
his bright colors through sexual selection in the same man- 
ner as, for instance, the peacock or pheasant in our first 
class of cases ; and the female in the same manner as the 
female Rhynchsea or Turnix in our second class of cases. 
But there is much difficulty in understanding how this 

of Tanagra rubra can be distinguished from the young females (Audu- 
bon, ' Ornith. Biography,' vol. iv. p. 392), and so it is with the nestlings 
of a blue nuthatch, Dendrophila frontalis of India ( Jerdon, ' Birds of India,' 
vol. i. p. 389). Mr. Blyth also informs me that the sexes of the stone- 
chat, Saxicola rubicola, are distinguishable at a very early age. 



212 SEXUAL SELECTION: BIRDS. [Pabt XL 

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 liumming- 
birds the males greatly exceed in number the females, 
while with other species inhabiting the same country the 
females greatly exceed the males. If, then, we might as- 
sume that during some former lengthened period the males 
of the Juan Fernandez species had greatly exceeded the 
females in number, but that during another lengthened 
period the females had greatly exceeded the males, we 
could understand how the males at one time, and the 
females at another time, might have been rendered beauti- 
ful 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 remarkable to be passed over without 
notice. 

We have now seen in numerous instances, iinder all 
six classes, that an intimate relation exists between the 
plumage of the young and that of the adults, either of one 
sex or both sexes. These relations are fairly well ex- 
plained on the principle that one sex — this being in the 
great majority of cases the male — first acquired through 
variation and sexual selection bright colors or other orna- 
ments, and transmitted them in various ways, in ac- 
cordance with the recognized laws of inheritance. Why 
variations have occurred at different periods of life, even 
sometimes with the species of tlie same group, we do not 
know ; but with respect to the form of transmission, one 
important determining cause seems to have been tlie age 
at which the variations first appeared. 

From the principle of inheritance at corresponding 
ages, and from any variations in color which occurred in the 



Chap. XVI.] COLOR AND PROTECTION. 213 

males at an early age not being then selected, on the con- 
trary being often eliminated as dangerous, while 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 
modified. 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 both are brightly 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 brightly-colored species being more bril- 
liantly colored than tbeir 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) 
brightly-colored, and as these form whole groups we may 
infer that their early progenitors were likewise brightly- 
colored. With this exception, if we look to the birds of 
the world, it appears that their beauty has been greatly 
increased since that period, of which we have a partial 
record in their immature plumage. 

O71 the Color of the Plumage hi relation 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 
protection. There can, however, be no doubt, as formerly 
remarked, that both sexes of many birds have had their 
colors modified for this purpose, so as to escape the notice 
of their enemies; or, in some instances, so as to approach 
their prey unobserved, in the same manner as owls have 
had their plumage rendered soft, that their flight may not 
be overheard. Mr. Wallace remarks^" that " it is only in 
^'^ 'Westminster Review,' July, ISC'?, p. 5. 



2U SEXUAL SELECTION: BIRDS. [Part II. 

the tropics, among forests that never lose their foliage, that 
we find whole groups of hirds whose chief color is green." 
It will be admitted by every one, who has ever tried, how 
difficult it is to distinguish parrots in a leaf-covered tree. 
Nevertheless, 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 appar- 
ently exposed to nearly the same dangers. It is there- 
fore probable that strongly-pronounced colors have been 
acquired by tree-haunting birds through sexual selection, 
but that green tints have had an advantage throiagh nat- 
ural selection over other colors for the sake 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 the ground ! Animals inhabiting deserts offi'r 
the most striking instances, for the bare surface affijrds no 
concealment, and all the smaller quadrupeds, reptiles, and 
birds, depend for safety on their colors. As Mr. Tristram 
has remarked,^' in regard to the inhabitants of the Saha- 
ra, all are protected by their " isabelline or sand-color." 
Calling to my recollection the desert-birds which I had 
seen in South America, as well as most of the ground- 
birds in Great Britain, it appeared to me that both sexes 
in such cases are generally colored nearly alike. Ac- 
cordingly, I applied to Mr. Tristram, with respect to the 
birds of the Sahara, and he lias kindly given me the fol- 
lowing information : There are twenty-six species, belong- 
ing to fifteen genera, which manifestly have had their 
plumage colored in a protective manner; and this coloring 
is all the more striking, as with most of these birds it is 

"' ' Ibi.'^,' 1859, vol. i. p. 429, et acq. 



Chap. XVI.] COLOR AND PROTECTION. 215 

different from that of their congeners. Both sexes of thir- 
teen 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 the other thirteen species, three belong to 
genera in which the sexes usually differ from each other, 
yet they have the sexes alike. In the remaining ten spe- 
cies, the male differs fi-om 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 
both 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 the lower surfaces of the males alone have been 
diversified through sexual selection, for the sake of orna- 
ment. Here, as both sexes are equally well protected, we 
clearly see that the females have not been prevented 
through natural selection from inheriting the colors of 
their male parents : we must look to the law of sexually- 
limited transmission, as before explained. 

In all parts of the world both sexes of many soft-billed 
birds, especially those which frequent reeds or sedges, 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 spe- 
cially 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 
tlie belief that such colors have been gained through sex- 
ual selection, from being attractive. Many of the soft- 



216 SEXUAL SELECTION: BIRDS. [Part H. 

billed birds are songsters ; and a discussioTi 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 pro- 
tection, such as the jack-snipe, woodcock, and night-jar, 
are likewise marked and shaded, according to our stand- 
ard of taste, with extreme elegance. In such cases we 
may conclude that both natural and sexual selection have 
acted conjointly for protection and ornament. Whether 
any bird exists which does not possess some special at- 
traction, 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 thing, to attribute the result to the direct action 
of the conditions of life. 

There are many birds both sexes of which are conspic- 
uously thougli not brilliantly colored, such as the numer- 
ous black, white, or piebald species ; and these colors are 
])robably the result of sexual selection. With the common 
blackbird, capercailzie, black-cock, black Scoter-duck (Oi- 
demia), 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 proba- 
ble that the complete or partial blackness of botli 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 transmission to 



Chap. XVI.] CONSPICUOUS COLORS. 217 

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 afforded adds greatly to their beauty ; we 
see this in the bright-yellow beak of the male blackbird, 
in the crimson skin over the eyes of the black-cock and 
capercailzie, in the variously and brightly colored beak 
of the Scoter-drake (Oidemia), in the red beak of the 
chough [Corvus graculus, Linn.), of the black swan, and 
black stork. This leads me to remark that it is not at all 
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 at the base of 
the 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 the time of pairing," 
There is no greater improbability in toucans being encum- 
Tsered with immense beaks, though rendered as light as 
possible by their cancellated structure, for an object false- 
ly appearing to us unimportant, namely, the display of 
fine colors, than that the male Argus pheasant and some 

^' No satisfactory explanation has ever been offered of the immense 
size, and still less of the bright colors, of the toucan's beak. Mr. Bates 
('The Naturalist on the Amazons,' vol. ii. 1863, p. 341) states that they 
use their beak 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. 

^3 Ramphastos carinatus, Gould's ' Monograph of Ramphastidae.' 
29 



218 SEXUAL SELECTION: BIRDS. [Part IL 

otlier birds sliould be encumbered with plumes so long as 
to impede tlieir flight. 

In the same manner, as the males alone of various spe- 
cies 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 (Chasmo- 
rhynchus), the Antarctic goose [Bernicla antarctica), the 
silver-pheasant, etc., while the females are brown or ob- 
scurely mottled. Therefore, on the same principle as 
before, it is prol)able that both sexes of many birds, such 
as white cockatoos, several egrets with their beautiful 
plumes, certain ibises, gulls, terns, etc., have acquired 
their more or less completely white 2)lumage through sex- 
ual selection. The species which inhabit snowy regions 
of course come under a different head. The white plu- 
mage of some of the above-named birds appears in both 
sexes only when they are mature. This is likewise the 
case with certain gannets, tropic-birds, etc., and with the 
snow-goose (Anser hyperhorens). 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 the case of the Anastomtis 
oscitans previously alluded to, we have still better evi- 
dence that the white plumage is a nuptial character, for it 
is developed, only during the summer ; the young 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 during the winter and in the young 
state. On the other hand, Avith 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 pui'e white, or much paler-colored than during the 



Chap. XVI.] CONSPICUOUS COLORS. 219 

breeding-season. These latter cases offer another instance 
of the capricious manner in which sexual selection appears 
often to have acted," 

The cause of aquatic birds having acquired a white 
plumage so much more frequently than terrestrial birds, 
probably depends on their large size and strong powers 
of flight, so that they can easily defend themselves or es- 
cape from birds of prey, to which, moreoA^er, they are not 
much exposed. Consequently sexual selection has not 
here been interfered with or guided for the sake of pro- 
tection. No doubt, with birds which roam over the oj:)en 
ocean, the males and females could find each other much 
more easily when made conspicuous either by being per- 
fectly white, or intensely black ; so that these colors may 
possible serve the same end as the call-notes of many land- 
birds. A white or black bird, when it discovers and flies 
doAvn to a carcass floating on the sea or cast up on the 
beach, will be seen from a great distance, and will guide 
other birds of the same and of distinct species, to the 
prey ; but as this would be a disadvantage to the first 
finders, the individuals which were the wliitest or blackest 
would not thus have procured 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 ele- 

^ On Larus, Gavia, and Sterna, see Macgillivray, ' Hist. Brit. Birds,' 
vol. V. pp. 515, 584, 626. On the Anser hyperboreus, Audubon, ' Ornith. 
Biography,' vol. iv. p. 562. On the Anastomus, Mr. Blyth, in ' Ibis,' 
1867, p. 173. 

^^ It may be noticed that with vultures, which roam far and wide 
through the higher regions of the atmosphere, like marine birds over 
the ocean, three or four species are almost wholly or largely white, and 
many other species are black. This fact supports the conjecture that 
these conspicuous colors may aid the sexes in finding each Other during 
the breeding-season. 



220 SEXUAL SELECTION: BIRDS. [Pakt IL 

ment as taste, we can understand how it is that within the 
same group of birds, with habits of life nearly the same, 
there should exist white or nearly white, as well as black, 
or nearly black species — for instance, white and black 
cockatoos, storks, ibises, swans, terns, and petrels. Pie- 
bald birds likewise sometimes occur in the same groups, 
for instance, the black-necked swan, certain terns, and the 
common magpie. That a strong contrast in color is agree- 
able to birds, we may conclude, by looking through any 
large collection of specimens or series of colored plates, 
for the sexes frequently 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 in the female. 

It would even appear that mere novelty, or change for 
the sake of change, has sometimes acted like a charm on 
female birds, in the same manner as changes of fashion 
with us. The Duke of Argyll says ^^ — and I am glad to 
have the unusual satisfaction of following for even a short 
distance in his footsteps — "I am more and more convinced 
that variety, mere variety, must be admitted to be an ob- 
ject and an aim in Nature." I wish the Duke had ex- 
plained what he here means by Nature. Is it meant that 
the Creator of the universe ordained diversified results for 
His own satisfaction, or for that of man? The former no- 
tion seems to me as much wanting in due reverence as the 
latter in probability. Capriciousness of taste in the birds 
themselves appears a more fitting explanation. For ex- 
ample : the males of some parrots can hardly be said to 
be more beautiful, at least according to our taste, than the 
females, but they differ from them in such points as the 
male having a rose-colored collar instead of, as in the fe- 
male, "a bright emeraldine narrow green collar;" or in 
the male having a black collar instead of " a yellow dcnii- 
collar in front," with a pale roseate instead of a plum-blue 

'« 'The Journal of Travel,' edited by A. Murray, vol. i. 1868, p. 286. 



Chap. XVI.] NOVELTY ADMIRED. 221 

head." As so many male birds have for their chief orna- 
ment elongated tail-feathers or elongated crests, the short- 
ened tail, formerly described in the male of a humming- 
bird, and the shortened crest of the male goosander almost 
seem like one of the many opposite 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 apparently been 
appreciated for the sake of novelty. The young of the 
Ardea asha are white, the adults being dark slate-colored ; 
and not only the young, but the adults of the allied JBuphus 
coromandus in their winter plumage are white, this color 
changing into a rich golden-buff during the breeding-sea- 
son. It is incredible that the young of these two species, 
as well as of some other members of the same family,^® 
should have been specially rendered pure white and thus 
made conspicuous to their enemies ; or that the adults of 
one of these two species should have been specially ren- 
dered white during the winter in a country which is never 
covered with snow. On the other hand, we have reason 
to believe that whiteness has been gained by many birds 
as a sexual ornament. We may therefore conclude that 
an early progenitor of the Ardea asha and the Huplius 
acquired a white plumage for nuptial purposes, and trans- 
mitted this color to their young ; so that the young and 
the old became white like certain existing egrets ; the 
whiteness having afterward been retained by the young 
while exchanged by the adults for more strongly-pro- 

" See Jerdon on the genus Palieornis, ' Birds of India,' vol. i. pp. 
258-260. 

^^ The young of Ardea rufesce)is and A. ccerulea of the United States 
are likewise white, the adults being colored in accordance with their spe- 
cific names. Audubon (' Ornith. Biography,' vol. iii. p. 416 ; vol. iv. p. 
88) seems rather pleased at the thought that this remarkable change of 
plumage will greatly " disconcert the systematists." 



222 SEXUAL SELECTION: BIRDS. [Paut II. 

nouuccd tints. But if we could look still further back- 
Avanl in time 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 gularts, the colors of whicli are the reverse of those 
of A. as/ia, for the young are dark-colored and the adults 
white, the young having retained a former state of plu- 
mage. It appears, therefore, that the progenitors in their 
adult condition of the Ardea asha, the Jiiq)hus, and of 
some allies, have undergone, during a long line of descent, 
the following changes of color: firstly a dark shade, sec- 
ondly pure white, and thirdly, owing to another change 
of fashion (if I may so express myself), their present slaty, 
reddish, or golden-biiff tints. These successive changes 
are intelligible only on the principle of novelty having 
been admired by birds for the sake of novelty. 

JSummary of the Mwr Chapters on Birds. — Most male 
birds are highly pugnacious during the breeding-season, 
and some possess weapons especially 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 di'ive away or kill their rivals, but have 
special means for charming the female. With some it is 
the power of song, or of emitting strange cries, or of pro- 
ducing instrumental music, and the males in consequence 
difier from the females in their vocal organs, or in the 
structure of certain feathers. From the curiously-diversi- 
fied means for producing various sounds we gain a high 
idea of the importance of this means of courtship. Many 
birds endeavor to charm the females by love-dances or 
antics, performed on the ground or in the air, and some- 
times at prepared places. But ornaments of many kinds, 



Chap. XVI.] SUMMARY. - 223 

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 
fighting with their rivals. The males of very many spe- 
cies do not assume their ornamental dress until they ar- 
rive at maturity, or they assume it only during the breed- 
ing-season, or the tints then become more vivid. Certain 
ornamental appendages become enlarged, turgid, and 
bright-colored, during the very 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 affiiir, 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 cei'tain in- 
dividual 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 in which the sexes differ, 
the males differ much more from each other than do the 
females ; this is well shown in certain closely-allied repre- 
sentative species in which the females can hardly be dis- 
tinguished, while the males are quite distinct. Birds in a 



224 SEXUAL SELECTION: BIRDS. [Part IL 

state of nature offer individual differences which would 
am])ly suffice for the work of sexual selection ; but we 
have seen that they occasionally present more strongly- 
marked variations, which recur so frequeutly that they 
would immediately be fixed, if they served to allure the 
fenuile. The laws of variation will have determined the 
nature of the initial changes, and largely influenced the 
final result. The gradations, which may be observed be- 
tween the males of allied species, indicate the nature of 
the steps which have been passed through, and explain in 
the most interesting manner certain characters, such as 
the indented ocelli of the tail-feathers of the peacock, and 
the wonderfully-shaded ocelli of 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 some- 
times 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 pro- 
duced some definite effect on both sexes, the more impor- 
tant result will have been an increased tendency to fluc- 
tuating variability or to augmented individual dift'erences ; 
and such differences will have afforded an excellent ground- 
work for the action of sexual selection. 

The laws of inheritance, irrespectively of selection, 
appear to have determined whether the chai-acters ac- 
quired by the males for the sake of ornament, for pro- 
ducing various 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 sometimes have 
been transmitted in one way and sometimes in another is, 



Chap. XVI.] SUMMARY. 225 

in most cases, not known ; but the period of variability 
seems often to have been the determining cause. Wlien 
the two sexes have inherited all characters in common 
they necessarily resemble each other ; but, as the suc- 
cessive variations may be diiferently transmitted, every 
possible gradation may be found, even within the same 
genus, from the closest similarity to the widest dissimi- 
larity between the sexes. With many closely-allied spe- 
cies, following nearly the same habits of life, the males 
have come to differ from each other chiefly through the 
action of sexual selection ; while the females have come to 
differ chiefly from partaking in a greater or lesser degree 
of the characters thus acquired by the males. The efiects, 
moi'eover, of the definite action of the conditions of life, 
will not have been masked in the females, as in the case 
of the males, by the accumulation through sexual selection 
of strongly-pronounced colors and other ornaments. The 
individuals of both sexes, however aftected, will have been 
kept at each successive period nearly uniform by the free 
intercrossing of many individuals. 

With the sjiecies, in which the sexes differ in color, 
it is possible that at first there existed a tendency to 
transmit the successive variations equally to both sexes ; 
and that the females were prevented from acquu-ing the 
bright coloi-s of the males, on account of the danger to 
which they would have been exposed during incubation. 
But it would be, as far as I can see, an extremely difiicult 
process to convert, by means of natural selection, one form 
of transmission into another. On the other hand, there 
would not be the least difliculty in rendering a female 
dull-colored, the male being still kept bright-colored, by 
the selection of successive variations, which were from the 
first limited in their transmission to the same sex. Whether 
the females of many species have actually been thus modi- 
fied, must at present remain doubtful. When, through 



220 SEXUAL SELECTION: BIRDS. [Pakt IL 

the law of the equal transmission of characters to both 
sexes, the females have been rendered as conspicuously 
colored as the males, their instincts have often been modi- 
fied, and they have been 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 brightly-colored than the males. They liave, also, 
become so quarrelsome that they often fight together like 
the males of the most pugnacious species. K, as seems 
probable, they habitually drive away rival females, and 
by the display of their bright colors or other charms en- 
deavor to attract the males, we can understand how it is 
that they have gradually been rendered, by means of sex- 
ual selection and sexually-limited transmission, more beau- 
tiful than the males — the latter being left unmodified or 
only slightly modified. 

Whenever the law of inheritance at corresponding 
ages prevails, but not that of sexually-limited transmission, 
then if the parents vary late in life — and we know that 
this constantly occurs with our poultry, and occasionally 
Avith other birds — the young will bo left unaflt'Ctod, 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 left unaSected. When variations in bright- 
ness or in other conspicuous characters occur early in life, 
as no doubt often happens, they will not be acted on 
through sexual selection until the period of reproduction 
arrives ; consequently, 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 



Chap. XVI.] SUMMARY. 237 

unaffected, and therefore like each other. With species 
having a distinct summer and winter phimage, the males 
of which either resemble or differ from the females during 
hoth seasons or during the summer alone, the degrees and 
kinds of resemblance between the young and the old are 
exceedingly complex ; and this 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 that the beauty 
of our existing species, if we look to the whole class, has 
been largely increased since that period of which the im- 
mature plumage gives us an indirect record. Many birds, 
especially those which live much on the ground, have un- 
doubtedly been obscurely colored for the sake of protec- 
tion. 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 orna- 
mented through sexual selection. Finally, from the facts 
given in these four chapters, we may conclude that weap- 
ons for battle, organs for producing sound, ornaments of 
many kinds, bright and conspicuous colors, have gener- 
ally been acquired by the males through variation and 
sexual selection, and have been transmitted in various 
ways according to the several laws of inheritance — the fe- 
males and the young being left comparatively but little 
modified. ^^ 

^' I am greatly indebted to the kindness of Mr. Sclater for having 
looked over these four chapters on birds, and the two following ones on 
mammals. By this means I have been saved from making mistakes about 
the names of the species, and from giving any facts which are actually 
known to this distinguished naturalist to be erroneous. But of course 
he is not at all answerable for the accuracy of the statements quoted by 
me from various authorities. 



228 BEXUAL SELECTION: MAMMALS. [Pabt H 



CHAPTER XVII. 

Secondary Sexual Chakactees op Ma^imals. 

The Law of Battle. — Special "Weapons, confined to the Males. — Cause of 
Absence of Weapon.s in the Female. — Weapons common to both 
Se.xes, yet primarily acquired by the Male. — Other Uses of such Weap- 
ons. — Their High Importance. — Greater Size of the Male. — Means of 
Defence. — 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 figlitinp;, engage in 
desperate conflicts during the season of love. Two male 
hares have 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 " hardly a skin is without scars." * I observed the 
same fact with the hides of the guanaooes in Patagonia ; 
and on one occasion several were so absorbed in fighting 
that they fearlessly rushed close by me. Livingstone 
speaks of the males of tlie many animals in Southern 

' 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,' 184G, p. 2G9. On beavers, Mr. A. H. Green, in ' Jour- 
nal of Lin. Soc. Zoolog.' vol. x. 1809, p. SG2. 



Chap. XVII.] LAW OF BATTLE. 229 

Africa as almost invariably showing the scars received in 
former contests. 

The law of battle prevails with aquatic as with terres- 
trial mammals. It is notorious how desperately male seals 
fight, both with their teeth and claws, during the breed- 
ing-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, and turn on their sides and twist about ; " so 
that it is believed by some naturalists that the frequently 
deformed state of their lower jaws is caused by these 
struggles. ** 

All male animals which are furnished with special 
weapons 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 inex- 
tricably locked together, showing how miserably the vic- 
tor and vanquished had perished.^ No animal in the 
world is so dangerous as an elephant in must. Lord Tan- 
kerville has given me a graphic descrijDtion of the battles 
between the wild-bulls in Chillingham Park, the descend- 
ants, degenerated in size but not in courage, of the gigan- 
tic Hos 2)fimigenius. In 1861 several contended for mas- 
tery ; and it was observed that two of the younger bulls 
attacked in concert the old leader of the herd, overthrew 
and disabled him, so that he was believed by the keepers 

2 On the battles of seals, see Captain C. Abbott in ' Proc. Zool. Soc.' 
1868, p. 191; also Mr. H. Brown, ibid. 1869, p. 436; also L. Lloyd, 
'Game-Birds of Sweden,' 1867, p. 412; also Pennant. On the sperm- 
whale, sec Mr. J. H. Thompson, in 'Proc. Zool. Soc' 1867, p. 246. 

' See Scrope (' Art of Deer-stalking,' p. 17) on the locking of the 
horns with the Cervus elaphus. Richardson, in ' Fauna Bor. Americana,' 
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. 



230 SEXUAL SELECTION: MAMMALS. [Pabt IL 

to be lying mortally wounded in a neighboring wood. 
But a few days afterward one of the young bulls singly 
approached the wood ; and then the " monarch of tlie 
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 me that when 
he resided in the Falkland Islands he imported a young 
English stallion, which, with eight mares, frequented the 
liills near Port William. On these hills there were two 
wild stallions, each with a small troop of mares ; " and it 
is certahi 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 captain who had charge of the 
horses, and who, on riding to the spot, found one of the 
two stallions engaged with the English horse, while the 
other was driving away the mares, and had already sepa- 
rated four from the rest. The captain settled the matter 
by driving the whole party into the corral, for the wild- 
stallions would not leave the mares." 

Male animals already provided with efiicient cutting or 
tearing teeth for the ordinary purposes of life, as in the 
carnivora, insectivora, and rodents, are seldom furnished 
with weapons especially adapted for fighting 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 horn- 
less. 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 ante- 
lo|)es, the musk-deer, camel, horse, boar, various apes, 
seals, and the walrus, ofier instances of these several cases. 



Chap. XVII.] LAW OF BATTLE. 231 

In the females of the walrus the tusks are sometimes quite 
absent.* In the male elephant of India and in the male 
dugong ^ the upper incisors form offensive weapons. In 
the male narwhal one alone of the upper teeth is de- 
veloped into the well-known, spirally-twdsted, so-called 
horn, which is sometimes from nine to ten feet in length. 
It is believed that the males use these horns for fighting 
together ; for " an unbroken one can rarely be got, and oc- 
casionally one may be found with the point of another 
jammed into the broken place." ' The tooth on the oppo- 
site side of the head in the male consists of a rudiment 
about ten inches in length, which is embedded in the jaw. 
It is not, however, very uncommon to find double-horned 
male narwhals in which both teeth are well developed. In 
the females both teeth are rudimentary. The male ca- 
chalot has a larger head than that of the female, and it no 
doubt aids these animals in their aquatic battles. Lastly, 
the adult male ornithorhynchus is provided with a remark- 
able apparatus, namely, a spur on the fore-leg, closely 
resembling the poison-fang of a venomous snake ; its use 
is not known, but we may suspect that it serves as a 
weapon of offence.' It is represented by a mere rudiment 
in the female. 

When the males are provided with weapons which the 
females do not possess, there can hardly be a doubt that 
they are used for fighting with other males, and that they 
have been acquired through sexual selection. It is not 
probable, at least in most cases, that the females have 

* Mr. Lamont ('Seasons with the Sea-Horses,' 1861, p. 143) says that 
a good tusk of the male walrus weighs four pounds, and is longer than 
that 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. R. Brown, ' Proc. Zool. Soc' 1868, p. 429, 

^ Owen, ' Anatomy of Vertebrates,' vol. iii. p. 283. 

« Mr. R. Brown, in ' Proc. Zool. Soc' 1869, p. 553. 

' Owen on the Cachalot and Ornithorhynchus, ibid. vol. iii. pp. 638, 641. 



232 SEXUAL SELECTION: MAMMALS. [Part IL 

actually been saved from acquiring such weapons, owing 
to their being useless and superfluous, or in some way in- 
jurious. On the contrary, as they are often used by the 
males of many animals for various purposes, more especially 
as a defence against their enemies, it is a surprising fact 
that they are so poorly developed or quite absent in the 
females. No doubt with female deer the development 
during each recurrent season of great branching horns, 
and with female elephants the development of immense 
tusks, would have been a great waste of vital power, on 
the admission that they were of no use to the females. 
Consequently variations in the size of these organs, lead- 
ing to their suppression, would have come under the con- 
trol of natural selection, and, if limited in their transmission 
to the female offsi:>ring, would not have interfered with their 
development through sexual selection in the males. But 
how on this view can we explain the presence of horns in 
the females of certain antelopes, and of tusks in the 
females of many animals, which are only of slightly less 
size than in the males ? The explanation in almost all 
cases must, I believe, be sought in the laws of transmis- 
sion. 

As the reindeer is the single species in the whole fam- 
ily of Deer in which the female is furnished with horns, 
though somewhat smaller, thinner, and less branched than 
in the male, it might naturally be thought that they must 
be of some special use to her. There is, however, some 
evidence opposed to this view. The female retains her 
horns from the time when they are fully developed, namely, 
in September, throughout the winter, until May, when she 
brings forth her young ; while the male 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 sheds his horns during the 
winter, it is very improbable that they can be of any spe- 



Chap. XVII.] LAW OF BATTLE. 233 

cial service to the female at this season, which includes the 
larger proportion of the time during which she bears 
horns. Nor is it probable that she can have inherited 
horns from some ancient progenitor of the whole family 
of deer, for, from the fact of the males alone of so many 
species in all quarters of the globe possessing horns, we 
may conclude that this was the primordial character of 
the group. Hence it appears that horns must have been 
transferred from the male to the female at a period sub- 
sequent to the divergence of the various species from a 
common stock ; but that this was not effected for the sake 
of giving her any special advantage.® 

We know that the horns are developed at a most un- 
usually early age in the reindeer ; but what the cause of 
this may have been is not known. The effect, however, 
has apparently been the transference of the horns to both 
sexes. It is intelligible, on the hypothesis of pangenesis, 
that a very slight change in the constitution of the male, 
either in the tissues of the forehead or in the gemmules of 
the horns, might lead to their early development ; and, as 
the young of both sexes have nearly the same constitu- 
tion before the period of reproduction, the horns, if devel- 
oped at an eai'ly age in the male, would tend to be de- 
veloped equally in both sexes. In support of this view, 
we should bear in mind that the horns are always trans- 
mitted through the female, and that she has a latent 
capacity for their development, as we see in old or dis- 
eased females.' Moreover the females of some other 

^ On the structure and shedding of the horns of the reindeer, Hoff- 
berg, ' Amoenitates Acad.' vol. iv. 1*788, p. 149. See Richardson, 'Fauna 
Bor. Americana,' p. 241, in regard to the American variety or species; 
also Major W. Ross King, ' The Sportsman in Canada,' 1866, p. 80. 

'Isidore Geoffroy St.-Hilaire, 'Essais de Zoolog. Generale,' 1841, p. 
513. Other masculine characters, besides the horns, are sometimes sim- 
ilarly transferred to the female ; thus Mr. Boner, in speaking of an old 



234 SEXUAL SELECTION: MAMMALS. [Part IL 

species of deer, either normally or occasionally, exhibit 
rudiments of horns ; thus the female of Ccrvidiis moscha- 
tiis has " bristly tufts, ending in a knob, instead of a horn ; " 
and " in most specimens of the female Wapiti ( Cervtis 
Canadensis) there is a sharp bony protuberance in the 
place of the horn." "* From these several considerations 
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 iu 
the males, and their consequent transmission to both 
sexes. 

Turning to the sheath-horned ruminants: with ante- 
lopes a graduated series can be formed, beginning with 
the species, the females of which are completely destitute 
of horns — passing to those which have horas so small as 
to be almost rudimentary, as in Antilocapra Americana 
— to those which have fairly well-developed horns, but 
manifestly smaller and thinner than in the male, and 
sometimes of a different shape," and ending with those in 
which both sexes have horns of equal size. As with the 
reindeer, so with antelopes, there exists a relation be- 
tween the period of the development of the horns and 
their transmission to one or both sexes ; it is therefore 
probable that their presence or absence in the females of 

female chamois ('Chamois Hunting in the Mountains of Bavaria,' 18G0, 
2d edit. p. 363), says, " not only was the head very male-lookinfr, but along 
the back there was a ridge of long hair, usually to be found only in 
bucks." 

'" On the Cervulus, Dr. Gray, ' Catalogue of the Mammalia in British 
Museum,' part iii. p. 220. On the Cervns Canadensis or Wapiti see Hon. 
J. D. Caton, 'Ottawa Acad, of Nat. Sciences,' May, 1868, p. 9. 

" For instance, the horns of the female Arit. Euchore resemble those 
of a distinct species, viz. the Ant. Dorcas var. Corine, see Dcsmarest, 
* Manunalogie,' p. 455. 



Chap. XVII.] LAW OF BATTLE. 235 

some species, and their more or less perfect condition in 
the females of other species, depend, not on their being 
of some special use, but simply on the form of inheritance 
which has prevailed. It accords with this view that even 
in the same restricted genus both sexes of some species, 
and the males alone of other species, are thus provided. 
It is a remarkable fact that, although the females of Anti- 
lope bezoartica 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 dis- 
eased. The males of this species have long, straight, 
spirated horns, nearly parallel to each other, and directed 
backward. Those of the female, when present, are very 
different in shape, for they are not spirated, and, spread- 
ing widely, bend round, so that their points are directed 
forward. It is a still more remarkable fact that in the 
castrated male, as Mr. Blyth informs me, the horns are of 
the same peculiar shape as in the female, but longer and 
thicker. In all cases the differences between the horns of 
the males and females, and of castrated and entire males, 
probably depend on various causes — on the more or less 
complete transference of male characters to the females — 
on the former state of the progenitors of the species — and 
partly, perhaps, on the horns being differently nourished, 
in nearly the same manner as the spurs of the domestic 
cock, when inserted into the comb or other parts of the 
body, assume various abnormal forms from being differ- 
ently nourished. 

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 latter.'^ In several domestic breeds 
of the sheep and goat, the males alone are furnished with 
horns ; and it is a significant fact that, in one such breed 
of sheep on the Guinea coast, the horns are not devel- 
*2 Gray, 'Catalogue Mamm. Brit. Mus.' part iii. 1852, p. 160. 



23G SEXCTAL SELECTION: MAMMALS. [Pakt IL 

oped, as Mr. Winwood Reade informs me, in tlie castrated 
male ; so tliat they are affected in this respect like the horns 
of stags. In some breeds, as in that of North Wales, 
in which both sexes are properly horned, the ewes are 
very liable to be hornless. In these same sheep, as I have 
been informed by a trustworthy witness who purposefy 
inspected a flock during the lambing-season, the horns at 
birth are generally more fully developed in the male than 
in the female. With the adult inus\i-ox (Ovibos niosc/ia- 
tus) the horns of the male are larger than those of the 
female, and in the latter the bases do not touch." In re- 
gard 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 cow-ban- 
teng (Jios sondaicus) the horns are remarkably small, 
and inclined much backward. In the domestic races of 
cattle, both of the humped and humpless types, the horns 
are short and thick in the bull, longer and more slender 
in the cow and ox ; and in the Indian buffalo they are 
sliorter and thicker in the bull, longer and more slender 
in the cow. In the wild-gaour [B. gaurm) the horns are 
mostly both longer and thicker in the bull than in the 
cow."" Hence with most sheath-horned ruminants the 
horns of the male are either longer or stronger than those 
of the female. With the Hhmoceros simus, as I may here 
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." 
From these various facts we may conclude that horns of 
all kinds, even when equally developed in both sexes, 
were primarily acquired by the males in order to conquer 

'' Richardson, ' Fauna Bor. Americana,' p. 2lS. 
'* ' Land and water,' 1867, p. 346. 

'' Sir Andrew Smith, ' Zoology of South Africa,' pi. xix. Owen, ' Anat- 
omy of Vertebrates,' voL iii. p. 624. 



Chap. XVII.] LAW OF BATTLE. 237 

other males, and have been transferred more or less com- 
pletely to the female, in relation to the force of the equal 
form of inheritance. 

The tusks of the elephant, in the different species or 
races, differ according to sex, in nearly the same manner 
as the horns of ruminants. In India and Malacca the 
males alone are provided with well-developed tusks. The 
elephant of Ceylon is considered 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 exclusively males." '^ The African 
elephant is undoubtedly distinct, and the female has 
large, well-developed tusks, though not so large as those 
of the male. These differences in the tusks of the scA'eral 
races and species of elephants — the great variability of 
the horns of deer, as notably in the wild-reindeer — the 
occasional j^resence of horns in the female Antiloiye bezo- 
artica — the presence of two tusks in some few male nar- 
whals — the complete absence of tusks in some female 
walruses — are all instances of the extreme variability of 
secondary sexual characters, and of their extreme 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 for other purposes. The elephant uses his tusks in 
attacking the tiger; according to Bruce, he scores the 
trunks of trees until they can be easily thrown down, and 
he likewise thus extracts the farinaceous cores of palms ; 
in Africa he often uses one tusk, this being always the 
same, to probe the ground and thus to 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 

i« Sir J. Emerson Tennent, 'Ceylon,' 1859, vol. ii. p. 274. For Ma- 
lacca, ' Journal of Indian Archipelago,' vol. iv. p. 357. 



238 SEXUAL SELECTION: MAMMALS. [Part IL 

single blow of his great horns. Many similar facts could 
be given. One of the most curious secondary uses to 
which the horns of any animal are occasionally put, is 
that observed by Captain Hutton," with the wild-goat 
(Capra (pgagrus) of the Himalayas, and, as it is 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 so much 
need this strange kind of shield. 

Each male animal iises his weapons in his own pecu- 
liar 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 as easily as a child. 
Goats and certain species of sheep, for instance the Ovis 
cycloceros 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 scimitar-shaped horn, as 
Avith a sabre. When the 0. cycloceros attacked a large 
domestic ram, who was a noted bruiser, he conquered him 
by the sheer novelty of his mode of fighting, always clos- 
ing at once with his adversary, and catching him across 
the face and nose with a sharp drawing jerk of his head, 
and then bounding out of the way before the blow could 
be returned." In Pembrokeshire a male goat, the master 
of a flock which during several generations had run wild, 
Avas known to have killed several other 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 

" 'Calcutta Journal of Nat. Hist.' vol. ii. 18 13, p. 526. 

•8 Mr. Hh'th, in 'Land and Water,' March, 1867, p. 134, on the an- 
thority of Captain Hutton and others. For the wild Pembrokeshire 
goats see the 'Field,' 18G9, p. 150. 



Chap. XVII.l LAW OF BATTLE. 239 

opponent ; but the Italian buffalo is said never to use his 
horns, he gives a tremendous blow with his convex fore- 
head, and then tramples on his fallen enemy with his 
knees — an instinct which the common bull does not pos- 
sess." Hence a dog who pins a buffalo by the nose is im- 
mediately crushed. We must, however, remember that 
the Italian buffalo has long been domesticated, and it is 
by no means certain that the wild parent-form had simi- 
larly shaped horns. Mr, Bartlett informs me that when 
a female Cape buffalo {Buhalus Gaffer) was turned into an 
enclosure with a bull of the same species, she attacked 
him, and he in return pushed her about with great vio- 
lence. But it was manifest to Mr. Bartlett that had not 
the bull shown dignified forbearance, he could easily have 
killed her by a single lateral thrust with his immense 
horns. The giraffe uses his sl)ort hair-covered horns, 
which are rather longer in the male than in the female, in 
a curious manner ; for with his long neck he swings his 
head to either side, almost upside down, with such force, 
that I have seen a hard plank deeply indented by a single 
blow. 

"With antelopes it is sometimes difficult to imagine 
how they can possibly use their curiously-shaped horns ; 
thus the spring-boc {Ant. euehore) has rather short up- 
right horns, with the sharp points bent inward almost at 
a right angle, so as to face each other ; Mr, Bartlett does 
not know how they are used, but suggests that they 
would inflict a fearful wound down each side of the face 
of an antagonist. The slightly-curved horns of the Oryx 
leucoryx (Fig. 61) are directed backward, and are of such 
length that their points reach beyond the middle of tlie 
back, ov^r which they stand in an almost parallel line. 
Thus they seem singularly ill-fitted for fighting ; but Mr, 

" M. E. M. Bailly, " Sur I'usage des Cornes," etc., ' Annal. des Sc. 
Nat.' torn. '\. 1824, p. 369. 



240 



SEXUAL SELECTION : MAMMALS. 



[Part IL 



Bartlett informs inc that whon two of these animals pre- 
pare for battle, they kneel down, with their heads between 
their front legs, and in this attitude the liorns stand near- 
ly parallel and close to the ground, with the points di- 
rected forward and a little upward. The combatants 
then gradually approach each other and endeavor to get 
the uj)turned points under each other's bodies ; if one suc- 
ceeds in doing this he suddenly springs "up, thro^\dng up 




Fig. 61. — Oryx leucoryx, male (from the Knowslcy Menagerie). 

his head at the same time, and can thus wound or per- 
haps even transfix his antagonist. Both animals always 
kneel down so as to guaixl as far as possible against this 
manoeuvre. It has been recorded that one of these ante- 
lopes has used his horns with effect even against a lion ; 
yet, from being forced to place his head between the fore- 
legs in order to bring the points of the horns forward, he 
would generally be under a great disadvantage when at- 
tacked by any other animal. It is, therefore, not probable 
that the horns have been modified into their present great 
length and peculiar position, as a protection against 
beasts of prey. We can, however, see that as soon as 



Chap. XVII.] LAW OF BATTLE. 341 

some ancient male progenitor of the Oryx acquired mod- 
erately long horns, directed a little backward, he would 
be compelled in his battles with rival males to bend his 
head somewhat inward or downward, as is now done by 
certain stags ; and it is not improbable that he might 
have acquired the habit of at first occasionally and after- 
ward of regularly kneeling down. In this case it is al- 
most certain that the males which possessed the longest 
horns would have had a great advantage over others with 
shorter horns ; and then the horns would gradually have 
been rendered longer and longer, through sexual selection, 
until they acquired their present extraordinary length 
and position. 

With stags of many kinds the branching of the horns 
offers a curious case of difiiculty ; for cei-tainly a single 
straight point would inflict a much more serious wound 
than several diverging points. In Sir Philip Egerton's 
museum there is a horn of the red-deer (Cerviis ela- 
phus) thirty inches in length, with "not fewer than 
fifteen snags or branches ; " and at Moritzburg there 
is still preserved a pair of antlers of a red-deer, shot in 
1699 by Frederick I., each of which bears the aston- 
ishing number of thirty-three branches. Richardson 
figures a pair of antlers of the wild-reindeer with twenty- 
nine points.'"' From the manner in which the horns 
are branched, and more especially from deer being 
known occasionally to fight together by kicking with 
their forefeet,'** M. Bailly actually came to the con- 

^* Owen, on the Horns of Red-deer, ' British Fossil Mammals,' 1846, 
p. 478; 'Forest Creatures,' by Charles Boner, 1861, pp. 62, 76. Rich- 
ardson on the Horns of the Reindeer, ' Fauna Bor. Americana,' 1829, 
p. 240. 

21 Hon. J. D. Caton (' Ottawa Acad, of Nat. Science,' May, 1868, p. 9), 
says that the American deer fight with their forefeet, after " the ques- 
tion of superiority has been once settled and acknowledged in the herd '' 
30 



242 SEXUAL SELECTION: MAMMALS. [Part IT. 

elusion that their horns were 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 Colinsay, who has long and carefully observed 
the habits of red-deer, and he informs me that he has never 
seen some of the branches brought into action, but that 
the brow-antlers, from inclining downward, are a great 
protection to the forehead, and their points are likewise 
used in attack. Sir Philip Egerton also informs me, in 
regard both to red-deer and fallow-deer, that when they 
fight 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 exclusively for pushing and 
fencing. Nevertheless, with some species the upper 
branches are used as weapons of ofience ; when a man 
was attacked by a Wapiti deer ( Cervus Canadensis) in 
Judge Caton's 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 forefeet, except when he 
rolled his head to one side to take a new observation pre- 
paratory to a plunge." In this position the terminal points 
of the horns were directed against his adversaries. " In 
rolling his head he necessarily raised it somewhat, because 
his antlers were so long that he could not roll his head 
without raising them on one side, while on the other side 
they touched the groimd." The stag by this procedure 
gradually drove the party of rescuers backward, to a 

Bailly, " Sur I'usage des Comes," 'Annales des Sc. Nat.' torn. ii. 1824, 
p. 371. 



Chap. XVII.] LAW OF BATTLE. 243 

distance of 150 or 200 feet ; and the attacked man was 
killed." 

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 this conclusion. Nor do the branching 
horns, though highly important as a means of defence 
against rival stags, appear perfectly well adapted for this 
pui'pose, as they are liable to become interlocked. The 
suspicion has therefore crossed my mind that they may 
serve partly as ornaments. That the branched antlers of 
stags, as well as the elegant lyrated horns of certain ante- 
lopes, with their graceful double curvature (Fig. 62), are 
ornamental in our eyes, no one will dispute. If, then, the 
horns, like the splendid accoutrements of the knights of old, 
add to the noble appearance of stags and antelopes, they 
may have been partly modified for this purpose, though 
mainly for actual service in battle ; but I have no evidence 
in favor of this belief. 

An interesting case has lately 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 Cervus 
Virginianus abounds. About fourteen years ago he first 
heard of spike-horn bucks. These became from year to 
year more common ; about five years ago he shot one, and 
subsequently another, and^ now they are frequently killed. 
" The spike-horn differs greatly from the common antler 
of the G. Yirginianus. It consists of a single spike, more 

°2 See a most interesting account in the Appendix to Hon. J. D. 
Caton's paper, as above quoted. 

" ' The American Naturalist,' Dec. 1869, p. 552. 



244 SEXUAL SELECTIOX : MAMMALS. [Part IL 

slender than the antler, and scarcely half so long, project- 
ing forward from the brow, and terminating in a very 




Fio. 62.— Strepslccros Kudu (from Andrew Smith's 'Zoology of South Africa') 

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 under- 



Chap. XVII.] LAW OF BATTLE. 245 

brush (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 common antler. With this 
advantage the spike-horn bucks are gaining upon the 
common bucks, and may, in time, entirely supersede them 
in the Adirondacks. Undoubtedly the first spike-horn 
buck was merely an accidental freak of Nature. But his 
spike-horns gave him an advantage, and enabled him 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." 

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 with serious 
effect downward." The walrus, though having so short a 
neck and so unwieldy a body, " can strike either upward, 
or downward, or sideways, with equal dexterity." " The 
Indian elephant fights, as I was informed by the late Dr. 
Falconer, in a different manner according to the position 
and curvature of his tusks. When they are directed for- 
ward and upward he is able to fling a tiger to a great dis- 
tance — 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 off the hoodah." 

Very few male quadrupeds possess weapons of two 
distinct kinds specially adapted for fighting with rival 
males. The male muntjac-deer (Cervulus), however, 

** Pallas, 'Spicilegia Zoologica,' fasc. xiii. 17*79, p. 18. 

^^ Lamont, 'Seasons with the Sea-Horses,' 1861, p. 141. 

^^ See also Corse (' Philosoph. Transact.' 1*799, p. 212) on the manner 
in which the short-tusked Mooknah variety of the elephant attacks other 
elephants. 



246 SEXUAL SELECTION: MAMMALS. [Part IL 

offers an exception, as he is provided with horns and ex- 
serted canine teeth. But one form of weapon has often 
been rephiced in the course of ages by another form, as 
we may infer from what follows. With ruminants the 
deYeloj)ment of horns generally stands in an inverse rela- 
tion with that of even moderately well-developed canine 
teeth. Thus camels, guanacoes, chevrotains, and musk- 
deer, are hornless, and they have efficient canines ; these 
tei'th being " always of smaller size in the females than in 
the males." The Camelidae have in their upper jaws, in 
addition to their true canines, a pair of canine-shaped in- 
cisors.^' Male deer and antelopes, on the other hand, pos- 
sess 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 their battles. 
AYith Antilope montaiia 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 
certain other antelopes and deer have been known occa- 
sionally to exhibit rudiments of these teeth." 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 widely like camels and guana- 
coes. Whenever the adult male possesses canines now in 
an inefficient state, while the female has either none or 
mere rudiments, we may conclude that the early male pro- 
genitor of the species was provided with efficient canines, 

-' Owen, ' Anatomy of Vertebrates,* vol. iii. p. 349. 

28 Sec Riippell (in ' Proc. Zoolog. See' 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 ('Palasont. Memoirs and Notes,' vol. 
i. 1808, p. 576) on canines in an adult female deer. In old males of the 
musk-deer the canines (Pallas, 'Spic. Zoolog.' fasc. xiii. 1779, p. 18) 
sometimes grow to the length of three inches, whiWin old females a ru. 
diment projects scarcely half an inch above the gums. 



Chap. XVII.] LAW OF BATTLE. 347 

which had been partially transferred to the females. The 
reduction of these teeth in the males seems to have fol- 
lowed from some change in their manner of fighting, often 
caused (but not in the case of the horse) by the develop- 
ment of new weapons. 

Tusks and horns are manifestly of high 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 
elephant, have been known to weigh respectively 150, 160, 
and 180 pounds; and even greater weights have been as- 
signed by some authors.^' With deer, in which the horns 
are periodically 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 and a quarter 
pounds. With sheep, although the horns are not periodi- 
cally renewed, yet their development, in the opinion of 
many agriculturists, entaUs a sensible loss to the breeder. 
Stags, moreover, 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 instance, with horns extending five and a 
half feet from tip to tip, although so skilful in their use 
that he will not touch or break a dead 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." '" The 

^'^ Emerson Tennent, 'Ceylon,' 1859, vol. ii. p. 2Y5 ; Owen, 'British 
Fossil 'Mammals,' 1846, p. 245. 

^<' Richardson, ' Fauna Bor. Americana,' on the moose, Alces palmata, 
p. 236, 23*7 ; also, on the expanse of the horns, 'Land and Water,' 1869, 
p. 143. See also Owen, ' British Fossil Mammals,' on the Irish elk, pp. 
447, 455. 



248 SEXUAL SELECTION: MAMMALS. [Part H. 

tips of the horns of the great Irish elk were actually 
eight feet apart ! While the horns are covered with 
velvet, which lasts with the red-deer for about twelve 
weeks, they are extremely sensitive to a blow ; so that in 
Germany the stags at this time change their habits to a 
certain extent, and avoid dense forests, frequenting young 
woods and low thickets.*' These facts remind us that 
male birds have acquired ornamental plumes at the cost 
of retarded flight, and other ornaments at the cost of some 
loss of power in their battles with rival males. 

"With quadrupeds, when, as is often the case, the sexes 
differ in size, the males are, I believe, always larger and 
stronger. This holds good in a marked manner, as I am 
informed by jNIr. Gould, with the marsupials of Australia, 
the males of which appear to continue growing until an 
unusually late age. But the most extraordinary case is 
that of one of the seals (Callorhinus icrsimis), a full- 
grown female weighing less than one-sixth of a full-grown 
male." The greater strength of the male is invariably 
displayed, as Hunter long ago remarked," 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 quadrupeds are also more courageous and pugna- 
cious than the females. There can be little doubt that 
these characters have been gained, partly through sexual 
selection, owing to a long series of victories 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 cour- 
age, whether due to so-called spontaneous variability or 
to the effects of use, by the accumulation of which, male 

2' 'Forest Creatures,' by C. Boner, 1861, p. 60, 

•'" See the very intcrcstinji paper by Mr. J. A Allen in 'Bull. Mus. 
Comp. Zoolog. of Cambridge, United States,' vol. ii. No. 1, p. 82. The 
weights were ascertained by a careful observer, Captain Bryant 

'' 'Animal Economy,' p. 45. 



Chap. XVII.] GREATER SIZE OF THE MALE. 249 

quadrupeds have acquired these characteristic qualities, 
occurred rather late in life, and were consequently to a 
large extent limited in their transmission to the same sex. 
Under this point of view I was anxious to obtain in- 
formation in regard to the Scotch deer-hound, the sexes 
of which differ more in size than those of any other 
breed (though blood-hounds differ considerably), or than 
in any wild canine species known to me. Accordingly, I 
applied to Mr. Cupples, a well-known breeder of these 
dogs, who has weighed and measured many of his own 
dogs, and who, with great kindness, has collected for me 
the following facts from various sources. Superior male 
dogs, measured at the shoulder, range from twenty-eight 
inches, which is low, to thirty-three or even thirty-four 
inches in height; and in weight from eighty pounds, 
which is low, to one hundred and twenty, or even more 
pounds. The females range in height from twenty-three 
to twenty-seven or even twenty-eight inches; and in 
weight from fifty to seventy, or even eighty pounds." 
Mr. Cupples concludes that from ninety-five to one hun- 
dred pounds for the male, and seventy for the female, 
would be a safe average ; but there is reason to believe 
that formerly both sexes attained a greater weight. Mr. 
Cupples 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 

3* See also Richardson's ' Manual on the Dog,' p. 59. Much valuable 
information on the Scottish deer-hound is given by Mr. McNeill, who 
first called attention to the inequality in size between the sexes, in 
Serope's ' Art of Deer Stalking.' I hope that Mr. Cupples will keep to 
his intention of -publishing a full account and history of this famous 
breed. 



250 SEXUAL SELECTION: MAMMALS. [Pakt IL 

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 ex- 
perience 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 sev- 
eral weeks afterward, a bitch-puppy will occasionally be 
larger than any of the dogs, but they are invariably 
beaten by them later." Mr. McNeill, of Colinsay, con- 
cludes that " the males do not attain their full growth till 
over two years old, though the females attain it sooner." 
According to Mr. Cupples's experience, male dogs go on 
groAving 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 fourteen 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 are almost exclusively used for coursing, for, as 
Mr. McNeill informs me, the females 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. Cupples, 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, courage, and the best will 
have been bred from. As, however, the males . do not 
attain their full dimensions until a rather late period in 
life, they will have tended, in accordance with the law 
often indicated, to transmit their characters to their male 



Chap. XV 11.] 



MEANS OF DEFENCE. 



251 



offspring alone ; and thus the great inequality in size be- 
tween 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 defence against the 
attacks of other males. Some kinds of deer use, as we 
have seen, the upper branches of their horns chiefly or ex- 
clusively for defending themselves ; and the Oryx ante- 
lope, as I am informed by Mr. Bartlett, fences most skil- 
fully with his long, gently-curved horns ; but these are 
likewise used as organs of offence. Rhinoceroses, as the 
same observer remarks, in fighting pai-ry each other's side- 
long blows with their hoi'us, which loudly clatter together, 
as do the tusks of 
boars. Although wild- 
boars fight desperate- 
ly together, they sel- 
dom, according to 
Brehm, receive fatal 
blows, as these fall on 
each other's tusks, or 
on the layer of gristly 
skin covering the shoul- 
der, which the Giermau 
hunters call the shield ; 
and here we have a 
part S25ecially modified for defence. With boars in the 
prime of life (see Fig. 63) the tusks in the lower jaw 
are used for fighting, but they become in old age, as 
Brehm states, so much curved inward and upward, over 
the snout, that they can no longer be thus used. They 
may, however, still continue to serve, and even in a still 
more effective manner, as a means of defence. In com- 
pensation for the loss of the lower tusks as weapons of 
offence, those in the upper jaw, which always project a 




Fig. 63. — Head of coinmnn-wilrt boar, in 
prime of life (from Breiim). 



253 



SEXUAL SECECTION: MAMMALS. 



[Part IL 



little latcrnlly, increase so much in length during old age, 
and curve so much upward, that they can be used as a 
means of attack. Nevertheless an old boar is not so dan- 
gerous to man as one at the age of six or seven years."* 

In the full-grown male Babirusa pig of Celebes (Fig. 
64), the lower tusks are formidable weapons, like those of 




Fig. 64.— Skull ol the babirtiga Pig (from Wallace's ' Malay Archipelago '). 

the 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 near- 
ly resemble horns than teeth, and are so manifestly useless 
as teeth that the animal was formerly supposed to rest 
his head by hooking them on to a branch. Their convex 

« Brehm, ' Thierleben,' B. ii. s. "729, "732. 



Chap. XVII.] MEANS OF DEFENCE. 253 

surfaces would, however, if the head were held a little 
laterally, serve as an excellent guard; and hence, per- 
haps, it is that in old animals they " are generally broken 
off, as if by fighting." '" Here, then, we have the curious 
case of the upper tusks of the Babirusa regularly assum- 
ing, during the prime of life, a structure which apparently 
renders them fitted only for defence ; while in the Euro- 
pean boar the lower and opposite tusks assume in a less 
degree and only during old age nearly the same form, and 
then serve in like manner solely for defence. 




Fig. 65.— Head of Ethiopian Wart-hoa:, from 'Proc. Zool. Soc' 1869. (I now 
find that this drawing represents the head of a female, but it serves to show, 
on a reduced scale, the characters of the male.) 

In the wart-hog [Phaeochoerus mthiopicus. Fig. 65) 
the tusks in the upper jaw of the male curve upward dur- 
ing the prime of life, and, from being pointed, serve as for- 
midable weapons. The tusks in the lower jaw are sharper 
than those in the upper, but from their shortness it seems 
harHly possible that they can be used as weapons of at- 
tack. They must, however, greatly strengthen those in the 

'* See Mr. Wallace's interesting account of this animal, ' The Malay 
Archipelago,' 1869, vol. i. p. 435. 



254 SEXUAL SELEGTIOX: MAMMALS. [Pakt IL 

upper jaw, from being ground so as to fit closely against 
their bases. Neither the upper nor the lower tusks ap- 
pear to have been specially modified to act as guards, 
though, no doubt, they are thus used to a certain extent. 
But the wart-hog is not destitute of other special means 
of protection, for there exists, on each side of the face, be- 
neatli the eyes, a rather stiff, yet flexible, cartilaginous, 
oblong pad (Fig. 65), whicli 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 tusks of au opponent, would 
be turned upward, and would thus protect in an admira- 
ble manner the somewhat prominent eyes. These boars, 
as I may add on the authority of Mr. Bartlett, when fight- 
ing together, stand directly face to face. 

Lastly, the African river-hog {Potamochoerus penicil- 
latus) has a hard cartilaginous knob on each 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 the purpose 
of the above-described projections and excrescences, that 
these were covered with blood, and were scored and 
abraded in an extraordinary manner. 

The mane of the lion forms a good defence against the 
one danger to which he is liable, namely, the attacks of 
rival lions : for the males, as Sir. A. Smith informs me, 
engage in terrible battles, and a young lion dares not ap- 
proach 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 in- 
jured, but the tiger at last succeeded in ripping up his 



Chap. XVII.] MEANS OF DEFENCE. 255 

belly, and in a few minutes he was dead." " The broad 
ruff round the throat and chin of the Canadian lynx (Felis 
Canadensis) is much longer in the male than in the fe- 
male ; but whether it serves as a defence I do not know. 
Male seals are well known to fight despei-ately together, 
and the males of certain kinds {Otaria jubatay^ have 
great manes, while the females have small ones or none. 
The male baboon of the Cape of Good Hope ( Cynocepha- 
lus 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, excepting 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 
terrible battles; but an experienced hunter told Judge 
Caton that he had never observed any thing 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 en- 
deavor to seize one another by the neck." It does not, 
however, follow from the foregoing statements, that when 

^^ 'The Times,' Nov. 10, 1857. In regard to the Canada lynx, see 
Audubon and Bachman, ' Quadrupeds of North America,' 1846, p. 139. 

S3 Dr. 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 female, deserves to be called 



256 SEXUAL SELECTION: MAMMALS. [Part IL 

the hair on the neck serves as a defence, 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 
(Cerviis elephas) serve as a great protection to him when 
hunted, for the dogs generally endeavor to seize him by 
the throat ; but it is not probable that these hairs were spe- 
cially developed for this purpose; otherwise the young 
and the females would, as we may feel assured, have been 
equally protected. 

On Preference or Choice in Pairing, as shown hy either 
Sex of Quadrupeds. — Before describing, in the next chap- 
ter, the differences between the sexes in voice, odor emit- 
ted, and ornamentation, it will be convenient here to con- 
sider 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 docs the male, when not a polygamist, select any par- 
ticular 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 chap- 
ter, on Birds, a considerable 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 of organiza- 
tion 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, as so incessantly occurs, 
by several males, she would often have the opportunity, 
while they were fighting together, of escaping with, or at 
least of temporarily pairing with, some one male. This 



Chap. XVII.] PREFERENCES IN PAIRING. 257 

latter contingency has often been observed in Scotland 
with female red-deer, as I have been informed by Sir Philip 
Egerton.'" 

It is scarcely possible that much should be known 
about female quadrupeds exerting in a state of nature any 
choice in their marriage unions. The following very cu- 
rious details on the courtship of one of the eared seals 
Callorhimis ursinus, are given " on the authority of Cap- 
tain Bryant, who had ample opportunities for observation. 
He says : " Many of the females on their arrival at the isl- 
and where they breed appear desirous of returning to some 
particular male, and frequently climb the outlying rocks to 
overlook the rookeries, calling out and listening as if for a 
familiar voice. Then, 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 mean- 
while 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 hai*sh 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, carrying them as cats do their kittens. Those still 
higher up pursue the same method until the whole space 

2' Mr. Boner in his excellent description of the habits of the red-deer 
in Germany (' Forest Creatures,' 1861, p. 81) says, "While the stag is de- 
fending 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. 

*> Mr. J; A. Allen in ' Bull. Mas. Comp. Zoolog. of Cambridge, United 
States,' vol. ii. No. 1, p. 99. 



258 SEXUAL SELECTION : MAMMALS. [Paut IL 

is occupied. Frequently a struggle ensues between the 
two males for the possession of the same female, and both 
seizing her at once ]>ull 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 fierce- 
ly driving off all intruders. This surveillance always 
keeps him actively occupied." 

As so little is known about the courtship of animals 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 bestow their affections ; and tender recollections are as 
potent over them as they are known to be in other cases, 
where higher 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 
comi)anion of vulgar appearance, there often springs up 
between the pair a devotion which no time can afterward 
subdue. The passion, for such it really is, becomes of a 
more than romantic endurance." Mr, Mayhew, who at- 
tended chiefly to the smaller breeds, is convinced that the 
females are strongly attracted by males of large size." The 
well-known veterinary Blaine states " 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 

*> ' Dogs : their Management^' by E. Mayhew, M. R. C. V. S., 2d edit 
1864, pp. 187-192. 

«' Quoted by Alex. Walker 'On Intermarriage,' 1838, p. 276; see alflo 
p. 244. 



Chap. XVII.] PKEFERENCES .IN PAIRING. 259 

regard to a female retriever and a spaniel, both of which 
became enamoured with terrier-dogs. 

Mr. Cupples infoi'ms me that he can personally vouch 
for the accuracy of the following more remarkable case, 
in which a valuable and wonderfully-intelligent female 
terrier loved a retriever, belonging to a neighbor, to such 
degree that she had often to be dragged away from him. 
After their permanent separation, although repeatedly 
thowing milk in her teats, she would never acknowledge 
she courtship of any other dog, and, to the regret of her 
owner, never bore puppies. Mr, Cupples also states that 
a female deer-hound now (1868) in his kennel has 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 deer-hounds living with her, all in 
the prime of life. Mr. Cupples has observed that the fe- 
male generally favors a dog whom she has associated with 
and knows ; her shyness 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 Yeldersley House, a great breeder of dogs, in- 
forms me that he has known some instances ; he cites the 
case of one of his own deer-hounds, who would not take 
any notice of a particular female mastiff, so that another 
deer-hound had to be employed. It would be superfluous 
to give other cases, and I will only add that Mr. Barr, 
who has carefully bred many blood-hounds, states that in 
almost every instance particular individuals of the oppo- 
site sex show a decided preference for each other. Finally 
Mr. Cupples, after attending to this subject for another 
year, has recently written to me : "I have had full con- 
firmation of my former statements, that dogs in breeding 
form decided preferences for each other, being often in- 
fluenced by size, bright color, and individual character, as 
well as by the degree of their previous familiarity." 



260 SEXUAL SELECTION: MAMMALS. [Pabi IL 

In regard to horses, Mr. Blcnkiron, the greatest breed- 
er 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 fa- 
mous Monarque, for instance, would never consciously 
look at the dam of Gladiateur, and a trick had to be prac- 
tised. We can partly see the reason why valuable race- 
horse stallions, which are in such demand, should be so 
particular in their choice. Mr. Blenldron has never known 
a mare to 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'e- 
prennent d'une jument, et negligent toutes les autres." 
He gives, on the authority of Baelen, similar facts in re- 
gard to bulls. HoflFberg, in describing the domesticated 
reindeer of Lapland, says, " Ftemine majores et fortiores 
mares praj cseteris admittunt, ad eos confugiunt, a juniori- 
bus agitatjc, qui lios in fugam conjiciunt." " A clergyman, 
who has bred many pigs, assures me that sows often reject 
one boar and immediately accept another. 

From tliese facts there can be no doubt that with most 
of our domesticated quadrupeds strong individual antipa- 
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 quad- 
rupeds 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 charac- 
ters in a higher degree tlian other males ; but what these 
characters are, we can seldom or never discover, with cer- 
tainty. 

*3 ' Traits de I'llc^rcd. Nat.' torn. ii. 1850, p. 296. 
** * Amoenitates Acad.' vol. iv. 1788, p. 160. 



CxiAP. XVIII.] VOCAL ORGANS. 261 



CHAPTER XVIII. 

Secondary Sexual Characters of Mammals — continued. 

Voice. — ^Eemarkable Sexual Peculiarities in Seals. — Odor. — Development 
of the Hair. — Color of the Hair and Skin. — Anomalous Case of the 
Female being more ornamented than the Male. — Color and Ornaments 
due to Sexual Selection. — 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 Quadrumana. — Simimary. 

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 their mother ; but such 
uses need not here be considered. We are concerned only 
with the difference between the voices of the two 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 ; and some, as the gu-affe and porcupine,*, are said to 
be completely mute excepting at this season. As the 
throats (i. e., the larnyx and thyroid bodies'*) of stags be- 
come periodically enlarged at the commencement of the 
breeding-season, it might be thought that their powerful 
voices must be then in some way of high importance to 
them ; but this is very doubtful. From information given 
to me by two experienced observers, Mr, McNeill and Sir 
P. Egerton, it seems that young stags under three years 

1 Owen, * Anatomy of Vertebrates,' vol. iii. p. 585. ' Ibid. p. 595. 



262 SEXUAL SELECTION: MAMMALS. [Part IL 

old do not roar or hollow ; and that the old ones hegin 
bellowing at the commencement of the breeding-season, 
at first only occasionally and moderately, while they rest- 
lessly wander about in search of the females. Their bat- 
tles are prefaced by lond and prolonged bellowing, but 
during the actual conflict they ai'e silent. Animals of all 
kinds which 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 
their nervous excitement, which leads to the spasmodic 
contraction of almost all the muscles of the body, as when 
a man grinds his teeth and clinches his hands in rage or 
agony. No doubt stags challenge each other to mortal 
combat by bellowing ; but it is not likely that this habit 
could have led through sexual selection, that is, by the 
loudest-voiced males having been the most successful in 
their conflicts, to the periodical enlargement of the vocal 
organs ; for the stags with the most powerful voices, unless 
at the same time the strongest, best-armed, and most coura- 
geous, would not have gained any advantage over their 
rivals with weaker voices. The stags, moreover, which 
had weaker voices, though not so well able to challenge 
other stags, would have been drawn to the place of com- 
bat as certainly as those with sti'onger voices. 

It is possible that the roaring of the lion may be of 
some actual service to him in striking terror into his ad- 
versary ; for when enraged he likewise erects his mane 
and thus instinctively tries to make himself appear as ter- 
rible as possible. But it can hardly be supposed that the 
bellowing of the stag, even if it be of any service to liira 
in this way, can have been important enough to have led 
to the periodical enlargement of the throat. Some writ- 
ers suggest that the bellowing serves as a call to the fe- 
male ; but the experienced observers above quoted inform 
me that female deer do not search for the male, though 



Chap. XVIIL] VOCAL ORGANS. 263 

the males search eagerly for the females, as indeed might 
he 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 countries imitate her 
cry. If we could believe that the male had the power to 
excite or allure the female by his voice, the periodical en- 
largement of his vocal organs would be intelligible on the 
principle of sexual selection, together with inheritance 
limited to the same sex and season of the year ; but we 
have no evidence in favor of this view. As the case 
stands, the loud voice of the stag during the breeding-sea- 
son does not seem to be of any special service to him, 
either during his coui'tship, 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 
have produced an inherited effect on the vocal organs of 
the stag, as well as of other male animals ? This appears 
to me, with our present state of knowledge, the most prob- 
able view. 

The male gorilla has a tremendous voice, and when 
adult is furnished with a laryngeal sac, as is likewise the 
adult male orang.* The gibbons rank among the noisiest 
of monkeys, and the Sumatra species {Hylohates syndac- 
tylus) is also furnished with a laryngeal sac ; but Mr. 
Blyth, who has had opportunities for observation, does 
not believe that the male is more noisy than the female. 
Hence, these latter monkeys probably use their voices as a 
mutual call ; and this is certainly the case with some 
quadrupeds, for instance, with the beaver.** Another gib- 

8 See, for instance, Major W. Ross King (' The Sportsman in Canada,' 
1866, pp. 53, 131) on the habits of the moose and wild-reindeer. 
* Owen, ' Anatomy of Vertebrates,' vol. iii. p. 600. 
^ Mr. Green, in 'Journal of Linn. Soc' vol. x. Zoology, 1869, p. 362. 



264 SEXUAL SELECTION : MAMMALS. [Part IL 

l)on, the II. agilis, is highly remarkable, from having the 
power of emitting a complete and correct octave of musi- 
cal notes,' 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 the American 
Mycetes caraya are one-third larger in the male than in 
the female, and are wonderfully powerful. These mon- 
keys, when the weather is warm, make the forests resound 
during the morning and evening witli their overAvhelming 
voices. The males begin the dreadful concert, in which 
the females, with their less powerful voices, sometimes 
join, and which is often continued during many hours. 
An excellent observer, Rengger,' could not perceive that 
they were excited to begin their concert by any special 
cause ; he thinks that, like many birds, they delight in 
their own music, and try to excel each other. Whether 
most of the foregoing monkeys have acquired their power- 
ful voices in order to beat their rivals and to charm the 
females — or whether the vocal organs have been strength- 
ened and enlarged through the inherited effects of long- 
continued use without any particular good being gained 
— I will not pretend to say ; but the former view, at least 
in the case of the Ilylohates aglUs, seems the most prob- 
able. 

I may here mention two very curious sexual pecu- 
liarities occurring in seals, because they have been sup- 
posed by some writers to affect the voice. The nose of 
tlie male sea-elephant (Jlacrorhinus proboscldeits), when 
about three years old, is greatly elongated during the 
breeding-season, and can then be erected. In this state it 
is sometimes a foot in length. The female at no period 
of life is thus provided, and her voice is different. That 

* C. L. Martin, ' General Introduction to the Nat. Hist, of Marnm. 
Animals,' 1841, p. 431. 

■• ' Naturgeschichte der Saugethiere von Paraguay,' 1830, s. 15, 21. 



Chap. XVIII.] ODORS. EMITTED. 265 

of the male consists of a wild, hoarse, gurgling noise, 
which is audible at a great distance, and is believed to be 
strengthened by the proboscis. Lesson compares the 
erection of the proboscis to the swelling of the wattles of 
male gallinaceous birds while they court the females. In 
another allied kind of seal, namely, the bladder-nose 
{^Gystophora cristata), the head is covered by a great 
hood or bladder. This is internally supported by the sep- 
tum of the nose, which is produced far backward and rises 
into a 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 be sometimes so loud as to be heard four miles 
off"." When attacked by man they likewise roar or bel- 
low ; and whenever irritated the bladder is inflated. 
Some naturalists believe that the voice is thus strength- 
ened, but various other uses have been assigned to this 
extraordinary structure. Mr. R. Brown thinks that it 
serves as a protection against accidents of all kinds. This 
latter view is not probable, if what the sealers have long 
maintained is correct, namely, that the hood or bladder is 
very poorly developed in the females and in the males 
while young. * 

Odor. — With some animals, as with the notorious 
skunk of America, the overwhelming odor which they 
emit appears to serve exclusively as a means of defence. 
With shrew-mice (Sorex) both sexes j)ossess abdominal 

^ On the sea-elephant, see an article by Lesson, in ' Diet. Class. Hist. 
Nat.' torn. xiii. p. 418. For the Cystophora or Stemmatopus, see Dr. 
Dekay, 'Annals of Lyceum of Nat. Hist. New York,' vol. i. 1824, p. 94. 
Pennant has also collected information from the sealers on this animal. 
The fullest account is given by Mr. Brown, who doubts about the rudi- 
mentary condition of the bladder in the female, in ' Proc. Zoolog. Soc' 
1868, p. 435. 

31 



266 SEXUAL SELECTION: MAMMALS. [Paut il. 

scent-glands, ami tlierc can be little doubt, from the man- 
ner in which their bodies are rejected by birds and beasts 
of prey, that their odor is protective ; nevertheless, the 
glands bi'come enlarged in the males during the breeding- 
season. In many qiuidrupeds the glands are of the same 
size in both sexes;" but their use is not known. In other 
species tlie glands are confined to the males, or are more 
developed in them 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 rank effluvium of the male goat is well known, 
and that of certain male deer is wonderfully strong and 
persistent. On the banks of the Plata I have perceived 
the whole air tainted with the odor of the male Cervus 
campestris, at the distance of half a mile to the leeward 
of a herd ; and a silk handkei-chief, in which I carried home 
a skin, though repeatedly used and washed, retained, 
when first unfolded, traces of the odor for one year and 
seven months. This animal does not emit its strong odor 
until more than a year old, and if castrated while young 
never emits it." Besides the general odor, with which 
the whole body of certain ruminants appears to be perme- 
ated during the breeding-season, many deer, antelopes, 
sheep, and goats, possess odoriferous glands in various 
situations, more especially on their faces. The so-called 

• As with the castoreum of the beaver, sec Mr. L. 11. Morgan's most 
interesting work, ' The American Beaver,' 1868, p. 300. Pallas (' Rpie. 
Zoolog.' fasc. viii. 1*779, p. 23) has well discussed the odoriferous glands 
of maunnals. Owen ('Aiiat. of Vertebrates,' vol. iii. p. fi34) also gives 
an account of these glands, including those of the elephant, and (p. 763) 
those of shrew-mice. 

'" Rengger, ' Naturgeschichtc der Siiugcthicre von Paragiiay,' 1830, 9. 
866. This observer also gives some curious particulars in regard to the 
odor emitted. 



Chap. XVIII.] ODORS EMITTED. 267 

tear-sacs or suborbital pits come under this head. These 
glands seci-ete a semifluid fetid matter, which is sometimes 
so copious as to stain the whole face, as I have seen in the 
case of an antelope. They are " usually larger in the male 
than in the female, and their development is checked by 
castration." " According to Desmarest they are altogether 
absent in the female of Antilope subgutturosa. Hence, 
there can be no doiibt that they stand in some close rela- 
tion with the reproductive functions. They are also 
sometimes present, and sometimes absent, in nearly-allied 
forms. In the adult male musk-deer {3Iosc/ms moschife- 
7-ii.s), 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-sac, from its 
position, is necessarily confined to the male, and forms an 
additional scent-organ. It is a singular fact that the mat- 
ter secreted by this latter gland does not, according to 
Pallas, change in consistence, or increase in quantity, 
dui-ing the rutting-season ; nevertheless, this naturalist 
admits that its presence is in some way connected with 
the act of reproduction. He gives, however, only a con- 
jectural and unsatisfactory explanation of its use.'"'' 

In most cases, when during the breeding-season the 
male alone emits a strong odor, this probably serves to ex- 
cite 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 which are far from agreeable to us ; and that 
dogs, though they will not eat carrion, snifi" and roll in it. 

" Owen, ' Anatomy of Vertebrates,' vol. iii. p. 632. See, also. Dr. 
Murie's observations on their glands in ' Proe. Zoolog. Soc' 1870, p. 340. 
Desmarest, on the Antilope subgutturosa, ' Mammalogie,' 1820, p 455. 

'2 Pallas, ' Spicilegia Zoolog.' fasc. xiii. 1*799, p. 24 ; Desmoulins, 
' Diet. Class. d'Hist. Nat.' torn. iii. p. 586. 



268 SEXUAL SELECTION : MAMMALS. [Part IL 

From the reasons given wlien discussing the voice of the 
stag, we may reject the idea that the odor serves to bring 
tlic females from a distance 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 he of 
considerable importance to the male, inasmuch as large 
and complex glands, furnished with muscles for everting 
the sac; and for closing or opening the orifice, have in 
some cases been developed. The development of these 
organs is intelligible tlirough sexual selection, if the more 
odoriferous males are the most successful in winning the 
females, and in leaving oftspring to inherit their gradually- 
perfected glands and odors. 

Development of the Hair. — We have seen that male 
quadrupeds often have the hair on their necks and shoul- 
ders much more developed than in the females ; and many 
additional instances could be given. This sometimes 
serves as a defence to the male during his battles; but 
whether the hair in most cases has been specially devel- 
oped for this purpose is very doubtful. We may feel 
almost certain that this is not the case, when a thin and 
narrow crest runs along the whole length of the back ; for 
a crest of this kind Avould afford scarcely any i)rotection, 
and the ridge of the back is not a likely place to be in- 
jured ; nevertheless such crests are sometimes confined to 
the males, or are much more developed in them than in 
the females. Two antelopes, the Traf/elaphus scn'ptxs " 
(see Fig. 68, p. 285) and Portnx picta, may be given as 
instances. The crests of certain stags and of the male 
wild-goat stand erect, when these animals are enraged or 
terrified ; '* but it can hardly be supposed that they have 

'^ Dr. Gray, ' (ilcaninps from the >ronagerie at Knowslcy,' pi. 28. 

'^ .Iudn;e Caton on the wapiti, ' Transact. OUawa Acad. Nat. Sciences,' 
ISr.S, pp. 36, 40; Hlvth, 'Land and Water,' on Capra (egagrm, 1867, 
p. 37. 



Chap. XVIII.] DEVELOPMENT OF HAIR. 269 

been acquired for the sake of exciting fear in their ene- 
mies. One of the above-named antelopes, the Portax 
picta^ 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 North Africa, 
a member of the sheep family, the front-legs are almost 
concealed by an extraordinary growth of hair, which de- 
pends 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 
than 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. The bull alone has curled 
hair on the forehead." In three closely-allied subgenera 
of the goat family, the males alone possess beards, some- 
times of a large size ; in two other subgenera both sexes 
have a beard, but this disappears in some of the domestic 
breeds of the common goat ; and neither sex of the Hemi- 
tragus has a beard. In the ibex the beard is not devel- 
oped during the summer, and is so small at other seasons 
that it may be called rudimentary." With some monkeys 
the beard is confined to the male, as in the Orang, or is 
much larger in the male than in the female, as in the Myce- 
tes caraya and Pithecia satanas (Fig. 66). So it is with 
the whiskers of some species of Macacus," and, as we have 
seen, with the manes of some species of baboons. But 
with most kinds of monkeys the various tufts of hair about 
the face and head are alike in both sexes. 

The males of various members of the Ox family (Bo- 

^^ ' Hunter's Essays and Observations,' edited by Owen, 1861, vol. i. 
p. 236. 

'^ See Dr. Gray's ' Cat. of Mammalia in British Museum,' part iii. 
1852, p. 144, 

" Rengger, ' Saugethiere,' etc., s. 14 ; Desmarest, ' Mammalogie,' p. 66. 



270 



SEXUAL SELECTION: MAMMALS. 



[I'AKT n. 



vidjc), and of certain antelopes, are furnished with a dew- 
lap, or great fold of skin on the neck, which is much less 
developed in the female. 

Now, what must we conclude Avith respect to such 
sexual differences as these ? No one will pretend that the 







Fig. 66.— Pithecia Satanae, male (from Brehm). 

boards of certain male goats, or the dewlap of the bull, 
or the crests of hair along the backs of certain male ante- 
lopes, are of any direct or ordinary use to them. It is 
possil)le that the immense beard of the male Pithecia, 
and the large beard of the male Orang, may protect their 
tliroats wlien fighting ; for the keepers in the Zoological 
(Jurdens inform me that many monkeys attack each other 
by the throat : but it is not probable that the beard has 



Chap. XVIII.] DEVELOPMENT OF HAIR. 37I 

been developed for a distinct purpose from that which the 
whiskers, mustache, and other tufts of hair on the face, 
serve ; and no one will suppose that these are useful as a 
protection. Must we attribute to mere purposeless varia- 
bility in the male all these appendages of hair or skin ? 
It cannot be denied that this is possible ; for, with many- 
domesticated quadrupeds, certain characters, apparently 
not derived through reversion from any wild parent-foi-m, 
have appeared in, and are confined to, the males, or are 
more largely developed in them tlian in the females — for 
instance, the hump in the male zebu-cattle of India, the 
tail in fat-tailed rams, the arched outline of the forehead 
in the males of several breeds of sheep, the mane in the 
ram of an African breed, and, lastly, the mane, long hairs 
on the hinder legs, and the dewlap in the male alone, of 
the Berbura goat.^® The mane which occurs in the rams 
alone of the above-mentioned African breed of sheep, is a 
true secondary sexual character, for it is not developed, 
as I hear from Mr. Winwood Reade, if the animal be cas- 
trated. 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 augmented ; 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 
known that the African ram with a mane was descended 
fi'om the same primitive stock with the other breeds of 
sheep, or the Berbura male goat witb his mane, dewlap, 
etc., from the same stock with other goats ; and if selec- 

'* See the chapters on these several animals in voL i. of my ' Varia- 
tion of Animals under Domestication ; ' also vol. ii. p. '73 ; also chap. xx. 
on the practice of selection by semi-civilized people. For the Berbura 
goat, see Dr. Gray, ' Catalogue,' ibid. p. ISV. 



273 SEXUAL SELECTION: MAMMALS. [Part U. 

tion has not been applied to these characters, then they 
must be due to simple variability, together with sexually- 
limited inheritance. 

In this case it would appear reasonable to extend the 
same view to the many analogous characters occurring in 
animals under a state of nature. Nevertheless, I cannot 
persuade myself that this view is applicable in many 
cases, as in that of the extraordinary development of hair 
on the throat and fore-legs of the male Ammotragus, or 
of the immense beard of the male Pithecia. With those 
antelopes in which tlie male when adult is more strongly 
colored than the female, and with those monkeys in which 
this is likewise the case, and in which the hair on the fiice 
is of a different color from that on the rest of the head, 
being arranged in the most diversified and elegant man- 
ner, it seems probable that the crests and tufts of hair 
have been acquired as ornaments ; and this I kn6w is the 
opinion of some naturalists. If this view be correct, 
there can be little doubt that they have been acquired, or 
at least modified, through sexual selection. 

Color of the JIair and of the Naked Skin. — I will 
first give briefly all the cases, known to me, of male quad- 
ru2)eds diftering in color from the females. With Marsu- 
pials, as I am informed by Mr. Gould, the sexes rarely 
difter in this respect ; but the great red kangaroo offers a 
striking exception, "delicate blue being the prevailing 
tint in those parts of the female which in the male are 
red." " In the Didelphis o})ossum of Cayenne the female 
is said to be a little more red than the male. With Ro- 
dents 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 

" Osphranter rufus, Gould, 'Mammals of Australia,' vol. u. 1863. 
Oil the Didelphis, Desmarest, ' Mammalogie,' p. 256. 



Chap. XVIII.] ORNAMENTAL COLORS. 273 

at others, and the fur of the male is generally brighter 
than that of the female," ^° Dr. Gray informs me that he 
specified the African squirrels, because, from their unusu- 
ally bright colors, they best exhibit this difference. The 
female of the Mus minutus of Russia is of a paler and 
dirtier tint than the male. In some few bats the fur of 
the male is lighter and brighter than in the female.''* 

The terrestrial Carnivora and Insectivora rarely exhib- 
it sexual differences of any kind, and their colors are al- 
most always exactly the same in both sexes. The ocelot 
{Felis pardalis)^ however, offers an exception, for the col- 
ors of the female, compared with those of the male, are 
"moins apparentes, le fauve etant plus tei'ne, le blanc 
moins pur, les raies ayant moins de largeur et les taches 
moins de diam^tre." " The sexes of the allied Felis mitis 
also differ, but even 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, sometimes differ considerably in color, and 
they present, as we have already seen, other remarkable 
sexual differences. Thus the male of the Otaria nigres- 
cens of the southern hemisphere is of a rich brown shade 
above ; while the female, who acquires her adult tints 
earlier in life than the male, is dark gray above, the young 
of both sexes being of a very deep chocolate color. The 
male of the northern Phoca Groenlandica is tawny gray, 
with a curious saddle-shaped dark mark on the back; the 
female is much smaller, and has a very different appear- 
ance, being " dull white or yellowish straw-color, with a 

2» 'Annals and Mag. of Nat. Hist.' Nov. ISBY, p. 325. On the Mus 
minutus, Desmarest, ' Mammalogie,' p. 304. 

^' J. A. Allen, in ' Bulletin of Mus. Comp. Zoolog. of Cambridge, Uni- 
ted States,' 1869, p. 207. 

^^ Desmarest, ' Mammalogie,' 1820, p. 223. On Felis mitis, Rengger, 
ibid. s. 194. 



274 SEXUAL SELECTION: MAMMALS. [Part IL 

tawny liuo on tlic Lack;" tlic yoinig at first are pure 
white, and can " hardly be distinguished among the icy 
hummocks and snow, their color thus acting as a protec- 
tion."" 

With TJuminants sexual differences of color occur more 
commonly than in any other order. A difierence of this 
kind is general with the Strepsicerene antelopes ; thus the 
male nilghau [Portax jyicfa) is bluish-gray and much 
darker than the female, with the square white })atch on 
the throat, the white marks on the fetlocks, and the black 
spots on the ears, all much more distinct. We have seen 
that in this species the crests and tufts of hair are likewise 
more develojjcd in the male than in the hornless female. 
The male, as I am informed by Mr. Blyth, without shed- 
ding liis hair, periodically becomes darker during the 
breeding-season. Young males cannot be distinguished 
fi'om young females until above twelve months old ; and 
if the male is emasculated before this period, he never, 
according to the same authority, changes color. Tlie im- 
portance of this latter fact, as distinctive of sexual color- 
ing, becomes obvious, when we hear"* that neither the red 
summer-coat nor the blue winter-coat of the Virginian deer 
is at all aftectcd by emasculation. With most or all of 
the highly-ornamented species of Tragelaphus the males 
are darker than the hornless females, and their crests of 
hair are more fully develojjed. In the male of that mag- 
nificent antelope, the Dcrbyan Eland, the body is redder, 
the whole neck much blacker, and the white band which 
separates these colors, broader, than in the female. Tn 
the Cape Eland also, the male is slightly darker than the 
female." 

'^'Dr. Murie on the Otaria, ' Proc. Zool. Soc' 1869, p. 108. Mr. K. 
I?rown, on the P. Grocnlandka, ibid. 1868, p. 417. Sec aljJO on the colors 
of seals, Dcsmarcst, ihid. pp. 24.^, 249. 

" JikIrc Caton, in 'Trans. Ottawa Acad, of Nat. Sciences.' 1868, p. 4. 

«• Dr. Gray, ' Cat of Manim. in Brit. Mus.' part iii. 1852, pp. 134-142 ; 



Chap. XVIII.] ORNAMENTAL COLORS. 275 

In the Indian Black-buck {A. bezoartica), wliicli belongs 
to another tribe of antelopes, the male is very dark, almost 
black ; while the hornless female is fawn-colored. We 
have in this species, as Mr. Blyth informs me, an exactly 
parallel series of facts as with the Portax picta, namely, in 
the male periodically changing color during the breeding- 
season, in the effects of emasculation on this change, and 
in the young of both sexes being undistinguishable from 
each other. In the Antilope nlger the male is black, the 
female as well as the young 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 as in the female brown ; in the 
brindled gnu [A. gorgon) "the colors of the male are 
neai'ly the same as those of the female, only deeper and 
of a brighter hue."^® Other analogous cases could be 
added. 

The Banteng bull {Bos sotzdaicus) of the Malayan 
archipelago 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 the female 
Copra aegagrus is said to be more uniformly tinted than 

also Dr. Gray, ' Gleanings from the Menagerie of Knowsley,' in which 
there is a splendid drawing of the Oreas Derbianus : see the text on 
Tragelaphus. For the Cape Eland ( Oreas canna), see Andrew Smith, 
' Zoology of South Africa,' pis. 41, 42. There are also many of these 
antelopes in the Zoological Society's Gardens. 

2s On the Ant niger, see ' Proc. Zool. Soc' 1850, p. 133. With re- 
spect to an allied species, in which there is an equal sexual difference in 
color, see Sir S. Baker, ' The Albert Nyanza,' 1866, vol. ii. p. 327. For 
the A. sing-sing, Gray, ' Cat. B. Mus.' p. 100. Desmarest, ' Mammalogie,' 
p. 468, on the A. caama. Andrew Smith, ' Zoology of South Africa,' on 
the Gnu. 



276 SEXUAL SELECTION: MAMMALS. [Pabt IL 

their respective males. Deer rarely present any sexual 
(lifFcrences in color. Judge Caton, bowever, informs me 
that with the males of the Wapiti deer [Cervus Canaden- 
sis) the neck, belly, and legs, are much darker than the 
same parts in the female ; but during the winter the darker 
tints gradually fade away and disappear. I may here 
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- 
pared with those given in a previous chapter of closely- 
allied or representative species of birds which differ from 
each other only in their nuptial jilumage.'" The females 
of Cerviis jxiludosics 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 
characterize the adult males.^* Lastly, the mature male 
of the beautifully colored and spotted Axis deer is con- 
siderably darker, as I am informed by Mr. Blyth, than 
the female ; and this hue the castrated male never ac- 
quires. 

The last Order which we have to consider — for I am 
not aware that sexual differences in color occur in the 
other mammalian groups — is that of the Primates. The 
male of the Ziemur macaco is coal-black, while the female 
is reddish-yellow, but highly variable in color." Of the 
Quadrumana of the New World, the females and young 
of Mycetes caraya are grayish-yellow and alike ; in the 

'^ 'Ottawa Academy of Sciences,' May 21, 1868, pp. 3, 5. 

'* S. Miiller, on the Banteng, 'Zoog. Indischen Archipel' 1839-1844, 
tab. 35 : see also Raflflcs, as quoted by Mr. Blyth, in ' Land and Water,' 
1867, p. 476. On goats. Dr. Gray, 'Cat. Brit. Mus.' p. 146 ; Desmarest, 
' Mammalogie,' p. 482. On the Cervus paludosus, Rengger, ibid. s. 345. 

'* Sclater, 'Proe. Zool. Soc' 1866, p. 1. The same fact has also been 
f\jlly ascertained by MM. Pollen and Van Dam. 



Chap, XVIII.] ORNAMENTAL COLORS. 277 

second year the young male becomes reddish-brown, in 
the tliird year black, excepting the stomach, which, how- 
ever, becomes quite black in the fourth or fifth year. There 
is also a strongly-marked difference in color between the 
sexes in Mycetes senicuhis and Cebus capiccinus ^ the young 
of the former and I believe of the latter species resembling 
the females. With Pithecia leucocephala the young like- 
wise 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 Ateles marginatus is 
tinted yellow in the male and white in the female. Turn- 
ing to the Old "World, the males of Hylobates hoolocJc 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 Cercojyithecus Diana the head of the adult 
male is of an intense black, while that of the female is dark 
gray ; in the former the fur between the thighs is of an 
elegant fawn-color, in the latter it is paler. In the equally 
beautiful and curious mustache monkey {Cercopithecus 
cephus) the only difference 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 strongly 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 MuUer, 
the male of Semnopithecus chrysomelas is nearly black, 
the female being pale brown. In the Cercopithecus cyno- 
surus and griseo-viridis one part of the body which is con- 
fined to the male sex is of the most brilliant blue or green, 

3" On Mycetes, Rengger, ibid. s. 14; and Brehm, 'Illustrirtes Thier- 
leben,' B, i. s. 96, lOY. On Ateles, Desmarest, ' Mammalogie,' p. 75. 
On Hylobates, Blyth, ' Land and Water,' 1867, p. 135. On the Semno- 
pithecus, S. MUller, ' Zoog. Indischen Archipel.' tab. x. 



278 SEXUAL SELECTION: MAMMALS. [Part IL 

and contrasts strikingly with the naked skin on the liiiider 
part of the l>ody, whicli is vivid red. 

Lastly, in the Baboon family, the adult male of Ci/no- 
cephalus hamadryas differs from the female not only by 
his immense mane, but slightly in the color of the hair 
and of the naked callosities. In the drill ( Cynocephalus 
leucophceus) the females and young are much paler- 
colored, with less green, than the adult males. No 
other member of the whole class of mammals is colored 
in so extraordinary a manner as the adult male mandrill 
( Cynoceplialus viormon). 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 cuisscs et 
le grand espace nu de leurs fesses sont ^galeraent colores 
du rouge le plus vif, avec un melange de bleu qui ne 
manque reellement pas d'el6gance." ^* Wlien 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 
compare with those of the most brilliant birds. Another 
most remarkable peculiarity is that when the great ca- 
nine teeth are fully developed, immense protuberances of 
bone are formed on each cheek, which are deeply fur- 
rowed longitudinally, and the naked skin over them is 
brilliantly colored, as just described. (Fig. 67.) In the 
adult females and in the young of both sexes these protu- 
berances are scarcely perceptible; and the naked parts 
are much less brightly colored, the face being almost 

*' Gervais, 'Hist. Nat. des Maminiftrcs,' 1854, p. 103. Figures are 
given of the skull of the male. Dcsinarest, ' Marainalogie,' p. 70. 
Geofifroy St.-Ililaire aud F. Cuvier, 'Hist. Nat. dcs Mauun.' 1824, toiu. i. 



Chap. XVIII.] 



ORNAMENTAL COLORS. 



279 



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 strong- 
ly or brightly colored than the female, and differs in a 




Fig. 67.— Head of male Mandrill (from Gervais ' Hist. Nat des Mammiferes'). 

greater degree from the young of both sexes. But as a 
reversed style of coloring is characteristic of the two 
sexes with some few birds, so with the Rhesus monkey 
{Macaeus rhesus) the female has a large surface of naked 



280 SEXUAL SELECTION: MAMMALS. [Part IL 

skin rouiul the tail, of a brilliant carmine red, which pe- 
riodically becomes, as I was assured by the keepers in the 
Zoological Gardens, even more vivid, and her face is also 
pale red. On the other hand, with the adult male and with 
the young of both sexes, as I saw in the Gardens, neither 
the naked skin at the posterior end of the body, nor the 
face, shows a trace of red. It appears, however, from some 
published accounts, that the male does occasionally, 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 superciliary ridges, 
he follows the common rule of the male excelling the 
female. 

I have now given all the cases known to me of a dif- 
ference in color between the sexes of mammals. The 
colors of the female either do not differ in a sufficient 
degree from those of the male, or are not of a suitable 
nature to afford her jjrotection, and therefore cannot be 
explained on this principle. In some, perhaps in many 
cases, the differences may be the result of variations con- 
fined to one sex and transmitted to the same sex, without 
any good having been thus gained, and therefore without 
the aid of selection. We have instances of this kind with 
our domesticated animals, as in the males of certain cats 
being rusty-red, while the females are tortoise-shell col- 
ored. Analogous cases occur under nature : Mr. Bartlett 
has seen many black varieties of the jaguar, leopard, vul- 
pine, plialaiiger, and wombat; and he is certain that all, 
or nearly all, were males. On the other hand, both sexes 
of wolves, foxes, and apparently of American squirrels, 
are occasionally born black. Hence it is quite possible 
that with some mammals the blackness of the males, es- 
pecially when this color is congenital, may simply be the 



Chap. XVIII.] ORNAMENTAL COLORS. 281 

result, without the aid of selection, of one or more varia- 
tions having occurred, which from the first were sexually 
limited in their transmission. Nevertheless, it can hardly 
be admitted that the diversified, vivid, and contrasted col- 
ors of certain quadrupeds, for instance, of the above-men- 
tioned monkeys and antelopes, can thus be accounted for. 
We should bear in mind that these colors do not appear 
in the male at birth, as in the case of most ordinary va- 
riations, but only at or near maturity ; and that, unlike 
ordinary variations, if the male - be emasculated, they 
never appear or subsequently disajjjjear. It is on the 
whole a much more probable conclusion that the strong- 
ly-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. The probability of this view is 
strengthened by the diiferences in color between the sexes 
occurring almost exclusively, as may be observed by 
going through the previous details, in those groups and 
sub-groups of mammals which present other and distinct 
secondary sexual characters ; these being likewise due to 
the action of sexual selection. 

Quadrupeds manifestly take notice of color. Sir S. 
Baker repeatedly observed that the African elephant and 
rhinoceros attacked with special fury white or gray horses, 
I have elsewhere shown ^^ that half-wild horses apparently 
prefer pairing with those of the same color, and that herds 
of fallow-deer of a different color, though living together, 
have long kept distinct. It is a more significant fact that 
a female zebra would not admit the addresses of a male 
ass until he 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 

2^ 'The Variation of Animals and Plants under Domestication,' 1868, 
vol. ii. pp. 102, 103. 



282 SEXUAL SELECTION: MAMMALS. [Part U. 

mere color, which had so strong an effect as to get the 
better of every thing else. But the male did not require 
this, the female being an animal somewhat similar to him- 
self, was sufficient to rouse him." '' 

In an early chapter we have seen that the mental 
powers of the higher animals do not differ in kind, though 
so 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 the negro of 
Africa raises the flesh on his face into parallel ridges "or 
cicatrices, high above the natural surface, which unsight- 
ly deformities are considered great personal attractions " " 
— as negroes, as well as savages in many parts of the 
world, paint their faces with red, blue, white, or black bars 
— so the male mandrill of Africa appears to have acquired 
his deeply-furrowed and gaudily-colored face from having 
been thus rendered attractive to the female. No doubt it 
is to us a most grotesque notion that the posterior end of 
the body should have been colored for the sake of orna- 
ment even more brilliantly than the face ; but this is really 
not more strange than that the tails of many birds should 
have been especially decorated. 

"With mammals we do not at present possess any evi- 
dence that the males take pains to display their charms 
before the female ; and the elaborate manner in which this 
is performed by male birds, is the strongest argument in 
favor of the belief that the females admire, or are excit- 
ed by, the ornaments and colors displayed before them. 
There is, however, a striking parallelism between mam- 
mals and birds in all their secondary sexual characters, 
namely, in their weapons for fighting with rival males, in 

'3^ 'Essays and Observations by J. Hunter,' edited by Owen, 1861, 
vol. i. p. 194. 

" Sir S. Baker, ' The Nile Tributaries of Abyssinia,' 1867. 



Chap. XVIII.] EQUAL TRANSMISSION 283 

their ornamental appendages, and in tlieir colors. In both 
classes, when the male differs from the female, the young 
of both sexes almost always resemble each othei*, 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 for reproduction; if emasculated 
he either never acquires such characters or subsequently 
loses them. In both classes the change of color is some- 
times 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 sti'ongly 
colored than the female, and is ornamented with larger 
crests either of hair or feathers, or other appendages. In 
a few exceptional cases the female in both classes is more 
highly ornamented than the male. With many mammals, 
and at least in the case of one bird, the male is more odor- 
iferous than the female. In both classes the voice of the 
male is more powerful than that of the female. Consider- 
ing 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 safely 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 Ornamental Characters to both 
Sexes. — With many birds, ornaments, which analogy leads 
us to believe were primarily acquired by the males, have 
been transmitted equally, or almost equally, to both sexes ; 
and we may now inquire how far this view may be ex- 
tended to mammals. With a considerable number of spe- 
cies, especially the smaller kinds, both sexes have been 
colored, independently of sexual selection, for the sake of 



284 SEXUAL SELECTION : MAMMALS. [1'akt H. 

protection ; l)ut not, as far as I can judge, in so many 
cases, nor in nearly so striking a manner as in most of the 
lower classes. Auduljon remarks tliat he often mistook 
tlie musk-rat,'"^ while sitting on the banks of a muddy 
stream, for a clod of earth, so complete was the resem- 
blance. The hare on her form is a familiar instance of 
concealment through color ; yet this princi])le ])artly fails 
in a closely-allied species, namely, the rabbit, for, as this 
animal runs to its burrow, it is made conspicuous to the 
sportsman and no doubt to all beasts of prey, by its up- 
turned ])ure-white tail. No one has ever doubted that the 
quadrupeds which inhabit snow-clad regions have been 
rendered w^hite to protect them from their enemies, or to 
favor their stealing on their prey. In regions where snow 
never lies long on the ground a white coat would be inju- 
rious; consequently species thus colored are extremely 
rare in the hotter parts of the world. It deserv'^es notice 
that many quadrupeds, inhabiting moderately cold regions 
although they do not assume a white winter dress, become 
paler during this season ; and this apparently is the direct 
result of the conditions to which they have long been ex- 
j)Osed. Pallas '* states that in Siberia a change of this na- 
ture occurs with the wolf, two species of Mustcla, the do- 
mestic horse, the Equus hemioniis, the domestic cow, two 
species of antelopes, the musk-deer, the roe, the 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 were gradually 
to extend their range into regions perpetually covered 

2* Mber zibethicm, Audubon and Bachnmn, ' The Quadrupeds of North 
America,' 1846, p. 109. 

** 'Novae species Quadrupedum e Glirium ordine,' 1778, p. 7. What 
I have called the roe ia the Capreolxts Sibiriais subecatidaius of Pallas. 



Chap. XVIII ] 



EQUAL TRANSMISSION. 



285 



with snow, the pale winter coats would probably be ren- 
dered, through natural selection, whiter and whiter by de- 
grees, until they become as white as snow. 

Although we must admit that many quadrupeds have 




Fig. 68.— Tragelaphus Rcriptus, male (from the Knowsley Menagerie). 

received their present tints as a protection, yet with a host 
of species the colors are far too conspicuous and too sin- 
gularly arranged to allow us to suppose that they serve 
for this purpose. We may take as an illustration certain 
antelopes : when we see that the square white patch on 



286 SEXUAL SELECriON : MAMMALS. [Pabt IL 

the throat, tlie white marks on tlie fetlocks, and tlie round 
hhick s{)ot8 on the ears, are all more distmct in the male 
of the Portax. picta^ than iu 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 tlie shoulder are 




Fio. 69.— Damalis pygarga, male (from the Knowsley Menajrerie). 

more distinct in the male Oreas Derby arms than in the fe- 
male — when we see a similar difference between the sexes 
of the curiously ornamented Tragelaphus scriptus (Fig, 
68) — we may conclude that these colors and various 
marks have been at least intensified through sexual selec- 
tion. It is inconceivable tliat such colors and marks can 
be of any direct or ordinary service to those animals; and 



Chap. XVm.] EQUAL TRANSMISSION. 287 

as they have almost certainly been intensified through 
sexual selection, it is probable that they were originally 
gained through this same process, and then partially 
transferred to the females. If this view be admitted, 
there can be little doubt that the equally singular colors 
and mai-ks 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 {Strep- 
siceros Kudu, Fig. 62) have narrow white vertical lines on 
their hinder flanks, and an elegant angular wliite mark on 
their foreheads. Both sexes in the genus Damalis are very 
oddly colored ; in D. pygarga the back and neck are pur- 
plish-red, shading on the flanks into black, and abruptly 
separated from the white belly and a large wliite space on 
the buttocks ; the head is still more oddly colored, a large 
oblong white mask, narrowly edged with black, covers the 
face up to the eyes (Fig. 69) ; 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 Damalis alhifrons the coloring of the head 
differs from that in the last si^ecies in a single white stripe 
replacing the three stripes, and in the ears being almost 
wholly white. " After having studied to the best of my 
ability the sexual differences of animals belonging to all 
classes, I cannot avoid the conclusion that the cmiously- 
arranged colors of many antelopes, though common to 
both sexes, are the result of sexual selection primai-ily ai> 
plied 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. Mi*. Wallace believes'* that 

3' See the fine plates in A. Smith's 'Zoology of South Africa,' and Dr. 
Gray's ' Gleanings from the Menagerie of Knowsley.' 
2^ ' Westminster Review,' July 1, 1867, p. 5. 



288 SEXUAL SELECTION : MAMMALS. [Part II. 

the striped coat of the tiger " so assimilates with the ver- 
tical stems of the bamboo, as to assist greatly in conceal- 
ing him from his approaching prey." But this view does 
not appear to me satisfactory. We have some slight evi- 
di'nce that his beauty may be due to sexual selection, for 
in two species of Felis analogous marks and colors are 
rather brighter in the male than in the female. The Zebra 
is conspicuously striped, and stripes on the open plains of 
South Africa cannot afford any protection. BurchelP' 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 by any other quadruped." 
Here we have no evidence of sexual selection, as through- 
out the whole group of the Equidie, the sexes are identical 
in color. Nevertheless, he who attributes the white and 
dark vertical stripes on the flanks of various antelopes to 
sexual selection, will probably extend the same view to 
the Royal Tiger and beautiful Zebra. 

We have seen in a former chapter that when young 
animals belonging to any class follow nearly the same 
habits of life with their parents, and yet are colored in a 
difterent manner, it may be inferred that they have re- 
tained the coloring of some ancient and extinct progeni- 
tor. In the family of pigs, and in the genus Tapir, the 
young are marked with longitudinal stripes, and thus 
difter from every existing adult species in these two 
groups. With 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 female) — to species in 
which neither the old nor the young are spotted. I will 

»» 'Travels in South Africa,' 1824, vol. ii. p. 315. 



Chap. XVIII.] SPOTS AND STRIPES. 289 

specify some of the steps in this series. The Mantchurian 
deer ( Cervus Mantchuriciis) is spotted during the whole 
year, but the spots are miich plainer, as I have seen in the 
Zoological Gardens, during the summer, when the gen- 
eral 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 {Ilyelaphus porcimcs) the 
spots are extremely conspicuous dm-ing the summer when 
the coat is reddish-brown, but quite disappear during the 
winter when the coat is brown." In both these species 
the young are spotted. In the "Virginian deer the young 
are likewise spotted, and about five per cent, of the adult 
animals living in Judge Caton's park, as I am informed 
by him, temporarily exhibit at the period when the red 
svimmer-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 com- 
plete absence of spots at all seasons in the adults ; and 
lastly, to their absence at all ages, 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 descendani,s of some ancient 
species which, like the Axis deer, was spotted at all ages 
and seasons. A still more ancient progenitor probably 
resembled to a certain extent the IIyo7noschiis aquaticus 
— for this animal is spotted, and the hornless males have 
large exserted canine teeth, of which some few true deer 
still retain rudiments. It offers, also, one of those inter- 
esting cases of a form linking together two groups, as it is 

^^ Dr. Gray, ' Gleanings from the Menagerie of Knowsley,' p. 64. Mr. 
BIyth, in speaking (' Land and Water,' 1869, p. 42) of the hog-deer of 
Ceylon, says it is more brightly spotted with white than the common hog- 
tleer, at the season when it renews its horns. 
32 



290 SEXUAL SELECTION: MAMMAIi^. [Part II. 

intermediate in certain osteological characters between 
the pachyderms and ruminants, which were formerly 
thought to he quite distinct/' 

A curious diificulty here arises. If we admit that col- 
ored spots and stripes have been acquired as ornaments, 
how comes it that so many existing deer, the descendants 
of an aboriginally 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 orna- 
ments ? I cannot satisfactorily answer this question. We 
may feel nearly sure that the spots and stripes disap- 
peared in the progenitors of our existing species at or near 
maturity, so that they were retained by the young, and, 
owing to the law of inheritance at corresponding ages, by 
the young of all succeeding generations. It may have 
been a great advantage to the lion and puma, from the 
open nature of the localities which they commonly haunt, 
to have lost their stripes, and to have been thus rendered 
less conspicuous to their prey ; and if the successive vari- 
ations, by which this end was gained, occurred rather late 
in life, the young would have retained their stripes, as we 
know to be the case. In regard to deer, pigs, and tapirs, 
Fritz Milller has suggested to me that these animals, by 
the removal through natural selection of their spots or 
stripes, would have been less easily seen by their enemies ; 
and 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 ex- 
planation, but it is rather strange that the young should 
not have been equally well protected, and still more 
strange that with some species the adults should have 
retained their spots, either partially or completely, during 
part of the year. We know, though we cannot explain 

*' Falconer and Cautley, ' Proc. Geolog. Soc' 1843; and Falconer's 
' Pal. Memoirs,' vol. i. p. 196. 



Chap. XVIIL] QUADRUMANA. 291 

the cause, that when the domestic ass varies and becomes 
reddish-brown, gray or black, the stripes on the shoulders 
and even on the spine frequently disappear. Very few 
horses, except dun-colored kinds, exhibit 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 disappear- 
ance of the spots and stripes in our adult existing deer, 
pigs, and tapirs, may be due to a change in the genei'al 
color of their coats ; but whether this change was effected 
through sexual or natural selection, or was due to the di- 
rect action of the conditions of life, or some other unknown 
cause, it is impossible to deside. 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 conti- 
nent are destitute of stripes, not having even the cross 
shoulder-stripe, while those which inhabit Africa are con- 
spicuously striped, with the partial exception of A. tcenio- 
pus, which has only the cross shoulder-stripe and generally 
some faint bars on the legs ; and this species inhabits the al- 
most intermediate region of Upper Egypt and Abyssinia." 

Quadrumana. — Before we conclude, it will be advisa- 
ble to add a few remarks co those already given on the 
ornamental characters of monkeys. In most of the spe- 
cies the sexes resemble each other in color, but in some, 
as we have seen, the males differ from the females, espe- 
cially 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 beautiful 

*2 'The Variation of Animals and Plants under Domestication,' 1868, 
vol. i. pp. 61-64. 

43 'Proc. Zool. Soc' 1862, p. 164. See, also. Dr. Hartmann, 'Ann. 
d. Landw.' Bd. xliii. s. 222. 



292 



SEXUAL SELECTION: MAMMALS. 



[Part IL 



a manner, and an- iurni^lRMl with such curious and elegant 
crests ot'liair, that we can hardly avoid looking at these 
characters as having been gained for the sake of orna- 
ment. The accompanying figures (Figs. 70 to 74) serve 




Fio. 70.— Head of Semnopithccus nibicundus. This and the followinpr flpmres 
(from Prof. Gervaisi are jrivcn to ghow the odd arrangement and develop- 
ment of lUe hair on the head. 

to show the arrangement of the hair on the face and head 
in several species. It is scarcely conceivable that these 
crests of hair and strongly-contrasted colors of the fur 
and skin can be the result of mere variability without the 
aid of selection ; and it is inconceivable that they can be 
of any ordinary use to these animals. If so, they have 
probably been gained through sexual selection, though 
transmitted equally, or almost equally, to both sexes. 



Chap. XVIIL] 



QUADRUMANA. 



293 



With many of the Quadrumana, we have additional evi- 
dence of the action of sexual selection in the greater size 
and strength of the males, and in the greater develoj^ment 
of their canine teeth, in comparison with the females. 




Fig 71.— Head of Semnopithecu6 comatus. Fig. 72.— Head of Cebus capucinus. 





Fig. 73.— Head of Ateles marginatus. 



Fig. 74— Head of Cebus vellerosus. 



With respect to the strange manner in which both 
sexes of some species are colored, and of the beauty of 
others, a few instances will suffice. The face of the Cer- 
copithecus petaiirista (Fig. 75) is black, the whiskers and 
beard being white, with a defined, round, white spot on 



294 



SEXUAL SELECTION : MAMMALS. [Paut 11. 



the nose, covered with short white hair, which gives to 
the animal an ahiu.sl hidicrous aspect. The Semnojnthe- 




l"i(i. 75.— Ciicoi)i(hccu8 pctaurista (I'lom Brehm). 



Chap. XVIII.] QUADRUMANA. 295 

cus frontatus likewise has a blackish face with a long 
black beard, and a lai'ge 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 Cercocehus ^thiops 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 difierent color from the rest of the head, 
and, when different, are always of a lighter tint,^* beiug 
often pure white, sometimes bright yellow, or reddish. 
The whole face of the South- American Srachyurus calvus 
is of a "glowing scarlet hue ; " but this color does not 
appear until the animal is nearly mature." The naked 
skin of the face differs wonderfully in color in the various 
species. It is often brown or flesh-color, with parts per- 
fectly white, and often as black as that of the most sooty 
negro. In the Brachyurus, the scarlet tint is brighter 
than that of the most blushing 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 known to Mr. Bartlett, in which 
the adults of both sexes have strongly-colored faces, the 
colors are dull or absent during early youth. This like- 
wise holds good with the Mandrill 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 
every reason to believe that the colors were acquired 
through sexual selection ; and we ai'e naturally led to 
extend the same view to the foregoing species, though 

** I observed this fact in the Zoological Gardens ; and numerous 
cases may be seen in the colored plates in GeofFroy St.-Hilaire and F, 
Cuvier, 'Hist. Nat. des Mammiferes,' torn. i. 1824. 

** Bates, ' The Naturalist on the Amazons,' 1863, vol. ii. p. 310. 



296 SEXUAL SELECTION : MAMMALS. [Pakt IL 

both sexes when adult liave their faces colored in llie 
same nianniT. 

Althougli, according to our taste, nuiuy kinds of mon- 
keys are far from beautiful, other species are universally 
admired for their elegant ai)i)i'arance and briglit colors. 
The /Sijnuojnthectis nemmus, tliough peculiarly colored, is 
described as extremely pretty ; the orange-tinted face is 
surrounded by long whiskers of glossy whiteness, with a 
line of chestnut red over the eyebrows ; the fur on the 
back is of a delicate gray, with a square patch on the 
loins, the tail and the forearms all of a pure white ; a 
gorget of chestnut surmounts the chest ; the hind-thighs 
are black, with the legs chestmit red. I will mention only 
two other monkeys on account of their beauty ; and I 
have selected these as they present slight sexual differ- 
ences in color, which renders it in some degree probable 
that both sexes owe their elegant a2)pearance to sexual 
selection. In the mustache-monkey •( 6'tTco/)^7/tcc^<5 ce- 
2)}n(s), the general color of the fur is mottled greenish, 
with tlie 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 delicate 
blue, clothed on the lower edge with a thin black mus- 
tache; the whiskers are orange-colored, with the upper 
])art black, forming a band which extends backward 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 another monkey, deserv- 
edly called Cercopithecus Diana (Fig. 76) ; 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 ; 



Chap. XVIII.] 



SUMMARY. 



297 



the face and ears are intensely black, finely contrasted 
with a white transverse crest over the eyebrows and with 



"*^''%: 

^-^1 




J [I. it — ( ( K (.[jitiii (.ub Diaua (fiom Bithm). 

a long white peaked beard, of which the basal portion is 
black." 

■'^ I have seen most of the above-named monkeys in the Zoological 
Society's Gardens. The description of the Semnopitheciis nemceus is taken 
from Mr. W. C. Martm's 'Nat. Hist, of Mammalia,' 1841, p. 460; see 
also pp. 475, 523. 



298 SEXUAL SELECTION: MAMMALS. [Part IL 

In tliosc and many oilier monkeys, the beauty and 
pinifular arrangement of tlieir colors, and still more the 
diversilied and ek'gant arrangement of the crests and 
tufts of hair on tlieir heads, force the conviction on my 
mind that these characters have been acquired through 
sexual selection exclusively as ornaments. 

Nummary. — 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 size, strength, courage, and pugnacity of the male, 
his special weapons of offence, as well as his special means 
of defence, have all been acquired or modified through 
that form of selection which I have called sexual selec- 
tion. This does not depend on any superiority in the 
general struggle for life, but on certain individuals of one 
sex, generally the male sex, having been successful in 
conquering other males, and on their having left a larger 
number of offspring to inherit their superiority, than the 
less successful males. 

There is another and more peaceful kind of contest, 
in Avliich the males endeavor to excite or allure the fe- 
males by various charms. This may be effected 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 may have been strengthened by use during 
maturity, under the powerful excitements of love, jealousy, 
or rage, and 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 
females, seem in most cases to be merely ornamental, 
though they sometimes serve as a defence against rival 
males. There is even riasun to suspect that the branch- 



Chap. XVIII.] SUMMARY. 299 

ing horns of stags, and tlie elegant horns of certam ante- 
lopes, though properly serving as weapons of offence or 
of defence, have been partly modified for the sake of orna- 
ment. 

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 colors, 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 colored in some species in the most 
brilliant manner. The colors of the male in other cases 
may be due to simple variation, without the aid of selec- 
tion. But when the colors are diversified and strongly- 
pronounced, when they are not developed until near ma- 
turity, 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 consj^iicuous or curiously 
ari'anged, without being of the least apparent use as a pro- 
tection, and especially when they are associated with va- 
rious other ornamental appendages, we are led by anal- 
ogy to the same conclusion, namely, that they have been 
acquired through sexual selection, although transmitted 
to both sexes. That conspicuous and diversified colors, 
whether confined to the mafes or common to both sexes, 
are as a general rule associated in the same groups and 
subgroups with other secondary sexual characters, serv- 
ing for war or for ornament, will be found to hold good 
if we look back to the various cases given in this and the 
last chapter. 

The law of the equal transmission of characters to 
both sexes, as far as color and other ornaments are con- 



300 SEXUAL SELECTION : MAMMALS. [Part IL 

cerned, has prevailed far more extensively with mammals 
than with birds ; but in regard to weapons, such as horns 
and tusks, these have often lieen transmitted either exclu- 
sively, or in a much higher degree, to the males than to 
the female. This is a surprising circumstance, for as the 
males generally uSe their weapons as a defence against 
enemies of all kinds, these weapons would have been of 
service to the females. Their absence in this sex can be 
accounted for, as far as we can see, only by the form of 
inheritance which has prevailed. Finally, with quadru- 
peds the contest between the individuals of the same sex, 
whether peaceful or bloody, has with the rarest excep- 
tions been confined to the males ; so that these have been 
modified through sexual selection, either for fighting with 
each other or for alluring the opposite sex, far more com- 
monly than the females. 



Chap. XIX. ] SEXUAL DIFFERENCES. 301 



CHAPTER XIX. 

Secondary Sexual Characters of Man. 

Differences between Man and "Woman. — Causes of such Differences and of 
Certain Characters common to both Sexes. — Law of Battle. — Differ- 
ences in Mental Powers — and Voice. — On the Influence of Beauty in 
determining 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 species of 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-pro- 
nounced muscles. Owing to the relation which exists 
between muscular development and the projection of the 
brows,* the superciliary ridge is generally more strongly 
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 tribes the women are said, 
whether truly I know not, to differ slightly in tint from 
the men; and with Europeans, the women are perhaps 
the more brightly-colored of the two, as may be seen when 
both sexes have been equally exposed to the weather. 

Man is more courageous, pugnacious, and energetic 
than woman, and has a more inventive genius. His brain 
is absolutely larger, but whether relatively to the larger 

' Schaaffhausen, translation in ' Anthropological Review,' Oct. 1868, 
pp. 419, 420, 42*7. 



303 SEXUAL SELECTION: MAN. [Part D. 

size of his l^ody, in comparison with that of woman, has 
not, I holieve, been fully ascertained. In woman the face 
is rounder ; the jaws and the base of the skull smaller ; 
the outlines of her body rounder, in parts more prominent ; 
and her pelvis is broader than in man;' 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 
ai)i>i'ar. The beard, for instance, is a secondary sexual 
character, and male children are beardless, though at an 
early age they have abundant hair on their heads. It is 
probably due to the rather late appearance in life of the 
successive variations, by which man acquired his masculine 
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 ; 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 interme- 
diate between the child and the man.' Again, as the young 
of closely-allied though distinct sjjecies do not differ nearly 
80 much from each other as do the adults, so it is with 
the children of the different races of man. Some have 
even maintainiMl that race-differences cannot be detected 
in the infantile skull. ^ In regard to color, the new-born 

^ Eckcr, translation in 'Anthropological Review,' Oct. 1868, pp. 351- 
356. The comparison of the form of the skull, 'n men and women has 
been followed out with much care by Welcker. 

* Packer and Welcker, il)id. pp. 352, 355; Vogt, 'Lectures on Man.' 
Eng. translat. j). 81. 

■• Schaaffhausen, ' Anthruiiolog. Review,' ibid. p. 429. 



Chap. XIX.] SEXUAL DIFFERENCES. 303 

negro child is reddish nut-brown, which soon "becomes 
slaty-gray ; the black color being fully developed within 
a year in the Soudan, but not until three years in Egypt. 
The eyes of the negro are at first blue, and the hair chest- 
nut-brown rather than black, being curled only at the ends. 
The children of the Aiistralians immediately after birth 
are yellowish-brown, and become dark at a later age. 
Those of the Guaranys of Paraguay are whitish-yellow, 
but they acquire in the course of a few weeks the yellow- 
ish-brown tint of their parents. Similar observations have 
been made in other parts of America.^ 

I have specified the foregoing familiar differences be- 
tween the male and female sex in mankind, because they 
are curiously the same as in the Quadrumana. With 
these animals the female is mature at an earlier age than 
the male ; at least this is certainly the case with the Cehus 
azaroe.^ With most of the species the males are larger 
and much stronger than the females, of which fact the 
gorilla ofiers a well-known instance. Even in so trifling a 
character as the greater prominence of the superciliary 
ridge, the males of certain monkeys difier from the ■ fe- 
males,^ 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 sim- 

^ Pruner-Bey, on negro infants, as quoted by Vogt, ' Lectures on 
Man,' Eug. translat. 1864, p. 189 : for further facts on negro infants, as 
quoted from Winterbottom and Camper, see Lawrence, ' Lectures on 
Physiology,' etc. 1822, p. 451. For the infants of the Guaranys, see 
Kengger, ' Siiugethiere,' etc. s. 3. See also Godron, ' De I'Espece,' torn. 
ii. 1859, p. 253. For the Australians, Waitz, ' Introduct. to Anthropol- 
ogy,' Eng. translat. 1863, p. 99. 

^ Rengger, 'Siiugethiere,' etc. 1830, s. 49. 

' As in Macaem cynomolgus (Desmarest, ' Mammalogie,' p. 65) and in 
Hylohates agilis (GeoflFroy St.-Hilaire and F. Cuvier, 'Hist. Nat. des 
Manun.' 1824, torn. 1. p. 2). 



304 SEXUAL SELECTION: MAN. [Part 11 

ilar difference between the two sexes in the Australians. 
Witli monkeys, when there is any difference in the voice, 
that of tlie male is more jjowerful. We have seen that 
certain male monkeys have a well-develojx'd heard, which 
is quite deficient, or much less developed, in the female. 
No instance is known of the beard, whiskers, or mustache 
being larger in a female than in the male monkey. Even 
in the color of the beard there is a curious parallelism 
between man and the Quadrumana, for when in man the 
beard differs in color from the hair of the head, as is often 
tlie case, it is, I believe, invariably of a lighter tint, being 
often reddish. I have observed this fact in England, and 
Dr. Hooker, who attended to this little point for me in 
Kussia, found no exception to the rule. In Calcutta, Mr. 
J. Scott, of the Botanic Gardens, was so kind as to ob- 
serve with care the many races of men to be seen there, as 
well as in some other parts of India, namely, two races in 
Sikhim, the Bhoteas, Hindoos, Burmese, and Chinese. 
Although most of these races have very little hair on the 
face, yet he always found that when there was any differ- 
ence in color between the hair of the head and the beard, 
the latter Avas invariably of a lighter tint. Now with 
monkeys, as has already been stated, the beard frequently 
differs in a striking manner in color from the hair of the 
head, and in such cases it is invariably of a lighter hue, 
being often ])ure white, sometimes yellow or reddish.' 

8 'Anthropological Review,' Oct. 18G8, p. 353. 

' Mr. Blyth informs me tliat he has never seen more than one instance 
of tlie 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 
and confined Macacus ciinomolgus, whose mustaches were " remarkably 
long and human-Hke." Altogether this old monkey presented a ludicrous 
lesemblance to one of the reigning monarchs of Europe, after whom he 
was universally nicknamed. In certain races of man the hair on the 
head hardly ever becomes gray ; thus Mr. D. Forbes has never seen, as 



Chap. XIX.] SEXUAL DIFFERENCES. 305 

In regard to the general hairiness of the body, the wom- 
en 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.'" Lastly, male mon- 
keys, like men, are bolder and fiercer than the females. 
They lead the troop, and when there is danger come to 
the front. We thus see how close is the j^arallelism be- 
tween the sexual differences of man and the Quadrumana. 
With some few species, however, as with certain baboons, 
the gorilla, and orang, there is a considerably greater dif- 
ference between the sexes, 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 the case 
of mankind. 

The secondary sexual characters of man are all highly 
variable, even within the limits of the same race or sub- 
species ; and they differ much in the several races. These 
two rules generally hold good throughout the animal 
kingdom. In the excellent observations made on board 
the N'ovara, " the male Australians were found to exceed 
the females by only sixty-five millimetres in height, while 
with the Javanese the average excess was two hundred 
and eighteen millimetres, so that in this latter race the dif- 
ference in height between the sexes is more than thrice 
as great as with the Australians. The numerous measure- 
ments of various other races, with respect to stature, the 
circumference of the neck and chest, and the length of the 
backbone and arms, which were carefully made, nearly all 

he informs me, an instance with the Aymaras and Quichuas of South 
America. 

'" This is the case with the females of several species of Hylobates, 
see Geoffroy St.-Hilaire and F. Cuvier, ' Hisf. Nat. des Mamm.' tom. i. 
Se3, also, on H. lar. 'Penny Encyclopfedia,' vol. ii. pp. 149, 150. 

" The results were deduced by Dr. Weisbach from the measurements 
made by Drs. K. Scherzer and Schwarz, see ' Reise der Novara : Anthro- 
polog Theil.' 1867, s. 216, 231, 234, 236, 239, 269. 



306 SEXUAL SELECTION: MAN. [Part IL 

showed that the males differed much more from each other 
than did the females. This fact indicates that, as far as 
these characters arc concerned, it is the male which has 
Leon chiefly modified, since the races diverged from their 
common and primeval source. 

The development of the beard and the hairiness of the 
body differ remarkably in the men belonging to distinct 
races, and even to different families in the same race. We 
Europeans see this among ourselves. In the island of St. 
Kilda, according to Martin," the men do not acquire 
beards, whicli are very thin, until the age of thirty or 
upward. On the Europ»o- Asiatic Continent, beards pre- 
vail luitil we pass beyond India, though with the natives 
of Ceylon they are frequently absent, as was noticed in 
ancient times by Diodorus.'^ Beyond India beards dis- 
appear, as with the Siamese, Malays, Calmucks, Chinese, 
and Jajjanese ; nevertheless the Ainos, " who inhabit the 
northernmost islands of the Japan archipelago, are the 
most hairy men in the w^orld. With negroes the beard is 
scanty or absent, and they have no whiskers ; in both 
sexes the body is almost destitute of fine down." On the 
other hand, the Papuans of the Malay archipelago, who 
are nearly as black as negroes, possess well-developed 
beards. " In the Pacific Ocean the inhabitants of the Fiji 
archipelago have large bushy beards, while those of the 

'•- 'Voyage to St. Kilda' (3d edit. 1753), p. 37. 

'3 Sir J. E. Teunent, 'Ceylon,' vol. iL 1859, p. 107. 

" Quatrefages, ' Revue des Cours Scientifiques,' Aug. 29, 1868, p. 
630; Vogt, 'Lectures on Man,' Eng. translat. p. 127. 

'* On the beards of negroes, Vogt, 'Lectures,' etc. ibid. p. 127; 
Waitz, 'Introduct. to Anthropology,' Engl, translat. 18C3, 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 aa 
hairy as those of Europeans. 

"= Wallace, ' The Malay Arch.' vol. ii. 1869, p. 178. 



Chap. XIX.] SEXUAL DIFFERENCES. 307 

not-distant archipelagoes of Tonga and Samoa are beard- 
less ; 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 splen- 
did 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 during 
old age. With the tribes of North America, Catlin esti- 
mates that eighteen out of twenty men are completely des- 
titute by nature of a beard ; but occasionally there may 
be seen 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 differ from all the surrounding 
tribes in having a small beard, and even some hair on the 
body, but no whiskers.'® I am informed by Mr. 1). 
Forbes, who particularly attended to this subject, that the 
Aymaras and Quichuas 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 corresponding 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 some 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 from each 
other so much as with most other races of mankind.'^ This 

" Dr. J. Barnard Davis on Oceanic Races, in ' Anthropolog. Review,' 
April, 18Y0, pp. 185, 191. 

'8 Catlin, 'North American Indians,' 3d edit. 1842, vol. ii. p. 221. On 
the Guaranys, see Azara, ' Voyages dans I'Amerique Merid.' torn. ii. 
1809, p. 58 ; also Rengger, 'Saugethiere von Paraguay,' s. 3. 

^^ Prof, and Mrs. Agassiz (' Journey in Brazil,' p. 530) remark that 



308 SEXUAL SELECTION: MAN. [Part II. 

fact is analogous witli what occurs with some allied mon- 
keys ; thus the sexes of the chimpanzee are not as different 
as those of the gorilla or orang."" 

In the previous cha^ttcrs we have seen that vrith mam- 
mals, birds, fislies, insects, etc., many characters, whicli 
there is every reason to believe were primarily gained 
through sexual selection by one sex alone, have been trans- 
ferred to both sexes. As this same form of transmission 
has apparently prevailed to a large extent with mankind, 
it will save much useless repetition if we consider the 
characters peculiar to the male sex together with certain 
other characters common to both sexes. 

Law of Battle. — With barbarous nations, for instance 
with the Australians, the women are the constant cause of 
war both between the individuals of the same tribe and 
between distinct tribes. So no doubt it was in ancient 
times ; " nam fuit ante Helenam mulier teterrima belli 
causa." With the North American Indians, the contest 
is reduced to a system. That excellent observer, Hearne,"' 
^vys : " It has ever been the custom among these people 
for the men to wrestle for any woman to whom they are 
attached ; and, of course, the strongest party always car- 
ries off the prize. A weak man, imless he be a good hunt- 
er, and well-beloved, is seldom permitted 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 oc- 

the sexes of the American Indians differ less than those of the negroes 
and of the higher races. See also Rcngger, ibid. p. 3, on the Guaranys. 

'" Riitimeyer, ' Die Grenzen der Thierwelt ; eiiie Betrachtung zu Dar- 
win's Lehre,' 1868, s. 54. 

*' 'A Journey from Prince of Wales Fort,' 8vo edit. Diiblin, ITOe, 
p. 104. Sir J. Lubbock ('Origin of Civilization,' 1870, p. 09) gives other , 
and similar cases in North America. For the Guanas of South America 
Bee Azara, ' Voyages,' etc., tom. ii. p. 94. 



Chap. XIX.] LAW OF BATTLE. 309 

casions, 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 or more 
years old, as before that age they cannot conquer their ri- 
vals. 

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 re- 
version 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 become reduced through 
disuse, as would the teeth, through the not well understood 
principles of correlation and the economy of growth ; for 
we everywhere see that parts which are no longer of ser- 
vice are reduced in size. By such steps the original in- 
equality between the jaws and teeth in the two sexes of 
mankind would ultimately have been quite obliterated. The 
case is almost parallel with that of many male Ruminants, 
in which the canine teeth have been reduced to mere rudi- 
ments, or have disappeared, apparently in consequence of 
the development of horns. As the prodigious difierence 
between the skulls of the two sexes in the Gorilla and 

^^ On the fighting of the male gorilla, see Dr. Savage, in ' Boston 
Journal of Nat. His.' vol. v. 184*7, p. 423. On Presbyiis entellus^ see 
the ' Indian Field,' 1869, p. 146. 



310 SEXUAL SELECTION : MAN. [Part IL 

Orang stands in close relation with the development of 
the immense canine teeth in the males, we may infer that 
the reduction of the jaws and teeth in the early male pro- 
genitors of man 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, rug- 
ged outline of body, his greater courage and pugnacity, 
are all due in chief part to inheritance from some early 
male progenitor, who, like the existing anthropoid apes, 
was thus characterized. These characters will, however 
liave been preserved or even augmented during the long 
ages while man was still in a barbarous condition, by the 
strongest and boldest men having succeeded best in the 
general struggle for life, as well as in securing wives, and 
thus having left a large number of offspring. It is not 
probable that the greater strength of man was primarily 
acquired through the inherited effects of his liaving 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 posses- 
sion 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 mutual subsistence ; and thus their greater 
strength will have been kept up. 

Difference in the Mental Poioers of the two Sexes. — 
With respect to differences of this nature between man 
and woman, it is probable that sexual selection has played 
a very important part. I am aware that some writers 
doubt whether there is any inherent difference ; but this 
is at least probable from the analogy of the lower animals 
which present other secondary sexual characters. No one 



Chap. XIX.] MENTAL POWERS OF MAN AND WOMAN. 311 

will dispute 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 pas- 
sage in Mungo Park's Travels, and by statements made 
by many other travellers. Woman, owing to her maternal 
instincts, displays these qualities toward her infants in an 
eminent degree ; therefore it is likely that she should often 
extend them toward her fellow-creatures. Man is the ri- 
val 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 unfortu- 
nate 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 attaining to a higher emi- 
nence, in whatever he takes up, than woman can attain — 
whether requiring 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, sculpture, music — comprising composi- 
tion and performance, 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 deviation of averages, so well illustrated 
by Mr. Galton, in his work on " Hereditary Genius," tliat 
if men are capable of decided eminence over women in 



312 SEXUAL SELECTION : MAN. [Part IL 

many pulvjects, the average standard of mental power in 
man must 1:)0 above that of woman. 

The half-hiiman male progenitors of man, and men in a 
savage state, have struggled together during many gener- 
ations for the possession of the females. But mere bodily 
strength and size would do little for victory, unless asso- 
ciated with courage, perseverance, and determined 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 man, 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 invent and fashion weapons, requires the aid of the 
higher mental faculties, namely, observation, reason, in- 
vention, or imagination. These various faculties will thus 
have been continually put to the test, and selected during 
manhood ; they will, moreover, have been strengthened 
by use during this same period of life. Consequently, in 
accordance with the principle often alluded to, we might 
expect that they would at least tend to be transmitted 
chiefly to the male off'spring at the corresjjonding period 
of manhood. 

Now, when two men are put into competition, or a 
man with a woman, who possess every mental quality in 
the same perfection, with the exception that the one has 
liighcr energy, perseverance, and courage, this one will 
generally become more eminent, whatever the object may 
be, and will gain the victory." He may be said to possess 
genius — for genius has been declared by a great authority 

23 J. Stuart Mill remarks ('The Subjection of Women,' 1869, p. 122), 
" The thinf:;s in which man most excels woman are those which require 
most plodding, and long hammering at single thoughts." ^Vhat is this 
but energy and perseverance ? 



Chap. XIX.] MENTAL POWEES OF MAN AND WOMAN. 313 

to be patience ; and patience, in this sense, means unflinch- 
ing, undaunted perseverance. But this view of genius is 
perhaps deficient ; for without the higher powers of the 
imagination and reason, no eminent success in many sub- 
jects can be gained. But these latter as well as the for- 
mer faculties will have been developed in man, partly 
through sexual selection — that is, through the contest of 
rival males, and j)artly 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 thus gained will have been transmitted 
more fully to the male than to the female ofisj^ring. Thus 
man has ultimately become superior to woman. It is, 
indeed, fortunate that the law of the equal transmission 
of characters to both sexes has commonly prevailed 
throughout the whole class of mammals ; otherwise it is 
probable that man would have become as superior in 
mental endowment to woman, as the peacock is in orna- 
mental plumage to the peahen. 

It must be borne in mind that the tendency in charac- 
ters acquired at a late period of life by either sex, to be 
transmitted to the same sex at the same age, and of char- 
acters acquired at an early age to be transmitted to both 
sexes, are rules which, though general, do not always hold 
good. If they always held good, we might conclude (but 
I am here wandering beyond my proper bounds) that the 
inherited eflects of the early education of boys and girls 
would be transmitted equally to both sexes ; so that the 
present inequality between the sexes in mental power 
coiild not be efiaced 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 rea- 
son and imagination exercised to the highest point ; and 
33 



314 SEXUAL SELECTION: MAX. [Paut IL 

tlien she would proLiibly transmit tliose qualities chiefly 
to her adult daughters. The whole body of women, how- 
ever, could not be thus raised, unless during many genera- 
tions the women who excelled in the above robust virtues 
were married, and produced oftspring in larger numbers 
than other women. As before remarked with respect to 
bodily strength, although men do not now fight for the 
sake of obtaining wives, and this form of selection has 
passed away, yet they generally have to undergo, dui-hig 
manhood, a severe struggle in order to maintain them- 
selves and their families ; and this will tend to keep up or 
even increase their mental powers, and, as a consequence, 
the present inequality between the sexes.'* 

Voice and Musical Poicers. — In some species of Quad- 
rumana there is a great difference between the adult sexes, 
in the power of the voice and in the development of the 
vocal organs ; and man appears to have inherited this dif- 
ference 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."" "With respect to the cause of this difference 
between the sexes, I have nothing to add to the remarks 
made in the last chapter on the probable effects of the 
long-continued use of the vocal organs by the male under 
the excitement of love, rage, and jealousy. According 

'* An observation by Vogt bears on this subject : he says, it is a " re- 
markable circumstance, that the difference 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 Iluschkc from his measurements of 
negro and German skuUs." But Vogt admits (' Lectures on Man," Eng. 
translat. 186-4, p. 81) that more observations are requisite on this point, 

'' Owen, ' Anatomy of Vertebrates,' vol. iii. p. t>03. 



Chap. XIX.] MUSICAL TOWERS. 315 

to Sir Duncan Gibb,'" the voice differs in the different 
races of mankind ; and with the natives of Tartary, 
China, 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, though 
not a sexual character in man, must not here be passed 
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 per- 
fected in relation to the propagation of the species. In- 
sects and some few spiders are the lowest animals Avhich 
voluntarily produce any sound; and this is generally 
effected by the aid of beautifully-constructed stridulating 
organs, which are often confined to the males alone. The 
sounds thus produced consist, I believe in all cases, of the 
same note, repeated rhythmically ; '^ and this is sometimes 
pleasing even to the ears of man. Their chief, and in 
some cases exclusive use appears to be either to call or to 
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 
apparatus for inhaling and expelling air, with a pipe capa- 
ble of being closed at one end. Hence when the primeval 
members of this class were strongly excited and their 
muscles violently contracted, purposeless sounds would 
almost certainly 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 variations. The Amphibians are the lowest Ver- 
tebrates which breathe air ; and many of these animals, 
namely, frogs and toads, possess vocal organs, which are 

26 'Journal of the Anthropolog. Soc' April, 1869, pp. Ivii., Ixvi. 
^^ Dr. Scudder, " Notes on Stridulation," in ' Proc. Boston Soc. of 
Nat. Hist.' vol. xi. April, 1868. 



316 SEXUAL SELECTION: MAN. [Part IL 

incessantly used during the breeding-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 
largely birds use their vocal organs as a means of court- 
ship ; 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. Both sexes of other species, or 
the females alone, 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 evi- 
dence that these organs are used by male mammals to 
charm the females. The American Mycetes caraya per- 
haps forms an exception, as does more probably one of 
those apes which come nearer to man, namely, the Ilylo- 
hates agilis. This gibbon has an extremely loud but mu- 
sical 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 

'* Given in W. C. L. Martin's ' General Introduct. to Nat. Hist, of 
Mamm. Animals,' 1841, p. 432 ; Owen, ' Anatomy of Vertebrates,' vol. iii. 
p. 600. 



Chap. XIX.] MUSICAL POWERS. . 317 

of the gibbon's composition, excepting as regards its 
loudness." Mr. Waterhouse then gives the notes. Prof. 
Owen, who is likewise a musician, confirms the foregoing 
statement, and remarks 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 almost all other animals, it is highly 
probable that it utters its musical notes especially during 
the season of courtship. 

The perception, if not the enjoyment, of musical ca- 
dences and of rhythm is probably common to all animals, 
and no doubt depends on the common physiological nature 
of their nervous systems. Even Crustaceans, which are 
not capable of producing any voluntary sound, possess 
certain auditory hairs, which have been seen to vibrate 
when the proper musical notes are struck.^' It is 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." '" With 
all those animals, namely insects, amphibians, and birds, 
the males of which during the season of courtship inces- 
santly produce musical notes or mere rhythmical sounds, 
we must believe that the females are able to appreciate 
them, and are thus excited or charmed ; otherwise the 
incessant efforts of the males and the complex structures 
often possessed exclusively by them would be useless. 

With man song is generally admitted to be the basis 
or origin of instrumental music. As neither the enjoy- 
ment nor the capacity of producing musical notes are 
faculties of the least direct use to man in reference to his 
ordinary habits of life, they must be ranked among the 

^^ Helmholtz, ' Theorie Phys. de la Musique,' 1868, p. 187. 
»" Mr. R. Brown, in ' Proc. Zool. Soc' 1868, p. 410, 



318 SEXUAL SELECTION: MAN. [Part IL 

most mysterious with wliicli he is endowed. Tliey are 
present, thougli in a very rude and as it appears almost 
hvtent condition, in men of all races, even the most savage ; 
but 80 different is the taste of the diiferent races, that our 
music gives not tlie least pleasure to savages, and their 
music is to us hideous and unmeaning. Dr. Seenian, in 
some interesting remarks on this subject," " doubts 
whether even among the nations of Western Europe, inti- 
mately connected as they are by close and frequent inter- 
course, the music of the one is interpreted in the same sense 
by the others. By travelling eastward we find that there 
is certainly a diiferent 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 
before-mentioned gibbon, the capacity of producing, and 
no doubt of appreciating, musical notes, we have every 
reason to believe that man possessed these faculties at a 
very remote period, for singing and music are extremely 
ancient arts. Poetry, which may be considered as the 
offspring of song, is likewise so ancient that many persons 
have felt astonishment that it should have arisen during 
the earliest ages of which we have any record. 

The musical facidties, which are not wholly deficient 
in any race, are capable of prompt and high development, 
as we see with Hottentots and Negroes, who have readily 
become excellent musicians, although they do not practise 
in their native countries any thing that we should esteem 
as music. But there is nothing anomalous in this circum- 
stance : some species of birds which never naturally sing, 
can without much difficulty be taught to perform ; thus 

2' ' Journal of Anthropolog. Soc' Oct. ISYO, p. civ. See also the sev- 
eral later chapters in Sir John Lubbock's ' Prehistoric Times,' second 
edition, 1869, which contains an admirable account of the habits of sav- 
ages. 



Chap, XIX.] MUSICAL POWERS. 319 

the 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 quite possible or probable that a 
progenitor of the sparrow may have been a songster. It 
is a much more remarkable fact that parrots, which belong 
to a group distinct from the Insessores, and have differ- 
ently-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 extremely rash to assume that parrots are 
descended from some ancient progenitor which was a 
songster. Many analogous cases could be advanced of 
organs and instincts oi'iginally adapted for one purpose, 
having been utilized for some quite distinct purpose.^" 
Hence the capacity for high musical development, which 
the savage races of man possess, may be due either to our 
semi-human progenitors having practised some rude form 
of music, or simply to their liaving acquired for some dis- 
tinct purposes the proper vocal organs. But in this latter 
case we must assume that they already possessed, as in 
the above instance of the parrots, and as seems to occur 
with many animals, some sense of melody. 

Music affects every emotion, but does not by itself ex- 
cite in us the more terrible emotions of horror, rage, etc. 
It awakens tlie gentler feelings of tenderness and love, 

22 Since this chapter has been printed I have seen a valuable article 
by Mr. Chauncey Wright (' North Amer. Review,' Oct. 1870, p. 293), 
who, in discussing the above subject, remarks : " There are many conse- 
quences of the ultimate laws or uniformities of Nature through which 
the acquisition of one useful power will bring with it many resulting ad- 
vantages as well as limiting disadvantages, actual or possible, which the 
principle of utility may not have comprehended in its action." This 
principle has an important bearing, as I have attempted to show in the 
second chapter of this work, on the acquisition by man of some of his 
mental characteristics. 



320 SEXUAL SELECTIOX : MAN. [Paut II. 

■\virKli readily pass into devotion. It likewise stirs up in 
us the sensation of triumph and the glorious ardor for 
war. Those powerful and mingled feelings may well give 
rise to the si-nse of sublimity. We can concentrate, as 
])r. Seeniaiin observes, greater intensity of feeling in a 
single musical note than in pages of writing. Nearly 
the same emotions, but much weaker and less complex, 
are probably felt by birds when the male pours forth his 
full volume of song, in rivalry with other males, for the 
sake of captivating the female. Love is still the com- 
monest theme of our own songs. As Herbert Spencer 
remarks, music " arouses dormant sentiments of which we 
had not conceived the possibility, and do not know the 
meaning ; or, as Richter says, tell 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 instinc- 
tively used. Monkeys also express strong feelings in dif- 
ferent tones — anger and impatience by low — fear and 
pain by high notes." The sensations and ideas excited in 
us by music, or by the cadences of impassioned oratory, 

*' 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 that the cadences used in emotional speech 
afford the foundation from which music has been developed ; while I 
conclude that musical notes and rhythm were first acquired by the male 
or female progenitors 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 ex- 
pressed in speech. Mr. Spencer does not offer any satisfactory explana- 
tion, nor can I, why high or deep notes should be exi)ressivc, both with 
man and the lower animals, of certain emotions. Mr. Spencer gives also 
an interesting discussion on the relations between poetry, recitative, and 
8ong. 

" Rcngger, ' Siiugethiere von Paraguay,' s. 49. 



Chap. XIX.] MUSICAL POWERS. 321 

appear from their vagueness, yet depth, like mental re- 
versions to the emotions and thoughts of a long-past age. 
All these facts with respect to music become to a cer- 
tain extent intelligible if we may assume that musical 
tones and rhythm were used by the half-human progeni- 
tors of man, during the season of courtship, when animals 
of all kinds are excited by the strongest passions. In 
this case, from the deeply-laid principle of inherited asso- 
ciations, musical tones would be likely to excite in us, in 
a vague and indefinite manner, the strong emotions of a 
long-past age. Bearing in mind that the males of some 
quadrumanous animals have their vocal organs much 
more developed than in the females, and that one anthro- 
pomorphous species pours forth a whole octave of musical 
notes and may be said to sing, the suspicion does not ap- 
pear improbable that the progenitors of man, either the 
males or females, or both sexes, before they had acquired 
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 hardly any means of judging whether the 
habit of singing was first acquired by the male or female 
progenitors of mankind. 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.'^ But 
if so, this must have occurred long ago, before the pro- 
genitors of man had become sufliciently human to treat 
and value their women merely as useful slaves. The im-. 
passioned 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 

*^ See an interesting discussion on this subject by Hackel, ' Generelle 
Morph.' B. ii. 1866, s. 246. 



323 SEXUAL SELECTION: MAN. [Part IL 

which, at an extremely remote period, Iiis half-human an- 
cestors aroused each other's ardent passions, during their 
mutual courtship and rivalry. 

On the Influence of Beauty in determining the Mar- 
riages of Mankind. — 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 con- 
cerned witli primeval times, and our only means of form- 
ing 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 difierent races prefer women hav- 
ing certain characteristics, or conversely that the women 
prefer certain men, we have then to inquire whether such 
choice, continued during many generations, would pro- 
duce any sensible cfiect on the race, either on one sex on 
both sexes; this latter circumstance dejjending on the 
form of inheritance which prevails. 

It will be well first to show in some detail that sav- 
ages pay the greatest attention to their personal appear- 
ance." That they have a passion for ornament is notori- 
ous ; and an English philosopher goes so far as to main- 
tain 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." 

2* A full and excellent account of the manner in which savages in all 
parts of the world ornament themselves is given by the Italian traveller, 
Prof. Mantega/.za, ' Rio de la Plata, Viaggi e Studi,' 1867, pp. 5^5-545 ; 
all the following statements, when other references are not given, are 
taken from this work. Sec, also, Waitz, 'Introduct. to Anthropolog.' 
Eiig. transl. vol. i. 1863, p. 275, et passim. Lawrence also gives very 
full details in his ' Lectures on Physiology,' 1822. Since this chapter 
was written, Sir J. Lubbock has pubhshed his 'Origin of CrviUzafion,' 
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 dye- 
ing their teeth and hair, and piercing their teeth. 



Chap. XIX.] LOVE OF ORNAMENTS. 323 

The extravagance of the naked Indians of South America 
in decorating themselves is shown " by a man of large 
stature gaining with difficulty enough by the labor of a 
fortnight to procure in exchange the chica necessary to 
paint himself red," " The ancient barbarians of Europe 
during the 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 ex- 
amined with the same attention as clothed nations, it 
would have been perceived that the most fertile imagina- 
tion and the most mutable caprice have created the fash- 
ions 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 diiferent 
countries 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. Not 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 much more common 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 personal 
attractions." In the Arab countries no beauty can be 
perfect until the cheeks " or temples have been gashed." ^* 

^^ 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. 

3»'The Nile Tributaries,' 1867; 'The Albert N'yanza,' 1866, voli. 
p. 218. 



324 SEXUAL SELECTION: MAN. [Part IL 

111 South America, as lIiuul)oltlt remarks, " a mother 
would be accused of culpable indiflference toward lier diil- 
dren, 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 World the shape of the skull was formerly 
modified during infancy in the most extraordinary man- 
ner, as is still the case in many places, and such deformi- 
ties are considered ornamental. For instance, the savages 
of Colombia '^ deem a much flattened head an " essential 
point of beauty." 

The hair is treated with especial care in various coun- 
tries ; it is allowed to grow to full length, so as to reach 
the ground, or is combed into " a compact frizzled mop, 
which is the Papuan's })ride and glory." *" In Northern 
Africa " a man recjuires a period of from eight to ten 
years to perfect his coiffure." With other nations the 
head is shaved, and in parts of South America and Africa 
even the eyebrows are eradicated. The natives of the 
Upper Nile knock out the four front teeth, saying that 
they do not wish to resemble brutes. Further south, the 
Batokas knock out the two upper incisors, which, as Liv- 
ingstone*' remarks, gives the face a hideous appearance, 
owing to the growth 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 great chief Sebituani tried in vain to alter 
this fashion. In various parts of Africa and in the Malay 
Archipelago the natives file the incisor teeth into points 
like those of a saw, or pierce them with holes, into which 
they insert studs. 

29 Quoted by Prichanl, ' Phys. Ilist. of Mankind.' 4th edit. vol. L 
1851, p. 321. 

*" On the Papuans, Wallace, 'The Malay Archipelago,' vol. ii. p. 445. 
On the coiffure of the Africans, Sir S. Baker, 'The Albert N'yanza,' vol 
. L p. 210. 

" ' Travels,' p. 533. 



Chap. XIX.] LOVE OF ORNAMENTS. 335 

As the face with iis is chiefly admired foi" 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, with rings, sticks, feathers, 
and other ornaments, 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 Botocudos 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 ex- 
cited, when he sold his tembeta^-ihe large colored piece 
of wood which is passed through the hole. In Central 
Africa tlie women perforate the lower lip and wear a crys- 
tal, which, from the movement of the tongue, has "a 
wriggling motion indescribably ludicrous during conver- 
sation." The " wife of the chief of Latooka told Sir S. Ba- 
ker *" that his wife would be much improved if she would 
extract her four front teeth from the lower jaw, and wear 
the long pointed polished crystal in her under lip." Far- 
ther south with the Makalolo, the upper lip is perforated, 
and a large metal and bamboo ring, called a pelele, 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 women wear these things ? ' the venera- 
ble chief, Chinsurdi, was asked. Evidently surprised 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 

42 'The Albert N'yanza,' 1866, vol. i. p. 217. 



326 SEXUAL SELECTION: MAN. [Part IL 

without the pelele? She would not be a woman at all 
with a mouth like a man, but no board.' " " 

Hardly any part of the body, which can be unnaturally 
modilied, has escaped. The amount of sufiering thus 
caused must have been wonderfully great, 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 dis- 
tinguish the tribes. As with savages the same fashions 
prevail for long periods,** mutilations, from whatever 
cause first made, soon come to be valued as distinctive 
marks. But self-adornment, vanity, and the admiration 
of others, seem to be the commonest motives. In regard 
to tattooing, I was told by the missionaries in New Zea- 
land, that when they tried to persuade some girls to give 
up thei)ractiec. they answered, "We must just have a few 
lines on our lips ; else when we grow old we shall be so 
very iigly." With the men of New Zealand, a most 
capable judge " says, " To have fine tattooed 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 the chin are 
thought by tlie women in one part of Africa to be irresisti- 
ble attractions. *" In most, but not all parts of the world, 
the men, are more highly ornamented than the women, 

^^Livingstone, 'British Association,' 1860; report given in the 
' AthcncPum,' July 7, 1860, p. 29. 

** Sir S. Baker (ibid. vol. i. p. 210), speaking of the natives of Central 
Africa, says, "Every tribe has a distinct and unchanging f;ishion for 
dressing the hair." See Agassiz (' Journey in Brazil,' 1868, p. 318) on 
the invariability of the tattooing of the Amazonian Indians. 

** Rev. R. Taylor, 'New Zealand and its Inhabitants,' 1855, p. 152. 

** Mantegazza, ' Viaggi e Studi,' p. 542. 



Chap. XIX.] BEAUTY. 327 

and often in a diiferent 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 to use, 
the finest ornaments. Lastly, it is a remarkable fact, as 
proved by the foregoing quotations, that the same fash- 
ions in modifying the shape of the head, in ornamenting 
the hair, in painting, tattooing, 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 
which are followed by so many distinct nations are due to 
tradition from any common source. They rather indicate 
the close similarity of the mind of man, to whatever race 
he may belong, in the same manner as the almost univer- 
sal habits of dancing, masquerading, and making rude 
pictures. 

Having made these preliminary remarks on the admi- 
ration 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. As I have heard it main- 
tained that savages are quite indifferent about the beauty 
of their women, valuing them solely as slaves, it may 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 *' gives an amusing 
account of a Bushwoman, who used so much grease, red 
ochre, 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." 
^ ' Travels in South Africa,' 1824, vol. i. p. 414. 



338 SEXUAL SELECTION: MAN. [Part H. 

Mr. "Winwood llcade informs mc tliat the negroes of the 
West Coast often discuss the beauty of their women. 
Some competent observers have attributed the fearfully 
common practice of infanticide partly to the desire felt by 
the women to retain their good looks," In several regions 
the women wear charms and love-philters to gain the affec- 
tions of the men ; and j\Ir. Brown enumerates four plants 
used for this purpose by the women of Northwestern 
America." 

Ileariie/" who lived many years with the American 
Indians, and who was an excellent observer, says, in speak- 
ing of the women, " Ask a northern Indian what is beauty, 
and he will answer, a broad flat 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 em» 
pire, says, " Those women are preferred who have the 
Mandschu form; that is to say, abroad 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 purpose, as " it seems, of exhibiting its 
beauty, as contrasted with the eye of the red-haired bar- 
barians." 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 

** See, for references, ' Gcrland iiber das Aussterben der Naturvolker,* 
1868, s. 51, 5,*?, 55; also Azara, ' Voyagjs,' etc., torn. ii. p. 116. 

••' On the vegetable productions used by the Northwestern Americau 
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,' vol. ii. 
1859, p. 107. 



Chap. XIX.] BEAUTY. 329 

far from being too prominent, according to our ideas, in 
the natives of Ceylon ; yet " the Chinese in the seventh 
century, accustomed to the flat features of the Mogul 
races, were surprised at the prominent noses of the Cinga- 
lese ; 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, who 
ai"e reckoned beautiful in proportion as they display this 
form of face." The Siamese have small noses with diver- 
gent 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 they consider their own 
females to be much more beautiful than those of Eu- 
rope." '' 

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." 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 are similarly characterized ; and, ac- 
cording to Burton, the Somal men " are said to choose 
their wives by ranging them in a line, and by picking her 

^^ Prichard, as taken from Crawfurd and Finlayson, ' Phys. Hist, of 
Mankind,' vol. iv. pp. 534, 535. 

53 " Idem illustriasimus viator dixit mihi prsecinctorium vel tabula 
faeminse, quod nobis teterrimum est, quondam permagno aestimari ab 
hominibus in hac gente. Nunc res mutata est, et censet talem confor- 
mationem minime optandam est." 



330 SEXUAL SELECTION: MAX. [Part IL 

out who projects forthcst a tergo. Nothing can be more 
hateful to a negro tlian tlie opposite form." " 

Witli respect to color, the negroes rallied ]\Iungo Park 
on the wliitoness of his skin and the prominence of his nose, 
both of which they considered as " unsightly and minat- 
ural conformations." He in return praised the glossy jet 
of their skins and the lovely depression of their noses ; 
this they said was " honey-moxith," 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 white- 
ness may be partly attributed, according to this same 
traveller, to the belief held by most negroes that demons 
and spirits are white. 

The Banyai of the more southern part of the continent 
are negroes, but " a great many of them are of a light coflfee- 
and-milk color, and, indeed, this color is considered hand- 
some throughout the whole country ; " so that here we 
have a ditFerent standard of taste. With the Kaftres, 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 com- 
mon 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 Kaffre. I 
have heard of one unfortunate man who Avas so very fair 
that no girl would marry him." One of the titles of the 

" 'The Anthropological Review,' Nov. 1864, p. 237. For additional 
references, see Waitz, ' lutroduct. to Anthropology,' Eng. translat. 1803, 
vol i. p. 105. 



CHiP. XIX.] BEAUTY. 331 

Zulu king is, "You who are black."" Mr. Galton, in 
speaking to me about the natives of Soiithern Africa, re- 
marked that their ideas of beauty seem very different fi'om 
ours ; for in one tribe two slim, slight, and pretty girls were 
not admired by the natives. 

Turning to other quarters of the world : in Java, a 
yellow, not a white girl, is considered, according to Ma- 
dame Pfeiffer, 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 disli'ke 
our white skin, and that the North Americans admire " a 
tawny hide." In South America, the Yura-caras, who in- 
habit 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.*' 

In several of the tribes of North America the hair on 
the bead grows 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 ofiice 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 for the sake of beauty, that 
cutting it off was the severest punishment which he could 
inflict on them. In both halves of the continent the na- 

65 'Mungo Park's Travels in Africa,' 4to, 1816, pp. 53, 131. Burton's 
statement is quoted by Schaaff hausen, ' Archiv fiir Anthropolog.' 1866, 
s. 163. On the Banyai, Livingstone, ' Travels,' p. 64. On the Kafirs, 
the Rev. J. Shooter, ' The Kafirs of Natal and the Zulu Country,' 1857, 
p. 1. 

5^ For the Javanese and Cochin- Chinese, see Waitz, ' Introduct. to 
Anthropology,' Eng. translat. vol. i. p. 305. On the Yura-caras, A. 
d'Orligny, as quoted in Pritchard, ' Phys. Hist, of Mankind,' vol. v. 3d 
edit. p. 476. 



332 SEXUAL SELECTION: MAN. [Part H. 

tives 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 Isl- 
and in the nortli to Tierra del Fuego in the south. When 
York jMinster, 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 missionarj^, who Avas left for a time with them, 
to strijj him naked, and pluck the hairs from his face and 
body, yet he was far from a hairy man. This fashion is 
carried to such an extreme 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 Calmucks 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 oflf, and be like 
Japanese men." The New-Zealanders are beardless ; they 
carefully pluck out the hairs on the face, and have a 
saying that " there is no woman for a hairy man. " " 

" North American Indians,' by G. Catlin, 3d. edit. 1842, vol. i. p. 49; 
vol. ii. p. 227. On the natives of Vancouver Island, see Sproat. ' Scenes 
and Studies of Savage Life,' 1868, p. 25. On the Indians of Paraguay, 
Azara, 'Voyages,' torn. ii. p. 105. 

** On the Siamese, Pritchard, ibid. vol. iv. p. 533. On the Japanese, 
Veitch in ' Gardeners' Chronicle,' 1860, p. 1104. On the New-Zealanders, 
Mautcgazza, ' Viaggi e Studi,' 1867, p. 626. For the other nations men- 



Chap. XIX.] BEAUTY. 333 

On the other hand, bearded races admire and greatly 
value their beards ; among the Anglo-Saxons every part 
of the body, according to their laws, 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." " In the East, men swear solemnly by their 
beards. "We have seen that Chinsurdi, the chief of the 
Makalolo in Africa, evidently thought that beards were a 
great ornament. With the Fijians in the Pacific the 
beard is " profuse and bushy, and is his greatest pride ; " 
wliile 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." '"' 

We thus see how widely the different 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 en- 
deavored to express their highest ideal of beauty and 
grandeur." Under this point of view it is well to com- 
pare in our mind the Jupiter or Apollo of the Greeks with 
the Egyptian or Assyrian statues ; and these with the 
hideous bass-reliefs on the ruined buildings of Central 
America. 

I have met with very few statements opposed to the 
above conclusion. Mr. Winwood Reade, however, who 
has had ample opportunities for observation, not only 
with the negroes of the West Coast of Africa, but with 

tioned, see references in Lawrence, 'Lectures on Physiology,' etc. 1822, 
p. 272. 

" Lubbock, 'Origin of Civilization,' 18Y0, p. 321. 

*" Dr. Barnard Davis quotes Mr. Pritchard 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 Legislation,' 
3d. edit. 1837, p. 136. 



334 SEXUAL SELECTION: MAN. [Part IL 

those of tlie interior who have never associated with 
Europeans, is convinced that their ideas of beauty are on 
the whole the same as ours. He lias repeatedly found that 
he agreed with 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 
themselves very scantily provided. Mr. Reade feels 
doubtful what kind of nose is most ajipreciated : 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 an object of admiration. We should, however, bear 
in mind tliat the depi-essed and very broad noses and pro- 
jecting jaws of the negroes of the West Coast are excep- 
tional types with the inhabitants of Africa. Notwith- 
standing the foregoing statements, Mr. Reade 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 truth of the principle, long ago insisted on by 
Humboldt," that man admires and often tries to exagger- 
ate whatever characters Nature may have given him, is 
shown in many ways. The practice of beardless races 

*' The Fuegians, as I have been informed by a nussionary who long 
resided with them, consider European women as extremely beautiful ; 
but from what 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, Captain Burton, believes that a 
woman whom we consider beautiful is admired throughout the world, 
'Anthropological Review,' March, 18C4, p. 245. 

** ' Personal Narrative,' Eiig. translat. vol. iv. p. 518, and elsewhere. 
Mantegazza, in his ' Viaggi e Studi,' 1867, strongly insists on this same 
principle. 



Chap. XIX.] BEAUTY. 335 

extirpating every trace of a beard, and generally all the 
hairs on the body, offers 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 practised, especially in Xorth and South Amer- 
ica, in order to exaggerate some natural and admired pe- 
culiarity. Many American Indians are known to admire 
a head flattened to such an extreme degree as to appear 
to us like that of an idiot. The natives on the north- 
western 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 " ad- 
mire a broad, smooth forehead, and in order to produce it 
they fasten a plate of lead on the heads of the new-born 
children." On the other hand, " a broad, well-rounded 
occiput is considered a great beauty " by the natives of 
the Fiji islands." 

As with the skull, so with the nose ; the ancient Huns 
during the age of Attila were accustomed to flatten the 
noses of their infants with bandages, " for the sake of ex- 
aggerating a natural conformation." With the Tahitians, 
to be called long-nose is considered as an insult, and they 
compress the noses and foreheads of their children for the 
sake of beauty. So it is with the Malays of Sumatra, the 
Hottentots, certain Negroes, and the natives of Brazil." 

^ On the skulls of the American tribes, see Nott and Gliddon, * Types 
of Mankind,' 1854, p. 440 ; Pritchard, ' Phys. Hist, of Mankind,' vol. i. 3d 
edit. p. 321 ; on the natives of Arakhan, ibid. vol. iv. p. 537. Wilson, 
'Physical Ethnology,' Smithsonian Institution, 1863, p. 288; on the 
Fijians, p. 290. Sir J. Lubbock (' Prehistoric Times,' 2d edit. 1869, p. 
506) gives an excellent resume on this subject. 

«5 On the Huns, Godron, 'De I'Espece,' tom. ii. 1859, p. 300. On the 
Tahitians, Waitz, ' Anthropolog.' Eng. translat. vol. i. p. 305. Marsden, 



336 SEXUAL SELECTION: MAN. [Part H. 

Tlie Chinese have by nature unusually small feet;" 
and it is well kn<»wn lliat the women of the upper elasses 
distort their feet to make them still smaller. Lastly, Hum- 
boldt thinks that the American Indians prefer coloring 
their hodies with red ])aint in order to exaggerate their 
natural tint ; and until recently European women added 
to their naturally bright colors by rouge and white cos- 
metics; but I doubt whether many barbarous nations 
liave had any such intention in painting themselves. 

In the fashions of our own dress we see exactly the 
same princijile and the same desire to carry every point 
to an extreme; we exhibit, also, the same spirit of emula- 
tion. But the fashions of savages are far more permanent 
than ours ; and whenever their bodies are artificially mod- 
ified this is necessarily the case. The Arab women of 
the Ui)per Nile occupy about three days in dressing their 
hair; they never imitate other tribes, " but simply vie 
with each other in the superlativeness of their own style." 
Dr. Wilson, in speaking of the compressed skulls of vari- 
ous American races, adds, " Such usages are among the 
least eradicable, and long survive the shock of revolu- 
tions that change dynasties and efi*ace more important 
national peculiarities." " The same principle comes large- 
ly into play in the art of selection; and we can thus un- 
derstand, as I have elsewhere explained,"* the wonderful 
development of all the races of animals and plants which 
are ke])t merely for ornament. Fanciers always wish each 
character to be somewhat increased ; they do not admire 

quoted by Pritchard, ' Phys. Hist, of Mankind,' 3d edit. vol. v. p. 67. 
Lawrence, ' Lectures on Physiolop;y,' p. 337. 

'^ This fact was ascertained in the ' Reise der Novara : Anthropolog. 
Theil,' Dr. Weisbach, 1807, s. 265. 

" ' Smithsonian Institution,' 1863, p. 289. On the fashions of Arab 
women. Sir S. Baker, 'The Nile Tributaries,' 1807, p. 121. 

^8 ' The Variation of Animals and Plants under Domestication,' vol. i. 
p. 214 ; vol. ii. p. 240. 



Chap. XIX.] BEAUTY. 337 

a medium standard ; they certainly do not desire any great 
and abrupt change in the character of their breeds ; they 
admire solely what they are accustomed to behold, but 
they ardently desire to see each characteristic feature a 
little more developed. 

No doubt the perceptive powers of man and the lower 
animals are so 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 no more than why certain bodily sensations 
are agreeable and others disagreeable. It is certainly not 
true that there is in the mind of man any universal stand- 
ard of beauty with respect to the human body. It is, how- 
ever, possible that certain tastes may in the course of time 
become inherited, though I know of 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 this no doubt is true with the more 
civilized nations, in which intellect is highly appreciated ; 
but a nose twice as prominent, or eyes twice as large as 
usual would not be an approach in structure to any of the 
lower animals, and yet would be utterly hideous. The 
men of each race prefer what they are accustomed to be- 
hold ; they cannot endure any great change ; but they like 
variety, and admire each characteristic point carried to a 
moderate extreme.'" Men accustomed to a nearly oval 
face, to straight and regular features, and to bright colors, 
admire, as we Europeans know, these points when strongly 
developed. On the other hand, men accustomed to a 
broad face, with high cheek-bones, a depressed nose, and 

** Schaaff hausen, ' Arohiv fiir Anthropologic,' 1866, s. 164. 

™ 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 with that here given. 
34 



338 SEXUAL SELECTION: MAN. [Part IL 

a black skin, admire these points strongly developed. No 
doul)t characters of all kinds may easily be too niucli de- 
veloped for beauty. Hence a perfect beauty, which im- 
plies many characters modified in a particular manner, will 
in every race be a prodigy. As the great anatomist Bi- 
chat long ago said, if every one were cast in the same 
mould, there would be 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 in our 
women a little exaggerated beyond the then existing com- 
mon standard. 



Chap. XX.] SEXUAL SELECTION: MAN. 339 



CHAPTER XX. 

Secondary Sexual Characters op Man — continued. 

On the EiFects of the Continued Selection of "Women according to a 
Ditt'erent Standard of Beauty in each Eace. — 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 Hus- 
bands. — 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 barbar- 
ous races ornaments, dress, and external appearance, are 
highly valued ; and that the men judge of the beauty of 
their women by widely-different standards. We must 
next inquire whether this preference and the consequent 
selection 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 
sexes. 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 through sexual selection by 
the females would commonly be transferred to the oft- 
spring of both sexes. If any change has thus been ef- 
fected it is almost certain that the different races will have 
been differently modified, as each has its own standard of 
beauty. 

With mankind, especially with savages, many causes 



340 SEXUAL SELECTION: MAN. [Part IL 

interfere with tlic action of sexual selection as far as the 
bodily frame is concerned. Civilized men are largely at- 
tracted by the mental charms of women, by their wealth, 
and especially by their social position ; for men rarely 
marry into a mucli lower rank of life. The men who suc- 
ceed in obtaining the more beautiful women, will not have 
a better chance of leaving a long line of descendants than 
other men with plainer wives, with the exception of the 
few who bequeath their fortunes according to primogeni- 
ture. With respect to the opposite form of selection, 
namely, of the more attractive men by the women, al- 
thougli in civilized nations women 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 largely depends on their intellectual powers and energy, 
or on the fruits of these same powers in their forefathers. 

There is, however, reason to believe that sexual se- 
lection has effected something in certain civilized and 
semi-civilized nations. Many persons are convinced, as it 
appears to me with justice, that the members of our aris- 
tocracy, 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 of beauty, than the 
middle classes ; yet the middle classes are placed under 
equally fivvorable conditions of life for the perfect devel- 
opment of the body. Cook remarks that the superiority 
in personal appearance " which is observable in tlie erees 
or nobles in all the otlier islands (of the Pacific) is found 
in the Sandwich islands ; " but this may be chiefly due to 
their better food and manner of life. 

The old traveller Chardin, in describing the Persians, 
says their "blood is now highly refined by frequent inter- 



Chap. XX.] SEXUAL SELECTION: MAN. 341 

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 Geor- 
gian or Circassian mother." He adds that they inherit 
their beauty, " not from their ancestors, for without the 
above mixture, the men of rank in Persia, who are de- 
scendants 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,** who makes 
this statement, says that the women of San-Giuliano are 
famous at the present day as the most beautiful in the 
island, and are sought by artists as models. But it is ob- 
vious that the evidence in the above cases is doubtful. 

The following case, though relating to savages, is well 
worth giving from its curiosity. Mr. Winwood Reade 
informs 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 worse-looking slaves and to 
sell them." It need hardly be added that with all sav- 
ages female slaves serve as concubines. That this negro 
should have attributed, whether rightly or wrongly, the 
fine appearance of his tribe to the long-continued elimina- 
tion of the ugly women, is not so surprising as it may at 
first appear ; for I have elsewhere shown that negroes 

' These quotations are taken from Lawrence (' Lectures on Physiol- 
ogy,' etc. 1822, p. 393), who attributes the beauty of the upper classes in 
England to the men having long selected the more beautiful women. 

' " Anthi-opologie," 'Revue des Cours Scientifiques,' Oct. 1868, p. 
Y21. 



342 SEXUAL SELECTION: MAN. [Part IL 

fully appreciate the importance of selection in the breed- 
ing of their domestic animals," and I could give from Mr. 
Reade additional evidence on this head. 

On the Causes which prevent or check the Action of 
Sexual Selection with Savages. — The chief causes are, 
firstly, so-called communal marriages or promiscuous in- 
tercourse ; secondly, infanticide, especially of female in- 
fants ; thirdly, early betrothals ; and lastly, the low esti- 
mation 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 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 
courtshij). Now it is asserted that there exist at the pres- 
ent day tribes which practise what Sir J. Lubbock by 
courtesy calls communal marriages ; that is, all the men 
and women in the tribe are husbands and wives to each 
other. The licentiousness of many savages is no doubt 
astonishingly great, but it seems to me that more evi- 
dence is requisite before we fully admit that their existing 
intercourse is absolutely promiscuous. Nevertheless all 
those who have most closely studied the subject,* and 

2 ' The Variation of Animals and Plants under Domestication,' vol. i. 
p. 207 

* Sir J. Lubbock, 'The Origin of Civilization,' 1870, chap. iii. espe- 
cially pp. 60-07. Mr. McLennan, in his extremely valuable work on 
'Primitive Marriage,' 18G5, p. 163, speaks of the union of the sexes "in 
the earliest times as loose, transitory, and in some degree promiscuous." 
Mr. McLennan and Sir J. Lubbock have collected much evidence on the 
extreme licentiousness of savages at the present time. Mr. L. H. Mor- 
gan, in hi.s interesting memoir on the classificatory system of relaticnsliip 
(' Proc. American Acad, of Sciences,' vol. vii. Feb. 1868, p. 475) con- 
cludes that polygamy and all forms of marriage during primeval times 



Chap. XX.] INTERFERING CAUSES. 343 

whose judgment is worth much more than mine, believe 
that communal marriage was the original and universal 
form throughout the world, including the intermarriage 
of brothers and sisters. The indirect evidence in favor 
of this belief is extremely strong, and rests chiefly on the 
terms of relationship which are employed between the 
members of the same tribe, implying a connection with 
the tribe alone, and not with either parent. But the sub- 
ject 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 communal marriages, or where 
the marriage-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 have been completely ignored, especially as 
the women in most savage tribes nurse their infants for a 
long time. Accordingly in many cases the lines of de- 
scent are traced through the mother alone, to the exclusion 
of the father. But in many other cases the terms em- 
ployed 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 bar- 
barous tribe, exposed to all sorts of danger, might be so 
much more important, owing to the need of mutual pro- 
tection 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 that 
this view of the case is by no means sufficient. 

The terms of relationship used in difierent parts of the 
world may be divided, according to the author just 
quoted, into two great classes, the classificatory and de- 
scriptive — the latter being employed by us. It is the 

were essentially unknown. It appears, also, from Sir J. Lubbock's work, 
that Bachofen likewise believes that communal intercourse originally 
prevailed. 



344 SEXUAL SELECTION: MAN. [Part H. 

classificatory system which so strongly leads to the belief 
that communal and other extremely loose forms of mar- 
riage were originally universal. But, as far as I can see, 
there is no net-essity on this ground for believing in abso- 
lutely promiscuous intercourse. Men and women, like 
many of the lower animals, might formerly have entered 
into strict though temporary unions for each birth, and in 
this case nearly as much confusion would have arisen in 
the tenns of relationship as in the case of promiscuous in- 
tercourse. As far as sexual selection is concerned, all that 
is required is that choice should be exerted before the par- 
ents unite, and it signifies little whether the unions last 
for life or only for a season. 

Besides the evidence derived from the terms of rela- 
tionship, other lines of reasoning indicate the former wide 
prevalence of communal marriage. Sir J. Lubbock in- 
geniously accounts ^ for the strange and widely-extended 
habit of exogamy — that is, the men of one tribe always 
taking wives from a distinct tribe — by communism hav- 
ing been the original form of marriage ; so that a man 
never obtained a wnfe for himself unless he captured her 
from a neigliboring 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 might ultimately have be- 
come the universal habit. We can also, according to Sir 
J. Lubbock,* thus imderstand "the necessity of expiation 
for marriage as an infringement of tribal rites, since, ac- 
cording 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 most curious body of facts show- 
ing that in old times high honor was bestowed on women 
who were utterly licentious ; and this, as he explains, is 

' Address to British Association ' On the Social and Religious Condi- 
tion of the Lower Races of Man,' 1870, p. 20. 



Chap. XX.] INTERFEKING CAUSES. 345 

intelligible, if we admit that promiscuous intercourse was 
the aboriginal and therefore long-revered custom of the 
tribe." 

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. McLennan, and Sir J. Lubbock, yet from the forego- 
ing and several other lines of evidence it seems certain 
that the habit of marriage has been gradually developed, 
and that almost promiscuous intercourse was once ex- 
tremely common throughout the world, Nevertheless, 
from the analogy of the lower animals, more particularly 
of those whicli come nearest to man in the series, I cannot 
believe that this habit prevailed at an extremely remote 
period, when man had hardly 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, as 
seems to be the case with the Orang. Several kinds, as 
some of the Indian and American monkeys, are strictly 
monogamous, and associate all the year round with their 
wives. Others are polygamous, as the Gorilla and sev- 
eral American species, and each family lives separate. 
Even when this occurs, the families inhabiting the same 
district are probably to a certain extent social : the Chim- 
panzee, for instance, is occasionally met with in large 
bands. Again, other species are polygamous, but several 
males, each with their own females, live associated in a 

* ' 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. 



346 SEXUAL SELECTION : MAX. [Part IL 

body, as with several species of Baboons.' We may in- 
deed conclude from Avliat we know of the jealousy of all 
male quadrupeds, arnMjd, as many of them are, with spe- 
cial weapons for battling with their rivals, that promis- 
cuous intercourse in a state of nature is extremely improb- 
able. 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 otherwise assist their females and young 
offspring, were to select the more attractive females, this 
would suffice for the work of sexual selection. 

Therefore, if we look far enough back in the stream of 
time, it is extremely improbable that primeval men and 
women lived promiscuously together. Judging from the 
social habits of man as he now exists, and from most sav- 
ages being polygamists, the most probable view is that 
primeval man aboriginally lived in small communities, 
each with as many Avives as he could support and obtain, 
whom he would have jealously guarded against all other 
men. Or he may have lived with several wives by him- 
self, 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, estab- 
lishes himself as the head of the community." * The 
younger males, being thus expelled and wandering about, 
would, when at last successful in finding a partner, pre- 
vent too close interbreeding within the limits of the same 
family. 

' Brehm (' Illust. Thierleben,' B. i. p. 77) says CynoccpJialm hama- 
dryas lives in great troops containing twice as many adult females as 
adult males. See Rengger on American polygamous species, and Owen 
(' Anat. of Vertebrates,' vol. ili. p. 746) on American monogamous spe- 
cies. Other references might be added. 

* Dr. Savage, in ' Boston Journal of Nat. Hist.' vol. v. 1845-47, p. 
423. 



Chap. XX.] INTERFERING CAUSES. 347 

Although savages are now extremely licentious, and 
although communal marriages may formerly have largely 
prevailed, yet many tribes practise some form of mar- 
riage, but of a far more lax nature than with 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, accord- 
ing to Sir J. Lubbock,' " that deatli alone can separate hus- 
band and wife." An intelligent Kandyan chief, of course 
a polygamist, " was perfectly scandalized at the utter 
barbarism of living with only one wife, and never parting 
until separated by death." It was, he said, "just like the 
Wanderoo monkeys." Whether savages who now enter 
into some form of marriage, either polygamous or monog- 
amous, have retained 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 
throughout the world, and there is reason to believe that 
it prevailed much more extensively during former times." 
Barbarians find it difficult to support themselves and their 
children, and it is a simple plan to kill their infants. In 
South America some tribes, as Azara states, formerly de- 
stroyed so many infants of both sexes, that they were on 
the point of extinction. In the Polynesian Islands wom- 
en 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. Wherever infanticide 

9 ' Prehistoric Times,' 1869, p. 424. 

'" Mr. McLennan, 'Primitive Marriage,' 1865. See especially on ex- 
ogamy and infanticide, pp. 130, 138, 165. 



348 SEXUAL SELECTION : MAN. [Part IL 

prevails the struggle for existence will be in so far less 
severe, and all the members of the tribe will have an al- 
most 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 most 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 esti- 
mation set on them and their happier fate, when few in 
number, are assigned by the women themselves, and by 
various observers, as additional motives for infanticide. 
In Australia, where female infanticide is still common, Sir 
G. Grey estimated the proportion of native women to 
men as one to three ; but others say as two to three. In 
a village on the eastern frontier of India, Colonel Maccul- 
loch found not a single female child." 

When, owing to female infanticide, the women of a 
tribe are few in number, the habit of capturing wives 
from neighboring tribes would naturally arise. Sir J. 
Lubbock, however, as we have seen, attributes the prac- 
tice, 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 com- 
munities being very small, in which case, marriageable 
women would often be deficient. That the habit of cap- 
ture was most extensively practised during former times, 
even by the ancestors of civilized nations, is clearly shown 
by the preservation of many curious customs and cere- 
monies, of which Mr. McLennan has given a most inter- 

" Dr. Garland ('Ueber das Aussterben dcr Naturvolker,' 1868) has 
collected much information on infanticide, see especially s. 27, 51, 54. 
Azara ('Voyages,' etc., torn. ii. pp. 94, 116) enters in detail on the mo- 
tives. See also McLennan (ibid. p. 139) for cases in India. 



Chap. XX.] INTERFERING CAUSES. 349 

esting 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 
craft, it is not probable that they would have selected the 
more attractive women ; they would have been too glad 
to have seized on any woman. But as soon as the prac- 
tice 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 have tended to keep all the people inhabiting the 
same country nearly uniform in character ; and this would 
have greatly interfered with the power of sexual selection 
in differentiating the tribes. 

The scarcity of women, consequent on female infanti- 
cide, leads also to another practice, namely, polyandry, 
which is still common in sevei-al parts of the world, and 
which formerly, as Mr. McLennan believes, prevailed al- 
most universally ; but this latter conclusion is doubted by 
Mr. Morgan and Sir J. Lubbock." Whenever two or 
more men are compelled to marry one woman, 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 attrac- 
tive 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 

" ' Primitive Marriage,' p. 208 ; Sir J. Lubbock, ' Origin of Civiliza- 
tion,' p. 100. See also Mr. Morgan, loc. cit., on former prevalence of 
polyandry. 



350 SEXUAL SELECTION: MAN. [Part H. 

personal appearance.'* The very ugly men would perhaps 
altogether fail in getting a wife, or get one later in life, 
but the handsomer men, although the most successful in 
obtaining wives, would not, as far as we can see, leave 
more offspring to inherit their beauty than the less hand- 
some husbands of the same women. 

Early Betrothals and Slavery of Women. — "With many 
savages it is the custom to betroth the females wliile mere 
infants ; and this would effectually prevent preference be- 
ing 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 
fi'om their husbands by the more powerful men ; and this 
often happens in Australia, America, and other parts of 
the world. The same consequences with reference to 
sexual selection would to a certain extent follow when 
women are valued almost exclusively as slaves or beasts 
of burden, as is the case with most 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 would greatly interfere with, or completely stop, 
the action of sexual selection. On the other hand, the 
conditions of life to which savages are exposed, and some 
of their habits, are favorable to natural selection ; and 
this always comes into play together with sexual selec- 
tion. Savages are known to suffer severely from recur- 
rent famines ; they do not increase their food by artificial 
means ; they rarely refrain from marriage,'* and generally 

13 « Voyaf^cs,' etc., torn. ii. pp. 92-95. 

" Burchell says (' Travels in South Africa,' vol. ii. 1824, p. 58), that 
among the wild nations of Southern Africa, neither men nor women ever 
pass their lives in a state of celibacy. Azara (' Voyages dans I'Amerique 



Chap. XX.] MANNER OF ACTION. 351 

marry young. Consequently they must be subjected to 
occasional hard struggles for existence, and the favored 
individuals will alone survive. 

Turning to primeval times when men had only doubt- 
fully attained the rank of manhood, they would probably 
have lived, as already stated, either as polygamists or 
temporarily as monogamists. Their intercourse, judging 
from analogy, would not then have been promiscuous. 
They would, no doubt, have defended their females to the 
best of their power from enemies of all kinds, and would 
probably have hunted for their subsistence, as well as for 
that of their oftspring. The most powerful and able 
males would have succeeded best in the struggle for life 
and in obtaining attractive females. At this early period 
the progenitors of man, from having only feeble powers 
of reason, would not have looked forward to distant con- 
tingencies. They would have been governed more by 
their instincts and even less by their reason than are 
savages at the present day. They would not at that 
period have partially lost one of the strongest of all in- 
stincts, common to all the lower animals, namely, the love 
of their young offspring; and consequently they would 
not have practised infanticide. There would have been 
no ai'tificial scarcity of women, and polyandry would not 
have been followed ; there would have been no early be- 
trothals ; women would not have been valued as mere 
slaves ; both sexes, if the females as well as the males 
were permitted to exert any choice, would have chosen 
their partners, not for mental charms, or property, or 
social position, but almost solely from external appear- 
ance. All the adults would have married or paired, and 
all the offspring, as far as that was possible, would have 
been reared; so that the struggle for existence would 

Merid.' torn. ii. 1809, p. 21) makes precisely the same remark in regard 
to the wild Indians of South America. 



352 SEXUAL SELECTION: MAN. [Part IL 

have been periodically severe to an extreme degree. 
Thus during those primordial times all the conditi(ms for 
sexual selection would have been much more favorable 
than at a later period, when man had advanced in his 
intellectual powers, but had retrograded 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 much more powerful at a very 
remote period than at the present day. 

On the Manner of Action of Sexual Selection with 
3fankincl. — With primeval men under the favorable con- 
ditions just stated, and with those savages who at the 
present time enter into any marriage-tie (but subject to 
greater or less interference according as the habits of 
female infanticide, early betrothals, etc., are more or less 
practised), sexual selection will probably have acted in 
the following manner : The strongest and most vigorous 
men — those who could best defend and hunt for their 
families, and during later times the chiefs or head-men — 
those who were provided with the best weapons and who 
possessed the most property, such as a larger number of 
dogs or other animals, would have succeeded in rearing a 
greater average number of offspring, than would the 
weaker, poorer, and lower members of the same tribes. 
There can, also, be no doubt that such men would gener- 
ally have been 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. Un- 
til recently, as I hear from Mr. Mantell, almost every girl 
in New Zealand, who was pretty, or promised to be 
pretty, was tapu to some chief. With tlie Kaffi-es, as Mr. 
C. Hamilton states," " the chiefs generally have the pick 

'' ' Authropological Review,' Jan. 1870, p. xvi. 



Chap. XX.] MANNER OF ACTION. 353 

of the women for many miles round, and are most perse- 
vering in establishing or confirming their privilege." We 
have seen that each race has its own style of beauty, and 
we know that it is natural to man to admire each charac- 
teristic point in his domestic animals, dress, ornaments, 
and personal appearance, when carried a little beyond the 
common standard. If, then, the several foregoing proposi- 
tions be admitted, and I cannot see that they are doubtful, 
it would be an inexplicable 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 gen- 
erations modify to a certain extent the chai'acter of the 
tribe. 

With our domestic animals, when a foreign breed is 
introduced 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, 
whenever the means of comparison exist, a greater or less 
amount of change. This follows from unconscious selec- 
tion during a long series of generations — that is, the pres- 
ervation of the most approved individuals — ^without any 
wish or expectation of such a result on the part of the 
breeder. So, again, if two careful breeders rear during 
many years animals of the same family, and do not com- 
pare them together or with a common standard, the ani- 
mals are found after a time to have become, to the surprise 
of their owners, slightly different." Each breeder has im- 
pressed, as Von Nathusius well expresses it, the character 
of his own mind — ^his own taste and judgment — on his 
animals. What reason, then, can be assigned why similar 
results should not follow from the long-continued selection 
of the most admired women by those men of each tribe 

'* ' The Variation of Animals and Plants under Domestication,' voL 
ii. pp. 210-21'7. 



354 SEXUAL SELECTION: MAN. [Part IL 

who were able to rear to maturity the greater nuniher of 
cliihlren ? This would be unconscious selection, lor an 
eliect would be produced, independently of any wish or 
expectation on the part of the men who preferred certain 
women to others. 

Let us sujipose the members of a tribe, in which some 
fomi of marriage was practised, to spread over an unoc- 
cujjied continent ; they would soon split up into distinct 
hordes, which would be separated irom each other by 
various barriers, and still more effectuall)^ by the incessant 
wars between all barbarous nations. The hordes would 
thus be exposed to slightly difterent conditions and habits 
of life, and would sooner or later come to difter 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 savages 
preferring certain women to others. Thus the differences 
between the tribes, at first very slight, would gradually 
and inevitably be increased to a greater and greater 
degree. 

With animals in a state of nature, many characters 
proper to the males, such assize, 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 

" An ingenious writer argues, from a comparison of the pictures of 
Raphael, Rubens, and modem French artists, that the idea of beauty is 
not absolutely the same even throughout Europe : see the ' Lives of 
Haydn and Mozart,' by M. Pombet, Eng. translat. p. 2*78. 



Chap. XX.] MANNER OF ACTION. 355 

animals, such as bright colors and various ornaments, have 
been acquired by the more attractive males having been 
preferred by the females. There are, however, exceptional 
cases in which the males, instead of having been the se- 
lected, have been the selectors. We recognize such cases 
by the females having been rendered more highly orna- 
mented than the males — their ornamental characters having 
been transmitted exclusively or chiefly to their female 
offspring. One such case has been described in the order 
to which man belongs, namely, with 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 their 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 decked this 
sex in order to charm the females. As women have long 
been selected for beauty, it is not surprising that some of 
the successive variations should have been transmitted in 
a limited manner ; and consequently that women should 
have transmitted their beauty in a somewhat higher degree 
to their female than to their male offspring. Hence women 
have become more beautiful, as most persons will admit, 
than men. Women, however, certainly transmit most of 
their characters, including beauty, to their offspring of both 
sexes ; so that the continued preference by the men of 
each race of the more attractive women, according to their 
standard of taste, would tend to modify in the same man- 
ner 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 most common), 



35G SEXUAL SELECTION : MAX. [Part II 

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 the j)ro- 
genitors of man. Man in all probability owes his beard, 
and perhaps some other characters, to inheritance from an 
ancient progenitor who gained in this manner his orna- 
ments. But this fonn 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 lovers, or of afterward changing their hus- 
bands, 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. 

Ilearne describes how a woman in one of the tribes of 
Arctic America repeatedly ran away from her husband 
and joined a beloved man ; and with the Charruas of South 
America, as Azara states, the power of divorce is perfectly 
free. With the Abiponcs, when a man chooses a wife he 
bargains with the parents about the price. But, " it fre- 
quently ^happens that the girl rescinds what has been 
agreed upon between the parents and the bridegroom, 
obstinately rejecting the very mention of marriage." She 
often runs away, liides herself, and thus eludes the bride- 
groom. 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 pro- 
tect her ; if, however, she is satisfied, the matter is settled 
forthwith." In Tierra del Fuego a young man first obtains 
the consent of the parents by doing them some service, and 
then he attempts to carry off the girl ; " but if she is un- 
willing, she hides herself in the woods until her admirer is 
heartily tired of looking for her, and gives up the pursuit ; 
but this seldom happens." "With the Calmucks there is a 
regular race between the bride and bridegroom, the for- 



Chap. XX.] MANNER OF ACTION. 357 

mer 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." So with the wild tribes of the 
Malay archipelago there is a similar racing-match ; and it 
appears from M. Bourien's account, as Sir J. Lubbock re- 
marks, 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." 

Turning to Africa : the Kaffres buy their wives, and 
girls are severely beaten by their fathers if they will not 
accept a chosen husband ; yet it is manifest from many 
facts given by the Rev. Mr. Shooter, that they have con- 
siderable power of choice. Thus very ugly, though rich 
men, have been known to fail in getting wives. The girls, 
before consenting to be betrothed, compel the men to show 
themselves oif, first in front and then behind, and " exhibit 
their paces." They have been known to propose to a 
man, and they not rarely run away with a favored lover. 
With the degraded Bushwomen of South 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 in- 
forms me that " the women, at least amortg the more in- 
telligent pagan tribes, have no difiiculty in getting the 
husbands whom they may desire, although it is considered 
unwomanly to ask a man to marry them. They are quite 

^8 Azara, 'Voyages,' etc. torn. ii. p. 23. Dobrizhoffer, 'An account 
of the Abipones,' vol. ii. 1822, p. 20Y. Williams on the Fiji Islanders, 
as quoted by Lubbock, ' Origin of Civilization,' 1870, p. 79. On the 
Fuegians, King and Fitz Roy, ' Voyages of the Adventure and Beagle,^ 
vol. ii. 1839, p. 182. On the Calmucks, quoted by McLeunan, 'Primi- 
tive Marriage,' 1865, p. 32. On the Malays, Lubbock, ibid. p. 76. The 
Rev. J. Shooter, 'On the Kafirs of Natal,' 1857,' pp. 52-60. On the 
Bushwomen, Burchell, 'Travels in South Africa,' vol. ii. 1824, p. 59. 



358 SEXUAL SELECTION: MAN. [Part H. 

capable of falling in love, and of forming tender, passion- 
ate, and faithful attachments." 

We thus see that witli savages the women are not in 
quite so abject a state in relation to marriage as has often 
been supposed. They can temj)t the men whom they 
prefer, and can sometimes reject those whom they dis- 
like, either before or after marriage. Preference on the 
part of the women, steadily acting in any one direc- 
tion, would ultimately affect the character of the tribe ; 
for the women would generally choose not merely the 
handsomer 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 well en- 
dowed. The same result would obviously follow in a still 
more marked manner if there Avas selection on both sides ; 
that is, if the more attractive and at the same time more 
powerful men were to prefer, and were prefeiTcd by, the 
more attractive women. And these two forms of selection 
seem actually to have occurred, whether or not simulta- 
neously, with mankind, especially during the earlier pe- 
riods of our long history. 

We will now consider in a little more detail, relatively 
to sexual selection, some of the characters which distin- 
guish the several races of man from each other and from 
the lower animals, namely, the more or less complete ab- 
sence of hair from 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 differ- 
ent races, as we have seen in the last chapter how differ- 
ent is the standard of beauty in these respects. These 
characters will therefoi'e probably have been acted on 
through sexual selection ; but we have no means of judging, 
as far as I can see, whether they have been acted on 
chiefly througli tlie male or female side. The musical 
faculties of man have likewise been already discussed. 



Chap. XX.] ABSENCE OF HAIR. 359 

Absence of Hair on the Body^ and its Development on 
the Face and Head. — From the presence of the "woolly 
hair or lanugo on the human foetus, 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 hair 
is an inconvenience and probably an injury to man even 
under a hot climate, for he is thus exjjosed to sudden 
chills, especially during wet weather. As Mr. Wallace 
remarks, the natives in all countries are glad to protect 
their naked backs and shoulders with some slight cover- 
ing. No one supposes that the nakedness of the skin is 
any direct advantage to man, so that his body cannot have 
been divested of hair through natural selection," Nor 
have we any grounds for believing, as shown in a for- 
mer chapter, that this can be due to the direct action of the 
conditions to which man has long been exposed, or that 
it is the result of correlated development. 

The absence of hair on the body is to a certain extent 
a secondary sexual character ; for in all parts of the world 
women are less hairy than men. Therefore we may rea- 

" 'Contributions to the Theory of Natural Selection,' 18*70, p. 346. 
Mr. Wallace believes (p. 350) " that some intelligent power has guided 
or determined the development of man ; " and he considers the hair- 
less condition of the skin as coming under this head. The Rev. T. R. 
Stabbing, in commenting on this view (' Transactions of Devonshire 
Assoc, for Science,' 1870) remarks that, had Mr. Wallace " employed 
his usual ingenuity on the question of man's hairless skin, he might have 
seen the possibility of its selection through its superior beauty or the 
health attaching to superior cleanliness. At any rate it is surprising 
that he should picture to himself a superior intelligence plucking the 
hair from the backs of savage men (to whom, according to his own ac- 
count, it would have been useful and beneficial), in order that the de- 
scendants of the poor shorn wretches might, after many deaths from cold 
and damp in the course of many generations," have been forced to raise 
themselves in the scale of civilization through the practice of various 
arts, in the manner indicated by Mr. Wallace. 



360 SEXUAL SELECTION: MAN, [Part H. 

sonably suspect that tliis is a character whicli has been 
gained through sexual selection. We know that the faces 
of several species of monkeys, and large surfaces at the pos- 
terior end of the body in other species, have been denuded 
of hair; and this we may safely attribute to sexual selec- 
tion, 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. As 
these animals gradually reach maturity the naked surfaces, 
as I am informed by Mr. Bartlett, grow larger, relatively 
to the size of their bodies. The hair, however, appears to 
have been removed in these cases, not for the sake of nu- 
dity, but that the color of the skin should be more fully 
displayed. So, again, with many birds the head and 
neck have been divested of feathers through sexual 
selection, for the sake of exhibiting the brightly-colored 
skin. 

As woman has a less hairy body than man, and as 
this character is common to all races, we may conclude 
that our female semi-human progenitors were probably 
first partially divested of hair; and that this occurred at 
an extremely remote j^eriod before the several races had 
diverged from a common stock. As our female progeni- 
tors gradually acquired this new character of nudity, they 
must have transmitted it in an almost equal degree to 
their young offspring of both sexes ; so that its transmis- 
sion, as in the case of many ornaments with mammals and 
birds, has not been limited either by age or sex. There is 
nothing surprising in a partial loss of hair having been 
esteemed as ornamental by the ape-like progenitors of 
man, for we have seen that with animals of all kinds in- 
numerable strange characters have been thus esteemed, 
and have consequently been modified through sexual 
selection. Nor is it surprising that a character in a slight 
degree injurious should have been thus acquired; for we 



Chap. XX.] ABSENCE OF HAIR. 361 

know that this is the case with the plumes of some birds, 
and with the horns of some stags. 

The females of certain anthropoid apes, as stated in a 
former chapter, are somewhat less hairy on the under sur- 
face than are the males ; and here we have what might 
have afforded a commencement for the process of denu- 
dation. With respect to the completion of the process 
through sexual selection, it is well to bear in mind the 
New-Zealand proverb, " There is no woman for a hairy 
man," All who have seen photographs of the Siamese 
hairy family will admit how ludicrously hideous is the 
opposite extreme of excessive hairiness. Hence the King 
of Siam had to bribe a man to marry the first hairy wom- 
an in the family, who transmitted this character to her 
young offspring of both sexes.^" 

Some races are much more hairy than others, espe- 
cially on the male side ; but it must not be assumed that 
the more hairy races, for instance Europeans, have re- 
tained a primordial condition more completely than have 
the naked races, such as the Calmucks or Americans. It 
is a more probable view that the hairiness of the former 
is due to partial reversion, for characters which have long 
been inherited are always apt to return. It does not ap- 
pear that a cold climate has been influential in leading to 
this kind of reversion ; excepting perhaps with the ne- 
groes, who have been reared during several generations, 
in the United States," and possibly with the Ainos, who 

2" ' The Variation of Animals and Plants under Domestication,' vol. ii. 
1868, p. 327. 

** 'Investigations into Military and Anthropological Statistics of 
American Soldiers,' by B. A. Gould, 1869 ; p. 568 : Observations were 
carefully made on the pilosity of 2,129 black and colored soldiers, while 
they were bathing ; and, by looking to the published table, " it is mani- 
fest at a glance that there is but little, if any, difference 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 
35 



302 SEXUAL SELECTION: MAN. [Part IL 

inhabit the nortlicrn islands of the Japan archipelago. 
But the laws of inheritance are so complex that we can 
seldom understand their action. If the greater hairiness 
of certain races he the result of reversion, unchecked by 
any form of selection, the extreme variability of this char- 
acter, even within the limits of the same race, ceases to be 
remarkable. 

With respect to the beard, if we turn to our best 
guide, namely the Quadrumana, we find beards equally 
well developed in both sexes of many species, but in 
others, 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 ac- 
quired their beards as an ornament through sexual selec- 
tion, transmitting them in most cases, in an equal or near- 
ly equal degree, to their offspring of both sexes. We 
know from Eschricht " that, with mankind, the female as 
well as the male foetus is furnished with much hair on the 
face, especially round the mouth ; and this indicates that 
we are descended from a progenitor of which both sexes 
were bearded. It appears therefore at first sight prob- 
able that man has retained his beard from a very early 
period, while woman lost her beard at the same time 
when her body became almost completely divested of 
hair. Even the color of the beard with mankind seems to 

smootli bodies. It should be particularly observed that pure blacks 
and mulattoes were included in the above enumeration ; and this is an 
unfortunate circumstance, as in accordance with the principle, the truth 
o*" which I have elsewhere proved, crossed races would be eminently 
liable to revert to the primordial hairy character of their early ape-like 
progenitors. 

** " Ueber die Richtung dcr Haare am Menschlichen Ktirper," in 
Miiller's ' Archiv fiir Anat. und Phys.' 1837, s. 40. 



Chap. XX.] BEARDS. 363 

have been inherited from an ape-like progenitor; for when 
there is any diiference in tint between the hair of the head 
and the beard, the latter is lighter colored in all monkeys 
and in man. There is less improbability in <;he men of 
the bearded races having retained their beards from pri- 
mordial times, than in the case of the hair on the body ; 
for with those Quadrumana, in which the male has a 
larger beard than that of the female, it is fully developed 
only at maturity, and the later stages of development 
may have been exclusively transmitted to mankind. We 
should then see what is actually the case, namely, our 
male children, before they arrive at maturity, as destitute 
of beards as are our female children. On the other hand, 
the great variability of the beard within the limits of the 
same race and in different races indicates that reversion 
has come into action. However this may be, we must 
not overlook the part which sexual selection may have 
played even during 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 pride in their beards. The women, no doubt, 
participate in these feelings, and if so sexual selection can 
hardly have failed to have effected something in the 
course of later times.''^ 

^' Mr. Sproat (' Scenes and Studies of Savage Life,' 1868, p. 25) sug- 
gests, with reference to the beardless natives of Vancouver's Island, that 
the custom of plucking out the hairs on the face, " continued from one 
generation to another, would perhaps at last produce a race distinguish 
able by a thin and straggling growth of beard." But the custom would 
not have arisen until the beard had already become, from some inde- 
pendent cause, greatly, reduced. Nor have we any direct evidence that 
the continued eradication of the hair would lead to any inherited effect. 
Owing to this cause of doubt, I have not hitherto alluded to the belief 
held by some distinguished ethnologists, for instance M. Gosse of Gene- 
va, that artificial modifications of the skull tend to be inherited. I have 



304 SEXUAL SELECTION: MAN. [Part H. 

It is rather difficult to form a judgment how the long 
hair on our heads became developed. Eschricht "* states 
that in the human fa»tus the hair on the face during the 
fifth month is longer than that on the head ; and this in- 
dicates that our semi-human progenitors were not fur- 
nished with long tresses, which consequently must have 
been a late acquisition. This is likewise 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 with the American 
natives it not rarely reaches to the ground. Some species 
of Semnopithecus have their heads covered with moder- 
ately long hair, and this probably serves as an ornament 
and was acquired through sexual selection. The same 
view may 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 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 best kind of evidence that 
the color of the skin has been modified through sexual 
selection is wanting in the case of mankind ; for the sexes 
do not difter in tliis respect, or only slightly and doubt- 
fully. On the other hand, we know from many facts al- 
ready given that the color of the skin is regarded by the 
men of all races as a highly-important element in their 
beauty ; so that it is a character which would be likely to 
be modified through selection, as has occurred in innumer- 

no wish to dispute this conclusion ; and we now know from Dr. Brown- 
Sequard's remarkable observations, especially those recently communi- 
cated (1870) to the British Association, that with guinea-pigs the effects 
of oi^erations are inherited. 

" 'Uebcr die UiclitunK,' ibid. s. 40. 



Chap. XX.] SUMMARY. 365 

able instances with the lower animals. It seems at first 
sight a monstrous supposition that the jet blackness of 
the negro has been gained through sexual selection ; but 
this view is supported by various analogies, and we know 
that negroes admire their own blackness. With mam- 
mals, when the sexes difter 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 shall be transmitted to both sexes or to one 
alone. The resemblance of Pithecia satanas with his jet- 
black skin, white rolling eyeballs, and hair parted on the 
top of the head, to a negro in miniature, is almost ludi- 
crous. 

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 good reason to believe that the red, 
blue, orange, almost white and black tints of their skin, 
even when common to both sexes, and the bright colors 
of their fur, as well as the ornamental tufts of hair about 
the head, have all been acquired tlirough sexual selection. 
As the newly-born infants of the most distinct races do 
not differ nearly as much in color as do the adults, al- 
though their bodies are completely destitute of hair, we 
have some slight indication that the tints of the different 
races were acquired subsequently to the removal of the 
hair, which, as before stated, must have occurred at a 
very early period. 

Summary. — We may conclude that the greater size, 
strength, courage, pugnacity, and even energy of man, in 
comparison with the same qualities in woman, were ac- 
quired during primeval times, and have subsequently been 
augmented, chiefly through the contests of rival males for 
the possession of the females. The greater intellectual 
vigor and power of invention in man are probably due to 



3G6 SEXUAL SELECTION: MAN. [Part IL 

natural selection combined with the inherited effects of 
hahit, for the most able men will have succeeded best in 
defending and providing for tliemselves, their wives and 
oflsj)ring. As far as the extreme intricacy of the subject 
permits us to judge, it appears that our male ape-like pro- 
genitors acquired their beards as an ornament to charm or 
excite the opposite sex, and transmitted them to man as 
he now exists. The females apparently were first de- 
nuded of hair in like manner as a sexual ornament ; but 
they transmitted this character almost equally to both 
sexes. It is not improbable that the females were modi- 
fied in other respects for the same purpose and through 
the same means ; so that women have acquired sweeter 
voices and become more beautiful than men. 

It deserves particular attention that with mankind all 
the conditions for sexual selection were much more favor- 
able, during a very early period, when man had only just 
attained to the rank of manhood, than during later times. 
For he w^ould then, as we may safely conclude, have been 
guided more by his instinctive passions, and less by fore- 
sight or reason. He would not then have been so utterly 
licentious as many savages now are ; and each male woukl 
have jealously guarded his wife or wives. lie would not 
then have practised infanticide ; 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 con- 
cerned, in chief part during a very remote epoch ; and 
this conclusion throws light on the remarkable fact tliat 
at the most ancient period, of which we liave as yet ob- 
tained 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 
Belection has played in the history of man, want scien- 



Chap. XX.J SUMMARY. 367 

tific precision. He who does not admit this agency in 
the case of the lower animals, will properly disregard 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, however, been shown that 
the races of man differ from each other and from their 
nearest allies among the lower animals, in certain charac- 
ters which are of no service to them in their ordinary 
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, etc. Hence these and other such points could 
hardly fail to have been slowly and gradually exagger- 
ated from the more powerful and able men in each tribe, 
who would succeed in rearino- the largest number of off- 
spring, having selected during many generations as their 
wives the most strongly-characterized and therefore most 
attractive women. For my own part I conclude that of 
all the causes which have led to the differences in exter- 
nal appearance between the races of man, and to a certain 
extent between man and the lower animals, sexual selec- 
tion has been by far the most efficient. 



3G8 GENERAL SUMMARY [I-aut II. 



CHAPTER XXI. 

General Summary and Conclusion. 

Main Conclusion that Man is descended from some Lower Form. — Man- 
ner of Development. — Genealogy of Man. — Intellectual and Moral 
Faculties. — Sexual Selection. — Concluding Remarks. 

A BRIEF summary will here 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 
speculative, 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 long endure ; 
but false views, if supported by some evidence, do little 
harm, as 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 arrived at in this work, and now 
held by many naturalists who are well competent to form 
a sound judgment, is that man is descended from some 
less highly-organized form. The grounds upon \Yhich this 
conclusion rests will never be shaken, for the close simi- 
larity between man and the lower animals in embryonic 
development, as well as in innumerable points of structure 



Chap. XXI.] AND CONCLUDING REMARKS. 369 

and constitution, both of high and of the most trifling im- 
portance — the rudiments which he retains, and the abnor- 
mal reversions to which he is occasionally liable — are facts 
which cannot be disputed. They have long been known, 
but until recently they told lis nothing with respect to 
the origin of man. Now, when viewed by the light of 
our knowledge of the whole organic Avorld, their meaning 
is unmistakable. The great principle of evolution stands 
up clear and firm, when these groups of facts are consid- 
ered in connection with others, such as the mutual afiini- 
ties of the members of the same group, their geographical 
distribution in past and present times, and their geological 
succession. It is incredible that all these facts should 
speak falsely. He who is not content to look, like a sav- 
age, 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 re- 
semblance of the embryo of man to that, for instance, of 
a dog — the construction of his skull, limbs, and whole 
frame, independently of the uses to which the parts may 
be put, on the same plan with that of other mammals — 
the occasional reappearance of various structures, for in- 
stance, of several distinct muscles, which man does not 
normally possess, but w^hich are common to the Quadru- 
mana — and a crowd of analogous facts — all point in the 
plainest manner to the conclusion that man is the co-de- 
scendant 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 facul- 
ties. These differences 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 
occasionally subjected to a severe struggle for existence, 



370 GENERAL SUMMARY [Part H. 

and natural selection will have effected whatever lies with- 
in its scope. A succession of strongly-marked variations 
of a similar nature arc by no means requisite; slight 
fluctuating ditfcrences in the individual suflice for the 
work of natural selection. 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 selection. Modifications formerly of importance, 
though no longer of any special use, will be long inher- 
ited. When one part is modified, other parts will change 
through the principle of correlation, of which we have in- 
stances in many cm-ious cases of correlated monstrosities. 
Something may be attributed to the direct and definite 
action of the surrounding conditions of life, such as abun- 
dant food, heat, or moisture ; and lastly, many characters 
of slight physiological importance, some indeed of con- 
siderable importance, have been gained through sexual 
selection. 

No doubt man, as well as every other animal, presents 
structures which, as far as we can judge with our little 
knowledge, are not now of any service to him, nor have 
been so during any former period of his existence, either 
in relation to his general conditions of life, or 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 productions, and 
if the unknown causes which produce them were to act 
more uniformly, they would probably become common to 
all the individuals of the species. We may hope hereafter 
to understand something about the causes of such occa- 
sional modifications, especially through the study of mon- 
strosities : hence the labors of experimentalists, such as 
those of M. Camille Dareste, are full of promise for the 



Chap. XXL] AND CONCLUDING REMARKS. 37I 

future. In the greater number of cases, we can only say 
that the cause of each slight variation and of each mon- 
strosity lies much more in the nature or constitution of 
the organism, than in the nature of the surrounding con- 
ditions ; though new and changed conditions certainly 
play an important part in exciting organic changes of all 
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 appropriately called, subspecies. Some of these, 
for instance, the Negro and European, are so distinct that, 
if specimens had been brought to a naturalist without any 
further information, they would undoubtedly have been 
considered by him as good and true species. Neverthe- 
less all the races agree in so many unimportant details of 
structure and in so many mental peculiarities, that these 
can be accounted for only through inheritance from a com- 
mon progenitor ; and a progenitor thus characterized 
would probably have deserved to rank as man. 

It must not "be supposed that the divergence of each 
race from the other races, and of all the races from a com- 
mon stock, can be traced back to any one pair of progeni- 
tors. On the contrary, at every stage in the process of 
modification, all the individuals which were in any way 
best fitted for their 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 
and neglects all the inferior individuals. 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 



372 GENERAL SUMMARY [Part II. 

from the nature of the organism and tlie action of the sur- 
rounding conditions, or from clianged habits of life, no 
single i)air will have been modified in a much greater de- 
gree than the other pairs which inhabit the same country, 
for all will have been continually blended through free 
intercrossing. 

I>y 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 
fomier condition of our early progenitors ; and can ap- 
proximately place them in their proper position in the 
zoological series. We thus learn that man is descended 
from a hairy quadruped, furnished with a tail and pointed 
ears, probably aboreal in its habits, and an inhabitant of 
the Old World. This creature, if its whole structure had 
been examined by a naturalist, would have been classed 
among the Quadruniana, as surely as would the common 
and still more ancient progenitor of the Old and New 
World monkeys. The Qnadrumana and all the higher 
mammals nre probably derived from an ancient marsupial 
animal, and this through a long line of diversified forms, 
either from some reptile-like or some amphibian-like crea- 
ture, and this again from some fish-like animal. In the 
dim obscurity of the jiast we can see that the early pro- 
genitor 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 developed. This animal seems to have been more 
like the larvie of our existing marine Ascidians than any 
other known form. 

Tlio greatest difficulty wliich presents itself, when we 
are driven to the above conclusion on the origin of man, 



Chap. XXI.] AND CONCLUDING REMARKS. 373 

is the high standard of intellectual power and of moral 
disposition which he has attained. But every one who 
admits the general principle of evolution, must see that 
the mental powers of the higher animals, which are the 
same in kind with those of mankind, though so different 
in degree, are capable of advancement. Thus the interval 
between the mental powers of one of the higher apes and 
of a fish, or between those of an ant and scale-insect, is 
immense. The development of these powers in animals 
does not offer any special difficulty ; for with our domesti- 
cated animals, the mental faculties are certainly variable, 
and the variations are inherited. No one doubts that 
these faculties are of the utmost importance to animals in 
a state of nature. Therefore the conditions are favorable 
for their development through natural selection. The 
same ccmclusion may be extended to man ; the intellect 
must have been all-important to him, even at a very 
remote period, enabling him to use language, to invent 
and make weapons, tools, traps, etc. ; by which means, in 
combination with 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, through a previous considerable 
advance, the half-art and half-instinct of language came 
into use ; for the continued use of language will have re- 
acted on the brain, and produced an inherited effect ; and 
this again will have reacted on the improvement of lan- 
guage. The large size of the brain in man, in comparison 
with that of the lower animals, relatively to the size of 
their bodies, may be attributed in chief part, as Mr. 
Chauncey Wright has well remarked,' to the early use of 
some simple form of language — that wondei-ful engine 
which affixes signs to all sorts of objects and qualities, 

1 On the " Limits of Natural Selection," in the ' North American Re- 
view,' Oct. 1870, p. 295. 



374 GENERAL SUMMARY [Part II. 

and excites trains of ihouglit which would never arise 
from the mere impression of the senses, and if they did 
arise could not be followed out. The higher intellectual 
powers of man, such as those of ratiocination, abstraction, 
self-consciousness, etc., will have followed from the con- 
tinued improvement of other mental faculties ; but with- 
out considerable culture of the mind, both in the race and 
in the individual, it is doubtful whether these high powers 
would be exercised, and thus fully attained. 

The development of the moral qualities is a more in- 
teresting and difficult problem. Their foundation lies in 
the social instincts, including in this term the family ties. 
These instincts are of a highly-complex nature, and in the 
case of the lower animals give special tendencies toward 
certain definite actions ; but the more important elements 
for us are love, and the distinct emotion of sympathy. 
Animals endowed with the social instincts take pleasure 
in each other's company, warn each other of danger, de- 
fend and aid each other in many ways. These instincts 
are not extended to all the individuals of the species, but 
only to those of the same community. As thej' are high- 
ly beneficial to the species, they have in all probability 
been acquired through natural selection. 

A moral being is one who is capable of comparing his 
past and future actions and motives — of approving of 
some and disapproving of others ; and the fact that man 
is the one being who with certainty can be thus desig- 
nated makes the greatest of all distinctions between him 
and the lower animals. But in our third chapter I have 
endeavored to show that the moral sense follows, firstly, 
from the enduring and always present nature of the 
social instincts, in which respect man agrees with the 
lower animals; and secondly, from his mental faculties 
being highly active arid his imju'essions of past events 
extremely vivid, in which respects he differs from the 



Chap. XXI.] AND CONCLUDING REMARKS. 375 

lower animals. Owing to this condition of mind, man 
cannot avoid looking backward and comparing the im- 
pressions of past events and actions. He also continually 
looks forward. Hence after some temporary desire or- 
passion has mastered his social instincts, he will reflect 
and compare the now weakened impression of such past 
impulses with the ever-present social instinct ; and he 
will then feel that sense of dissatisfaction which all unsat- 
isfied instincts leave behind them. Consequently he re- 
solves to act differently for the future — and this is con- 
science. Any instinct which is permanently 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 conduct, 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 himting it. 

Social animals are partly impelled by a wish to aid the 
membei's of the same 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 being able to express his 
desires by words, which thus become the guide to the aid 
required and bestowed. The motive to give aid is like- 
wise somewhat modified in man : it no longer consists 
solely of a blind instinctive impulse, but is largely influ- 
enced by the praise or blame of his fellow-men. Both 
the appreciation and the bestowal of praise and blame 
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 instinct, is also much 
strengthened by exercise or habit. As all men desire 
their own happiness, praise or blame is bestowed on 
actions and motives, according as they lead to this end ; 



376 GENERAL SUMMARY [Part II. 

and, as liappincss is an essential part of the general good, 
the greatest-happiness principle indirectly serves as a 
nearly safe standard of right and wrong. As the reason- 
ing powers advance and experience is gained, the more 
remote 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, from coming within 
the scope of public opinion, receive praise, and their 
opposites receive blame. But with the less civilized 
nations reason often errs, and many bad customs and base 
superstitions come within the same scope, and consequent- 
ly are esteemed as high virtues, and their breach as heavy 
crimes. 

The moral fticulties are generally esteemed, and with 
justice, as of higher value than the intellectual powers. 
But we should always 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 fact affords the strongest argument for educating 
and stimulating in all possible ways the intellectual fac- 
ulties 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 of men more vivid and strengthens the habit 
of recalling and comparing jiast impressions, will make 
the conscience more sensitive, and may even compensate 
to a certain extent for weak social affections and sym- 
pathies. 

The moral nature of man has reached the highest 
standard as yet .attained, partly through the advance- 
ment of the reasoning powers and consequently of a just 
])ublic opinion, but especially through the sympathies 
being rendered more tender and widely diffused tlirough 
the effects of habit, example, instruction, and reflection. 



CuAP. XXI.] AND CONCLUDING REMARKS. 377 

It is not improbable that virtuous tendencies may through 
long practice be inherited. With the more civilized races, 
the conviction of the existence of an all-seeing Deity has 
had a potent influence on the advancement of morality. 
Ultimately man no longer accepts the praise or blame of 
his fellows as his chief guide, though few escape this influ- 
ence, but his habitual convictions controlled by reason 
afibrd him the safest rule. His conscience then becomes 
his supreme judge and monitor. Nevertheless the first 
foundation or origin of the moral sense lies in the social 
instincts, including sympathy ; and these instincts no 
doubt were 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 other hand, a belief 
in all-pervading spiritual agencies seems to be universal ; 
and apparently follows from a considerable advance in the 
reasoning powers of man, 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 exist- 
ence. But this is a rash argument, as we should thus be 
compelled to believe in the existence of many cruel and 
malignant spirits, possessing only a little more power 
than man ; for the belief in them is far more general than 
of a beneficent Deity. The idea of a universal and benefi- 
cent Creator of the universe 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 
lowly-organized form, will naturally ask, " How does this 



378 GENERAL SUMMARY [Part II. 

bear on llie belief iu the immortality of the soul?" The 
barbarous races of man, as Sir J. Lubbock has shown, 
possess no clear belief of this kind ; but arguments de- 
rived 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 the minute germinal vesicle to the child 
either before or after birth, man becomes an immortal 
being ; and there is no greater cause for anxiety because 
the period in the gradually-ascending organic scale cannot 
possibly be determined.* 

I am aware that the conclusions arrived at in this work 
will be denounced by some as highly irreligious ; but he 
w^ho thns denounces them is bound to show why it is 
more irreligious to explain the origin of man as a distinct 
species by descent from some lower form, through the 
laws of variation 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, Avhich our minds refuse to accept as the result of 
blind chance. The understanding revolts at such a con- 
clusion, whether or not we are able to believe that every 
slight variation of structure, the union of each pair in 
marriage, the dissemination of each seed, and other such 
events, have all been ordained for some special purpose. 

Sexual selection has been treated at great length in 
these volumes ; for, as I have attempted to show, it has 
played an important part in the history of the organic 
world. As summaries have been given to each chaj)ter, 
it would be superfluous here to add a detailed summary. 

' The Rev. J. A. Picton gives a discussion to this effect iu his ' New 
Theories aud the Old Faith,' 1870. 



Chap. XXL] AND CONCLUDING REMARKS. 379 

I am aware that much remains doubtful, but I have 
endeavored to give a fair view of the whole case. In the 
lower divisions 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 two sexes 
combined in the same individual, or, what is still more im- 
portant, 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 sub-kingdoms, sexual 
selection has effected much ; and it deserves notice that 
we here find the intellectual faculties developed, but in 
two very distinct lines, to the highest standard, namely, 
in the Hymenoptera (ants, bees, etc.) among the Arthro- 
poda, and in the Mammalia, including man, among the 
Vertebrata. 

In the most distinct classes of the animal kingdom, 
with mammals, birds, reptiles, fishes, insects, and even 
crustaceans, the differences between the sexes follow al- 
most exactly 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 pug- 
nacity. They are provided, either exclusively or in a 
much higher degree than the females, with organs for pro- 
ducing vocal or instrumental music, and with odoriferous 
glands. They are ornamented with infinitely-diversified 
appendages, and with the most brilliant or conspicuous 
colors, often arranged in elegant patterns, while the fe- 
males are left unadorned. When 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 



380 GENERAL SUMMARY [Part II. 

organs for holding lier. These various structures for 
securing or charming the female are often developed in 
the male during only part of the year, namely, the breed- 
ing-season. They have in many cases been transferred in 
a greater or less degree to the females ; and in the latter 
case they appear in her as mere rudiments. They are lost 
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 the young of both sexes resemble each other ; 
and the female resembles her young oflfspring throughout 
life. In almost every great class a few anomalous cases 
occur in which there has been an almost complete trans- 
position of the characters proper to the two sexes ; the fe- 
males assuming 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 throughout all the higher divisions of the animal 
kingdom of one common cause, namely, sexual selection. 
Sexual selection depends on the success of certain in- 
dividuals over others of the same sex in relation to the 
propagation of the species ; while natural selection de- 
pends on the success of both sexes, at all ages, in relation 
to the general conditions of life. The sexual struggle .is 
of two kinds ; in the one it is between the individuals of 
the same sex, generally the male sex, 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 part- 
ners. This latter kind of selection is closely analogous to 
that which man unintentionally, yet effectually, brings to 
bear on his domesticated productions, when he continues 



Chap. XXI.] AND CONCLUDING REMARKS. 381 

for a long time choosing the most pleasing or useful indi- 
viduals, without any wish to modify the breed. 

The laws of inheritance determine whether characters 
gained through sexual selection by either sex shall be 
transmitted to the same sex, or to both sexes; as well as 
the age at which they shall be developed. It appears 
that variations which arise late in life are commonly trans- 
mitted to one and the same sex. Variability is the neces- 
sary basis for the action of selection, and is wholly inde- 
pendent of it. It follows 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, and through natural selec- 
tion 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 modifica- 
tions 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 differences must be in some manner 
highly important; and we know that they have been 
acquired in some instances at the cost not only of incon- 
venience, but of exposure to actual danger. 

The belief in the power of sexual selection rests chiefly 
on the following considerations : The characters which 
we have the best reason for supposing to have been thus 
acquired are confined to one sex ; and this alone renders 
it probable that they are in some way connected with the 
act of reproduction. These characters in innumerable in- 
stances are fully developed only at maturity ; and often 
during only a part of the year, which is always the breed- 
ing-season. The males (passing over a few exceptional 
cases) are the most active in courtship ; they are the best 
armed, and are rendered the most attractive in i^arious 



382 GENERAL SUMMARY [Part II. 

ways. It is to be especially observed that the males dis- 
play 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 display should be purposeless. Lastly, we have 
distinct evidence with some quadrupeds and birds that the 
individuals of the one sex are capable of feeling a strong 
antipathy or preference for certain individuals of the oppo- 
site sex. 

Bearing these facts in mind, and not forgetting the 
marked results of man's unconscious selection, it secms'to 
me almost certain that if the individuals of one sex were 
during a long series of generations to prefer pairing with 
ceitain individuals of the other sex, characterized in some 
peculiar manner, the offspring would slowly but surely 
become modified in this same manner. I have not at- 
tempted to conceal tliat, excepting when the males are 
more numerous than the females, or when polygamy pre- 
vails, it is doubtful how the more attractive males succeed 
in leaving a larger number of offspring to inherit their 
superiority in ornaments or other charms than the less 
attractive males ; but I have shown that this would prob- 
ably follow from the females — especially the more vigor- 
ous females, which would be the first to breed — preferring 
not only the more attractive but at the same time the 
more vigorous and victorious males. 

Although 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 an astonish- 
ing fact that the females of many birds and some mam- 
mals should be endowed with suflicient taste for what has 
apparently been effected through sexual selection ; and 
this is even more astonishing in the case of reptiles, fish, 
and insects. But we really know very little about the 



Chap. XXI.] AND CONCLUDING REMARKS. 383 

minds of the lower animals. It cannot be supposed that 
male Birds of Paradise or Peacocks, for instance, should 
take so much pains in erecting, spreading, and vibrating 
their beautiful plumes before the females for no purpose. 
We should remember the fact given on excellent authority 
in a former chapter, namely, that several peahens, when 
debarred from an admired male, remained widows 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 be 
able to appreciate the exquisite shading of the ball-and- 
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, as well as the primary feathers, are displayed in a 
manner quite peculiar to this one species during the act 
of courtship, and at no other time, were given to him as 
an ornament. If so, he must likewise admit that the fe- 
male was created and endowed with the capacity of ap- 
preciating such ornaments. I difier only in the convic- 
tion that the male Argus pheasant acquired his beauty 
gradually, through the females having preferred during 
many generations the more highly-ornamented males ; the 
aesthetic capacity of the females having been advanced 
through exercise or habit in the same manner as our own 
taste is gradually improved. In the male, through the 
fortunate chance of a few feathers not having been modi- 
fied, we can distinctly see how simple spots with a little 
fulvous shading on one side might have been developed 
by small and graduated steps into the wonderful ball-and- 
socket ornaments ; and it is probable that they were actu- 
ally thus developed. 

Every one who admits the principle of evolution, and 
yet feels great difficulty in admitting that female mam- 



384 GENERAL SUMMARY [Part II. 

iiKiIs, birds, reptiles, and fisli, could have acquired the 
liigh standard of taste which is implied by the beauty of 
the males, and which generally coincides with our own 
standard, should reflect that in each member of the verte- 
brate series the nerve-cells of the brain are the direct off- 
shoots of those possessed by the common progenitor of 
tlie whole group. It thus becomes intelligible that the 
brain and mental faculties should be capable under similar 
conditions of nearly the same course of development, and 
consequently of performing nearly the same functions. 

The reader who has taken the trouble to go through 
the several chaj^ters devoted to sexual selection will be 
able to judge how far the conclusions at which I have ar- 
rived are supported by sufficient evidence. If he accepts 
these conclusions, he may, I think, safely extend them to 
mankind ; but it would be superfluous here to repeat what 
I have so lately said on the manner in which sexual selec- 
tion has apparently acted on both the male and female 
side, causing the two sexes of man to differ in body and 
mind, and the several races to differ from each other in 
various characters, as well as from their ancient and low- 
ly-organized jn-ogenitors. 

He who admits the principle of sexual selection will 
be led to the remarkable conclusion that the cerebral sys- 
tem not only regulates most of the existing functions of 
the body, but has indirectly influenced the progressive de- 
veloi)nient of various bodily structures and of certain men- 
tal qualities. Courage, pugnacity, perseverance, strength 
and size of body, weapons of all kinds, musical organs, 
both vocal and instrumental, bright colors, stripes and 
marks, and ornamental appendages, have all been indi- 
rectly gained by the one sex or the other, through the 
influence of love and jealousy, tlirough the appreciation 
of the beautiful in sound, color, or form, and through the 
exertion of a choice ; and these powers of the mind mani- 



Chap. XXI.] AND CONCLUDING REMARKS. 385 

festly depend on the develoDment of the cerebral sys- 
tem. 

Man scans with scrupulous care the character and pedi- 
gree of his horses, cattle, and dogs, before he matclies 
them ; but when he comes to his own marriage he rarely, 
or never, takes any such care. He is impelled by nearly 
the same motives as are the lower animals when left to 
their own free choice, though he is in so far 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 refrain from marriage if in any marked degree 
inferior 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. All do good service 
who aid toward this end. When the principles of breed- 
ing and of inheritance are better understood, we shall not 
hear ignorant members of our legislature rejecting with 
scorn a plan for ascertaining by an easy method whether 
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 pov- 
erty is not only a great evil, but tends to its own increase 
by leading to recklessness in marriage. On the other 
hand, as Mr. Galton has remarked, if the prudent avoid 
marriage, while the reckless marry, the inferior members 
will 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 
consequent on his rapid multiplication ; and if he is to 
advance stUl higher he must remain subject to a severe 
36 



38G GENERAL SUMMARY [Part II. 

Struggle. Otherwise he would soon sink into indolence, 
and the more liighly-gifted men would not be more suc- 
cessful in the battle of life than the less gifted. Hence 
our natural rate of increase, though leading to many and 
obvious evils, must not be greatly diminished by any 
means. There should be open competition for all men ; 
and the most able should not be prevented by laws or cus- 
toms from succeeding best and rearing the largest number 
of otfspriiig. Important 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 
the social instincts, whicli afforded the basis for the devel- 
opment of the moral sense, may be safely attributed. 

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 per- 
sons. But there can hardly be a doubt that we are de- 
scended 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. lie who has seen a savage in his native 
land will not feel much shame, if forced to acknowledge 
lliat the blood of some more humble creature flows in his 



Chap. XXI.] AND CONCLUDING REMARKS. 387 

veins. For my own part, I would as soon be descended 
from that heroic little monkey, who braved his dreaded 
enemy in oi-der to save the life of his keeper ; or from 
that old baboon, who, descending from the mountains, 
carried away in triumph his young comrade from a crowd 
of astonished dogs — as from a savage who delights to tor- 
ture his enemies, offers up bloody sacrifices, practises in- 
fanticide without remorse, treats his wives like slaves, 
knows no decency, and is haunted by the grossest super- 
stitions. 

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 hopes for a still higher destiny in the 
distant future. But we are not here concerned with hopes 
or fears, only with the truth as far as our reason allows 
us to discover it. I have given the evidence to the best 
of my ability ; and we must 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 the solar system 
— with all these exalted powers — Man still bears in his 
bodily frame the indelible stamp of his lowly origin. 



IIlN-DEX. 



A. 

Abbott, C, on the battles of seals, U. 229. 

Abductor of the fifth metatarsal, presence 
ot in man. i. 123. 

Abercrombie, Dr>, on disease of the brain 
affecting speech, i. 56. 

Abiposes. ni.irriuge-customs of the, ii. 356. 

ABon-SiMBEL. caves of, i. 209. 

Abortion, prevalence of the practice ot, i. 
129. 

Abstraction, i. 60. 

Acal/fK stridulation ot i. 372. 

Acantluxliivti/luit capetwfUi, sexual differ- 
ences of color in, ii. 34. 

Accentor modnhirix. ii. 189. 

Acclimatization", difference ot, in differ- 
ent races of men. i. 209. 

AcJietidtr. striilul:itiou of the, I. 341, 342, 
84S ; rudimentary stridulating or^'ans in 
female, i. 'A\-i. 

Aci/iu« gu/cattis, elj'tra of the female, i. 
363. 

Acomus. development of spurs in the fe- 
male of, ii. 154. 

Aoridiidw, stridulation of the, i. 342, 345; 
rudimentary stridulating organs in fe- 
male, i. 34S. 

AcTiNo, i. 224. 

Aciiiiicp, brijfht colors of i. 813. 

Ad-Miral butterfly, i. 3i0. 

Adoption of the "young of other animals 
by female monkeys, i. 39. 

Advancement in the organic scale, Von 
Baer's definition oC i. 203. 

Aeby, on the difference between the skulls 
of man and the quadruiiiana. i. 1^3. 

^Esthetic faculty, not highly developed in 
savages, i. 62. 

Affection, iiiatcrnaL i. 39 ; manifestation 
oC by animals, i. .39 ; parental and filial, 
partly the result of natural selection, i. 
77 ; shown by birds in confinement, for 
certjiin persons, ii. 105 : mutual of birds, 
11. 104. 

Africa, probably the birthplace of man. 1. 
191 ; ijouth, crossed population of^ i. 217, 



South, retention of color by the Dutch 
in, i. 233 ; South, proportion of the sexes 
in the butterflies o^ i. 301 ; tattooing 
practised in. ii. 323 ; Northern, coiffure 
of natives of ii. 324. 

Agassiz, L., on conscience in dogs. i. 75; 
on the coincidence of the races, of man 
with zoological provinces. 1. 210; on the 
number of species of man, i. 21S; on the 
courtship of the land-snails, i. 815; on 
the brightness of the colors of male fishes 
during the breeding-season, ii. 12 ; on the 
frontal protuberance of the males, of 
Geoi>}uigiu< and Cichhi. ii. 13, 26 ; on the 
slight sexual differences of the South 
Americans, ii. 308 ; on the tattooing of 
the Aiuuzouian Indians, ii. 326. 

Age, in relation to the transmission of 
characters in birds, ii. 175; variation in 
accordance with, in birds, ii. 203. 

Age/wus Pfunniceiis, ii. 111. 

Ageronia /eronia, noise produced by, L 
375. 

Agrion. dimorphism in. i. 352. 

Agrion liamhiirii, sexes ot, i. 351. 

AC.RION1D.E, difference in the sexes ot, i 
361. 

Agrotis erclnmationiJi. i. 35S. 

AofE, tertian, dog suffei-ing from, i. 12. 

Aithiiru-H po/i/tmiu). young ot, ii, 211. 

AioNos, hairiness of the. ii. 306. 

A/c(i ton! (I, young of ii. 203. 

A/''^Ji palmatd. ii. 247. 

Alder and Hancock, >rM., on the uudl- 
branch mollusca. i. 817. 

Ai.(iKN, Mr., on the stridulation of &o/y<i«, 
i. 368. 

Allen, J. A., on the relative size of the 
sexes of Cal/orhinus ursinus, ii. 24S; 
on the mane of Otaria juhata, ii. 255: 
on the pairing of seals, ii. 257 ; on sexual 
ditt'erences in the color of bats. ii. 273. 

Allen. S., on the habits of //oploptenui, 
ii. 46; on the plumes of herons, ii. 79; 
on the vernal moult of IleroJias, biibul- 
cux, ii. SO. 

Allioatob, court.ship of the male, 1. 264^ 
ii. 27 ; roaring of the male, i. 322. 



INDEX. 



389 



Amadayat, pugnacity of male, li. 46. 

Amadina Lat/iami' display of plumage 
by the male, ii. 91. 

Amadina casianotis, display of plumage 
by the male, li. 91. 

Amazons, butterflies of the, 1. 801; fishes 
of the, ii. 17. 

America, variation in the skulls of abori- 
gines of, 1. 104 ; wide rangre of aborigines 
of, i. 211; lice of the natives of i. 212; 
general beardlessness of the natives of, 
ii. 307. 

America, North, butterflies of, 1. 301 ; In- 
dians of, vromen a cause of strife among 
the, ii. 308 ; Indians of, their notions of 
female beauty, ii. 327, 328. 

America, South, character of the natives 
o^ i. 208 ; population of parts of i. 216 ; 
piles of stones in, i. 224 ; extinction of 
the fossil horse ot, 1. 231 ; desert-birds of, 
U. 214; slight se.vual difference of the 
aborigines of, ii. 367 ; prevalence of infan- 
ticide in, ii. 347. 

American languages, often highly artifi- 
cial, 1. 103. 

Americans, wide geographical range of, i. 
108 ; and negroes, diflerence of, 1. 238 ; 
aversion of, to hair on the face, ii. 219 ; 
native, variability of, i. 219. 

Ammophila, on the jaws of, i. 232. 

Amniotraffus tragelaplius, hairy forelegs 
of ii. 269, 272. 

Amphibia, affinity o^ to the ganoid fishes, 
i. 196; vocal organs of the, ii. 315. 

Amphibi.ins, 1. 204, ii. 22; breeding while 
immature, ii. 206. 

Amphiaxus. i. 196. 

Amphipoda, males sexually mature while 
young, ii. 205. 

Amunopii III., negro character of features 
of, i. 210. 

Anal appendages of insects, i. 332. 

Analogous variation in the plumage of 
birds, ii. 71. 

Anas, ii. 172. 

Anas OGuta, male plumage of, ii. 81. 

Anaa boschas, male plumage of, 11. 81. 

Anas histHonica, ii. 205. 

Anastomus oscUams, sexes and young ot, 
11. 208; white nuptial plumage of, ii. 
218. 

Anatid-e, voices ot li, 57. 

Anax Junius, difference in the sexes o^ 1. 
351. 

Aj^glo-Saxons, estimation of the beard 
among the, 11. 333. 

Animals, cruelty of savages to, 1.91; do- 
mesticated, more fertile than wild, i. 127 ; 
characters common to man and, i. 178 ; 
domestic, change of breeds of, ii. 353. 

Annelida, 1. 318. 

Annulosa, i. 318. 

Anolis cristatellus, male, crest of, 11. 30 ; 
pugnacity of the male, ii. 30; throat- 
pouch of, ii. 31. 

AnoHum tessellatum, sounds produced 
by, 1. 373. 

Anser Canadensis, IL 112. 



Anser cygnoides. ii. 110; knob at the base 
of the beak of, ii. 124. 

Anser hyperboreus, whiteness of ii. 218. 

Antelope, prong-horned, homs of, 1. 279. 

Antelopes, generally polygamous, 1. 258 ; 
horns of^ i. 279, ii. 234 ; canine teeth of 
some male, ii. 230; use of horns of ii. 
259 ; dorsal crests in, 11. 268 ; dewlaps ot, 
11. 270 ; winter change of two species of, 
li. 284 ; peculiar markings oi^ ii. 285, 

Antennje, furnished with cushions in the 
male of Penth^, i. 333. 

Anthidium manicatum, large male of, 1. 
337. 

Anthocharis oardamines, 1. 376, 381 ; sex- 
ual difference of color in, 1. 396. 

Anthooharis genutia, 1. 381. 

Anthocharis sara, i. 381. 

Anthopjhora acervorum, large male of 1. 
337. 

Anthophora rettisa, difference of the sexes 
in, 1. 354. 

Anthu-s, moulting of, ii. 79. 

ANTHROPID.E, 1. 187. 

Antigua, Dr. Nicholson's observations on 
yellow fever in, 1. 236. 

Antics of birds, 11. 65. 

Antilocapra Americana, homs o^ i, 280, 
11. 234. 

AntUope bezoartica, horned females of ii. 
235, 237 ; sexual difference in the color 
of ii. 274. 

AntUope Dorcas and euchore, li. 234. 

Ant Hope euchore, horns of ii. 239. 

AntUope m-ontana, rudimentary canines 
in the young male of 11. 246. 

AntUope niger, sing-sing, caama, and 
gorgon. sexual differences ia the colors 
of ii. 275. 

AntUope orens, horns of i. 279. 

AntUope saiga, polygamous habits of, 1. 
2.58. 

AntUope strepsiceros, horns of 1. 279. 

AntUope subguttiirosa, absence of sub- 
orbital pits in, ii. 267. 

Antipathy, shown by birds in confine- 
ment, to certain persons, ii. 106. 

Ants, i. 179 ; playing together, 1. 38; mem- 
ory in, i. 44; intercommunication of, by 
means of the antennte, 1. 56 ; large size 
of the cerebral ganglia in, i. 140 ; soldier-, 
large jaws of 1. 149 ; difference of the 
sexes in, 1. 854 ; recognition of each other 
by, after separation, 1. 354. 

Ants, Wiiite, habits of, 1. 353. 

Anura, ii. 24. 

Apatania muUebris, male unknown, i. 
306. 

Apathzi-s, difference of the sexes in, 1. 355. 

Apatura Iri.% 1. 374, 376. 

Apes, anthropomorphous, 1. 189 ; differ- 
ence of the young, from the adult, 1. 18 ; 
building platforms, i. 51 ; probable 
speedy e.xtermination of the, i. 193; Gra- 
tiolet on the evolution of, 1. 222 ; semi- 
erect attitude of some, 1. 137 ; mastoid 
processes ot, 1. 137; influence of the jaw- 
muscles on the physiognomy of. 1. 139 ; 



390 



INDEX. 



fpmnlc, dcsfltiito of larpe oanlnes, 1. 150; 
linluitivc fiU'iiltU'S of. i. l.V); canine t«j<'th 
of mule, il. 'iiO ; feiiiHles of some, less 
li.iiry iK-ncith than the nmle.s, ii. .'{fil. 

Al'fM, lonjr-unncd, their mode of progres- 
sion, i. 1H7. 

Apia mellijicn, Inrpe male ot I. 837. 

Al'iil-I-O, (ireek statues of, ii. .333. 

Apoplexy in i'ehtm Az<ir(T, i. 12. 

Approbation, inlluence of the love ot, i. 
82, 88, 157, 15S. 

Appf.nua<;e8, anal, of insects, i. 332. 
proxmhtiiM nciiiiuUttiin, ii. IfiC. 

Agi'ATic birds, frequency of white plu- 
mage in. ii. 219. 

A(/iii/a cAri/miefos, ii. 100. 

Akab women, elaborate and peculiar coif- 
fure of, ii. *36. 

Araiis, pashinff of cheeks and temples 
among the, ii. 323. 

AnAcnNiDA, i. .321. 

Arakhan, artitioial widening of the fore- 
head by the natives of. ii. !i35. 

Arl/oricola, younff of, ii. 1S2. 

ArcheopteritJr, i. Ht6. 

AUCTI1D.E, coloration of the, 1. 883. 

Ardea axhii, rufeftcenn^ and cariUeu, 
changre of color in, ii. 221, 222. 

Ar</e<i c(Frii/e<i, breeding in immature 
plumage, ii. 205. 

Arf/eti yularis, change of plumage in, ii. 
222. 

Arcteij herodias, love-gestures of the male, 
ii. 65. 

An/ea ln<loriciana, age of mature plu- 
mage in, ii. 204 ; continued growth of 
crest and jiliitiics in the male ot, il. 207. 

Ar(le<i tii/ctiforii.r, cries of, ii. 48. 

Ardeo/a, young of, ii. 182. 

Ardetta, changes of plumage in, Ii. 170. 

Argenteuii., i. 2S. 

Argus pheasant, ii. 69, 93. 173; displ.iy of 
plumage bv the male, ii. 69; ocelliited 
spots of the. ii. 128, 135; gradation of 
clianicters in the, ii. 135. 

Argyll, Duke of. the fashioning of imple- 
ments peculiar to man, i. 50; on the con- 
test in man between right and wrong, i. 
100; on the physical weakness of man, 1. 
149 ; on the priinitive civili/jition of man, 
i. 174; on the plumage of the male .Vrgus 
phea.sant, ii..'>y; on Uronticfe Ben'/dmiiii, 
Ii. 145; on the nests of birds, ii. l.')9; on 
variety as an object in nature, ii. 220. 

Arf/i/nnis aff/tiia, coloring of the lower 
surface of. i. 384. 

Aricoria ej>ifiiM. sexual differences in the 

wings of i. asa. 

Aristocracy, ijicreased beauty of the, ii. 

340. 
Arms, proportions of, in soldiers and sailors, 

i. 112; direction of the hair on the, i. 

1S5. 
Arms and hands, free use of, indirectly cor- 

nlated with diminution of canines, i. 138. 
Arrest of development, i. 117. 
Arrow-heads, stone, general rcsemblAnce 

of; i. 224. 



Arrows, use of, 1. 224. 

Arteries, variations in the course of the, 
i. 104. 

Artery, effect of tying, upon the lateral 
channels, i. 112. 

Abtiiropoda, i. 318. 

Arts practised by savages, 1. 225. 

AsrENsios, colored incrustation on the 
rocks of. i. 317. 

Abcihia, affinity of the lancelet to, 1. 196; 
ta(li>ole-like larva; of, i. 197. 

AsciDiANS, i. 315; bright colors of some, L 
813. 

Axin lis, Asiatic and African species ot ii. 
291. 

Atimis t<TniopuA ii. 291. 

Ass, color-variations of the. ii. 291. 

AteUx, effects of brandy on an, L 12 ; ab- 
sence of the thumb in. i. 135. 

AteUx f>eeh4!lnith. ears of, i. 22. 

Ate/ex maryinatiix. color of the ruff of, ii. 
278; hair on the head of. ii. 105; on the 
recognitii)n of a dog by a turkey, ii. IOC; 
on the selection of a mate by female 
birds, ii. 199. 

Ateuclnin, stridulation oC i. 372. 

AteuvhuM ciciitricOKU-K. habits of, i. 365. 

Athaiid, proportions of the sexes in. i. 805. 

Attention, manifestations of, in animals, i. 
43. 

AiTDomN, v., on a h^Tnenopterous parasite 
with a sedentary male. i. 204. 

Audubon, J. J., on the pugnacity of male 
birds, ii. 41, 46; on Tetrao ciipido, ii. 
47; on An/en 7i >/ctlcorax, ii. 48; on 
iSfurnella luiioriciana, ii. 48 ; on tho 
vocal organs of Tetrno ciipido. ii. 53 ; on 
the drumming of the male Tetrao vm- 
be/liiM, ii. 59; on sounds pro<iuced by the 
niL'htJar. ii. 61 ; on Ardea herodin'ti and 
(iitluirten jota, ii. 65; on the spring 
change of color in some finches, ii. S3 ; 
on Mimiw poliiglottuM. ii. 112; on the 
turkey, ii. 114, 116; on variation in the 
male scarlet tanager, ii. 121 ; on the hab- 
its of Piirangtt (rutira. ii. 1.59; on local 
differences in the nests of the same spe- 
cies of birds, ii. KW; on the habits of 
woodpeckers, ii. 167; on Bombyrilla 
CdrolinenMix.W.Wl: on young females 
of Taiuigra tvxfifii a<'quiring male 
characters, ii. 172; on the immature plu- 
mage of thrushes*, ii. 177 ; on the inmia- 
ture plumage of birds, ii. 17^, et seq. ; on 
birds breeding in immature plumage, ii. 
205; on the growth of the crest and 
plumes in the male Ardea liidoriciand, 
ii. 206; on the change of color in some 
species of Ardea. ii. 221 ; on the specu- 
lum of Merffim oieiilUitiw, ii. 277; on 
the musk-rat, ii. 2S4. 

ArofHoN and ISachman, MM., on squirrels 
fighting, ii. 228; on the Canadian lynx, ii. 
2.55. 

ArsTEN, N. L., on AiwlU cn'stateUu«, U. 
81. 

Australia, half-castes killed by tho na- 
tives of; 1. 212 ; lice of the natives of; L 



INDEX. 



391 



212 ; not the birthplace of man, i. 191 ; 
prevalence of female infanticide in, ii. 

AirsTRALiA, South, variation in the skulls 
of aborijpnes of, i. 104. 

ArsTRAXiANS, color of new-born children 
of li. 303; relative height of the sexes 
of ii. 305 ; women a cause of war among 
the, ii. 808. 

Axis deer, sexual difference in the color 
of the, ii. 2T6. 

Aymakas, measurements of the, i. 115 ; no 
gray hair among the. ii. 304 ; hairlessness 
of the lace in the, ii. 307 ; long hair of the, 
ii. 331. 

AzARA, on the proportion of men and 
women among the (Juaranys. i. 302 ; on 
Palamedea cornnia, ii. 44; on the 
beards of the Guaranys, ii. 307 ; on strife 
for women among the Guanas, ii. 309 ; 
on infanticide, ii. 328, 347 ; on the eradi- 
cation of the eyebrows and eyelashes by 
the Indians of Paraguay, li. 3.32; on poly- 
andry among the Guanas, ii. 349; celi- 
bacy unknown among the savages of 
South America, ii. 350; on the freedom 
of divorce among the Charruas, ii. 356. 



Babbage, C, on the greater proportion of 
illegitimate female bu-ths, i. 292. 

Babikusa, tusks of the, ii. 252. 

Baboon, employing a mat for shelter 
against the sun, i. 51 ; manifestation of 
memory by a, i. 43 ; X'rotected from pun- 
ishment by its companions, i. 74; rage 
excited in, by reading, i. 41. 

Baboon, Cape, mane of the male, ii. 255; 
Hamadrj'as, mane of the male, ii. 255. 

Baboons, effects of intoxicating liquors on, 
i. 12; ears of, i. 22; manifestation of ma- 
ternal affection by, i. 38; using stones 
and sticks as weapons, i. 50 ; cooperation 
of i. 72 ; silence of on plundering e.xpe- 
ditions, i. 75; diversity of the ment.al 
faculties in. i. 106 ; hands of i. 134; hab- 
its of i. 136; variability of the tail in, i. 
144; apparent polygamy of i. 258; po- 
lygamous and social habits of ii. 345, 346. 

Bachman, Dr., on the fertihty of mulat- 
toes, i. 213. 

Baer, K. E., von, on embryonic develop- 
ment, i. 14. 

Bagehot, W., on the social virtues among 
primitive men, i. 89 ; on the value of 
obedience, i. 156; on human progress, i. 
160; on the persistence of savage tribes 
in classical times, i. 230. 

Bailly, E. M., on the fighting of stags, ii. 
241 ; on the mode of fighting of the Ital- 
ian butfalo, ii. 239. 

Bain, A., on the sense of duty, i. 68; aid 
springing from sjinpathy, i. 74; on the 
bases of sjTnpathy, 1. 78 ; on love of ap- 
probation, etc., 1. 82 ; on the idea of beau- 
ty, ii. 337. 



Baird, W., on a difference in color between 
the males and females of some Entozoa, 
i. 312. 

Baker, Mr., observation on the proportion 
of the sexes in pheasant-chicks, i. 297. 

Baker, Sir S., on the fondness of the Arabs 
for discordant music, ii. 64; on sexual 
difference in the colors of an antelope, ii. 
275 ; on the elephant and rhinoceros at- 
tacking white or gray horses, ii. 2S1 ; on 
the disfigurements practised by the ne- 
groes, li. 282; on the gashing of the 
cheeks and temples practised in Arab 
countries, ii. 323 ; on the coiffure of the 
North Africans, ii. 324; on the perfora- 
of the lower lip by the women of La- 
tooka, il. 325 ; on the distinctive chai-ac- 
ters of the coiffure of central African 
tiibes, ii. 326 ; on the coiffui-e of Arab 
women, ii. 336. 

"Balz" of the Black-cock, ii. 43, 96. 

Bantam, Sebright, i. 250. 285. 

Banteng, horns of ii. 236 ; sexual differ- 
ences in the colors of the. ii. 275. 

Banyai, color of the, ii. 330. 

Barbarism, primitive, of civilized nations, 
1. 174. 

Barbs, filamentous, of the feathers, in cer- 
tain birds, ii. 70. 

Barr, Mr., on sexual preference in dogs, li. 
259. 

Barrington, Daines, on the language of 
birds, i. 53; on the clucking of the hen, 
ii. 49 ; on the object of the song of birds, 
il. 50 ; on the singing of female birds, ii. 
51 ; on birds acquiring the songs of other 
birds, ii. 52 ; en the muscles of the lar- 
ynx in song-birds, ii. 53 ; on the want of 
the power of song by female bh-ds, ii. 
156. 

Barrow, on the widow-bird, ii. 93. 

Bartlett, A. V>.. on the ti-agopan, i. 261; 
on the development of the spurs, in 
Crofiftoptilon avritum^ i. 280; on the 
fighting of the males of Plectropterns 
gamhettma.W. H; on the knot, ii. 78; 
on display In male birds, ii. 83 ; on the 
display of plumage by the male Poly- 
plectron^ ii. 85; on CromoptVon auri- 
ttim and Pkag/anvs Wdl/ic/iii, ii. 89 ; 
on the habits of Lophopfior^t.'i. ii. 116; 
on the color of the mouth in Biiceros 
hicornis, ii. 123 ; on the incubation of 
the cassowan,', ii. 195 ; on the Cape Buf- 
falo, ii. 239 ; on the use of the horns of 
antelopes, ii. 240 ; on the fighting of male 
wart-hogs, ii. 254; on Ammotragiis tra- 
gehijjfiv,% ii. 269; on the colors of C'er- 
co])ithecnfi cephus, ii. 277; on the colors 
of the faces of monkeys, ii. 295; on the 
naked surfaces of monkeys, ii. 360. 

Bartram, on the courtship of the male 
alligator, ii. 27. 

Basque language, highly artificial, i. 59. 

Bate, C. S., on the superior activity of 
male Crustacea, i. 263; on the propor- 
tions of the sexes in crabs, i. 807 ; on the 
chelae of Crustacea, i. 320 ; on the relative 



392 



INDEX. 



Bizp of tho BPxra In rrnstnoea, I. 82-3 ; on 
the colors ofcrustacoii, i. 32(i. 

Bates, H. W., on vnriiition in the form of 
the lir.'ul of Amazonian Indians, i. 10"; 
on the proportion of the .loxes anionjj 
Amazonian Initterllies, i. 3(11 ; on pexual 
(lifferencfs in tlie winjrs of huttcrllies, 1. 
8;J5: on tlie (leld-ciiclcet, i. 342; on /'//- 
rmle* pii/c/ierriniiiti, i. 3.'jO; on the 
horns of 1 jiniellicom beetles, i. 8.59, 860; 
on the eolors of f'jticd/iir. etc.. i. 376 ; 
on the coloration of tropica! hiittorflies. 1. 
879; on tlic varialiiiily «( /'<ij>i7iu Simik- 
tri» ain\ ('hildreiKt: i. I}!MI; on male and 
female butterllies inhahitin)! dillVrent stJi- 
tions, i. 390; on mimickry, i. 3US; on the 
caterpillar of a Sphinx, 1. 402; on the 
vocal orpins of the umbrella-bird. ii. liC; 
on the toucans, li. 217 ; on Bracliyiirim 
culrtio, ii. 295. 

Batokas, linocking out two upper inci- 
sors, ii. 324. 

Batracuia, ii. 24; eagerness of male, i. 
263. 

Bats, sexual differences in the color of; ii. 
272. 

Battle, law of, i. 175; among beetles, i. 
363 ; among birds, ii. 88 ; among mam- 
mals, ii. 229, ft seq. ; in man, ii. 308. 

Beak, sexual difference in the forms of 
the, ii. 37 ; in the color of the, ii. 69. 

Beaks, of birds, bright colors of ii. 21T. 

Beard, development ot; in man, ii. 802 ; 
analogy of the, in man and the quadru- 
iiiana, ii. 304; variation of the develop- 
ment of the. in ditferent races of men, ii. 
806; estimation of. among bearded na- 
tions, ii. *?:? ; jn-obable origin of the, ii. 356. 

Beards, in monkeys, i. 1$4; of mammals, 
ii. 269. 

BEAi'TiKn, taste for the, in birds, ii. 103; 
in the quadruman.-i, ii.,2S2. 

Beauty, sense of. in animals, i. 61 ; appre- 
ciation of by binl.s. ii. 107; influence of, 
ii. 322. 327 ; "variability of the standard 
of, ii. 3rw3. 

Beavan. Lieut., on the development of the 
horns in Cerrtix Ehli. i. 279. 

Br.AVER, instinct and intelligence of the, 
i. 36, 87 ; voice of the, ii. 2W ; castoreum 
of the. ii. 266. 

Beaters, battles of male, ii. 228. 

BEnisTEiN. on female birds choosing the 
best .sinirers among tlie males, ii. 49; on 
rivalry in ,><on'_'--liirds. ii. 50; on the sing- 
ing of fi-niale liii-ds, ii. 51 ; on birds ac- 
quiring the .'iongs of other birds, ii. .52 ; 
on pairing the canary and siskin, ii. 110; 
on a subvariety of the monk i)igeon, ii. 
126; on spurred hen.s ii. 154. 

Bedooe, Dr.. on causes of difference in 
stiiture, i. HI. 

Bee-eater, ii. .53. 

Bkks. i. 70; destruction of drones and 
queens by, i. 77: pollen -baskets and 
stings of, i. 149; fernal<>. Mcoiidary sexu- 
al characters of, i. 246; ditl'erenco" of the 
sexes in, i. 8&1. 



Beeti-E, himinous larva of a. I. 33.'). 

Beetles, i. 8.55; size of the cerebral gan- 
glia in. 1. 140; dilatition of the fore tarsi 
in male. i. 883; blind, i. 856; etridulation 
of, i. 366. 

Belgium, ancient inhabitants of i. 228. 

Bell, Sir ('., on emotional mu.solcs in man, 
i. 5 ; '• snarling muscles," i. 122 ; on the 
h.ind. i. 136. 

Bell, T., on the numerical porportion of 
the sexes in moles, i. 296; on the newts, 
ii. 28 ; on the croaking of the frog. ii. 
25; on the difference in the coloration 
of the sexes in Zootocti Hripara, ii. 85; 
on moles fighting, ii. 228. 

Bell-bird, sexual difference in the color 
of the, ii. 75. 

Bell-birds, colors of, ii. 218. 

Benevolence, manifested by birds, 11 
104. 

Bennett, A. W.. on the habits oi Dronux- 
iix irrordtim. ii. 196. 

Bennett, Dr.. on birds of paradise, ii. 85. 

Bernield tinfcirciicd. colors of ii. 218. 

Bernicle gander pairing with a Canada 
goose, ii. 109. 

Bettonl K.. on local differences in the 
nests of It;ilian birds, ii. 16!?. 

Bik^teas, color of the beard in, ii. 804. 

Bhringd. disciform tail-feathers of ii. 86. 

Bihio, se.xual differences in the genus, L 
388. 

BicnAT, on beauty, ii. 888. 

Bile, colored, in inany animals, i. 814. 

Bl.MANA, i. Is3. 

Birds, imitations of the songs of other 
birds by, i. 42; dreaming, i. 44; lan- 
guage of i. 53; sense of beantv in, i. 61 ; 
I)leasure o£ in incubation, i. ^76; male, 
incubation by, i. 2o:i; and n'ptiles. alli- 
ance ot; i. 2(U; sexual ditl'erences in the 
beak of some. i. 247 ; migratory, arrival 
of the male before the female, i. 2.51 ; ap- 
parent relation between polygamy and 
marked sexual differences in, i. 261 ; 
monogamous. Uecominir polygainous un- 
der domestication, i. 262; e;igerne.ss of 
male in pursuit of the female, i. 26:}; 
wild, numerical proportion of the sexes 
in. i. 297 ; secondary sexual characters 
of, ii. 36; ditference of size in the sexes 
of, ii. 41 ; fights of male, witnessed by fe- 
males, ii. 46; display of male, to capti- 
vate the females, ii. 47; close attention 
of, to the songs of others, ii. .50; acquir- 
ing the song of their foster-jiarents. ii. 
52; brilli.ant, rarely good songsters, ii.. 53; 
love-antics and dances of; ii. (>5; colora- 
tion of; ii. 71. et Htqq. ; moulting oC ii. 
77, et seqq. ; unpaired, ii. 99 ; male, sing- 
ing out of season, ii. 102; mutual afl'ec- 
tion of, ii. 104; in confinement, distin- 
guish [jersons, ii. 105; hybrid, produc- 
tion of, ii. 109; Kuropean, number of 
species of. ii. 119; variability of ii. 119; 
p-adation of secondary sexual charactera 
in, ii. 129; obscurely colored, building 
concealed nests, ii. 161 ; young female 



INDEX. 



393 



acquiring' male characters, ii. 172 ; breed- 
ing in immature plumage, ii. 205 ; moult- 
ing of, ii. 204; aquatic, frequency of 
white plumage in, ii. 219 ; vocal court- 
ship of, ii. 315 ; naked skin of the head 
and neck in, ii. 377. 

Birgus latro, habits of, i. 325. 

BiEKBECK, Mr., on the finding of new 
mates by Golden Eagles, ii. 100. 

Birthplace of man, i. 191. 

BiETHS, numerical proportions of the sexes 
in, in animals and man, i. 255, 256 ; male 
and female, numerical proportion of, in 
England, i. 291. 

BiscHOFF, Prof., on the agreement be- 
tween the brains of man and of the 
Orang, i. 10 ; figure of the embryo of the 
dog, i. 15; on the convolutions of the 
brain in the human fcetus, i. 16; on the 
difference between the skuUs of man and 
the quadrumana, i. 183. 

Bishop, J., on the vocal organs of frogs, ii. 
26 ; on the vocal organs of corvine birds, 
ii. 52 ; on the trachea of the Merganser, 
ii. 57. 

Bison, American mane of the male, ii. 255. 

Bitterns, dwarl^ coloration of the sexes oC 
u. 170. 

Bisiura lobata, musky odor of the male, 
ii. 36 ; large size of male, ii. 41. 

Blackbird, sexual differences in the, i. 
260; proportion of the sexes in the, i. 
296; acquisition of a song by a, ii. 52; 
color of the beak in the sexes of the, ii. 
69, 217; pairing with a thrush, ii. 109; 
colors and nidification of the, ii. 162; 
young of the, ii. 210 ; sexual dilfurcnco 
in coloration of the, ii. 216. 

Black-buck, Indian, sexual difference in 
the color of the, ii. 275. 

Blackcap, arrival of the male, before the 
female, i. 251; young of the, ii. 210. 

Black-cock, polygamous, i. 261 ; propor- 
tion of the sexes in the, i. 297 ; pugnacity 
and love-dance of the, ii. 42 ; call of the, 
ii. 5S; moulting of the, ii. 79; duration 
of the courtship of the, ii. 96; se.xual 
difference in coloration of the, ii. 216; 
crimson eye-cere of the, ii. 217; and 
pheasant, hybrids o^ ii. 109. 

Black-grouse, characters of young, ii. 
177, 186. 

Blaokwall, J., on the speaking of the 
magpie, i. 57 ; on the desertion of their 
young by swallows, i. 80 ; on the supe- 
rior activity of male spiders, i. 263 ; on 
the proportion of the sexes in spiders, i. 
806 ; on sexual variation of color in spi- 
ders, i. 327 ; on male spiders, i. 328. 

Bladdek-nosf, Seal, hood of the, ii. 265. 

Blaine, on the affections of dogs, ii. 258. 

Blair, Dr., on the relative liability of Eu- 
ropeans to yellow fever, i. 234. 

Blake, C. C, on the jaw from La Naulette, 
i. 122. 

Blakiston, Capt, on the American snipe 
ii. 61 ; on the dances of Tetrao phagia- 
nellus, ii. 65. 



Blasius, Dr., on the species of European 
birds, ii. 119. 

Bled ins taiirus, hornlike processes of male, 
i. 363. 

Bleeding, tendency to profuse, i. 283. 

Blenkieon, Mr., on sexual preference in 
horses, ii. 260. 

Blennies, crest developed on the head of 
male during the breeding-season, ii. 12. 

BUthisa multipunctata, stridulation of, i. 
368. 

Bloch, on the proportions of the sexes in 
Fishes, i. 298. 

Blood, arterial, red color of, i. 314. 

Blood-pheasant, number of spurs in, ii. 
43. 

Bluebreast, red-throated, sexual differ- 
ences of the, ii. 187. 

Blumenbacu, on Man, i. 107; on the large 
size of the nasal cavities in American 
aborigines, i. 114; on the position of man, 
i. 182; on the number of species of man, 
i. 218. 

Bltth, E., ob.servations on Indian crows, 
i. 74; on the structure of the hand in 
species of If>/!ohate,% i. 135 ; on the as- 
certainment of the sex of nestling bull- 
finches by pulling out breast-feathers, ii. 
23 ; on the pugnacity of the males of 
Gallin uUi cri-siata, ii. 39 ; on the pres- 
ence of spurs in the female Euploca- 
mu^ erytkrophthalmu.% ii. 44; on the 
pugnacity of the amadavat, ii. 47 ; on the 
spoonbill, ii. 57 ; on the moulting of An- 
thus, ii. 79 ; on the moulting of bustards, 
plovers, .ind Galluti bankiva, ii.^\ on 
the Indian honey-buzzard, ii. 121; on 
sexual differences in the color or the eyes 
of hornbilLs, ii. 123 ; on Orioltm melano- 
cephalus, ii. 170; on PaimornU Javani- 
C218, ii. 171 ; on the genus Ardetta, ii, 
171 ; on the peregrine fhlcon, ii. 171 ; on 
young female birds acquiring male char- 
acters, ii. 172; on the immature plu- 
mage of birds, ii. 177; on representative 
species of birds, ii. 182 ; on the young of 
TurnUc, ii. 193; on anomalous young of 
Zaniiis ritfus and Coli/mbus glacialis, 
ii. 202 ; on the sexes and young of the 
sparrows, ii. 203 ; on dimorphism in some 
herons, ii. 205; on orioles breeding in 
immature plumage, ii. 205; on the sexes 
and young of Buphus and Annstomits, 
ii. 208 ; on the young of the blackcap 
and blackbird, ii, 210; on the young of 
the stonechat, ii. 211 ; on the white plu- 
mage of Aiuistonnts, ii. 219 ; on the horns 
of AntUope beeoartica, ii. 235 ; on the 
horns of Bovine animals, ii. 236; on the 
mode of fighting of Om« ot/clooeros, ii. 
238 ; on the voice of the Gibbons, ii. 263 ; 
on the crest of the male wild-goat, ii. 
268; on the colors of Portax picta., ii. 
274 ; on the colors of AntUope bezoar- 
tica, ii. 275 ; on the development of the 
horns in the Koodoo and Eland ante- 
lopes, i. 279 ; on the color of the Axis 
deer, ii. 276; on sexual difference of color 



394 



INDEX. 



In TTijlohate* hoolocl; W. 277 ; on the 
• hojf-deer, ii. i^O; on tlio beard and wlils- 
kors in the monkey bcconiinp white 
\\\Cx a>re, II. 304. 

Boar, wild, polytramous In Indi.i, 1. 2.'>9; 
use of the tusks by the, Ii. 24>') : flghtlnp 
of, Ii. 2M. 

BoiTARD and Corbi6, MM., on the trans- 
iiii.s.Hion of Re.vual pooulinrities in pipcons, 
I. 274 ; on the antipathy shown by some 
female plfjeons to certain males, Ii. 114. 

Boi.n. Mr., on the singing of a sterile hy- 
brid canary, ii. .'30. 

BoMnET, on "the variability of the standard 
of beauty in Kurope. 11.854. 

Jioni/»ui, <liffercnce of the se.xes In, I. S.'i.'i. 

BoMiiYciu.t. coloration of; L 382; pairing 
of the, I. 38S. 

Bomhj/cilla Carolmetm«, red appendages 
of ii. 171. 

Bomhifr cijnfhia. I. ."Wfi; proportion of the 
sexes in," i. Mill). R1I4; pairing of, I. .SSS. 

Bomhifx inori, (li!)erince of size of the 
male and female cocoons of; I. 335; pair- 
ing ot i. 388. 

Bomhyor Pemyi, proportion of sexes of, I. 
804. 

Bomhyx Yamomni.\.^fi\ M. Personn.at 
on, i. 301 ; proportion of sexes of; i. 304. 

Bonaparte, f. L., on the call-notes of the 
wild-turkey, Ii. 58. 

Bond, F., on' the finding of new mates by 
crows, II. 100. 

Bone, Implements of; skill displayed in 
making, I. l.SS. 

Boner, 0., on the transfer of male charac- 
ters to an old female chamois, il. 234; on 
the antlers of the red deer, Ii. 241 ; on the 
habits of stTgs. ii. 248 ; on the pairing of 
red deer, ii. 2.^6. 

Bones, lnerea,se of. In length and thick- 
ness, when carrying a greater weight, I. 

Bonnet, monkey, I. 185. 

BoOMERANO, i. 176. 

Boreiw fiyemalU, scarcity of the male, 1. 

306. 
BoRV St. Vincent, on the number of species 

of man, I. 218; on the colors of Labfus 

paro, ii. 15. 
BoK (/niirujt, horns of, Ii. 236. 
Bon primineniim, ii. 229. 
Bom Moni/aicHS, horns of; il. 2-36; colors of, 

ii. 27.'). 
BoTocunoR. I. 174; mode of life of. 1. 237; 

disfigurement of the ears and lower lip 

of the. ii. .325. 
Boucher de Perthes, J. C. dc, on the an- 
tiquity of man, 1. 3. 
Bourbon, proportion of the sexes In a 

species of^ Pupil io from, i. 301. 
BouRiKN, on the marriage-customs of the 

savages of the Malay Archipelago, ii. 

357. 
Bovip.E. dewlaps of, il. 270. 
BowEK-niui>8, ii. 98; habits of the, II. CO; 

ornamented plaving-places of; 1. 61, il. 

108. 



Bows, nse of. I. 224. 

BnArmoi'ODA. I. 315. 

BRAnivrEPiiAi.ir structure, possible ex- 
planation of, I. 142. 

Briich i/Hcehix, second pair of antennte In 
the male, i. 327. 

BRAnivfRA, I. 328. 

Bracln/uru-H ciilru*, scarlet fhce o£ il. 295. 

Brain, of man, agreement of the. with that 
of lower animals, 1. 10; convolutions o£ 
In the human fietus, I. 16; larger in 
some existing mammals than In their 
tertiary prototypes, I. 49; relation of the 
development of the, to the progress of 
language, 1. ."JS; disea.se of tlie, affecting 
speech. I. 56; Influence of development 
of ment-il faculties upon the size of the, 
1. 140; Influence of the development ol, 
on the spinal column and skull, I. 141 ; 
dilTerencc In the convolutions of; in dif- 
ferent races of men, i. 208. 

Brakenriixje. Dr., on the Influence of 
climate, i. 111. 

BRAUBAcn, Prof, on the quasi-religious 
feeling of a dog toward his master, I. 66; 
on the self-restraint of dogs. I. 7.5. 

Beauer, F., on diinoriihism in Xeuroth«- 
min. I. .3.52. 

Brazil, skulls found In caves of 1. 210; 
population of i. 216; compression of the 
nose by the natives of ii. 335. 

Break between man and the apes. i. 192. 

Bream, proportion of the sexes in the, 1. 
299. 

Breeding, age of, in birds, ii. 205. 

Breeding sea.son. .sexual characters mak- 
ing their appearance in the, In birds, II. 
78. 

BREint, on the effects of intoxicating liq- 
uors on monkeys, i. 12; on the recogni- 
tion of women by male Cynoi-ephali. I. 
13 ; on revenge taken by monkeys, 1. .39 ; 
on manifestations of maternal afft-ction 
by monkeys and baboons, i. .39; on the 
Instinctive dread of monkeys for ser- 
pents, I. 41 ; on a baboon using a mat for 
shelter fW)m the sun. 1. 51 ; on the use of 
sttmes as missiles by baboons, 1. 50 ; on 
the signal-eries of "monkeys, i. 55; on 
sentinels posted by monkeys, I. 71 ; on 
coiiperation of animals, i. " 72 ; on an 
eagle attiicking a young Cercopithecun, 
i. 73; on baboons in confinement pro- 
tecting one of their numtHT from pun- 
ishment, I. 75; on the habits of baboons 
when i>lundering, I. 75; on the diversity 
of the mental faculties of monkevs. i. 
106; on the habits of baboons, I. 13i); on 
polvgamy in Cyii(ici/>fi(i/iiM and ty/ms 
1. 2b8; on the numerical proportion ol^ 
the sexes in binls, i. 297 ; on the love 
dance of the Black -cwk, Ii. Hi; on Pala- 
medea connita, 11. 45; on the habits 
of the Black-grouse, ii. 46; on sound 
pixMluced by Hirds of Paradise, ii. 60; on 
assembl.iges of grouse, 11. 97; on the 
finding of new mates by bird.s, Ii. 102; 
on the fighting of wild-boars, Ii. 261 ; on 



INDEX. 



395 



the habits of Cynocephaliis hamadryaa, 
ii. 346. 

Brent, Mr., on the courtship of fowls, ii. 
113. 

Breslait, numerical proportion of male 
and female births in, i. '291. 

Bridgmam, Laura, i. 55. 

Brimstone butterfly, i. 380; sexual diifer- 
ence of color in the, 1. 396. 

British, ancient, tattooing practised by, ii. 
323. 

Broca, Prof., on the occurrence of the su- 
pra-condyloid foramen in the human hu- 
merus, i.''23 ; on the capacity of Parisian 
skulls at different periods, i. 1-tO ; on the 
influence of natural selection, i. 146 ; on 
hybridity in man. i. 212; on human re- 
mains from Les Eyzies, i. 228 ; on the 
cause of the difl'erence between Euro- 
peans and Hindoos, i. 231. 

Brodie, Sir B., on the origin of the moral 
sense in man, i. 60. 

Bkonn, H. G., on the copulation of insects 
of distinct species, i. 332. 

Bronze period, men of, in Europe, i. 
154. 

Brown, E., sentinels of seals generally fe- 
males, i. 71; on the battles of seals, ii. 
229; on the narwhal, ii. 231 ; on the oc- 
casional absence of the tusks in the fe- 
male walrus, ii. 231 ; on the bladder-nose 
seal, ii. 265 ; on the colors of the sexes in 
Phoca Gr(K,nlandioa^i\.'i,Ti\ on the ap- 
preciation of music by seals, ii. 317 ; on 
plants used as love-philters, by North 
American women, ii. 328. 

Brown-Seqitaed, Dr., on the inheritance 
of the effects of operations by guinea- 
pigs, ii. 364. 

Bruce, on the use of the elephant's tusks, 
ii. 237. 

Brulerie, p. de la, on the habits ot Ateit- 
chus cicatricomis, i. 365; on the stridu- 
lation of Ateuchus, i. 373. 

Beunnicii, on the pied ravens of the Feroe 
islands, ii. 121. 

Bryant, Captain, on the courtship of 
C<i/li)r7uiitw ursinu-% ii. 257. 

Sulxin UiKoti, thoracic projection of^ i. 361. 

Bucephalus capensis, difference of the 
sexes, of in color, ii. 28. 

BiKeros, nidification and incubation of; ii. 
161. 

Buceros bieornis, sexual differences in the 
coloring of the casque, beak, and mouth 
in, ii. 123. 

Buceros comtgatus, sexual difference in 
the beak of, ii. 69. 

Buchnek, L., on the origin of man, i. 4 ; 
on the want of self-consciousness, etc., in 
low savages, i. 60; on the use of the 
human foot as a prehensile organ, i. 130; 
on the mode of progression of the apes, 
1. 137. 

BroKLANi), F,, on the numerical propor- 
tion of the sexes in rats, i. 296 ; on the 
proportion of the sexes in the trout, i. 
299 ; on Ghimcera monstrosa, ii. 12. 



BtrcKLAND, "W., on the complexity of cri- 
noids, i. 59. 

Buckler, W., proportion of sexes of Lepi- 
doptera reared by, i. 304. 

BucKiNGiiAJisHiRE, numerical proportion 
of male and female births in, i. 291. 

Bucorax Abyssinicua, inflation of the 
neck-wattle of the male, during court- 
ship, ii. 69. 

Budytes Rati, i. 251. 

Buffalo, Cape, ii. 239. 

Buffalo, Indian, horns of the, ii. 236. 

Buffalo, Italian, mode of fighting of the, 
ii. 2:39. 

Buffon, on the number of species of man, 
i. 218. 

Bugs, i. 339. 

Buist, E., on the proportion of the sexes 
in salmon, i. 299; on the pugnacity of 
the male salmon, ii. 3. 

Bulbul, pugnacity of the male, ii. 89; 
display of under tail-coverts by the male, 
ii. 91. 

Bull, mode of fighting of the, ii. 238; 
curled frontal hair of the, ii. 269. 

Bullfinch, sexual differences in the, i. 
260; piping, ii. 50; female, singing of 
the, ii, 51 ; courtship of the, ii. 90 ; wid- 
owed, finding a new mate, ii. 101 : at- 
tacking a reed-bunting, ii. 106; nestling, 
sex ascertained by pulling out breast- 
feathers, ii. 205. 

Bullfinches distinguishing persons, ii. 
105; rivalry of female, ii. Ii6. 

Bulls, two young, attacking an old one, 
i. 72 ; wild," battles of. ii. 229. 

Bull-trout, male, coloring of, during the 
breeding season, ii. 14. 

Bunting, reed, head feathers of the male, 
ii. 91 ; attacked by a bullfinch, ii. 106. 

Buntings, characters of young, ii. 176. 

Buphus coromandus, sexes and young o^ 
ii. 208; change of color in, ii. 221, 222. 

BuECHELL, Dr., on the zebra, ii. 288; on 
the extravagance of a Bushwoman in 
adorning herself, ii. 327; celibacy un- 
known among the savages of South 
Africa, ii. 350 ; on the marriage-customs 
of the Bush women, ii. 357. 

Burke, on the number of species of man, 
i. 218. 

Burmese, color of the beard in. ii. 304. 

Burton, Captain, on negro ideas of female 
beauty, ii. 330 ; on a universal ideal of 
beauty, ii. 334. 

Bushmen, i. 151. 

Bushwoman, extravagant ornamentation 
ofa, ii. 327. 

BusHwo.MEN, hair of, i. 208 ; marriage-cus- 
toms of, ii. 3.58. 

Busk. Prof. O., on the occurrence of the 
supra-condyloid foramen in the human 
humerus, i. 28. 

Bustard, throat-pouch of the male, ii. 55; 
humming noise produced by a male, ii. 
62; Indian, ear-tufts ofa, ii. 70. 

Bustards, oeeuiTence of sexual differences 
and of polygamy among the, i. 260 ; love- 



396 



INDEX. 



postures of the ranic, il. 65; double moult 
iu, li. 78, 80. 

Bi'Ti.ER. A. O., on sexunl dilToronees in tho 
wind's of Arieoria ej/itim^ i. 335; on tho 
coloring of the sexes in speoies of Theclii, 
i. 377; on the reseinbhince of Iphiat 
(ihntcippe to n leaf, i. 3S1 ; on the rejec- 
tion of certain motlis and caterpillars by 
liz;u-<l8 and fi-ojrs, i. 404. 

BrxTERKLY, noise produced by a, 1. 375; 
Emperor, i. 374. 376 ; meadow brown, in- 
stability of the ocelhitcd spots of ii. 127. 

Bl'TTKKKLlKS. proportion of the sexes in. i. 
.100; fore-U'trs .itn>iilii((l in some male. i. 
8;J4; sexual dilHrfnee in the neuration 
of the wintrs of, i. 335; pufrn.icity of 
male, i, 374 ; protective resemblances of 
the lower surface of i. 379; displ.iy of 
the wind's by, i. 384; white, aliirhting' 
upon liits of paper, i. 387 ; attracted t)y a 
dead specimen of the same species, i. 387; 
courtslii|) of i. 3'^7: male and female, in- 
habitint: ditlcriMt stations, i. 389. 

Buxton, C. obsirvations on macaws, i. 73; 
on an instiince of benevolence in a parrot, 
ii. 105. 

Bu7.7..\RD, Indian honey-, variation in the 
crest of, ii. 121. 

O, 

Cabhaoe butterflies, i. 381, 

Cachalot, larjre head of the male. ii. 231. 

Cadences, iimsical, perception of, by ani- 
mals, ii. 317. 

Cecum, i. 2C; larjre, in the early progeni- 
tors of man, i. 198. 

Cairina mottcfuita, pugnacitj- of the male, 
ii. 89, 

Calliiina/u>a, chela? of flfrured, i. 820. 

Callionymux li/ra, characters of the male, 
ii. 7. 

Collorhiniid vrftimis, relative size of the 
sexes of, il. 248 ; c-ourtship of ii. 257. 

Cai.mucks, aversion of to hairs on the 
face, ii. 332 ; marriage-customs of the, ii, 
3.56. 

Caloten nigrihihris, sexual difiference in 
the color of ii. 34. 

Cambridge, O. Pickard, on the sexes of 
spiders, i. 306. 

Camel, canine teeth of male, ii. 280. 246, 

Campbell, J., on the Indian eleph.int, I, 
2iJ9; on the proportion of male and fe- 
male births in the harems of Siam. i, 294. 

Cam/>>//iijit('riix In i»i/iiiciiriix. i. 298. 

Canaries distiniruishintr persons, ii. 106. 

Canary, polygamy of the, i. 261 ; change 
of plumage in, alter moulting, i. 2ivt; fe- 
male, selecting the best singing male, ii. 
49 ; sterile hybrid, singing of a, ii. 50 ; fe- 
male, sinking ol the, ii. 51 ; selecting a 
greenfinch, ii. 110; and siskin, pairing ofl 
ii. 110. 

Caudal vertebrte, number of in macaques 
and baboons, i. 144; b-isal, of monkeys, 
embedded in the bo<ly, i. 14,5. 

Canestrini, G., on rudimentary characters 



and the origin of man, i. 4; on rudiment- 
aiT characters, i. 17, on the movement 
of tho ear in man, i. 20; on the vari.ibility 
of the vermiform appendage in man, 1. 
27; on the abnonnal (livision of the malar 
bone in man, i. 119; on abnormal condi- 
tions of the human uterus, i. 119; on tho 
persistence of the frontal suture in man, 
1. 120; on the projwrtion of the sexes in 
silk-moths, i. 300, 302. 

Canine teeth in man, I. 121 ; diminution 
of in man, i. 139; diminution ot, in 
horses, i. 139; disappearance of in male 
ruminant,s. i. 139; large, in the early pro- 
genitors of man, i. 198. 

CANI.VE.S, and horns, inverse development 
of ii. 245. 

Canoes, use of i. 132, 226, 

Cantlmrh, dilference of color in the sexes 
of a species of i. 355. 

Capercailzie, proportion of the sexes in 
the. i. 297 ; pugnacity of the male, ii. 42 ; 
l)ali-liig of the, ii. 47; autumn meetings 
of the, ii. .52; call of the, ii. 58; duration 
of the court.ship of ii. 96 ; behavior of the 
female, ii. 116; inconvenience of black 
color to the female, ii. 147; sexual dilfer- 
ence in coloration of the, ii. 216; crimson 
eye-cere of the male, ii. 217 ; polygamous, 
i, 269, 

Capital, i, 16.3. 

Capitonidx, colors and nidlfication of the, 
ii. 163. 

Copra (vgagrrm. ii. 238 ; crest of the male, 
ii. 26S ; sexual difference in the color o^ 
ii. 27.5. 

Capreo/ufi Sibiricu« mihecatulatux. ii. 281. 

Caprice, common to man and animals, i. 
62. 

Caprhnulflftx. noise made by the males of 
some species of with their wings, ii. .59. 

Cttprimulyus Viiginianitg, paiiing ot; iL 
47. 

Carabid.e, bright colors of i. 355. 

Carbonnier, on the natural history of tho 
j)ike, i. 299 ; on the relative size of the 
sexes in fishes, ii. 7. 

Carfineutt.% sexual difiference of color in, 
ii. 165. 

Carcinm m<F7)as, i. 322, 323, 

CarduelU elefians^ sexual differences of 
the beak in, ii. 37. 

Carnitora. marine, polysramous habits o^ 
i. 2.')9 ; sexual diU'erenceS in the colors ot 
ii. 273. 

Carp, numerical proportion of the sexes in 
the. i. 299. 

Carr. K.. on the peewit, ii. 46. 

Carkikr pigeon, late development of the 
wattle in the. i. 284. 

Carrion beetles, sti-idulation of i. 367. 

Carus, Pi-of v., on the development of the 
liorns in merino sheep, i. 280. 

Cassowary, sexes and incubation of the, 
ii. 195. 

Castoreum, ii. 266, 

Caxuiifiun ffiileiitii.'i, ii. 1915. 

Cat, convoluted body in the extremity of 



INDEX. 



397 



the tail of a, i. 29 ; sick, sympathy of a 
dog wth a, i. 74. 

Cataeact in Cebvs Aearm, i. 12. 

Catarrh, liability of Cebns Asarce to, i. 11. 

Catarkhine monkeys, i. ISS. 

Caterpillars, bright colors ot, i. 402. 

Cathartes aura, ii. 111. 

Cathartes jota, love-gestures of the male, 
ii. 65. 

Catlin, G., on the development of the 
beard among North American Indians, 
ii. 307 ; on the great length of the hah- in 
some North American tribes, ii. Sol. 

Caton, J. D., on the development of the 
horns in Cervtis Virginian us and stron- 
gyloceros, i. 279 ; on the presence of 
traces of horns in the female wapiti, ii. 
234 ; on the fighting of deer, ii. 241 ; on 
the crest of the male wapiti, ii. 26S ; on 
the colors of the Virginian deer, ii. 274 ; 
on sexual dilferences of color in the wa- 
piti, ii. 276 ; on the spots of the Yirginian 
deer, ii. 289. 

Cats, dreaming, i. 44 ; tortoise-shell, i. 274, 
276, 283 ; enticed by valerian, ii. 268 ; col- 
ors of, ii. 285. 

Cattle, domestic, sexual differences of, 
late developed, i. 281 ; rapid increase of, 
in South America, i. 130 ; domestic, 
lighter in winter in Siberia, i. 273 ; horns 
o^ i. 278, ii. 236; numerical proportion 
of the sexes in, i. 295. 

CV6««, maternal affection in a, i. 39 ; grada- 
tion of species of i. 219. 

Cebiis Ascirce, liability of, to the same dis- 
eases as man, i. 11 ; distinct sounds pro- 
duced by. i. 52 ; early maturity of the fe- 
male, ii. 303. 

Cebus capucintis, polygamous, i. 258 ; sex- 
ual differences of color in, ii. 277 ; hair on 
the head of, ii. 291. 

CehxiB vellerosus, hair on the head ol^ ii. 
291. 

CEcrooMTiD^ proportion of the sexes in, 
i. 305. 

Celibacy, unknown among the savages of 
South Afi-ica and South America, ii. 350. 

Centipedes, i. 330. 

Cephalopoda, absence of secondary sex- 
ual characters in, i. 316. 

Cephalopterua ornatux, ii. 55-57. 

CephalopteriDi peiuhiliger, ii. 57. 

Cerambyx heros, stridulant organ ot, 1. 
368. 

Ceratophora aspera. nasal appendages o^ 
ii. 32. 

Ceratophora Stoddartii, nasal horn of, ii. 
32. 

Cerceri«, habits of i. 353. 

Cercocebus J&hiops, whiskers, etc., o^ ii. 
295. 

Cercopithecus, young, seized by an eagle 
and rescued by the troop, i. 73 ; definition 
of species oi^ i. 219. 

Cercopithecus cep/iu.% gexual difference of 
color in, ii. 277, 296. 

Cercopit/ieeuf: ct/nomtrvs and grineo-viri- 
din, color of the scrotum in, ii. 277. 



CercopitJifcxis Diana, sexual differences 

of color in, u. 277, 296, 297. 
Cercopithecus griseo-viridis, i. 72. 
Cercopithecus petaurista, whiskers, etc., 

of, ii. 293. 
Ceres, of birds, bright colors of^ ii. 217. 
Ceriornis Te>nminckii, sweUing of the 

wattles of the male during courtship, ii. 

68. 
Cermilus, weapons of, ii. 245. 
Cenndv^ moschatvs, rudimentary horns 

of the female, ii. 234. 
Cermts alces, i. 279. 
Cervus campestris, odor of, ii. 266. 
Cervtis Canadensis, traces of horns in the 

female, ii. 234; attacking a man, ii. 242; 

sexual difference in the color of, ii. 276. 
Cerviis elajihus, battles of male, ii. 229; 

horns of, with numerous points, ii, 241. 
Cerinis Ekli. i. 279. 
Cervim mantehuricus, ii. 289. 
Cervus paludo»us, colors of ii. 276. 
Cervus strongyloceros, i. 279. 
Cermis Virginianus, i. 279; horns o^ in 

course of modification, ii. 243. 
Ceryle. male black-belted in some species 

of, ii. 165. 
Cetacea, nakedness of, i 142. 
Ceylon, frequent absence of beard in the 

natives of, ii. 306. 
Chaffinch, proportion of the se.xes in the, 

i. 297, 298 ; courtship of the, ii. 90. 
Chaffinches, ii. 51 ; new mates found by, 

u. 101. 
Chalcophaps Indicus, characters of young, 

ii. 177. 
Chalcod&ma atlas, sexual differences of i. 

857. 
Chetmceleon, sexual differences in the 

genu.s, ii. 32. 
Chamwleon bifurcus, ii. 32, 34. 
Ch<t»uvleon Otvenii, ii. 33, 34. 

CUA-MELEONS, ii. 31. 

Chamois, danger-signals o^ i. 71 ; transfer 
of male characters to an old female, ii. 
233. 

Cha7H(Tpetes nnicolor, modified wing- 
feather in the male, ii. 61. 

Chapuis, Dr., on the transmission of sex- 
ual peculiarities in pigeons, i. 274; on 
sti-eaked Belgian pigeons, i. 284, ii. 
150. 

Char, male, coloring o^ during the breed 
ing-season, ii. 13. 

Characters, male, developed in females, 
i. 271 ; natural, artificial exaggeration o^ 
by man, ii. 335; secondary sexual, trans 
mitted through both sexes, i. 270. 

Charadrius hiaticula and pluviaMs, 
sexes and j'oung of, ii. 207. 

Chardin on the Persians, ii. 340. 

Charms, worn by women, ii. 328. 

Charruas, treedom of divorce among the. 
ii. 356. 

Chasmorhynchns, difference of color in 
the sexes of ii. 75; colors of, ii. 218. 

Chastity, early estimation of, i. 92. 

Chatterers, sexual differences in, i. 260. 



398 



INDEX. 



riiEiBopTERA, absence of necondnry sex- 
ual clianu-ters in, i. '259. 

CiiKi..f: of cru.stace.1, i. 320, 827. 

CiiEi.oNiA, sexual differences in, il. 2C. 

Chenulopex yEgi/ptiaciis, wing-knobs o^ 
ii. 44. 

Chera progne. il. 80, 116. 

CuEST, proiiorlioiis of, in soldiers and sail- 
ors, !. 112; \m-ih\ of the Queehiia and 
Ayinara Indian.s, i. 11.5. 

CiiEVRoTAiss, eanine teeth of. ii. 24C. 

ChidMognathnji, stridulation of. i. 3T2. 

ChiiinoyiKtilnui Orantii, mandibles of, i. 
806. 

Cuii.DRF.!*, leffitimate and illeRitimato, pro- 
portion of the se.ve3 in, i. 292. 

C'liii.oE, lice of the natives of, I. 212 ; popu- 
lation of, 1. 217. 

C/iiiiuvr<i monxtrosa, bony process on the 
head of the male, ii. 12. 

Cui.M.KRoiD fishes, prehensile organs of 
male, il. 1. 

Chimpanzke, ii. 303; ears of the, 1. 21 ; rep- 
resentiitives of the eyebrows in the, i. 
25; platforms built by the, i. 85; crack- 
ing nuts with a stone, i. 49 ; hands of the, 
1. 1!33 ; absence of ma.stoid processes in 
the. i. 13S ; direction of the hair on the 
arms of the, i. 1S5; supposed evolution 
of the, i. 222 ; polvgamous and social 
habits of the, ii. 845." 

China, North, idea of female beauty In, ii. 
82S. 

CniNA, Southern, inhabitants of, i. 287. 

Chinese, use of flint tooKs by the, i. 176; 
dilliculty of distinguishing the races of 
the, i. 207; color of the beard in, ii. 304; 
general beanllessness of the, ii. 306; 
opinions of the, on the appearance of 
l.uroi)eans and Cingalese, ii. 329, 831; 
compression of the feet of, ii. 336. 

CniNsuRDi, his opinion of beards, ii. 829, 

sm. 

Chlamydera macuMa. ii. 67. 

Chtoeon. i)edimculated eyes of the male 

oC i. ;«2. 
CMoep/uiffa, coloration of the sexes in, ii. 

170. 
ChloroaxJtu Taniina (figured), I. ^15. 
Chorda Dors a lis, i. 199. 
Cuoiroii, red beak of the. ii. 217. 
CnRO.MiD.E, frontal protuberance in male, 

ii. 13 ; sexual difference in color of, ii. 20. 
C hn/Demys picia, long claws of the male, 

ii. 27. 
Cfiri/sococcyx, characters of young of, ii. 

177. 
C/>r>/8omela cerealis, bright colors o£ i. 

3.55. 
CHRYSOMELID.E, stridulatlon of, i. 867. 
Cicudii priiinonn, i. 341. 
Cuvulii neji/endeciiti. i. 341. 
CioAii.F., songs of the, i. 340 ; rudimentary 

sound-organs in females of. i. 34S. 
Cicatrix of a burn, causing modification 

of the facial bones, i. 141. 
CiriiUi, frontal protuberance of male, ij. 

18. 



CiMETifeRE dn Snd, Paris, I. 28. 
C'inc/omi/ijihus cruraliH, large size of 

male. ii. 41. 
CinciuM oquatictui, ii. 162. 

Cingalese, Chinese opinion of the appear- 
ance of the, ii. 329. 

CiHRiPEiiES, comiilemental males ot i. 247. 

Civilization, effects oC ujion natural se- 
lection, i. 164; influence ot; in the compe- 
tition of nations, L 230. 

Clanging of Geese, etc., ii. 49. 

Clapareue, K., on natural selection ap- 
plied to man, i. 132. 

Clarke, on the marriage-customs of the 
Calmucks. ii. .3.57. 

Classikication, 1. 181. 

C'LArs, C, on the sexes of Saphirina, L 
826. 

Cleft-pat.ate, inherited, i. 116. 

ClimacteriK erythropn, sexes o( ii. 197. 

Climate, i. Ill; cool, favorable to human 
l)rogress. i. 160; power of supporting ex- 
tremes of, by man, i. 22S ; want of con- 
nection of with color, i. 232. 

Cloaca, existence of a, in the early pro- 
genitors of man, i. 198. 

Cloacal pas.sage existing in the human 
embryo, i. 17. 

Cut II, origin of the, i. 225. 

Clucking of fowls, ii. 49. 

Clytiira i-putu-tata, stridulation o^ i. 867. 

Cobra, ingenuity of a, ii. 29. 

Coccus, i. 179. 

Coccyx, i. 28. 29 ; in the human embryo, i. 
16; convoluted body at the extremity of 
the, i. 29; embedded in the Ixxly. i. 145. 

CociiiN-CiiiNA, notions of beauty of the 
inhabitants of. ii. .329. 3:il. 

Cock, game, killing a kite, ii. 42; blind, 
fed by its companions, i. 74 ; comb and 
wattles of the. ii. 94 ; preference sho«Ti 
by the, for young hens, ii. 117; game, 
transparent zone in the liackles of a. ii. 
130. 

Cock of the rock. Ii. 96. 

Cockatoos, ii. 216, 218, 220; nestling, ii. 
105; black, immature plumage oC ii. ISO. 

Ccelenterata, absence of secondary sex- 
ual charaetcpR in. i. .312. 

Coffee, I'oMdiicss of monkeys for, i. 12. 

Cold, supposed i ffccts of, \'. 113; power of 
supporting, by man. i. 229. 

CoLEoi'TER,v, i. 355; stridulant organs o^ 
discussed, i. 869. 

Colling WOOD, C.. on the pugiutcity of the 
butterflies of Borneo, i. 375; on" butter- 
flies being attracted by a dead specimen 
of the same species, i. 3S7. 

Colombia, flattened heads of savages of^ ii. 
324. 

Colonists, success of the English as, i. 
172. 

Coloration, protective, in.bii-ds. ii. 213. 

Color, supi)osed to be dependent on light 
and heat. i. Ill; correlation of. with im- 
munity from certain poisons and p.<u«- 
sites. i. 2;W ; purpose of, in lepldoptera, 
i. 3&7; relation oC, to sexual functions, in 



INDEX. 



399 



fishes, ii. 14; difference of. in the sexes 
of snakes, ii. 27 ; sexual differences of, in 
lizards, ii. 34 ; influence of, in the pairing 
of birds of different species, ii. Ill; rela- 
tion of, to nidifieation, il. 159, 164 ; sexu- 
al differences of, in mammals, ii. 272, 280 ; 
recognition of, by quadrupeds, ii. 281 ; 
of children, in different races of man, ii. 
803 ; of the skin in man, ii. 364. 

Colors, admired alike by man and ani- 
mals, i. 62 ; bright, due to sexual selec- 
tion, i. 313 ; bright, among the lower ani- 
mals, i. 313, 314; bright, protective to 
butterflies and moths, i. 382 ; bright, in 
male fishes, ii. 7, 13; transmission of, in 
birds, Ii. 152. 

CoLQuuouN, example of reasoning in a 
retriever, i. 46. 

Columba pamerina, young of; ii. 180. 

Colymhus glacialis, anomalous young of, 
ii. 202. 

Co.MB, development ot, in fowls, i. 285. 

Combs and wattles in male birds, ii. 94. 

Community, preservation of variations 
useful to the, by natural selection, i. 149. 

C0MP0SIT.E, gradation of species among 
the, i. 219. 

CoMTE, C, on the expression of the ideal 
of beauty by sculpture, ii. 363. 

Conditions of hfe, action of changed, upon 
man, i. 109 ; influence of, on plumage of 
bu-ds, u. 188. 

Condor, eyes and comb of the, ii. 124. 

CoN.TUGATioNS, Origin o£ i. 59. 

Conscience, i. 87, 100 ; absence of, in some 
criminals, i. 88. 

Constitution, difference of, in different 
races of men, i. 208. 

Consumption, hability of Cebug Azarce to, 
i. 12 ; connection between complexion 
and, i. 235. 

Convergence, i. 221. 

Cooing of pigeons and doves, ii. 58. 

Cook, Captain, on the nobles of the Sand- 
wich Islands, ii. 340. 

Cope, E. D., on the dinosauria, i. 196 ; on 
the origin of genera, ii. 206. 

Cophotis ceylanica, sexual differences of 
ii. 31, 34. 

Copris, i. 359. 

Copris Jsidis, sexual differences of. i. 358. 

Copris lunaris, stridulation of, i. 369. 

Corals, bright colors ot, i. 313. 

C0EAL-8NAKE8, ii. 29. 

Cordyln«, sexual diflFerence of color in a 
species of; ii. 34. 

Corfu, habits of the chaffinch in, i. 298. 

Cornelius, on the proportions of the sexes 
in Liicamm Cerviis, i. 305. 

Corpora Wolfpiana, i. 199; agreement 
of, with the kidneys of fishes, 1. 16. 

Correlated variation, 1. 125. 

Correlation, influence of; in the produc- 
tion of races, i. 238. 

Corse, on the mode of fighting of the ele- 
phant, ii. 245. 

Cornis corone, ii. 100. 

Corvua graculua, red beak of, ii. 217. 



Cornun pica, nuptial assembly o^ ii. 98. 
Corydalis cornutue, large jaws of tho 
male, i. 332. 

Cofrmetarnis, ii. 173. 

Cosmetomis veayillarttis, elongation of 
wing-feathers in, ii. 69, 92. 

C0TINGID.E, sexual differences in, i. 260; 
coloration of the sexes of, ii. 169; resem- 
blance of the females of distinct species 
ot, ii. 184. 

Cottus scorpiiis, sexual dififerences in, ii. 9. 

Counting, origin of, i. 174 ; limited power 
of, in primeval man, i. 226. 

Courage, variabiUty of, in the same spe- 
cies, i. 39 ; universal high appreciation 
of; i. 91 ; importance of; i. 156; a charac- 
teristic of men, ii. 313. 

Courtship, greater eagerness of males in, 
i. 263 ; of fishes, ii. 2 ; of bu-ds, u. 47, 96. 

Cow, winter change of the, ii. 284. 

Crab, devil, i. 323. 

Crab, shore habits of; i. 322. 

Crabro cribrariu^, dflated tibiae of the 
male, i. 333. 

Crabs, proportions of the sexes in, i. 307. 

Cranz, on the inheritance of dexterity in 
seal-catching, i. 113. 

Crawfurd, on the number of species of 
man, i. 218. 

CrenUabrus masa and <7. melopa, nests 
built by, ii. 19. 

Crest, origin of, in Polish fowls, i. 275. 

Crests, of birds, ditl'erence of, in the sexes, 
ii. ISl ; dorsal hairy, of mammals, ii. 268. 

Cricket, field-, stridulation of the, i. 342 ; 
pugnacity of male, i. 349. 

Cricket, house-, stridulation of the, i. 342, 
349. 

Crickets, sexual differences in, i. 350. 

Ceioceridx, stridulation of the, i. 367. 

Ceinoidb, complexity oi, i. 59. 

Croaking of frogs, ii. 25. 

Crocodiles, musky odor of; during the 
breeding-season, ii. 27. 

Crocodilia, ii. 27. 

Crossbills, characters of young, ii. 176. 

Crosses in man, i. 217. 

Crossing of races, effects of the, i. 232. 

Orossoptilon auHtum, ii. 89, 158, 187; 
adornment of both sexes of; i. 280 ; sexes 
aUke in, ii. 170. 

Crotch, G. K., on the stridulation of bee- 
tles, i. 367, 370 ; on the stridulation of 
Eeliopathes, i. 372 ; on the stiidulation 
otAcalles, 1.912. 

Crow Indians, long hair of the, ii. 331. 

Crow, young of the, ii. 200. 

Crows, ii. 216; vocal organs of the, ii. 52; 
h\ing in triplets, ii. 102. 

Crows, canion, new mates found by, ii. 
100. 

Crows, Indian, feeding their blind com- 
panions, i. 74. 

Cruelty of savages to animals, i. 91. 

Crustacea, amphipod, males sexually ma- 
ture while young, ii. 206 ; parasitic, loss 
of Umbs by female, i. 247; prehensile 
feet and antenna ot, i. 248 ; male, more 



400 



INDEX. 



acHve than female, I. 268 ; parthenogen- 
esis In, i. 807 ; Bccondurj' sexual charac- 
ters of, i. 818; auditory hairs of ii. 817. 

Crystal worn in the lower lip by some 
Central African women, ii. 825. 

Cuckoo fowls, 1. 2S5. 

CiLirin^, i. 246, 889. 

Ciii-LEN, Dr., on the throat-pouch of the 
male Inistanl, ii. 5,5. 

Cultivation of iilants, probable origin o£ 
i. 161. 

CuppLKS, Mr., on the numerical proportion 
of the se.xes in (lops, sheep, and cattle, i. 
294,295; on the Scotch deerhound, il. 
249 ; on sc.vual preference in dogs, ii. 
259. 

CuRCULiONrD.E, Bcxual difference in length 
of snout In some, i. 247 ; hornlike pro- 
cesses in male, i. 862; musical, i. 366, 
868. 

CcniosiTT, manifestations of, by animals, 
i. 41. 

Curlews, double moult in, ii. 77. 

CuRsouEs. comparative absence of sexual 
ditference among the, i. 261. 

Curtis. J., on the proportion of the sexes 
in Athalia, i. 811.5. 

CuviER, F., on the recognition of women 
by male quadrumana, i. 1.3. 

CuviEU, G., views of. as to the position of 
man, i. 183; on in.stinct and intelligence, 
i. 86; on the number of caudal vertcbne 
in the mandrill, i. 144; on the position of 
the seals, i. 183; on lfe<;tocot>/le. i. 816. 

Ciinneeula suecica, sexual differences of 
ii. 187. 

Ci/aniilci/on. sexual difference in colors 
of, ii. 16,5; imiuatnre plumage of. ii. 180. 

Ci/c/ifun, sounds produced by. i. 370. 

Ci/cinia mend tea, sexual difference of col- 
or in, i. 386. 

Ci/gnua feitix, trachea ot^ ii. 57. 

Oi/ffnitK olor, white young of. ii. 202. 

Ci/tio Leila, instability of the ocellated 
sjjots of, ii. 127. 

Ci/iiantAtta, variation in the genus, ii. 
120. 

CVMPID.E, proportions of the sexes in, i. 
UK). 

Cynocephalufi, difference of the young, 
fmm the adult, i. 13 ; male, recognition 
of women by, i. 13 ; polygamous habits 
of species of i. 258. 

Ci/tiocep/iii/ii-H cJuiema, i. 40. 

Ciivru-ei>h<this geluda. i. 50. 

Ci/'iix-epfKi/iiK hamadri/as. i. 50; sexual 
ililfi relief of color in, ii. 278. 

Cynoceji/uilun leucoplms, colors of the 
sexes of, ii. 278. 

Ci/noceplialii/i mormon, colors of the male, 
ii. 278, 282. 296. 

CijnoceplKtlus porcariu«, mano of the 
male ii. 25.5. 

Oifpridina, proportions of the sexes in, 1. 
807. 

Ctprinidjb, proportion of the sexes in the, 
1.299. 

CypBiNiB^ Indian, ii. 17. 



CTPRoroTiONTrD.K, scxiial diflferencos In 

the, ii. 7, 9. 
Ci/priiitiM aiirattut. ii. 16. 
Ci/jiiiniiM plutxinuti, spawning of, ii. 15. 
Ci/jiriM. relations of the sexes in, 1. 307. 
CijHtoplwra crUtata, hood o^ ii. 266. 



D. 

Dactlo, sexnal difference of color in, iL 

166. 
Ducelo Oaudicfiavdi, young male oi; il. 

180. 
BAL-RfPA, a kind of ptarmigan, i. 297. 
Damiilis albifrone, peculiar markings ot 

ii. 287. 
Damalit pygarga, pecuUar markings o^ 

ii. 287. 
Dampness of clim.ite, supposed influence 

of, on the color of the skin, i. Ill, 233. 
DaniiidiF. i. 376. 
Dances of birds, ii. 65. 
Dancing, i. 224. 
Daniell. Dr.. his experience of residence 

in West Africa, i. 236. 
Darfcr, protuberances artificially pro- 
duced in. ii. 22:5. 
Dakwin, F., on the stridulation of Der- 

m£«tes Jinirinim, i. 368. 
Dasi/cfiira pudihunda, sexual difference 

of color in, i. 386. 
Davis, A. H.. on the pugnacity of the male 

stag-beetle, i. 364. 
Davis, J. B., on the capacity of the skull 

in various races of men, i. 140; on the 

beards of the I'olynesians, ii. 306. 
Death-rate higher in towns than in rural 

districts, i. 169. 
Death-tick. i. 878. 
De Candolle. ,Mph.. on a case of inherited 

power of moving the scalp, i, 19. 
Declensions, origin of, i. 59. 
Decoration in birds, ii. 68. 
DecticHx, i. 345. 
Deer, spots of young, ii. 176,288; horns 

of, ii. 232, 238"; use of horns of, ii. 240, 

251 ; size of the horns of ii. 247 ; female 

pairing with one male, while others are 

lighting for her, ii. 256; male, attracted 

by the voice of the female, ii. 263; male, 

oilor eniitted by. ii. 266; development of 

the horns in. i. 27s; horns of a, in course 

of nioditicition, ii. 248. 
Deer, Axis, sexual difference in the color 

of the. ii. 276. 
Deer, fallow, dilTerent colored herds of iL 

281. 
Deer, Mantehurian, ii. 289. 
Deer, Virginian, ii. 289; color of the, not 

affected by castration, ii. 274 ; colors oC 

ii. 276. 
Deerhound, Scotch, greater size of the 

male, i. 283, ii. 2,'4. 
Defensive organs of mamm.nls, ii. 2.51. 
Dk Geer, C. on a female spider destroying 

a. male, i. 829. 



INDEX. 



401 



Dekat, Dr., on the bladder-nose seal, ii. 
265. 

Demeraka, yellow fever in, i. 234. 

Dendrocygna, ii. 177. 

Dendrophila frontalis, young: of, ii. 211. 

Denny, H., on the lice of domestic ani- 
mals, i. 211. 

Dermestes imirintis, stridulation of, i. 368. 

Descent traced through the mother alone, 
ii. 343. 

Deserts, protective coloring of animals 
inhabiting, ii. 214. 

Desmaeest, on the absence of suborbital 
pits in Antilope subgutturosa, ii. 267; 
on the whiskers of Macacus, ii. 209; on 
the color of the opossum, ii. 275 ; on the 
colors of the se.xes of Jfu,9 minutius, ii. 
273; on the coloring of the ocelot, ii. 
273; on the colors of seals, ii. 273; on 
Antilope caama, 11.275; on the colors 
of goats, ii. 276 ; on sexual difference of 
color in Afeles marginatus, ii. 277; on 
the mandrill, ii. 278; on 3£acacu8 eyno- 
molg'iis, ii. 303. 

Desmoulins, on the number of species of 
man, i. 218 ; on the musk-deer, ii. 267. 

Desor, on the imitation of man by mon- 
keys, i. 42. 

Despine, p., on criminals destitute of con- 
science, i. 89. 

Development, embryonic, of man, i. 14, 
16; correlated, ii. 125. 

Devil, not believed in by the Fuegians, i. 
65. 

Devil-crab, i. 323. 

Devonian, fossil insect from the, i. 349. 

Dewlaps, of cattle and antelopes, ii. 270. 

jyiadema, sexual differences of coloring in 
the species of, i. 376. 

Diarlema anomala, mimicry by the fe- 
male of, i. 400. 

Diadema bolina. i. 400. 

Diamond-beetles, bright colors of, i. 355. 

Diaste.ma, occurrence of, in man, i. 121. 

Diastylidje, proportion of the sexes in, i. 
301. 

DiODORira, on the absence of beard in the 
natives of Ceylon, ii. 306. 

JXcruriDi, racket-shaped feathers in, ii. 70 ; 
nidiflcation of, ii. 160. 

IMcrurws')nacroc6rou.% change of plumage 
in, ii. 171. 

DidelphiH opossvm, sexual difference in 
the color of, ii. 272. 

Differences, comparative, between differ- 
ent species of bu-ds of the same sex, ii. 
184. 

Digits, supernumerary, more frequent in 
men than in women, i. 265 ; supernu- 
merary, inheritance of i. 276; supernu- 
merary, early development of i. 282. 

DiMORpms.M, in females of water-beetles, 1. 
333; in Neurothemis and Agrion, i. 
352. 

JHpeUcu^ Caniori, sexual differences of 
i. 358. 

DiPLOPODA, prehensUe limbs of the male, 
i. 330. 



Dipsas cynodon, sexual difference in the 
color of ii. 28. 

DiPTERA, i. 338. 

Disease, generated by the contact of dis- 
tinct peoples, i. 230. 

Diseases common to man and the lower 
animals, i. 11 ; differences of Uability to, 
in different races of men, i. 208; new, 
effects of upon savages, i. 229 ; sexually 
limited, i. 283. 

Display, coloration of Lepidoptera for, i. 
383; of plumage by male birds, ii. 82, 91. 

Distribution, wide, of man, i. 131 ; geo- 
graphical, as evidence of specific distinct- 
ness in man, i. 210. 

Disuse, effects of, in producing rudiment- 
ary organs, i. 18; and use of parts, ef- 
fects of, i. 112; of parts, influence of, on 
the races of men, i. 238. 

Divorce, freedom of, among the Charruas, 
ii. 356. 

Dixon, E. S., on the habits of the guinea- 
fowl, i. 261 ; on the pairing of different 
species of geese, ii. 109 ; on the courtship 
of peafowl, ii. 116. 

DoBRiznoFFER, ou the marriage-customs 
of the Alipones, ii. 357. 

Dogs, suffering from Tertian ague, i. 13; 
memory of, i. 43 ; domestic, progress o^ 
in moral quaUties, i. 49 ; distinct tones 
uttered by, i. 52 ; paralleUsm between his 
affection for his master and religious feel- 
ing, i. 65 ; sociability of the, i. 71 ; sym- 
pathy of with a sick cat, i. 74 ; sympathy 
of with his master, i. 74 ; possible use of 
the hair on the fore-legs of the, i. 185 ; 
races of the, i. 221 ; diverging when di-aw- 
ing sledges over thin ice, i. 45 ; dreaming, 
i. 44, 152 ; exercise of reasoning faculties 
by, i. 47 ; their possession of conscience, 
i. 75 ; numerical proportion of male and 
female births in, i. 294 ; sexual affection 
between individuals o^ ii. 258 ; howling 
at certain notes, ii. 317 ; rolling in carrion, 
ii. 267. 

Dolichocephalic structure, possible cause 
of i. 142. 

Dolphins, nakedness of i. 142. 

Domestic animals, races of, i. 221 ; change 
of breeds ofj ii. 352. 

Domestication, influence of in removing 
the sterility of h3'brids, i. 214. 

D'Orbigny, a., on the influence of damp- 
ness and dryness on the color of the skin, 
i. 232 : on the Yuracaras, ii. 331. 

Dotterel, ii. 195. 

DouBLEDAY, E., OU sexual differences in 
the wings of butterflies, i. 334. 

DouBLEDAY, H., On the proportion of the 
sexes in the smaller moths, i. 302 ; on the 
attraction of the males of Lnfsiocampa 
queriius and Satuniia carpini by tho 
female, i. 303 ; on the propoi-tion of the 
sexes in the Lepidoptera, i. 303 ; on the 
ticking of AnoMiim tessellatum, i. 373 ; 
on the structure ot Ageronia feronin. i. 
375 ; on white butterflies alighting upon 
paper, i. 378. 



402 



INDEX. 



DonoLAS, J. "W., on the sexual differences 
of the //emiptera, i. 339 ; on the colors 
of IJriHsh riomojitera, i. 841. 

Down, of birds, 11. 77. 

Jhraco. (Hilar appondapes of, II. 81. 

l)RA<ioNET, Ui'iiiini-ou.s. ii. 7. 

Draoon-fi-iks. caudal apj)enda(res of male, 
1. ftW ; relative size of llie sexes of, i. *J7; 
diffei-ence in the sexes of, i. 351 ; want of 
pupnacity by the male, i. 3.5;}. 

Drake, breeding pluinat'e of the. il. SI. 

DREA.M8, i. 44 ; a possible source of the be- 
lief in spiritual afreucie-s, i. 04. 

Drill, sexual difference of color in the, ii. 
2TS. 

Dromaim irrm-atnx, ii. 196. 

DromoUia. Saharan species o^ ii. 164. 

Dronoo shrike, ii. 171. 

Drongos, nieket-shaped feathers in the 
tails oC ii. 7(1. 80. 

Dryness, of cliuiate, supposed influence of, 
on the color of the skin, i. 233. 

Dn/ojHthecuM. i. IStl. 

DccK, harlequin, aire of mature phimape in 
the, ii. 2(>4 ; breeding in immature plu- 
mage, ii. 205. 

DccK, lonfT-tjiiled, preference of male, for 
certain females, ii. 117. 

Duck, pintail, pairing with a wigeon, ii. 
109. 

Duck, voice of the, ii. 57 ; pairing with a 
shield-drake, ii. 109 ; immature plumage 
of the, ii. 1»0. 

Duck, wild, sexual differences in the, 1. 
260; speculum and male characters of, 
1. 2S1 ; pairing with a pintail drake^ ii. 
110. 

Ducks, dogs and cats recognized by. ii. 106 ; 
wild, becoming polvgamous under partial 
domesticatiou, i. 2ftl. 

DuooNo, tusks ot ii. 231 ; nakedness o^ 1. 
142. 

DuJARDiN, on the relative size of the cere- 
bral ganglia in insects, i. 139. 

Duncan, Dr., on the fertility of early mar- 
riages, i. 167. 

DUPONT, M., on the occurrence of the sn- 
pra-condyloid foramen in the humerus 
of man, i". 28. 

Durand, J. P., on causes of variation, i. 109. 

DlTREAU de la Malic, on the songs of birds, 
i. .53 ; on the acquisition of an air by black- 
birds, ii. 52. 

Dutch, retention of their color by the, in 
South .\frica. i. liVi. 

Duty, sense of, i. 67. 

DuvAucEL, female Ilyiohates washing her 
young, i. 39. 

Dyaks. pride of, in mere homicide, i. 90. 

DyniiKteji, large size of males of i. 337. 

Dynastini, strldulation of. i. 369 

J>ytiMCtn<^ diinoriibisin of females of, i. 333; 
grrooved elytra of the female, i. 333. 

E. 

Eaole, young OrcoptVAeciM rescued from, 
by the troop, i. 72. 



Eaoi.r, white-headed, breeding In Imma- 
ture plumage, ii. 205. 

Kakles, golden, new mates found by, U. 
100. 

Ear, motion of the. 1. 20 ; external shell of 
the. useless in man, i. 21 ; rudimentary 
point (if the. in man. i. 21. 

Ears. i)iercing and ornamentation of the, 
ii. .32.5. 

Eclii'hui. i. 193. 

Kchini, bright colors of some, i. 818. 

EciiiNODERM ATA, abscnce of secondary sex- 
ual characters in, i. 812. 

EcKEH. figure of the human embrj-o. 1. 15; 
on sexual (litferences in the pelvis in man, 
ii. 3(»2 ; on tin- ]insence of a sagittal crest 
in .\ustr.ilians. ii. 3(4. 

EuENTATA. former wide range of in Amer- 
ica, i. 211; absence of secondary sexual 
characters in. i. 259. 

FiloliuM^ racket-shai)ed feathers in, ii. 70. 

EnwAuns, Mr., on the jiroportion of tho 
sexes in North American species of Pa- 
pilio. i. .SOI. 

EoERToN, Sir P., on the use of the antlers 
of deer, ii. 241 ; on the paiiing of red deer, 
ii. 257 ; on the bellowing of stags, ii. 261. 

Eggs, hatched by male fishes, ii. 19. 

Egret, Indian, sexes and young of^ ii. 203. 

Egrets, breeding plumage of, ii. 7!) ; white, 
ii. 21 S. 

EnRENHERG, On the mane of the male Ha- 
niadryas baboon, ii. 2.55. 

Ekrtikim. M.. on lltireUlti glaeiaiiH. ii. 117. 

Ehtchitita riifo<:hierea, habits of male, i. 
303. 

Eland, development of the horns of the, L 
2S0. 

Elands, sexual differences of color in, ii. 
274. 

Elii])komyin. sexual differences in, t. 838. 

EliiphvuM ii/iginoxuji, stridulation of^ i. 368. 

EUipn, ii. 30. 

Elaterid-e, proportions of the sexes in, 1. 
305. 

Elaters, luminous, i. SH5. 

Elephant, i. 193; nakedness of the. 1.145; 
rate of increase of the, i. 180; Indian, 
polvgamous habits of the, i. 259 ; pugna- 
city of the male. ii. 229 ; tusks of, ii. 231, 
232, 237, 247 ; Indian. iiio<le of tighting, 
of the, ii. 245 ; male, odor emittiHl by the, 
11. 266; attacking white or grav horses, 
ii. 281. 

Elevation of abode, modifWng influence 
of. i. 116. 

Elimination of inferior individuals, 1. 165. 

Elk, ii. 237 ; winter change of the, iL 284. 

Elk, Irish, horns of the, ii. 247. 

Ellice Islands, beards of the natives, ii. 
307. 3:«. 

Elliot, K., on the numerical proportion of 
the sexes in young rats, i. 296 ; on tho 
proportion of the se.\es in sheep, i. 296. 

Elliott, D. O.. on Peiecanus erythro- 
rhyn<ihufi. ii. 77. 

Elliott, Sir W., on the polygamous hab- 
its of the Indian wild -boor, i. 259. 



INDEX. 



403 



Ellis, on the prevalence of infanticide in 
Polynesia, ii. 347. 

Elphinstone, Mr., on local differences of 
stature among the Hindoos, i. 110; on 
the difficulty of distingTiishing the native 
races of India, i. 207. 

Elytra, of the females of Dytismis, Aci- 
livs, ilydroponm^ i. 333. 

Emberiza, characters of young, ii. 176. 

Emheriza miliaria, ii. 177. 

Emheriza schomichui, ii. 106 ; head-feath- 
ers of the male, ii. 91. 

Embryo of man, i. 14, 15; of the dog, 
i. 15. 

Embryos of mammals, resemblance of the, 
i.81. 

Emigration, i. 166. 

Emotions experienced by the lower ani- 
mals in common with man, ;. 38 ; mani- 
fested by animals, i. 41. 

Emperor moth, i. 385. 

Emulation of singing-birds, ii. 50. 

Emu, sexes and incubation of, ii. 196. 

Endurance, estimation of i. 91. 

Energy, a characteristic of men, ii. 313. 

England, numerical proportion of male 
and female births, in, i. 291. 

Engleheaet, Mr., on the finding of new 
mates by starlings, ii. 101. 

English, success of, as colonists, 1. 172. 

Engravers, short-sighted, i. 113. 

Entomostraca, i. 323. 

Entozoa, difference of color between the 
males and females of some, i. 312. 

Eocene, possible divergence of man dur- 
ing the, i. 192. 

EoLiD^ colors of, produced by the biliary 
glands, i. 314. 

Epeira, i. 828. 

Epeira nigra, small size of the male of i. 
829. 

Ephemera, i. 831. 

Ephemerid^ i. 350. 

Ephemerina, i. proportions of the sexes 
in, i. 806. 

Ephippiger mliiim, stridulating organs 
of i. 844, 348. 

Epicalia, sexual differences of coloring in 
the species ot; i. 876. 

Egmti hemicnim, winter change o^ ii. 284. 

Erateina, coloration of, i. 385. 

Erect attitude of man, i. 136. 

EscHRiCHT, on the development of hair in 
man, i. 24 ; on a lanuginous mustache 
in a female foetus, i. 25; on the want of 
definition between the scalp and the fore- 
head in some children, i. 186; on the ar- 
rangement of the hair in the human 
foetus, i. 186; on the hairiness of the face 
in the human foetus of both sexes, u. 862, 
363. 

Esmeralda, difference of color in the sex- 
es of, i. 356. 

Esox luHvs, i. 299. 

Esox retieulatiis, ii. 14. 

Esquimaux, i. 151, 160; their belief in the 
Inheritance of dexterity in seal-catching, 
i. 113 ; mode of Ufe oi;"i. 287. 



EstreMa amandava, pugnacity of the 
male, ii. 46. 

Evbaffis, se.xual differences of coloring in 
the species of; i. 377. 

Enckirus langimanus, sound produced 
by, i. 370. 

Eudromias morinelhm, ii. 194. 

Etdamjns jugulari-s, colors of the female, 
ii. 160. 

EuLER, on the rate of increase in the Uni- 
ted States, i. 126. 

Eiimomota »uperciliaris, racket-shaped 
feathers in the tail ef, ii. 70. 

Eiipetomena maeroura, colors of the fe- 
male, ii. 160. 

Enphema splendida, ii. 166. 

Euplocamw erythrophthalmim, posses- 
sion of spurs by the female, ii. 44. 

Euplma miitamas, mimickry of, by the 
female of Diadema anomala, i. 400. 

Europe, ancient inhabitants of, i. 228. 

Europeans, difference of fiom Hindoos, 
i. 231 ; hairiness of; probably due to re- 
version, ii. 361. 

Erirostopodii^, sexes of ii. 197. 

Eurygnathns, different proportions of the 
head in the sexes of i. .334. 

EtiMepha-rms, sexual differences of species 
of, ii. 37 ; young of, ii. 211. 

Exaggeration of natural characters by 
man, ii. 334. 

Exogamy, ii. 344, 848. 

Expression, resemblances in, between 
man and the apes, i. 184. 

Extinction of races, causes of i. 229. 

Eye, destruction of the, i. 112; change of 
position in, i. 141 ; obliquity of regarded 
as a beauty by the Cliinese and Japan- 
ese, ii. 328. 

Eyebrows, elevation of, i. 19 ; develop- 
ment of long hairs in, i. 24; in monkeys, 
i. 185; eradicated in parts of South 
America and Africa, ii. 324 ; eradication 
o^ by the Indians of Paraguay, ii. 332. 

Eyelids, colored black, in part of Africa, 
ii. 323. 

Eyelashes, eradication of; by the Indians 
of Paraguay, ii. 332. 

Eyes, difference in the color of in the sex- 
es of birds, ii. 123; pillared, of the male 
of Chloean, i. 381. 

Eyton, T. C, observations on the develop- 
ment of the horns in the fallow-deer, i. 
279. 

Eyzies, Les, human remains from, i. 228. 



F. 

Fabre, M., on the habits of Cerceris 1. 
353. 

Facial bones, causes of modification of 
the, i. 141. 

Faculties, mental, variation of in the 
sam.e species, i. 35 ; diversity of, in the 
same race of men, i. 105 ; inheritance of; 
i. 106; diversity of; in animals of the 
same species, i. 106 ; of birds, ii. 104. 



404 



L\DEX. 



Fakiks, Indian, tortures iinderRone by, 1. 

92. 
Fdico Uucorepfnilwt, ii. 205. 
FaU-o perenrinim. it. 1(W. 179. 
Fiilfo tinniineiiliiH. ii. 100. 
Falcon, percfjrino, new mate found by, U. 

100. 
Falconer, II., on the mode of flphtinjj of 
tlio Indian eicphnnt ii. 24i>; on canines 
in a female deer, ii. 24C; on llyomoschus 
a<]>iati4'iiit, ii. 2^9. 

Falkland iHlands, horses of, i. 227. 

Fallow-deer, ditlbrent colored herds ot 
ii. 2S1. 

Famines, frequencv of, among' savages, 1. 
229. 

Farr. Dr., on the structure of the uterus, 
i. US; on the effects of profligacy, i. 166; 
on the intlucnce of marriage on mortali- 
ty, i 169. 

Farrar, F. W., on the origin of language, 
i. 54 ; on the crossing or blending of lan- 
guages, i. OS; on the absence of the idea 
of (iod in certain races of men, i. 6:^ ; on 
early marriages of the poor, i. 167; on 
the middle ages. i. 172. 

Fashions, long prevalence of; among sav- 
ages, ii. 327, 336. 

Fave, Prof'., on the numerical proportion 
of male and female births in Nonvay and 
Kussia, i. 291 ; on the greater mort.'ility 
of male children at and before birth, i. 
292. 

Feathers, modified, producing sounds, ii. 
60; et »eqq., 1.56; elongatefl, in male 
binis, ii. 69, 93 ; racket-shaped, ii. 70 ; 
barbless and with filamentous barbs in 
certain birds, ii. 70 ; shedding of margins 
of, ii. 82. 

Feedino, liigh, probable influence of in 
the pairing of birds of different species, 
ii. 111. 

Feet, modification of in man, i. 136; thick- 
ening of the skin on the soles of the, 1. 
113. 

Feli^i C(inaifeiiiti\ throat-ruff of ii. 273. 

Felis pardalin and /'. tnitis. sexual differ- 
ences in the coloring of ii. 273. 

Female, behavior of the, during courtship, 
1. 2f4. 

Female birds, differences of, ii. 18.5. 

Females, presence of rudimeiit;iry male 
organs in, i. 199; preference of for cer- 
tain males, i. 254; pursuit of by males, 
i. 263; occurrence of secondary se.xual 
characters in, i. 267; development of 
male characters by, i. 271. 

Females and males, comparative mortali- 
ty of while young, i. 255, 267; compara- 
tive nuHibers of i, 252, 2.55. 

Femur and tibia, proportions of, in the 
Aymara Indians, i. 115. 

Fer(;u80N, Mr., on the courtship of fowls, il. 
11.3. 

Fertilization, phenomena of in plants, I. 
265; in the lower animals, i. 206. 

Fevers, immunity of Negroes and Mulat- 
tocB from, i. 234. 



Fihfr HhetfticJiA, protective coloring of^ ii. 
2.St. 

Fidelity of savages to one another, i. 91 ; 
importance of i. 156. 

Field-slaves, difference of^ ftom house- 
slaves, i. 237. 

Fi.iiANS, bur>-ing their old and sick parents 
alive, i. 74; estimation of the beard 
among the, ii. 3:^; admiration of^ for a 
broad occiput, ii. 335. 

Fi.ii Islands, beards of the natives, ii. 306, 
333; marriage-customs of the, ii. libO. 

Filial afl'ection, partly the result of natu- 
ral selection, i. 77. 

FiLr.M terminale, i. 29, 

Finch, racket-shaped feathers in the tail 
of a, ii. 70. 

Finches, spring change of color in, iL 82 ; 
British females of the, ii. 18.5. 

FiN(iERs, partiallv coherent, in species of 
Jli/lnhiite«. i. l:U. 

FiNi.AYSoN, on the Cochin-Chinese, il. 829, 

Fire, use of, i. 132, 176, 22.5. 

FisrnER, on the pugnacity of the male of 
J.ethriis cfpluiloten, i. Sfe. 

Fish, proportion of the sexes in, 1. 298; 
eagerness of male, i, 26;}, 

Fishes, kidneys of, represented bv Cor- 
pora Wolfliana in the human embr}-o, L 
16; male, hatching ova in their mouths, 
i. 202 ; receptacles for ova possessed by, 
i. 246 ; relative size of the sexes in, ii. 7 : 
fresh-water, of the tropics, ii. 17 ; protec- 
tive resi'inblances in, ii. 18; nest- build- 
ing, ii. 19; spawning of, ii. 18; sounds 
proiluced bv, ii. 22, 315; continued 
growth of, ii." 207. 

Flea-or pollicit< longus, similar variation 
of. in man, i. 124. 

Flint tools, i. 176. 

Flints, difficulty of chipping into form, 1. 
i:W. 

Florida, Quiwahiti major in, i. 298. 

Flounder, coloration of the, ii, 18. 

Flower, W. H., on the abductor of tho 
fifth metatarsal in apes, i. 12-3 ; on the 
I)osition of the Seals, i. Is;}; on the 
throat-pouch of the male Bustard, ii. 
55. 

Fly-catchers, colors and nidiflcation o^ 
ii. 162. 

FtETUS, human, woolly covering of the, L 
25 ; arrangement of the hair on. i. 186, 

Food, influence of upon stature, i. 110. 

Foot, prehensile, in the early progenitors 
ofman, i, 198; preliensile power of the, 
retiiined in some savages, i. 136. 

Foramen, supra-condyloid, exceptional oc- 
currence of in the humerus of man, i. 27, 
125 ; in the early progenitore of man, 1. 
198. 

Forbes, D., on the Aymara Indians, 1. 
115; on l(K-al variation of color in the 
Quechuas, 1. 237 ; on the liairlessness of 
the Aymarns and Quechuas. il. 307; on 
the long hair of the Ayuianis and Que- 
chuas. ii. 80,5. :«1. 

FoBEL, F., on wliitc young swans, iL 202. 



INDEX. 



405 



Formica rufa, size of the cerebral ganglia 
in, i. 139. 

Fossrts, absence o^ connecting man with 
tho apes, i. 193. 

Fowl, occurrence of spurs in the female, 
1. 271 ; game, early pugnacity o^ i. 285 ; 
Polish, early development of cranial pe- 
culiarities ot, i. 285; variations in plu- 
mage o^ ii. 71; examples of correlated 
development in the, ii. 124; domestic, 
breeds and subbreeds of, ii. 168. 

Fowls, spangled Hamburg, i. 272, 284; 
sexual peculiarities in, transmitted only 
to the same sex, i. 274 ; loss of secondary 
sexual characters by male, i. 275 ; inher- 
itance of changes of plumage by, i. 272 ; 
Polish origin of the crest in, i. 275 ; period 
of inheritance of characters by, i. 284 ; 
cuckoo-, i. 285; development of the 
comb in, i. 285; numerical proportion of 
the sexes in, i. 296; courtship of, ii. 112; 
mongrel, between a black Spanish cock 
and different hens, ii. 125; pencilled 
Hamburg, difference of the sexes in, ii. 
151 ; Spanish, sexual differences of the 
comb in, ii. 151 ; spurred, in both sexes, 
U.155. 

Fox, W. C, on some half-tamed vrild- 
ducks becoming polygamous, and on 
polygamy in the guinea-fowl and canary- 
bird, i. 261; on the proportion of the 
sexes in cattle, i. 295 ; on the pugnacity 
of the peacock, ii. 43 ; on a nuptial as- 
sembly of magpies, ii. 98 ; on the finding 
of new mates by crows, ii. 100; on par- 
tridges hving in triplets, ii. 103; on the 
pairing of a goose with a Chinese gander, 
ii. 110. 

Foxes, wariness of young in hunting dis- 
tricts, i. 48 ; black, ii. 280. 

Feakce, numerical proportion of male and 
female births in, i. 292. 

Francesco, B., on the Simian resemblances 
of man, i. 4. 

Fraser, C, on the different colors of the 
sexes in a species ot Squilla, i. 326. 

Fringilla cannaMna, ii. 82. 

Fringilla dris, age of matui'e plumags in, 
ii. 204. 

Fringilla cyanea, age of mature plumage 
in, ii. 204. 

Fringilla leucophrys, young o^ ii. 208. 

Fringilla spinus, ii. 110. 

Fringilla tristis, change of color in, in 
spring, ii. 82 ; young of; ii. 207, 

FR1NGILLID.E, resemblance of the females 
of distinct species o£ ii. 184. 

Frogs, ii. 24 ; male, temporary receptacles 
for ova possessed by, i. 246; ready to 
breed before the females, i. 252; vocal 
organs of ii. 28. 

Frontal bone, persistence of the suture 
in, i. 120. 

Fkitits, poisonous, avoided by animals, i. 

FuEGiANS, i. 160, 174; mental capacity of 
the, i. 83 ; quasi-reliipous sentiments of 
the, i. 65; power of sight in the, i. 114; 



skill of, in stone-throwing, i. 156 ; resist- 
ance of the, to their severe climate, i. 
150, 229 ; difference of stature among the, 
i. Ill ; mode of life of the, i. 237; resem- 
blance of, m mental characters, to Euro- 
peans, i. 223 ; aversion of, to hair on the 
face, ii. 332; said to admire Em-opean 
women, ii. 334. 

FtTLGORiD.!;, songs of the, i. 340. 

FuK, whiteness of, in arctic animals, in 
winter, i. 273. 

Fur-bearing animals, acquired sagacity 
of, i. 48. 

G. 

GalUcrex, sexual difference in the color of 
the irides in, ii. 123. 

Gallierex cristatuj), red caruncle occurring 
in the male during the breeding-season, 
ii. 76. 

GALLINACE.E, frequency of polygamous 
habits and of sexual differences in the, i. 
260 ; love-gestures of, ii. 65 ; decomposed 
feathers in, ii. 70 ; stripes of young, ii, 
176; comparative sexual differences be- 
tween the species oi, ii. 184, 185; plu- 
mage of, ii. 187. 

Gallinaceous birds, weapons of the male, 
ii. 42; racket-shaped feathers on the 
heads oi; ii. 70. 

Gallinula chUrropus, pugnacity of male, 
ii. 38. 

Gallinula crislata, pugnacity of the male, 
ii. 39. 

Galloperdia; spurs of ii. 44 ; development 
of spurs in the female, ii. 155. 

Gallophasis, young of ii. 182. 

Gallus banH-va, ii. 151 ; neck-hackles o^ 
ii. 81. 

Gallus Stanleiji, pugnacity of the male, ii. 
42. 

Galls, i. 146. 

Galton, Mr., on the struggle between the 
social and personal impulses, i. 99 ; on 
hereditary genius, i. 106; on the effects 
of natural selection on civilized nations, 
i. 161 ; on the sterility of sole daughters, 
i. 164; on the degree of fertility of people 
of genius, i. 165; on the early marriages 
of the poor, i. 167; on the ancient Greeks 
i. 171 ; on the Middle Ages, i. 171 ; on 
the progress of the United States, i. 172 ; 
on South Aiiican notions of beauty, ii. 
331. 

Gammarus, use of the chelae of, i. 331. 

Gammarus marin us, i. 323. 

Gannets, white only when mature, ii. 218. 

Ganoidei, i. 196. 

Ganoid fishes, i. 204. 

Gaour, horns of the, ii. 236. 

Gap between man and the apes, i. 192. 

Gaper, sexes and young of, ii. 208. 

Gardner, on an example of rationaUty in a 
Gelasimns, i. 324. 

Garrulus glandarixi^, ii. 100. 

Gartner, on sterihty of hybrid plants, L 
215. 



406 



INDEX. 



Gartf.ropoda. 1. 815; inilnionlferous, court- 
ship of. i. mri. 

GaxUroMfeiM, I. 200; nWinontion o^ 11. 19. 

GatUrOMteim Ifiiiriis, 11. 'i, 14, 19. 

GiuteroMtfiM tnichurini. ii. 2. 

Oastrophora. wings o^ brightly colored 
boneath, i. )i<i. 

Gaucuos, want of liumanity among the, 1. 
97. 

Gaudrt, M., on a fossil monkey, 1. 1S9. 

Garia seasonal change of ijluiiiago in, il. 
218. 

Gekse, clanging noise made by, ii. 49 ; pair- 
ing of ditlorcnt spicifs of. ii. 109; Cana- 
da, selection of mates t>y, ii. 112. 

Gegenbaur. ('., on the number of digits in 
the I(htliy(>i>terygia, i. 120; on the her- 
niajiliniilitism ol' the remote progenitors 
of the virttlmita, i. 199. 

GtUiKimuK. use of the enlarged chela of the 
male, i. 822; pugnacity of males ot, 1. 
82;} ; proportions of the sexes in a spe- 
cies of. i. 807 ; rational actions of a, i. 325; 
diffiTence of color in the sexes of a spe- 
cies of, i. 327. 

Gemmules, sexual selection ot, i. 297. 

Genesis, i. 310. 

Genius, ii. 312 ; hereditary, i. 106. 

Genius, fertility of men and women ot; i. 
165. 

Geoffeot Saint - HiLAiKE, Isid., on the 
recognition of women by male quadru- 
mana, i. 13 ; on the occurrence of a rudi- 
mentary tail in man, i. 2S ; on monstrosi- 
ties, i. los; on animal-like anomalies in 
the human structure, i. 120; on the cor- 
relation of monstrosities, i. 125; on the 
distribution of hair in man and monkeys, 
i. 143; on the caudal vertebne of mon- 
keys, i. 144; on correlated variability. 1. 
146; on the classification of man. i. 179; 
on the long hair on the heads of species 
of S,)n)i()jiif/i,cii.i. i. 1'^; on the hair in 
monkeys, i. IsO; on the development of 
horns in female deer. ii. 2*3 ; and F. Cu- 
vier, on the mandrill, ii. 27S; on llylo- 
bates, ii. 3o;?. 8ii5. 

Geocrapiiuai. (listritmtion, as evidence of 
speeilic (listinctions in man. i. 210. 

GEo.MCTK.r, biightly coloreil beneath, i. 3S5. 

Geo/i/iti(;iiM. frontal prolulnrance of male, 
ii. 13. 20; eggs hatcliiil by the male, in 
the mouth or branchial cavity, ii. 192. 

Georgia, change of color in Germans set- 
tled in, 1. 237. 

Geotrupex, stridulation of. i. 869, 870. 

Gerbe, M.. on the nest-building of Crenila- 
l/riM nuiMMa and (\ me/opn. ii. 19. 

Gerland. Dr.. on the prevalence of Infanti- 
cide, i. 90 ; ii. 32S. .348 ; on the extinction 
of races, i. 22a 229. 

Gervais, p., on the hairiness of the gorilla, 
I. 143 ; on the mandrill. U. 278. 

Gestuke-lanouage, i. 224. 

GiiosT-MOTii, sexual difference of color in 
the. i. 3s6, .390. 

Giiiii. Sir I)., on differences of the voice In 
dillerent races of men, ii. 815. 



Gin RON, IToolock. nose oi; 1. 184. 

(iiBBOss, voice of; ii. 263. 

OiRAKFF« mute, excejit in the rutting sea- 
son, ii. 201 ; Its mode of using the boms, 
ii. 2;W. 

GiRAUD - Teulox, on the cause of short 
Right i. 114. 

Glanders, communicable between man 
and the lower animals, i. 11. 

Glands, odoriferous, in mammals, 11. 266, 
207. 

Glareola, double moult in, ii. 77. 

GUtmeriii limlmta. diftenmce of color in 
the sexes of. i. 331. 

Glowworm, female, apterous, 1. 247 ; lumi- 
nosity of the, i. 3;35. 

Gnats," dances oC i. 339. 

Gnu, sexual difl'erences in the color of the, 
ii. 275. 

Goat, male, wild, falling on his horns, 11. 
23S; male, odor emitted by. ii. 260; male, 
wild, crest of the. ii. 20.S; Berbura, mane, 
dewlap, etc., of the male, ii. 271 ; Kemas, 
sexual difference in the color of the, ii. 
275. 

Goats, sexual differences in the horns o? 
1. 274; horns of, i. 2S0. ii. 235; domestic, 
sexual differences of late developed, i. 
293 ; beards of; ii. 209 ; mode of fighting 
of, ii. 23S, 239. 

Goatsucker, Virginian, pairing of the, ii. 
47. 

Gobies, nidification of, ii. 19. 

God, want of the idea of; in some races of 
men, i. 62. 

GoDRON, M., on variabilit}'. i. 108; on dif- 
ference of stature, i. 1 1 1 ; on the want of 
connection between climate and the color 
of the skin, i. 232 ; on the odor of the 
skin, i. 239; on the color of Infants, U. 
803. 

Goldfinch, ii. 5.3. 79; proportion of the 
sexes in the, i. 29S ; sexual difl'erences of 
the beak In the, ii. 87 ; courtship of the, 
ii. 91. 

GoLDiTSCH, North American, young o^ ii. 
207. 

GoLD-Fisn, ii. 16. 

GomphuK, proportions of the sexes In, 1. 
816; difference in the sexes o£ i. 351. 

Goiieptenjx lilnimiu. i. 8!S0 ; sexual differ- 
ence of color in, i. 396. 

GooDSiK. Prof., on the affinity of the lance- 
let to the ascidians, i. 196. 

Goosander, young of; ii. 181. 

Goose, Antarctic, colors of the, 11. 218. 

Goose, Canada, pairing with a Bernicle 
gander, ii. 109. 

GoosF, Chinese, knob on the beak of the, 
ii. 124. 

Goose, Egj-ptian, ii. 44. ■ 

Goose, Sebastopol. plumage of, ii. 69. 

Goose, Snow-, whiteness of the, ii. 218. 

Goose, Spur-winged, ii. 44. 

Gorilla, ii. 80S; semi-erect attitude of 
the, 1. 137; mastoid processes of the, i. 
13S, din^ction of the hair on the arms of 
the, i. 185; supposed evolution of the, i 



INDEX. 



407 



222; polygamy of the, i. 258, ii. 345, 346 ; 
voice of the, ii. 262 ; cranium of, ii. 303 ; 
fighting of male, ii. 309. 

GossE, P. H., on the pugnacity of the male 
Humming-birds, ii. 38. 

GossE, M., on the inheritance of artificial 
modifications of the skull, ii. 364. 

Gould, B. A., on variation in the length of 
the legs In man, i. 104; measurements of 
American soldiers, i. 110, 112 ; on the pro- 
portions of the body and capacity of the 
lungs in different races of men, i. 208 ; on 
the inferior vitaUty of mulattoes, i. 
213. 

Gould, J., on the arrival of male snipes be- 
fore the females, i. 251 ; on the nuiuerieal 
proportion of the sexes in birds, i. 297; 
on NeomorpTia, ii. 37 ; on the species of 
EiiMephanvAi^ ii. 37; on the Australian 
Musk-duck, ii. 37 ; on the relative size of 
the sexes in Biziura lohata and Cinclo- 
ramphus eruralis, ii. 41 ; on Lohivanel- 
hts lobatus, ii. 46 ; on the habits of Me- 
nura Alberii, Ii. 53; on the rarity of 
song in brilliant bii'ds, ii. 55; on Selas- 
phorus platycemt.% ii. 62; on the Bow- 
er-birds, ii. 66, 98; on the ornamental 
plumage of the Humming-birds, ii. 75 ; 
on the moulting of the ptarmigan, ii. 79 ; 
on the display of plumage by the male 
Humming-birds, ii. 82; on the shj-ness 
of adorned male birds, ii. 93 ; on the dee- 
oration of the bowers of Bower-birds, ii. 
107; on the decoration of their nests by 
Humming-birds, ii. 107 ; on variation in 
the genus Cynanthiis, ii. 121 ; on the col- 
or of the thighs in a male p.arakeet, ii. 
121; on Uroxticte Benjamini, ii. 145, 
146 ; on the nidiflcation of the Orioles, ii. 
160; on obscurely -colored birds building 
concealed nests, ii. 161 ; on Trogons and 
Kingfishers, ii. 165; on Australian par- 
rots, ii. 166; on Australian pigeons, ii. 
167 ; on the moulting of the pUirmigan, 
ii. 173; on the Immatm-e plumage of 
birds, ii. 178 et seq. ; on the Australian 
species of Turnix, ii. 192 ; on the young 
of AithurxM polytm us, ii. 211 ; on the 
colors of the bills of Toucans, ii. 217 ; on 
the relative size of the sexes in the Mar- 
supials of Australia, ii. 248; on the colors 
of the Marsupials, ii. 272. 

GouREAU, on the stridulation of Jfutilla 
Europcea, i. 355. 

Gout, sexually transmitted, i. 2S3. 

Gkaba, on the Pied Eavens of the Feroe 
Islands, ii. 121 ; on the Bridled Guille- 
mot, ii. 122. 

Geadation of secondary sexual characters 
in birds, ii. 129. 

Geallatores, absence of secondary sexu- 
al characters in, i. 261 ; double moult in 
some, ii. 77. 

GralHna, nidiflcation of, ii. 161. 

Gkasshoppers, stridulation of the, i. 346. 

Geatiolet, Prof., on the anthropomor- 
phous apes, i. 189; on the evolution of 
the anthropomorphous apes, i. 227. 



Gray, Asa, on the gradation of species 
among the Composite, i. 219. 

Gray, J. E., on the caudal vertebrse of 
monkeys, i. 145 ; on the presence of ru- 
diments of horns in the female of Cervu- 
Itts moschatiis, ii. 234; on the horns of 
goats and sheep, ii. 235 ; on the beard of 
the Ibex, ii. 269; on the Berbura goat, 
ii. 271 ; on sexual differences in the col- 
oration of Rodents, ii. 272 ; on the colors 
of the Elands, ii. 274 ; on the Sing-sing 
antelope, ii. 275; on the colors of goats, 
ii. 276 ; on the Hog-deer, ii. 289. 

" Greatest happiness principle," i. 93, 94. 

Greeks, ancient, i. 171. 

Green, A. H., on beavers fighting, ii. 228 ; 
on the voice of the beaver, ii. 263. 

Greenfinch, selected by a female canary, 
ii.llO. ^ '' 

Greg, W. E., on the early marriages of 
the poor, i. 167 ; on the ancient Greeks, 
i. 171 ; on the effects of natural selection 
on civilized nations, i. 161. 

Grenadiers, Prussian, i. lOS. 

Grey, Sir G.. on female infanticide in Aus- 
tralia, ii. 348. 

Greyhounds, numerical proportion of the 
sexes in, i. 255, 256 ; numerical propor- 
tion of male and female bhths in, i. 
294. 

Grouse, red, monogamous, i. 261 ; pugna- 
city of young male, ii. 46 ; producing a 
sound by scraping their wings upon 
the gi-ound, ii. 59 ; duration of courtship 
of^ ii. 96 ; colors and nidiflcation of, ii. 
163. 

Geube, Dr., on the occurrence of the su- 
pra-condyloid foramen in the humerus 
of man, i. 27. 

Cfriis Amerioanus, age of mature plumage 
in, ii. 204; breeding in immature plu- 
mage, ii. 205. 

OriM Virgo, trachea o£ ii. 57. 

GryUua cumpestris, i. 343 ; pugnacity of 
male, i. 849. 

CrryUiis domestic^, i. 343. 

Grypua, sexual differences in the beak in, 
ii. 37. 

Guanacoes, battles of; ii. 228; canino 
teeth of; ii. 246. 

Guanas, strife for women among the, ii. 
309 ; polj'andry among the, ii. 349. 

Guanche skeletons, occui-rence of tho 
supra-condyloid foramen in the humerua 
of, i. 28. 

Guaranys, proportion of men and women 
among, i. 292 ; color of new-born children 
of the, ii. 303 ; beards of the, ii. 307. 

GuE.NEE, A., on the sexes of Ilyperythra, 
i. 301. 

GuiLDiNe, L., on the stridulation of tho 
Locuatidm, i. 342. 

Guillemot, variety of the, ii. 122. 

GuiNE.i, sheep of^ with males only horned, 
i. 280. 

Guinea-fowl, monogamous, i. 361 ; occa- 
sional polygamy of the, i. 261 ; markmgs 
of the, u. 129. 



408 



INDEX. 



GuiNEA-pir.R, inherltanrc of tlic cflfects of 
operutions by, ii. StK. 

Gull, Instanoe of rcnsDninp in a. ii. 104. 

Gulls, seasonal chari(,'e of iiluiiiagu in, ii. 
218; white, ii. 218. 

GOntiier, Dr., on hcrmaphroditi.sin in 
«Scrra;i(M, i. 200; on male ti.-ilies liatch- 
Inp ova In their mouths, i. '201, Ii. 19; on 
mi.stakin^' infertile female lishes for 
male.s, i. 2SN ; on tlie j)rehensile orpans 
of mule I'lapiostomous fishes, ii. 2 ; on 
the pugnacity of the male salmon and 
trout, ii. 3 ; on tlie relative size of the 
8exes in fishes, ii. 7 ; on se.xual dift'or- 
ences in lislies, ii. 8 et ne/jq. ; on the ge- 
nus CalliimipniiJ), ii. 9; a protective re- 
Bemhlancp in a IMpe-tish, ii. 18; on the 
genus SolfiioKtoma. ii. 21 ; on Me(/a- 
lojihri/K in oil tana, ii. 25; on the colora- 
tion of frogs and toads, ii. 26; on sexual 
dill'erences in the Opliidiii, ii. 72 ; on dif- 
ferences of the sexes of lizards, ii. 80 et 
seqq. 

G^j/nunina Inis, ocellated spots of. ii. 127. 

Gypsies, unilbrmity ot; in various parts of 
the world, i. 233. 

H. 

Habits, bad, facilitated by familiarity, i. 
97; variability of the force of, i. liG. " 

Hackel. E.. on the origin of man, i. 4; 
on riKliinciitary charaet<.'rs, i. 17; on the 
canine tilth in man. i. 121; on death 
caused i>y iiillammation of the veruii- 
form appendage, i. 27 ; on the st«'ps by 
which man became a biped, i. 136; on 
man as a member of the Catarrhine 
prtm|), i. 191 ; on the po.sition of the Lc- 
jiHiriilu'. i. 194; on the genealogy of the 
Manunalia, i. 195; on the lancelet, i. 19(>; 
on the transparency of pelagic animals, 
i. 814; on the musical powers of women, 
ii. 821. 

Hagen, n., and Walsh, B. D., on Ameri- 
can neuroi)teni, i. 306. 

Hair, development of, in man, i. 24; char- 
acter of, supposed to be determined by 
light and heat, i. Ill; tribution of, in 
man, i. 144. ii. 359; possibly removed for 
ornamented i)Urpose.s, i. 143; arrange- 
ment ami direction of, i. 185; of the ear- 
ly progenitors of man. i. 198; diH'erent 
textui-e ot; in distinct races, i. 208; and 
skin, correlation of color of, i. 238; de- 
velopment of, in mammals, ii. 2C8; man- 
agement of, among ditterent peoples, ii. 
324; great length of, in souio North 
American tritx'S, ii. 331 ; elongation of 
the, on the human head, ii.3(;5. 

Hairiness. dilTerence of, in the sexes in 
man, ii. 305; variation of, in races of 
men, ii. 306. 

Hairs and excretory jjores, numerical re- 
lation of, in sheep, i. 239. 

Hairy family, Siamese, ii. 361. 

Hamadrvas baboon, turning over stones, 
L 72 ; moue of the mule, ii. 255. 



Hamilton-. C. on the cruelty of the Kaf- 
fres to animals, i. 91 ; on the engross- 
ment of the women by the KalTre chiefs, 
ii. :«2. 

Hammering, difficulty o£ i, 138. 

Hancock, A., on the colors of the nudi- 
branch mollusca, i. 317. 

Hanus, larger at birtli, in the children of 
laborers, i. 113; structure of, in the quad- 
rumana, i. 134; and arms, freedom ol^ in- 
directly correlated with diminution of 
canines, i. 138. 

Handwriting, inherited, i. 56. 

Harcocrt. E. Vernon, on Fringillu can- 
nahhui. ii. 82. 

Jfareldd y/aciiiliJi, ii. 117. 

Hare, protective coloring of the, U. 284. 

Hare-s. biittles of male, ii. 228. 

Harlan, Dr., on the difference between 
field and house slaves, i. 287. 

Harris, J. M., on the relation of com- 
plexion to climate, i. 2.36. 

Harris. T. W., on the Katy-did locust, 1. 
842 ; on the stridulation of the gniss- 
lioppers, i. 846; on (EcanVius niralU, i. 
850; on the coloring of Lcpidoptera, i. 
883 ; on the coloring of Saturn ia Jo. i. 383. 

Harry-long-legs, pugnacity of male, i. 
;539. 

Hart.man, Dr., on the singing of Cicada 
neptendecem, i. 340. 

Haughton, S., on a variation of the^«ror 
pul/icix lou{iii» in man, i. 124. 

Hawks, feeding orphan nestUng, ii. 10.3. 

Hayes, Dr., on the diverging of sledge- 
dogs on thin ice. i. 45. 

Head, altered position of, to suit the erect 
attitude of man, i. 138 ; hairiness of 
in man, t 142; processes of| in male 
beetles, i. 357 ; artificial alterations of the 
form of the, ii. 3;i5. 

Hearne. on strife for women among the 
North .\merican Indiiuis, ii. 308; on the 
North .Vmeriean Indians' notion of fe- 
male beauty, ii. 828; repeated elope- 
ments of a North American woman, ii. 
856. 

Heart, in the human embryo, 1. 16. 

Heat, supposed etfects of i. 111. 

llectocotijle. i. 316. 

Hedge-warbler, ii. 1S9; voimg of the, ii. 
200. 

Heel, small projection o^ in the Ajmam 
Indians, i. 115. 

Hegt, M., on the development of the spars 
in peacocks, i. 281. 

HELicoNiD.fi, i. 375; mimicry of, by other 
butterliies, i. 39S. 

Ilel iopotln'x. stridulation peculiar to the 
male, i. 371. 

Ueliothrix auricuiata, young ot, ii. ISO, 
ISl. 

Jlelij' pomatia. example of individual at- 
tachment in, i. 316. 

Hellins, J., proportions of sexes of Lcpi- 
doptera reared by, i. 304. 

Helmiioi.tz, on the \ibration of the audi- 
tory hairs of Crustacea, iL 317. 



INDEX. 



409 



IIemiptera, i. 839. 

Jiemitragus, beai-dless in both sexes, ii. 

269. 
Hepburn, Mr., on the autumn-song' of the 

water-ouzel, ii. 51. 
Ilepialiift hiimtiH, sexual difference of 

color in the, i. 3S6, 390. 
Herbs, poisonous, avoided by animals, i. 

SO. 
IlERMAPnitoniTiSM of embryos, i. 199. 
I/erodias biibu/ews, vernal moult of, ii. SO. 
Heron, love-gestures of a, ii. 65. 
Heron, Sir R., on the habits of peafowl, ii. 

115, 116, 146. 
Herons, decomposed feathers in, ii. 70; 

breeding-plumage of, ii. 78, 79; young 

of the, ii. 200 ; sometimes dimorphic, ii. 

205; continued growth of crest and 

plumes in the males of some, ii. 206; 

change of color in some, ii. 221. 
I/etcerina, difference in the sexes of, i. 

351 ; proportion of the sexes in. i. 306. 
I/eteroeerus, stridulation of, 1. 368. 
Hewitt, Mr., on a game-cock killing a 

kite, ii. 41 ; on the recognition of dogs 

and cats by ducks, ii.l06; on the pairing 

of a wild-duck wth a jiintail drake, ii. 

110; on the courtship of fowls, ii. 112; 

on the coupling of pheasants with com- 
mon hens, ii. 117. 
Hindoo, his horror of breaking his caste, 

i. 95, 98. 
Hindoos, local difference of stature among, 

i. Ill; diffei-ence of, from Europeans, i. 

231 ; color of the beard in, ii. 304. 
Hipparchia Ja/iira, instabihty of the 

ocellated spots of, ii. 127. 
ITipparchia, i. 375. 
Hipptocampim, development of, i. 202; 

marsupial receptacles of the male, ii. 20. 
Hippopotamus, nakedness of, i. 142. 
Hips, proportions of, in soldiers and sail- 
ors, i. 112. 
Hodgson, S., on the sense of duty, i. 68. 
Hoffberg, on the horns of the reindeer, 

ii. 233 ; on sexual preferences shown by 

reindeer, ii. 200. 
Hog, wart, ii. 253 ; river, ii. 254. 
Hog-deer, ii. 289. 
Holland, Su- H., on the effects of new 

diseases, i. 280. 
Homologous structures, correlated vai-ia- 

tion of, i. 125. 
Ho.vopteka, i. 340; stridulation of the, 

and orthoptera, discussed, i. 349. 
Honduras, Quiscahis major in, i. 29S. 
Honey-buzzard of India, variation in the 

crest of, ii. 121. 
Honey-suckers, moulting of the, ii. 79 ; 

Australian, nidification ol, ii. 161. 
Honor, law of, i. 95. 
Hooker, Jos., on the color of the beard in 

man, ii. 304. 
Hoolock Gibbon, nose of, i. 184. 
Hoopoe, ii. 53; sounds produced by the 

male, ii. 60. 
Hoplopterus armatus, wing-spurs of, ii. 

37 



HoRNBiLL, African, Inflation of the neck- 
wattle of the male during com-tship, ii. 
69. 

HoRNBiLLS, sexual difference in the color 
of the eyes in, ii. 123 ; nidification and 
incubation of, ii. 161. 

HoRNB, C, on the rejection of a brightly- 
colored locust by hzards and birds, i. 351. 

Horns, of deer, ii. 232, 237, 248; and canine 
teeth, inverse development of, ii. 245, 
sexual differences of, in sheep and goats, 
i. 273 ; lass of, in female merino sheep, i 
275 ; development of^ in deer, i. 278 ; de- 
velopment of, in antelopes, i. 280 ; from 
the head and thorax, in male beetles, i. 
857. 

Horse, polj'gamous, i. 258 ; canine teeth of 
male, ii. 230; ^\Tnter change of the, ii. 
2S4; fossil, extinction of the, in South 
America, i. 231. 

Horses, dreaming, i. 44 ; rapid increase of, 
in South America, i. 130 : diminution of 
canine teeth in, i. 138; of the Falkland 
Islands and pampas, i. 227; numerical 
proportion of the sexes in, i. 255, 256; 
lighter in wnter in Siberia, i. 273 ; sexual 
jireferenccs in, ii. 260; pairing preferent- 
ly with those of the same color, ii. 2S1 ; 
numerical proportion of male and female 
births in, i. 293; formerly striped, ii. 291. 

Hottentot women, peculiarities of. i. 217. 

Hottentots, lice of, i. 212 ; readily become 
nmsicians, ii. 318; notions of female 
beauty of the, ii. 329; compression of 
nose by, ii. 335. 

House-slaves, difference of, from field- 
slaves, i. 237. 

Huber, p., on ants placing together, i. 38; 
on memory in ants, i. 44 ; on the inter- 
communication of ants, i. 56 ; on the rec- 
ognition of each other by ants after sepa- 
ration, i. 3.54. 

Hue, on Chinese opinions of the appear- 
ance of Europeans, ii. 328. 

Human kingdom, i. 179. 

Human sacriiices, i. 66. 

Humanity, unknown among some sav- 
ages, i. 91 ; deficiency of, among savages, 
i.97. 

Humboldt, A. von, on the rationality of 
mules, i. 47 ; on a parrot preserving the 
language of a lost tribe, i. 228 ; on the 
cosmetic arts of savages, ii. 324; on tho 
exaggeration of natural characters by 
man, ii. 834; on the red painting of 
American Indians, ii. 336. 

Hume, D., on sjonpathetic feeUngs, i. 81. 

Hu.mmeng-bird, racket-shaped feathers in 
the tail of a, ii. 70 ; display of plumage 
by the male, ii. 88. 

Humming-birds, ornament their nests, i. 
63, ii. 107; polygamous, i. 260; propor- 
tion of the sexes in, i. 298, ii. 213; sexual 
differences in, ii. 87, 38, 145; pugnacity 
of male, ii. 38; modified primaries of 
male, ii. 62 ; coloration of the sexes of 
ii. 75; yoimg ot; ii. 211; nidification of 
the, ii. 160; colors of female, ii. 160. 



410 



IXDEX. 



llrMPnttEYS, II. N., on the habits of the 
Stiekle-baek, I. 262, ii. 2. 

Hunger, instinct of, i. 80. 

Huns, ancient, flattening of the nose by 
the, ii. S'-T). 

IluNTER, J., on the nnnilier of species of 
man, 1. 21 S; on secoiulary sexual cliarac- 
ter.s, I. 24.') ; on the trcncVal beliavior of 
female aniiiialB during courtship, i. 2(>4; 
on the nnisclcs of tlio L'u-vn.v m son^'- 
biixls, ii. i>i ; on the curled trontiil hair of 
the Hull. ii. 2(i9 ; on tlie rejection of an 
a.ss by a female zebra, ii. 2>>1. 

IlrNTEit, W. W., on tlie recent rapid in- 
crease of the SantalL, i. 12S; on the San- 
tali, i. 282. 

IIussEY, Mr., on a partridge di.<itingwisliing 
persons, ii. 1(1.5. 

llrTiiiiNsox, Colonel, example of reason- 
ing in a retriever, 1. 46. 

IlrrroN, C"a]>t.aln, on the male wild-goat 
falling on liis horns, ii. 2:?S. 

ncxLEY, T. II., on the structural asi'ee- 
inent of man with the apes, i. 3; ou the 
agreement of the brain in man with that 
of lower animals, i. 10; on the adult aie 
of the Orang. 1. 13; on the embryonic de- 
vilopnii'Mt of man, i. 14; on the oriu-in 
of num. i. 4. IT ; on variation in the slculls 
of the natives of A\istraliii, i. 104; on the 
at)ductor of the tilth metatarsal in apes, 
i. 123; on the position of man, i. 1S3; on 
the sub-orders of iiriiiiates, i. 1ST; on the 
LeniuridiC, i. 104; on the Dinosauaria, i. 
lOli; on tlie amphibian alliiiities of the 
Ichthyosaurians. i. I'Jij; on variability of 
the sliull in certain races of man, i. 21S; 
on the races of man, i. 210. 

IIvnuiD birds, production of, ii. 109. 

llYDROPiioniA communicable 'between man 
and the lower animals, i. 11. 

J/i/(l roporus, dimorphism of females of, 
i. 3.3.3. 

Ifi/ehtphvx porcintiB, ii. 2S9. 

Jfi/grogon iix. ii. 20. 

Ill/hi. sin^'iiiir species of. ii. 25. 

Ili/lohaiex. maternal atfection in a, i. 89; 
absence of the thumb in, i. 13."); upriirht 
progression of some species of, i. 13T; 
direction of the hair on the arms of spe- 
cies of, i. Is"); females of, less hairy be- 
low than males, ii. .30.'). 

JTi/IoIxiUm (i(iilitt. j. 135; hair on the arms 
of, i. Is5; musical voice of the, ii. 2(>4; 
superciliary ridge of; ii. 803 ; voice of, ii. 
81G. 

IIylubatei> Jwolock, se.xual difference of 
color iu, ii. 2T7. 

Hylobates lar, i. 135 ; hair on the arms of, 
i. 185. 

Ifi/lohiitc.i Iciicixrii.i. i. IS,'). 

liijUihiilix Kiiiiilacti/lHH, i. 135; laryngeal 
sac of. ii. 2tV!. 

llYMENOPTEn.v i. .35.3; large size of the cer- 
ebral ganglia in, i. 139 ; classification of, 
1. 181 ; sexual dillerenccs in the wings of, 
i. 835 ; aculeate, relative size of the sexes 
of, i. 837. 



IIvMENOPTEEON, parafiitic, with a scden- 

tai-y male, 1. 264. 
Ifi/omoKchim aqitaticw), 11. 289. 
lli/perythra, proportion of the sexes in, 1. 

301. 
Ifypogi/mna ilispar, sexual differenco of 

color in, i. 3?0. 
I/ypopyrd. coloration of, i. 854. 



I, 



Ibex, male, falling on his horns, il. 233; 

beard of the, ii. 269. 
Ibis, scarlet, young of the, Ii. 199; white, 

change of color of naked skin in, during 

tlie breeding-season, ii. TO. 
IbiH tantalim, age of mature plumage in, ii. 

204; breeding In immature plumage, ii. 

20.5, 206. 
Ibise-s, decomposed feathers in, ii. 71 ; 

white, ii. 21 S, and black, ii. 220. 
IriixEU.MOXiDjj, dillerence of the sexes In, 

i. 3.M. 

IrnTIIYOPTERYGH, 120. 
ICIITIIYOSAURIAN.S, ii. 190. 

Ideas, general, i. 60. 

Idiots, microcephalous, imitative faculties 
of, i. 55; microcephalous, tlieir characters 
and habits, i. 116. 

/tjitand iiiliereu/ata, ii. 31. 

Iguanas, ii. 30. 

Illegitimate .and legitimate children, pro- 
portion of the sexes in. i. 292. 

Imagination, existence ot; in animals, i. 44. 

Imitation, i. 3S; of niiin by monkeys, i. 
42; tendency to, in monkeys, microce- 
phalous idiots and savages, i. 55; In- 
fluence oC i. 155. 

Immature plum.age of birds, ii. 175, 179. 

Implacentata, i. 194. 

Lmplements, employed by monkeys, i. 49 ; 
fashioning of. ](eculiar to man, i. 51. 

Lmpregnation, period of; influence of, up- 
on sex. i. 293. 

Lmprovement. progressive, man alone sup- 
posed to be capable of, i. 48. 

Incisor teeth, knocked out or filed by 
some savages, ii. 324. 

Increase, rate of, i. 126; necessity of 
checks in, i. 1.30. 

Indecency, hatred of; a modem virtue, i. 
92. 

India, difficultj' of distinguishing the na- 
tive races of,"i. 20T; C'yprinidw of, ii. IT; 
color of the beard in riices of men of, ii. 
304. 

Indian. Xorth American, honored for scalp- 
ing a man of another tribe, i. 90. 

Individuality, i. 00. 

Individuation, i. 810. 

Jiitlopicus ciirlotta, colons of the sexes ofj 
ii. 16T. 

IsKANTiriDE, prev.ilence of. i.90, 129; sup- 
posed cause of, ii. 328; prevalenca and 
causes oi; ii. 847, et seq. 

Inferiority, supposed physical, of man, 1 
150. 



INDEX. 



411 



Infiammatio>" of the bowels, occurrence 

o^ in Cebtis Asarce, i. 12. 
Inheritance, i. 106 ; of etfects of use of 
vocal and mental organs, i. 56; of moral 
tendencies, i. 9S, 100; of long and short 
sip-ht, i. Hi; laws of, i. 2T0; sexual, i. 
276 ; sexually limited, li. 147. 

Inquisition, influence of the, i. 172. 

Insanitt, hereditary, i. 107. 

Insect, fossil, from the Devonian, i. 349. 

Insectivoka, ii. 272; absence of secondary 
sexual characters in, i. 259. 

Insects, relative size of the cerebral pan- 
gha in, i. 139 ; male, appearance of befors 
the females, i. 252 ; pursuit of female, by 
the males, i. 263 ; period of development 
of sexual characters in, i. 2S2 ; secondary 
sexual characters of, i. 831 ; stridulation 
of, ii. 315. 

Insessores, vocal organs of, ii. 52. 

Instep, depth of in soldiers and sailors, i. 
112. 

Instinct and intellig-ence, i. 36. 

Instinct, migratoiy, vanquishing the ma- 
ternal, i. 80, SI. 

Instinctive actions, the result of inheri- 
tance, i. 77. 

Instinctive impulses, dilference of tlie 
force of, i. 83, 85; and moral impulses, 
alliance of, i. S4. 

Instincts, i. 35 ; complex origin of, through 
natural selection, i. 37 ; possible origin of 
some, i. 37 ; acquired, of domestic auimaJs, 
i. 76 ; variabihty of the force of, i. 79 ; dif- 
ference of force between the social and 
other, i. 85, 99 ; utilized for now pm-poses, 
ii. 319. 

Instrumental music of birds, ii. 59, 64. 

Intellect, influence of, in natural selection 
in civiUzed society, i. 164. 

Intellectual faculties, their influence on 
natm-al selection in man, i. 152 ; probably 
perfected thi-ough natural selection, i. 
154. 

Intellioence, Mr. H. Spencer on the dawn 
of, i. 36. 

Intemperance, no reproach among sav- 
ages, i. 92; its destructiveness, i. 166. 

Intoxication in monkeys, i. 12. 

Iphius glaiKippe, i. 381. 

Iris, sexual difference in the color of the, 
in birds, ii. 69, 123. 

Iscnio-PUBic muscle, i. 122. 

Ithaginis cruentus, number of spui-s in, ii. 
44. 

lulvs, tarsal suckers of the males of, i. 330. 



J. 

.Tackals learning to bark from dogs, i. 43. 

Jaok-snipe, coloration of the, ii. 2i6. 

Jacquinot, on the number of species of 
man, i. 218. 

Jaegee, Dr., on the diflSculty of approach- 
ing herds of wild animals, i. 71 ; on the 
increase of length in bones, i. 112 ; on the 



deposition of a male Silver-pheasant on 

account of a spoiled plumage, ii. 11&. 
Jaguars, black, ii. 280. 
Janson, E. W., on the proportions of the 

sexes in Tomicu-a tUIosus, i. 305; on 

stridulant beetles, i. 867. 
Japan, encouragement of licentiousness 

in, i. 129. 
Japanese, general beardlessncss of the, ii. 

306; aversion of the, to whiskers, ii. 832. 
Jardine, Sir W., on the Argus pheasant, 

ii. 69. 93. 
Jareold, Dr., on modifications of the 

skuU induced by unnatural position, i. 

Javanese, relative height of the sexes o^ 
ii. 305 ; notions of female beauty, ii. .331. 

Jaw, influence of the muscles of the, upon 
the physiognomy of the apes, i. 183. 

Jaws, smaller in the same ratio with the 
extremities, i. 113; influence of food 
upon the size of i. 118; diminution of in 
man, i. 188 ; in man, reduced by correla- 
tion, ii. 309. 

Jay, voung of the, ii. 200 ; Canada, young 
of the, ii. 200. 

Jays, new mates found by, ii. 100; dis- 
tinguishing persons, ii. 105. 

Jeffreys, J. Gwyn, on the form of the 
shell in the sexes of the Gasteropoda, i. 
315 ; on the Influence of light upon the 
colors of shells, i. 817. 

Jelly-fish, bright colors of some, i. 313. 

Jenner, Dr., on the voice of the rook, ii. 
58 ; on the finding of new mates b.y mag- 
pies, ii. 99 ; on retardation of the genera- 
tive organs in birds, ii. 103. 

Jenyns, L., on the desertion of their young 
by swallows, i. 80 ; on male birds sing- 
ing after the proper season, ii. 103. 

Jeruon, Dr., on birds dreaming, i. 44 ; on 
the pugnacity of the male bulbul, ii. 39; 
on the puguacity of the male Ot-tygornis 
gii/df/N, ii. 42; on the spurs of Gallo- 
y>tv</;,/', ii. 44; on the habits of Lobita- 
vellu.i, ii. 46; on the spoonbfll, ii. 57; on 
the drumming of the Kalij-pheasant, ii. 
CO ; on Indian bustards, li. 62 ; on Otis 
Bengalensia, ii. 66; on the ear-tufts of 
Sypheotide.s auritus^ ii. 70; on the 
double moults of certain birds, ii. 79 ; on 
the moulting of the honey-suckers, ii. 79 ; 
on the moulting of bustards, plovers, and 
drongos, ii. SO ; on display in male birds, 
ii. 82 ; on the spring change of color in 
some finches, ii. 82; on the display of 
the under taU-coverts by the male bul- 
bul, ii. 91 ; on the Indian honey-buzzard, 
ii. 121 ; on sexual differences in the color 
of the eyes of hornbills, ii. 123 ; on the 
markings of the Tragopan pheasant, ii. 
128 ; on the nidification of the Orioles, ii. 
160; on the nidification of the hornbills, 
ii. 11)1 ; on the Sultan yellow-tit, ii. 167 ; 
on I'ulaiornis Javanictis, ii. 172; on the 
immatm-o plumage of birds, ii. 178, et 
seq. ; on representative species of bu'ds, 
ii. 182 ; on the habits of Turnix, ii. 193 ; 



412 



INDEX. 



on the continued Increase of beauty of 
the p»acock, ii. 207; on coloration in 
the genus l'tit<TorniM, ii. 221. 

Jevoss, W. S., on the migrations of man, 
1. 130. 

Jews, ancient use of flint tooLs by the, i. 
170; nniforinitv of, in various 7)arts of 
the world, i. 243 ; numerical proportion 
of male and female births among the, i. 
291 ; ancient tattooing practised by, ii. 
823. 

JoiiNSTOKE, Lieutenant, on the Indian ele- 
phant, i. 2iV,). 

JoLLOFS. fine appearance of the, ii. 341. 

Jones. .Vlbert, juxiportion of sc.\es of Le- 
pidojitera, roared by, i. 304. 

Juan Feenaxdez, humming-birds oC ii. 
212. 

Junonia, sexual differences of coloring in 
species o£ i. 377. 

Jupiter, Greek statues o£ ii. 3S3. 



Kaffp.e skull, occmTonce of the diastema 
in a, i. 121. 

Kaffkes, their cruelty to animals. 1. 90; 
Uce of the, i. 213; color of the, ii. 380; 
engrossment of the handsomest women 
by the chiefs of the, ii. 302: marriage- 
customs of the, ii. Si>~. 

Kalij-piieasant. drumming of the male, 
ii. 59; young of. ii. 182. 

KaUima. resemblance of, to a withered 
leaf, i. 3S0. 

Kangaroo, groat red, sexual difference in 
the color of, ii. 273. 

Kant, Immanuol, on duty, i. 67 ; on self- 
restraint, i. 88; on the number of species 
of man, i. 218. 

Katy-did. stridulation of the, i. 342. 

Keller, Dr.. on tlu' dilliculty of fashioning 
stone imiiloiiunts, i. 1;«. 

Kestrels, now mates found bv, ii. 100. 

Kidney, i. 112. 

King, W. R., on the vocal organs of Tetrao 
citpido, ii. 55; on the drumming of 
grouse, ii. 60 ; on the reindeer, ii. 2.33 ; 
on the attraction of male deer by the 
voice of the female, ii. 2C>3. . 

King and Fitzroy, on the marriage-cus- 
toms of the Fuegians, ii. 357. 

Kino-prows, niditication of. ii. 160. 

KiNGFisriRR, ii. 5:?; racket-shaped feathers 
in the tiiil of a, ii. 70. 

Kingfisuerb, colors and nidificaf ion of the, 
ii. 16:3, 165, 16S; imniatuio plumage of 
the, ii. ISO, 1S2; young of the, ii. 200. 

King Lory, ii. 166; immaluie plumage 
ofthe. ii. 180. 

Kingsley, C, x)n the sounds produced by 
Vmhrina. ii. 22. 

Kikuy and Spence, on the courtship of in- 
sects, i. 263; on sexual differences in the 
length of the snout in curculionidie, i. 
247 ; on the elytra of Ih/tincm, i. 333 ; on 
pef ullarities in the legs "of male insects, i. 



834 ; on the relative size ofthe sexes In !■- 
sects, i. 335 ; on the luminosity of Insects, 
i. 3:55; on the Fulgoridn>. i. 840 ; on the 
hal)it.s of Termites, i. 353 ; on difference 
of color in the sexes of beetles. 1. 356; on 
the horns of the male Liinellicorn beetles 
I. 859 ; on hornlike processes in m-'ile 
eurculionida". i. 36:3; on the pugnacity 
of the male f-tag-beetle. i. 364. 

Kite, killed by a game-cock. ii. 42. 

Knot, retention of winter plumage by the, 
ii. 78. 

Kvox, E., on the semilunar fold, i. 23 ; on 
the occurrence of the supra-condyloid 
foramen in the humerus of man, i. 27 ; 
on the features of the young Memnon, i. 
209. 

Koala, length ofthe caecum in, 1. 26. 

KoLREUTEii, on the sterility of hybrid 
jiiants. i. 215. 

KubiM e/lipfciprymniis, proportion ofthe 
sexes in, i. 296. 

Koonoo, develoi>ment of the horns of the, 
i. 279 ; markings of the, ii. 2S7. 

KOppen, F. T., on the migratory locust, 1. 
342. 

KoRUOFAN, protuberances artificially pro- 
duced in, ii. 323. 

Kowalevsky, a., on the affinitj- of the 
Ascidia to the A'ertebrata, i. 197. 

Kowalevsky, W., on the pugnacity of the 
male Capercailzie, ii. 42 ; on the pairing 
of the Capercailzie, ii. 47. 

Kkause, on a convoluted body at the ex- 
tremity of the tail in a Macacus and a 
cat, i. 29. 

KuppFER. Prof, on the affinity of the As- 
cidia to the Vertebrata, i. 197. 



L. 

Lahidocera Danrinii, prehensile organs 
of the male, i. 320. 

Labrus, splendid coloi-s of the species of, 
ii. 15. 

Labrus mixtiis. sexual differences in, ii. 9. 

Labrus pavo, ii. 15. 

Laceutilia, sexual differences of. ii. 80. 

Lafresnave, M. de, on Uhtls of Paradise, 
ii. 73. 

La.m.\rck. on the origin of man, i. 4. 

La.mellibrancuiat.^ i. 315. 

Lamellicorn beetles, horn-like pi-ocessos 
from the head and thorax of i. 357. 802 ; 
analogy of, to Kuminants, i. 361; influ- 
ence of sexual si-lection on. i. 36.'). 

Lamellicounia, stridulation of i. 36S. 

Lamont. Mr., on the tusks of the Ayah-us, 
ii. 231 ; on the use of its tusks by the 
Walru.s. ii. 245. 

Latnporu is porp/iyruru8,'co\ors ofthe fe- 
male, ii. 160. 

Lancelet. i. 196, 204. 

Landois. H.. on the pro<luction of sound 
by the Cicadcp. i. 340 ; on the stridulating 
organ of the Crickets, i. 344 ; on Dwti- 
cus, i. 845; on the stridiUating oi-gans of 



INDEX. 



41^ 



the Acridiidfe, i. 345; on the presence of 
rudimentary stridulating organs in some 
female Orthoptera, i. 34S ; on the stridu- 
lation of ]S^ecrophorii.% i. 367 ; on the 
stridulant organ of Cerambyx heros, i. 
36S; on the stridulating organs in the 
Coleoptera, 1. 370; on the ticking of 
Anobium,i. 373; on the stridulant or- 
gan of Geotrupes, i. 369. 

Language an art, i. 53 ; articulate, origin 
of, 1. 54; relation of the progress of, to 
the development of the brain, i. 55; ef- 
fects of inheritance in production of, 1. 
56 ; complex structure of, among barbar- 
ous nations, i. 59 ; natural selection in, i. 
59 ; gesture, i. 224 ; primeval, i. 226 ; of 
a lost tribe preserved by a parrot, i. 22S. 

Languages, presence of rudiments in, i. 
53 ; classification of, i. 58 ; variability of, 
i. 53 ; crossing or blending of, i. 53 ; com- 
plexity of, no test of perfection or proof 
of special creation, i. 60 ; resemblance of, 
evidence of community of origin, i. 182. 

Languages and species, identity of evi- 
dence of then- gradual development, i. 
57, 

Lanius, ii. 172; characters of young, li. 
177. 

Lanius I'tifu.s. anom.alous )-oung of, ii. 202. 

Lankester, E. E., on comparative longev- 
ity, i. 161, 164; on the destructive effects 
of intemperance, i. 166. 

Lanugo, of the human fcetus, i. 25 ; ii. 359. 

Lapponian language, highly artificial, i. 59. 

Lark, pi-oportion of the sextjs in the, i. 
298; female, singing of the, ii. 51. 

Larks, attracted by a mirror, ii. 107. 

Lartet, E., on the size of the brain in 
mammals, i. 49 ; comparison of cr.uiial 
capacities of skulls of recent and tertiary 
manoonals, i. 140; on JJri/opithectin, i. 
191. 

Lartis, seasonal change of plumage in, ii. 
218. 

Larva, luminous, of a Brazihan beetle, i. 
335. 

Larynx, muscles of the, in song-birds, ii. 
52. 

Lasiooampa qiiercus, attraction of males 
by the female, i. 303 ; sexual difference 
of color in, i. 386. 

Latham, K. G., on the migrations of man, 
i. 131. 

Latooka, perforation of the lower lip by 
the women of, ii. 325. 

Laurillasd, on the abnormal division of 
the malar bone in man, i. 119. 

L.\.WRENOE, W., on the superiority of sav- 
ages to Europeans in power of sight, i. 
114; on the color of negro infants, ii. 
303 ; on the fondness of savages for or- 
naments, ii. 322 ; on beardless races, ii. 
332 ; on the beauty of the English aris- 
tocracy, ii. 341. 

La YARD, E. L., on an Instance of rational- 
ity in a Cobra, ii. 29 ; on the pugnacity 
of Gallus Stanley i, ii. 42. 

Laycock, Dr., on vital periodicity, i. 12. 



Leaves, decaj-ing, tints of, i. 314. 

Lecky, Mr., on the sense of duty, i. 68 ; on 
suicide, i. 90; on the practice of ceUbaey, 
i. 92 ; his view of the crimes of savages, 
i. 93 ; on the gradual rise of morality, i. 
99. 

Leconte, J. L., on the stridulant organ in 
the Coprini and Dynastini, i. 369. 

Lee, IL, on the numerical proportion of 
the sexes in the trout, i. 299. 

Leg, calf of the, artificially modified, ii. 
324. 

Legitimate and illegitimate children, pro- 
portion of the sexes in, i. 292. 

Legs, variation of the length of the, in 
man, i. 104 ; proportions of, in soldiers 
and sailors, i. 112; fore-, atrophied in 
some male butterflies, i. 334 ; peculiar- 
ities of in male insects, i. 334. 

"LEK"ofthe black-cock and capercailzie, 
ii. 96. 

Lemoine, Albert, on the origin of language, 
i. 54. 

Lemur macaco^ sexual difference of color 
in, ii. 276. 

LEMURID.E. i. 187; their origin, i. 204; po- 
sition and derivation of the, i. 194 ; ears 
of the, i. 22 ; variabiUty of the muscles in 
the, i. 123. 

Lemurs, uterus in the, i. IIS; tailless spe- 
cies of, i. 187. 

Leopards, black, ii. 280. 

LEPIDOPTER.A, i. 374; numerical propor- 
tions of the sexes in the, i. 301 ; coloring 
of, i. 375; oceliated spots of, ii. 127. 

L^ejndosiren, i. 196, 204. 

Lenguas, disfigurement of the ears of the, 
ii. 325. 

Leptorhynehus angustatus, pugnacity of 
male, i. 363. 

Leptura teMacea, difference of color in the 
sexes of i. 356. 

Lequay, on the occurrence of the supra- 
coudyloid foramen in the humerus of 
man, i. 23. 

Leroy, on the wariness of young foxes in 
hunting-districts, i. 48 ; on the desertion 
of their young by swallows, i. 80. 

Lesse, valley of the, i. 28. 

Lesson, on the Bu-ds of Paradise, i. 260, 
ii. 93 ; on the sea-elephant, ii. 265. 

Lestiti bombylans, difference of the sexes 
in, i. 354. 

Let/irus cephalotes, pugnacity of the 
males of, i. 360, 364. 

Leuckaet, E., on the vesiculaprostatioa^ 
i. 30 ; on the influence of the age of par- 
ents on the se,x of offspring, i. 292. 

Lefator clamculcn muscle, i. 123. 

Libellula depressa, color of the male, i. 
352. 

Libei,lulid.e, relative size of the sexes ofj 
i. 337 ; ditference in the sexes ot, i. 351. 

Lice of domestic animals and man, i. 211. 

Licentiousness, prevalence of, among sav- 
ages, i. 92 ; a check upon population, i. 
129. 

Lichtensteln, on Chera progne, ii. 115. 



414 



INDEX. 



Liri:. inlifrltancc at corresponding periods 
of i. 271, 'iTli. 

LiCfiiT, supposed o(T(*cts of, i. Ill; Influ- 
ence ot; upon tlio colors of shells, i. 317. 

Lii.FOiiD, Lonl. tho ruff attracted by bright 
object.s, ii. 107. 

LimoKii lapponica, ii. 195. 

Liiiiiria, ii. 17'i. 

Linaria montana. 1. 29S. 

LiSN.Ers, views of, as to the position of 
m.in, i. is:?. 

Linnet, numerical proportion of the sex- 
es in tlie, i. 29S; crimson forehead and 
breast of tUe, ii. b'2 ; courtship of the, ii. 
90. 

Lini/phin, i. 32S. 

Lion, poly^ramous. i. 259 ; mane of the. de- 
fensive, ii. 254 ; roaring of the, ii. 262. 

Lions, stripes of young, ii. 176. 

Lii's, piercing of "the, by savages, ii. 325. 

LithohiuK, prehensile 'appendages of the 
female, i. 830. 

Lit/ioKi'd. coloration in. i. 3S-3. 

Littorhid lldorea, i. 315. 

LiviNiiSTONE. Dr., on the influence of 
dami)noss and dryness on tlic color of 
the skin, i. 233 ; on the liability of ne- 
groes to trojiical frvers after residence in 
a cold climate, i. 234; on the spur- 
winged goose, ii. 44 ; on weaver-birds, 
ii. 60; on an African night-jar, ii. 69, 92; 
on the l)attle-scars of South Afric.in male 
m;inuiial.s, ii. 22S; on the removal of the 
u])per inci-sors by the Batolcas!, ii. 824; 
on the perforation of the upper Hp by 
the Malcalolo, ii. 326: on the Banv.ii, ii. 
827. 

Livonia, numerical proportion of male and 
feiiKilo births in. i. 292. 

LiZAKDs, relative size of the se.vcs of, ii. 80; 
gular pouches of ii. 31. 

Lloyd, L., on the polygamy of the caper- 
cailzie and bustard, i. 261 ; on the numer- 
ical proportion of the sexes in the caper- 
cailzie and black-cock, i. 297 ; on the sal- 
mon, ii. 5 ; on the colors of tho sea-scor- 
pion, ii. 9; on the pugnacity of male 
grouse, ii. 42 ; on the capercailzie and 
bl.ick-cock, ii. 47, 52; on the call of the 
capercailzie, ii. 5S; on assemblages of 
grouse and snipes, ii. 97 ; on the pairing 
of a shield-drake with a common ducli, 
ii. 109; on the battles of seals, ii. 229; on 
the elk. ii. 238. 

LohieiineltiiA, wing-spurs in. ii. 4G. 

Local influences, eft'ect of, upon stature, i. 
110. 

LocKwooD, Mr., on tlio development of 
Ilippocdmpua. i. 201. 

LocisT. bright-colored, rejected by lizai-ds 
and birds, i. 3.00. 

LorrsT. migratory, i. 342. 

Loci'sriD.E, stridiilation of the, i. 341, 343 ; 
descent of the, i. 346. 

LoNGironx beetles, ditference of tlie sexes 
of, in color, i. 356 ; stridulation of, i. 36S. 

Lonsdale, Mr., on an example of personal 
attachment in JMUr pomatia, 1. 316. 



LopMonnANrmi, marsupial receptacles of 
the male. il. 20. 

Lf>j)li(i]ih(>run. habits of. ii. 116. 

Lojiliiiriiui (itni, sexual difl'erencc in color- 
ation of, ii. 216. 

Lophornin ornatuK ii. 73. 

LoKD. J. K., on Siibno lijcrtorlon, ii. 5. 

Lory, King, ii. 160; immature plumage of 
the, ii. 18). 

LovE-ANTics and dances of bu^ls. ii. 65. 

LowsE, B. T., on Mu«ca vomitoria, i. 140, 
839. 

Loriti. characters of young of, ii. 176. 

LrBBOCK, Sir J., on "the antiquity of man, 
i. 3; on tlie origin of man, i. 4; on tho 
inentiil capacity of savages, i. Sj ; on the 
origin of implements, i. 51 ; on the sim- 
plilication of languages, i. 60 ; on the ab- 
sence of the idea of God among certain 
races of men. i. 63 ; on the origin of tho 
belief in spiritual agencies, i. 06 ; on su- 
j)erstitions, i. 66; on tho sense of duty. i. 
6S; on the practice of bin-ying theold 
and sick among the Fljians. i. 74: non- 
])revalence of suicide among the lowest 
barbarians, i. 90; on the immorality of 
savages, i. 93; on Mr. Wallace's cLiiin to 
the origination of tlie idea of natural se- 
lection, i. 132 ; on the absence of remorse 
among sav.iges, i. 15-^; on the former bar- 
barism of ci\nlized nations, i. 174; on im- 
provements in the arts among savages. 1. 
175; on resemblances of the mental char- 
acters in dilfercnt races of men, i. 224 ; on 
the power of counting in primeval man, 
i. 225 ; on tlie aits pi-.ictisc-d by savages, 
i. 225; on the prehinsile organs of the 
male Labidocera Ddrtrhiii, i. 820; on 
Chloeon, i. 3.31 ; on Smijuthurtiit luteut>, 
i. 3;5S ; on strife tor women among the 
North American Indians, ii. 30s; on mu- 
sic, ii. 318; on the ornament;il pnictices 
of savages, ii. ;322; on the estimation of 
tho beard among the Anglo-Sa.xon.s, ii. 
833; on artificial deformation of the skull, 
ii. 835; on "communal marriages." ii. 
842,344; on exogamy, ii. ;i44, 34S ; on the 
Veddahs, ii. 347 ; on polyandry, ii. 349. 

LrcANiD.E, variabiUty of the m"andiblcs in 
the male, i. 364. 

Lucaniis, large size of males of, i. 836. 

Lucanus cerriiJ), numerical proportion of 
sexes of, i. 305; weapons of the male, i. 
364. 

Liw(inii.i elaphriH, use of mandibles o^ i. 
365 ; large jaws of male, i. 3:52. 

LlTCAS, Prosper, on sexual preference In 
horses and bulKs, ii. 260. 

Lunar periods, i. 204. 

Lund, I)r.. on skulls foimd in Brazilian 
caves, i. 210. 

Lungs, enlargement of, in the Quecliua and 
Aymani Indians, i. 1 15 ; a modified swim- 
bliidder, i. 198; different capacity of; in 
races of man, i. 208. 

Lr.MiNOSiTY in insects, i. 885. 

LuscHKA, Prof, on the termination of tho 
coccy.x, i. 29. 



INDEX. 



415 



LtrsT, mstinct of, i. So. 

Ltjstjet, comparatively innocuous, i. l&i. 

Z)/C(vna, sexual difl'erences of coloring iu 
species of, i. 3TS. 

Lyell, Sii- C., on the antiquity of man, i. 
8 ; on the origin of man, i. 4 ; on the par- 
allelism of the development of species and 
languages, i. 57 ; on the extinction of lan- 
guages, i. 58; on the Inquisition, i. 171; 
on the fossil remains of vertebrata, i. 193 ; 
on the fertility of mulattoes, i. 213. 

Ltkx, Canadian, tlu-oat-ruff of the, ii. 255. 

LYEE-BrRi), assemblies of; ii. 97. 



OT. 

Macacus, ears of, i. 22 ; convoluted body in 
the exti-emity of the tail of, i. 29 ; varia- 
bility of the tail in species of, i. 144 ; whis- 
kers of species of, ii. 269. 

Maoaciis cynomolgus, superciliary ridge 
of, ii. 303; beard and whiskers of, be- 
coming white with age, ii. 304. 

Macacus inornatus, 1. 145. 

Macacus kmotiis, facial spots of, ii. 295. 

Macacus radiatus, i. 1S4. 

Macacus rheftun, sexual diflerenco in the 
color of, ii. 279, 295. 

Macalistee, Prof, on variations of the 
palmaris accessor h(s muscle, i. 105; on 
muscular abnormalities in man, i. 123, 
124; on the greater variabihty of the 
muscles in men than in women, i. 266. 

Macaws, Mr. Buxton's obsei-vations on, 1. 
76 ; screams of, ii. 58. 

McCann, J., on mental individuaUty, i. 61. 

McClelland, J., on the Indian cypi-inidie, 
ii. 17. 

Macculloch, Colonel, on an Indian village 
%vithout any female children. ii> 348. 

Macculloch, Dr., on tertian ague in a dog, 
i. 13. 

Maggilliveay, W.. on the vocal organs of 
birds, i. 57; on the Egyptian goose, ii. 
44; on the habits of woodpeckers, ii. Cil; 
on the habits of the snipe, ii. 61 ; on the 
whitethroat, ii. 66; on the moulting of 
the snipes, ii. 79 ; on the moulting of the 
auatidie, ii. 81 ; on the finding of new 
mates by magpies, ii. 99 ; on the pauing 
of a blackbird and thrush, ii. 109 ; on pied 
ravens, ii. 121 ; on the guillemots, ii. 122 ; 
on the colors of the tits, ii. 166; on the 
Immature plumage of birds, ii. 178; et 
seqq. 

Mac?ietes, sexes and young of, ii. 207. 

Machetes jnignaa; numerical proportion 
of the sexes in, i. 297 ; supposed to be 
polygamous, i. 261; pugnacity of the 
male, ii. 39 ; double moult in, ii. 78. 

Mackintosh, on the moral sense, i. 67. 

MacLachlan, K., on Apatania muliebris 
and Boreus ki/emalls, i. 306; on the 
anal appendages of male insects, i. 332 ; 
on the pau'ing of dragon-flies, i. 337 ; on 
di-agon-fiies, i. 351, 352 ; on dimorphism 
in Agrio7i, i. 852 ; on the want of pugna- 



city in male dragon-flies, i. 353; on tho 
ghost-moth in the Shetland Islands, 1. 
390. 

McLennan, Mr., on the origin of the be- 
hef in spiritual agencies, i. 63; on the 
prevalence of licentiousness among sav- 
ages, i. 92, u. 342 ; on infanticide, i. 129, 
ii. 347; on the primitive barbarism of 
civilized nations, i. 174; on traces of the 
custom of the forcible capture of wives, 
i. 175, ii. 849 ; on polyandry, Ii. 349, 

McXeill, Mr., on the iise of the antlers of 
deer, ii. 242; on the Scotch decrhound, 
ii. 249 ; on the long haii-s ofrthe throat of 
the stag, ii. 256; on the beUo\ving of 
stags, ii. 261. 

Macrorhinus proboscideui, structure of 
the nose of, ii. 265. 

Magpie, power of speech of, i. 57 ; stealing 
bright objects, ii. 107 ; nuptial assembUes 
of, ii. 98 ; new mates found b.y, ii. 99 ; 
yoimg of the, ii. 200 ; coloration of the, 
li. 220. 

Magpies, vocal organs of the, ii. 52. 

Maillakd, M., on the proportion of the 
sexes in a species of Papitio from 
Bourbon, i. 301. 

Maine, Mr., on the absorption of one tribe 
by another, i. 154; on the want of a de- 
su-e for improvement, i. 160. 

Makalolo. perforation of the upper lip by 
the, ii. 325. 

Malar bone, abnormal division of, in man, 
i. 119. 

Malay Archipelago, marriage-customs of 
the savages of the, ii. 357. 

Malays, line of separation between the 
Papuans and the, i. 210; general beard- 
Ifssness of the, ii. 806: staining of the 
teeth among, ii. 323; aversion of some, 
to hairs on the face. ii. 332. 

Malays and Papuans, contrasted charac- 
ters of, i. 20S. 

Male animals, struggles of, for the posses- 
sion of the females, i. 251, 252; eager- 
ness of, in courtship, i. 263, 264; gener- 
ally more modified than female, i. 264, 
266 ; differ in the same way from females 
and young, i. 276. 

Male "characters developed in females, i. • 
271 ; transfer of, to female birds, ii. 185. 

Male, sedentary, of a hymenopterous 
parasite, i. 263. 

Malefactop.s, i. 16.5. 

Males, presence of rudimentary female 
organs in, 1. 200. 

Males and females, comparative mortality 
of, while young, i. 255, 267; comparative 
numbers of; i. 253, 255. 

Maliierbe, on the woodpeckers, ii. 166. 

Malthus, T., on the rate of increase of 
population, i. 126, 127, 129. 

Malueld^, nidification of the, ii. 161. 

Malurus, yoimg ot; ii. 207. 

Mamm^ 1. 246; rudimentary, in male 
mammals, i. 17, 80, 199-201; supernu- 
merary, in women, 1. 120 ; of male hu- 
man subject, i. 125. 



416 



INDEX. 



Mammalia, Prof. Owen's classification o^ 
i. IsO; pi'nfnJojry of the, i. I'.ir). 

Mammai.k. secondary sexual cliaracters of, 
ii. '2'J>; weapons of, ii. BJO; recent and 
tertiary, coiii|>arison of cranial capacity 
of, i. 140; relative size of the sexes of, 
ii. 248 ; pursuit of female, by the males, 
i. 208 ; i)amlleli,siii of. with birds in scc- 
ondary se.xual characters, ii. 28;}; voices 
of, u.sed especially during the breeding- 
season, ii. .SIC), 317. 

Man, variability of, i. 1(14; erroneously re- 
garded as more domesticated than other 
animals, i. 107; definitive orifrin of, i. 
22C; migi-aiions of. i. 131 ; wide distribu- 
tion of, i. 132; causes of the nakedness 
of, i. 14;$ ; 8Ui)posed phy.-^ical inferiority 
of, i. 150; numcric.'d proportions of the 
Bc.xes in, i. 255; a ineniher of tlie Catar- 
rhine group, i. 190; early imiiriiiitors of, 
i. 198; secondary sexual characters of; 
ii. 801 ; primeval condition of, ii. 851. 

Mandans, correlation of color and texture 
of hair in the, i. 239. 

Mandible, left, enlarged in the male of 
Tuph rode res dinlortun. i. 3;M. 

Mandlblf.s, use of the, in Ammopliila, i. 
332; large, of Corydalis cornutus, i. 
332; large, of male Lvcanus elaphm, i. 
882. 

Mandrill, number of c.iudal vertebrte in 
the, i. 144; colors of the male, ii. 279, 
2S2, 295. 

Manteoazza, Prof., on the ornaments of 
savages, ii. 322, et netjq. : on the bcard- 
lessness of the New-Zealanders, ii. 332 ; 
on the exaggeration of natural characters 
by man, ii. 885. 

Mantell, W., on the engrossment of pret- 
ty girls by the New-Zealand chiefs, ii. 
852. 

Mantis, pugnacity of species of, i. 849. 

Marcus Aurelius, on the origin of the 
moral sense, i. C8; on the influence of 
habitual thoughts, 1. 9". 

Mareca Penelope, ii. 109. 

Marks, ret^iiued throughout groups of 
birds, ii. 126. 

Marriage, inlluence of, upon morals, i. 
92; restraints upon, among savages, i. 
128; influence of, on mortality, i. 169; 
development of, ii. 345. 

Marriages, communal, ii. 342, 844; carlv, 
i. 108. 

Marshall, Mr., on the brain of a Bush- 
woman, i. 208. 

Marsupials, i. 194; possession of nipples 
by, i. 201 ; their origin from Monotreina- 
ta, i. 204; uterus of. i. \\>: (Uvelo|iment 
of the nietitiiting membraiu' in. i. 23; ab- 
dominal sacs of. i. 240; relative size of 
the sexes of, ii. 248 ; colors of, ii. 272. 

Marsi Tii'M, rudimentiiry, in male marsu- 
pials, i. 199. 

Martin, W. C. L., on alarm manifested by 
an orang at the sight of a turtle, i. 42 ; 
on the hair in Jlylohatei>, I. ISO; on a 
female American deer, il. 246; on the 



voice of Ilylohates affUin, ii. 264; on 

SemnopiVteciix nemtvwt. ii. 297. 
Martin, on the beards of the inhabitants 

of St. Kilda, ii. 300. 
Martins deserting their young, 1. 80. 
Martins, C on death caused by inflam- 
mation of the vermiform appendage, i. 

27. 
Mastoid processes in man and apes, i. 

188. 
^I.'.rDSLET, Dr., on the influence of the 

sense of smell in man, i. 23 ; on Laura 

liridgman. i. 57 ; on the development of 

the vocal organs, i. 57. 
Mayers. W. F., on the domestication of 

the goldfish in China, ii. 10. 
Mavhew, K., on the aft'ection between 

individuals of different sexes in the dog, 

ii. 258. 
Maynard. C. J., on the sexes of Chryse- 

11) y» picta, ii. 27. 
Meckel, on con-elated variation of the 

muscles of the arm and leg. i. 125. 
Mei)icine.s. eftect produced by, the same 

in man and in monkeys, i. 12. 
Meduxft. bright colors of some. i. 318. 
Megalitiiic structures, prevalence of; i. 

224. 
Megulophryu montana, sexual differences 

in, ii. 25. 26. 
Mefjdpicun rahdux, sexual difference of 

color in, ii. 100. 
Megamma, large size of males of i. 837. 
Meics, Dr. .\., on variation in the skulls of 

the natives of America, i. 104. 
Meinecke, on the numerical proportion of 

the sexes in butterflies, i. 800. 
Melii'iiaoidj^ Australian, nidification oi; 

ii. 101. 
J/e/ita, secondary se.xu.al characters ot i. 

322. 
J/e/oe. difference of color in the sexes of a 

species of; i. 850. 
Memory, manifestations of, in animals, i. 

4S. 
Memnon, young, i. 209. 
Mental characters, difterence of; in differ- 
ent races of men, i. 208. 
Mental faculties, variation of. in the same 

species, i. 85, 100; divcriity of, in the 

same race of men. i. 105; inheritance of. 

i. 106 ; similaritv of the. in different races 

of man, i. 223; of bird.s. ii. 108. 
Mental powers, difl'erence ot; in the two 

sexes in man. ii. 810. 
Mennra Albert!, ii. 98; song ot ii. 53. 
Jfenura superlxi, ii. 97, 98; long tails of 

both sexes of, ii. 157. 
Mk.i'.(;anser, trachea of the male, ii. 57. 
J/i ri/uti ciiciilhitiix, speculum of, i. 281. 
Mergus mergnnser. young of. ii. 181. 
Merganser serrator, male- plum.ige of, ii. 

hi. 
Metallura. splendid tail-feathers oC ii. 146. 
Mit/ioca ic/ineuinonides. large male o^ i. 

837. 
Meves, M., on the driniming ( f the snipe, 

ii. 61. 



INDEX. 



417 



Mexicaus, civilization of the, not foreign, 
i. 175. 

Meyer, on a convoluted body at the ex- 
tremity of the tail in a Macacus and a 
cat, i. 29. 

Metee, Dr. A., on the copulation of phrj-- 
ganidffi of distinct species, i. 332. 

MiGKATiONS of man, effects of; i. 130. 

Migratory instinct of birds, i. 76; van- 
quishing the maternal, i. SO, 87. 

Mill, J. S., on the origin of the moral 
sense, i. 68; on the "greatest happiness 
principle," i. 93 ; on the difference of the 
mental powers in the sexes of man, ii. 
312. 

Millipedes, i. 330. 

Milne-Edwards, H., on the use of the en- 
larged chela of the male Gelaeimus, i. 
322. 

Milrago levcmnis, sexes and young of, ii. 
197. 

Mimicry, i. 397. 

Mimus poli/glottu.% ii. 105. 

Mind, difference of, in man and the highest 
animals, i. 100 ; similarity of the, in dif- 
ferent races, i. 223. 

Minnow, proportion of the sexes in the, i. 
299, 300. 

Minnows, spa^^'ning habits of, ii. 15. 

Mirror, larks attracted by, ii. 107. 

MivART, St. George, on the reduction of 
organs, i. 18 ; on the ears of the Lemuroi- 
dea, i. 23 ; on variability of the muscles 
in Lemuroidea, i. 123, 131 ; on the caudal 
vertebras of monkej's, i. 114; on the 
classification of the primates, i. 150; on 
the orang and on man, i. 189; on differ- 
ences in the lemuroidea, i. 190; on the 
crest of the male newt, ii. 23. 

Mocking -TiiRURii, partial migration o% ii. 
105; young of the, ii. 209. 

Modifications, unser-i-iceable, i. 147. 

Moles, numerical proportion of the sexes 
in, i. 296 ; battles of male, ii. 228. 

MoUienesia petenensis, sexual difference 
In, ii. 9. 

MoLLTJSCA, beautiful colors and shapes of, 
i. 316; absence of secondary sexual char- 
acters in the, i. 315. 

MoLLuscoiDA, i. 197, 315. 

Monacanthxts scojyas, and 31. Peronii, 
sexual differences in, ii. 12. 

Mongolians, perfection of the senses in. 
i. 114. 

Monkey, protecting his keeper from a ba- 
boon, i. 75, 84 ; bonnet-, i. 184 ; rhesus, 
sexual difference in color of the, ii. 278, 
296 ; mustache-, colors of the, ii. 277. 

Monkeys, liability of, to the same diseases 
as man, i. 11 ; male, recognition of women 
by, i. 13 ; revenge taken by, i. 39 , ma- 
ternal affection in, i. 39 ; variability of the 
faculty of attention in, i. 43 ; using stones 
and sticks, i. 49 ; imitative faculties of, i. 
54; signal-cries oC i. 56; sentinels posted 
by, i. 71 ; diversity of the mental facul- 
ties in, i. 106; mutual kindnesses of, i. 
72 ; hands of the, i. 134 ; breaking hard 



fruits with stones, i. 134; basal caudal 
vertebrre of, embedded in the body, i. 145 ; 
human characters of, i. 184; gradation 
of species of i. 218; beards of; ii. 269; 
ornamental characters of, ii. 291 ; analogy 
of sexual differences of, with those of 
man, ii. 303 ; different degrees of differ- 
ence in the sexes of, ii. 307 ; expression 
of emotions by, ii. 320; generally mo- 
nogamous habits of, ii. 345; polygamous 
habits of some, ii. 345; naked surfaces of, 
ii. 360; American, manifestation of reason 
in, i. 47 ; American, direction of the hair 
on the arms of some, i. 185. . 

M0NOGA.MY, not primitive, i. 175. 

M0NOGENI8T8, i. 220. 

Ilononydius vseiidaoori, stridulation of, 
1. 371. 

MoNOTREMATA, 1. 194; development of the 
nictitating membrane in, i. 23; lactifer- 
ous glands of, i. 200 ; connecting mam- 
mals with reptiles, i. 204. 

Monstrosities, analogous, in man and 
lower animals, i. 109; caused by arrest of 
development, i. 116; correlation of; i. 125; 
transmission of, i. 216. 

Montagu, G., on the habits of the black 
and red grouse, i. 260 ; on the pugnacity 
of the rufi; ii. 39 ; on the singing of birds, 
ii. 49 ; on the double moult of the male 
pintail, ii. 81. 

Monteieo, Mi\, on Mueorax Abi/ssiniem. 
ii. 69. 

Monies de Oca, 1*1., on the pugnacity of 
male Humming-birds, ii. 38. 

3/onticola cyanea, ii. 164. 

Monuments, as traces of extinct tribes, i. 
228. 

Moose, battles of, ii. 229 ; horns of the, an 
incumbrance, ii. 248. 

Moral and instinctive impulses, alliance 
of, i. 85. 

Moral faculties, their influence on natural 
selection in man, i. 152. 

Moral rules, distinction between the high- 
er and lower, i. 90. 

Moral sense, origin of the, i. 98 ; so called, 
derived from the social instincts, i. 93, 94. 

Moral tendencies, inheritance of, i. 98. 

Morality, supposed to be founded in self- 
ishness, i. 93 ; test of the general wel- 
fare of the community, i. 94; gradual rise 
of i. 99 ; influence of a high standard of, 
i. 159. 

Morgan, L. H., on the Beaver, i. 36; on 
the reasoning powers of the Beaver, i. 45 ; 
on the forcible capture of wives, i. 175; 
on the eastoreum of the Beaver, ii. 266 ; 
marriage unknown in primeval times, ii. 
343 ; on Polyandry, ii. 349. 

Morris, F. O., on hawks feeding an orphan 
nestling, ii. 103. 

Mortality, comparative, of females and 
males, i. 256, 267, 292. 

Morton, on the number of species of man, 
i. 218. 

3fosc7nis mosclti/erue, odoriferous organs 
of, ii. 267. 



418 



INDEX. 



Jfotacillce, Indian, yomijr of, ii. 182. 

M0TII8, i. 3s'2 ; alisi-nco of mouth in aome 
male, i. 246; nptiTous fi-iimlc, i. 247; male, 
preliensile use of the tarsi l>y. i. 248; male, 
attracted by females, i. iiirZ; coloration 
of, i. 8b6; sexual diflerences of color in, 
i. 8&5. 

MoTMOT, racket-shaped feathers in the tail 
of a, ii. 70. 

Mori-T, double, ii. 173; double annual, in 
birds, ii. 77. 

Moulting of birds, ii. 204. 

Moults, piirtinl, ii. 79. 

MuD-TUKTLE, lonff claws of the male, ii. 2fi. 

MuL.\TTOF_s, persistent fertility ofi i. 213; 
immunity of. fi-om yellow fever, i. 2^54. 

MuLi;, sterilit)- and sirouj,' vitiility of the, i. 
213. 

Mules, rational, i. 47. 

MuLLKU, Ferd., on the Mexicans and Peru- 
\'ian9, i. 176. 

MClleu, Fritz, on astomntous males of 
7Wna/«, i. 247; on the disai)pearaneo of 
spots and stripes in adult mammals, ii. 
2U0; on the proportions of the sexes in 
some Crustacea, i. 307; on secondary 
se.Mial characters in various Crustaceans, 
i. 319, et seifi/. : on the luminous larva of 
a beetle, i. xiii; musical contest between 
male Cicadie. i. 341 ; on the se.xual ma- 
turitj" of younjf ampbipod Crustacea, ii. 
206. 

Miller. .T., on the nictitating' membrane 
and Semilunar fold, i. 2;!. 

MiJLLEK, Ma.x. on the orisrin of lanfruage, 
i. 55; stru^'«:le for life among the words, 
etc.. of laufTua^es. i. 5S. 

MC'LLEB, S.. on the IJantenp-. ii. 276; on the 
colors ot jSemnopit/iecu€ c/irt/ncmielas, ii. 
277. 

MuNTJAC-DEER, wcapous of the, ii. 245. 

MuRiE, J., on the reduction of organs, i. 18 ; 
on the ears of the J.emuroidea, i. 23 ; on 
variability of the muscles of the Lemuroi- 
dea, i. 123, 131 ; basal caudal vertebra; of 
Macacim inornalitK embedded in the 
l)ody, i. 145; on differences in the Lemu- 
roidea. i. 190; on the throat-pouch of the 
mule liustard, ii. 55; on the mane of 
Ot<n id JiiOat'i. ii. 255; on the sub-orbital 
pits of Kiiminants. ii. 267 ; on the colors 
of the sexes in Otaria nigreecens, ii. 
274. 

Murray, A., on the Pedioili of dilferent 
races of men, i. 211. 

Murray, T. A., on the fertility of Austra- 
lian women with white men. i. 212. 

Mus coninffa. i. 49. 

Mu« miniitiix, sexual difference in the col- 
or of, ii. 273. 

Muscn romitoria, i. 130. 

Mtwcicapit grixola. ii. 162. 

Munviciijia liiftiioxa, ii. 162. 

Muscicapn riiticil/ii, breedlnj; in imma- 
ture plumafre, ii. 205. 

Muscle, ischig-pubic, i. 123. 

Muscles. rudimentaiT, occurrence of, in 
man, i. 19; variability of the, i. 105; ef- 



fects of use and disuse upon, I. 112 ; ani- 
mal-like abnormalities of, in man. i. 122 ; 
correlated variation oC In the arm and 
leg. i. rJ5; variability of in the bands and 
fiH't, i. 131 ; of the jaws, intluence oC on 
the jihysiognomy of the Ajies. i. 139 ; ha- 
bitual spasms of, causing modifications 
of the facial bones, i. 141 ; of the early 
progenitor-s of man. i. 19b; greater varia- 
bility of the, in men than in women, i. 
266. 

MuscuLUS 8TEBNALIS, Prof. Turner on the, 
i. 19. 

Music, 1. 224; of birds, ii. 4S; discoi-dant, 
love of savages for, ii. 04 ; dilhrent ai)pre- 
ciation of. by different peoples, ii. 31s; 
origin of, ii. 317. 321 ; effects oC ii. 320. 

Musical cadences. percei)tion of by ani- 
mals, ii. 317; powers of man, ii. 314, et 

Musk-deer, canine teeth of m.ile, ii. 2."1, 

245. 240; male, odoriferous organs of the, 

ii. 267; winter change of the. ii. 2s5. 
Musk-duck, Australian, ii. 36; large size 

of male, ii. 41 ; of Guiana, pugnacity of 

the male. ii. 41. 
Musk-ox, horns of, ii. 230. 
Musk-rat. i)rotective resemblance of the, 

to a clod of eartlu ii. 284. 
3Inxopha(i(r, colors and nidification of the, 

ii. 163; both sexes of, cquallv brilliant, ii. 

169. 
Mussels opened by monkeys, i. 134. 
Mustacue-moskev, colors" of the, ii. 277, 

296. 
Mustaches, in monkeys, i. 1S4. 
J/uite/a, winter change of two species ot, 

ii. 2S4. 
Mutilations, healing of, i. 13. 
MiitiUa Kiiropnti. stiidulation of^ i. 35.5. 
Mutillldj;, absence of ocelli in female, i. 

Jli/cetes cara'ja. polygamous, i. 258; vo- 
cal organs ot ii. 2(54; bcird o^ ii. 269; 
sexual differences of color in, ii. 276 ; 
voice of, ii. 316. 

Mycetes seniculits, sexual difTerences of 
color in, ii. 276. 

Myriapoda, i. 830. 



N. 

Nagell on the influence of natural selec- 
tion on pbnt.s. i. 1,46; on the gi-adalion 
of species of plants, i. 219. 

Nails, colored yellow or purple in part of 
.\frica, ii. 322." 

NAIM.F.S, greater proportion of female ille- 
gitimate childi-en in, i. 292. 

Narwilai., tusks of tlie. ii. 231, 287. 

Nasal cavities, large size o^ in Ajnericau 
alwrigines, i. 114. 

Nascent organs, i. 18. 

Natiiushts, H. von, on the improved breeds 
of pigs, i. 222 ; on the breeding of domes- 
tic animals, ii. 3.W. 

Natural selection, its effects on the early 



INDEX. 



419 



progenitors of man. i. 131 ; influence of; 
on man, i. 145, 14S; limitation of the 
principle, i. 14G; influence of, on social 
animals, i. 149 ; Mv. Wallace on the limi- 
tation of, by the influence of the mental 
faculties in man, i. 1J)2 ; influence of. in 
the progress of the United States, i. 172. 

Natural and sexual selection contrasted, 
i. 269. 

Naulette, jaw from, largo size of the ca- 
nines in, 1. 122. 

Nbandeethal skull, capacity of the, i. 
140. 

Neck, proportion of, in soldiers and sailors, 
i. 112. 

Necrophoru,% stridulation of, i. 367, 371. 

Nectarinia, young of, ii. 1S2. 

Nectarinia, nidiflcation of, ii. 101 ; moult- 
ing of the, ii. 79. 

Negro, resemblance of a, to Europeans, in 
mental characters, i. 273. 

Negeo-women, their kindness to Mungo 
Park, i. 91. 

Negroes, character of, i. 208 ; lice of, i. 212 ; 
blackness of, i. 216, ii. 365; variabiUty of, 
1. 217, 218; immunity of, from yellow fe- 
ver, i. 234; difference of, from Americans, 
i. 238 ; disfigurements of the, ii. 282 ; col- 
or of new-born children of, ii. 302 ; com- 
parative beardlessness of, ii. 306; readily 
become musicians, ii. 318; appreciation 
of beauty of their women by, ii. 328, 330 ; 
idea of beauty among, ii. 334; compres- 
sion of the noss by some, ii. 335. 

Neolithic period, i. 176. 

Neomorpha, sexual ditferenco of the beak 
in, ii. 37. 

Nephila, i. 323. 

Nests, made by fishes, ii. 19; decoration 
of, by Humming-birds, ii. 107. 

Neumeistee, on a change of color in pig- 
eons after several moultings, i. 234. 

NE0RATION, difference of in the two sexes 
of some butterflies and hymcnopter.a, i. 
837. 

Neueopteea, 1. 306, 350. 

Keurothemis^ dimorphism in, i. 352. 

New Zealand, expectation by the natives 
of, of their extinction, i. 232 ; practice of 
tattooing in, ii. 326; aversion of native* 
of, to hairs on the face, ii. 332; pretty 
girls engrossed by the chiefs in, ii. 352. 

Newton, A., on the throat-pouch of the 
male bustard, ii. 55 ; on the difference be- 
tween the females of two species of Oxy- 
noius, ii. 184; on the habits of the phala- 
rope, dotterel, and godwit, ii. 195. 

Newts, ii. 23. 

Nicholson, Dr., on the non-immunity of 
dark Europeans from yellow fever, i. 236. 

Nictitating membrane, i. 23, 198. 

NiDiFicATioN, of fishes, ii. IS ; relation of, 
to color, ii. 159, 165 ; of British birds, ii. 
162. 

Night-heron, cries of the, ii. 48. 

Nightingale, arrival of the male before 
the female, i. 251 ; object of the song of 
the, ii. 49. 



Nightlngales, new mates found by, ii. 
101. 

Night-jar. selection of a mate by the fo- 
m.Tle, ii. Ill ; Australian, sexes of, ii. 197 ; 
coloration of the, ii. 216. 

NiGiiT-jAES, noise made by some male, 
with their wings, ii. 59 ; elongated feath- 
ers in,ii. 69, 92. 

Nilghau, sexual diff'erences of color in the, 
ii. 273. 

NiLssoN, Prof., on the resemblance of stone 
arrow-heads from various places, i. 224 ; 
on the development of the horns in the 
reindeer, i. 279. 

Nipples, absence of, in Monotremata, i. 200. 

NiTZSCii, 0. L., on the down of birds, ii. 77. 

NOCT0.E, brightly colored beneath, i. 885. 

NocTuiD.E, coloration of, i. 382. 

NoRDMAUN, A., on Tetrao -urogalloides, ii. 
96. 

Nomadic habits, imfavorable to human 
progress, i. 160. 

Norway, numerical proportion of male and 
female births in, i. 291. 

•Nose, resemblance of, in man and the apes, 
i. 184 ; piercing and ornamentation of the, 
ii. 325 ; flattening of the, Ii. 335 ; very flat, 
not admired in negroes, ii. 333. 

NoTT and GUddon, on the features of Ea- 
meses II., i. 209; on the features of 
Amunoph III., i. 210; on skulls from 
Brazilian caves, i. 210 ; on the immunity 
of negroes and mulattoes from yellow fe- 
ver, i. 234; on the deformation of the 
skull among American tribes, ii. 336. 

NuDiBRANcu mollusca, bright colors of; i. 
317. 

Numerals, Roman, i. 175. 

Nunemaya, natives of, bearded, ii. 307, 332 

O. 

Obedience, value of; i. 166. 

Observation, powers of, possessed by 
birds, ii. 105. 

Occupations, sometimes a cause of dimin- 
ished stature, i. Ill ; effect of, upon the 
proportions of the body, i. 112. 

Ocelli, absence of, in female MutiUidse, i. 
331. 

Ocelli of birds, formation and variability 
of the, ii. 126. 

Ocelot, sexual differences in the coloring 
of the, ii. 278. 

Ocijphaps lophotes, ii. 92. 

Odonata, i. 306. 

Odonestis potatoria, sexual difference of 
color in, i. 386. 

Odor, coiTclation of; \vith color of skin, i. 
239 ; emitted by snakes in the breeding- 
season, ii. 23 ; of mammals, ii. 265. 

(Eeantlms nivalis, difference of color in 
the sexes of, i. 351. 

Oidemia, ii. 216, 217. 

Olivier, on sounds produced by Pimelia 
striata, i. 373. 

Omaloplia brunnea, stridulation of, i. 
869. 



420 



INDEX. 



Onitis fureifer, procosses of anterior fem- 
ora of tlie male, and on the bead and 
thorax of the female, i. 361. 

Onthojihtigim. i. 860. 

Oiit/iiip/i(i(/ii.n ninffi/er, sexual dilTerence.s 
of, i. 85S ; variation in the horns of the 
male, i. 860. 

OniiDiA, sexual differences ot ii. 27. 

Opossum, wide range of; in America, i. 
211. 

Optio nerve, atrophy of the, caused by de- 
struction of the eye. i. 112. 

OK.VNG-OfTAN, ii. 308: IJisclioff on the 
agreement of the brain of the, with that 
of man, i. 11; adult age of the, i. 13; 
oars of the, i. 21 ; vermiform appcndatre 
of, i. 26; platfoniis built by the, i. 35; 
alarmed at tile sijrht of a turtle, i. 41 ; 
using a stick as a lever, i. 49 ; using mis- 
siles, i. 50 ; using the leaves of the Pan- 
danus as a night covering, i. 51 ; hands 
of the, 1. 134; absence of mastoid pro- 
cesses in the, i. 135; direction of the 
hair on the arms of the, i. 1^5; its aber- 
rant characters, i. ISS ; supposed evolu- 
tion of the, i. 222 ; voice of the. ii. 265 ; 
monogamous habits of the, Ii. 345 ; male, 
beard of the, ii. 2T0. 

ftR ant.es, treatment of by monkeys, i.l34. 

Orax<;i;-tip butterfly, i. 3T6, 3Sl. 

Orclientia Darwinii, dimorphism of males 
of, i. 322. 

Orche«tia Tuciiratinga, limbs of; i. 320, 
32T. 

Obdeai, i. 66. 

OreuH canna, colors of. ii. 274. 

Oreas Perbianus, colors of, ii. 274, 2S6. 

Organs, prehensile, i. 24S; utilized for 
new jmrposos. ii. 319. 

Orgaxio scale. Von IJaer's definition of 
jirogress in, i. 2(W. 

Orioi.ks. nidilication of, ii. 160. 

OrioliiM, siiecies of, breeding in immature 
plumage, ii. •i^\h, 200. 

Orio/iiJi jiie/ii/iocephaliis, coloration of tlie 
sexes in, ii. 170. 

Ornaments, prevalence of similar, i. 224 ; 
fondness ot savages for, ii. 324 ; of male 
birds, ii. 47. 

Ornamental characters, equal transmis- 
sion of, to both sexe.s, in mammals, ii. 
2S;i; of monkeys, ii. 291. 

Ornitlwptera <'ra'«us, i. 301. 

Ornithorhynchw), i. 192; spur of the 
male, ii. 231 ; reptilian tendency of, i. 196. 

Orocete« eri/throga^tra, young oi; ii. 210. 

Orront, Grotto of i. 28. 

Orsodacna atra, dilference of color in the 
sexes of; i. 367. 

Ortuoptera, i. !341 ; metamorpho.sis of, i. 
2S2 ; stridulating, auditory ajiparatus of, 
1. 8+B; colors of, i. 349; rudimentary 
stridulating organs in female, i. 349; 
stridulation of the, and Homoptei-a, dis- 
eu.ssod, i. 349. 

OrtyyorniH ffiilarU, pugnacitv of the 
male, ii. 42. 

Ortjctes, stridulation of, i. 869 ; sexual dif- 



ferences in the stridulant organs ot i. 
871. 

Orifr leucori/x, use of the horns of, ii. 289. 
251. 

Osphranter rii/us, sexual difTerence in the 
color of, ii. 272. 

Ostrich, African, sexes and incubation of 
the, ii. 196. 

Ostriches, stripes of young, ii. 176. 

Otdria jnhatu. mane" of the male, ii. 255. 

Otdria iiiyreMct'ii-n. difference in the colora- 
tion of the sexes ot; ii. 273. 

OtiM Bengaleim*, love-antics of the male, 
ii. 6.J. 

Otis tarda, polygamous, i. 261 ; throat- 
pouch of the male. ii. 55. 

OuzEi. ring, colors and nidificatlon of the, 
ii. 171. 

Ouzel, water, colors and nidiflcation of 
the, ii. 162. 

Ovibos moschatitfi, horns of, ii. 236. 

Ovipositor of insect.s. i. 246. 

OviH cycloceros, mode of fighting of, ii. 

OvrLE of man. i. 14. 

Owen, Prof., on the Corpora Wolfflana, i. 
16; on the great-toe in man, i. 16: on 
the nictitating membrane and semilunar 
fold, i. 23; on the development of the 
posterior molars in different races of 
man, 1. 26; on the length of the cjecum 
in the Koala, i. 26 ; on the coccygeal ver- 
tebrae, i. 29; on rudimentary structures 
belonging to the reproductive system, i. 
80; on abnormal conditions of the hu- 
man uterus, i. 119: on the number of 
digits in the Ichthyopterygia. i. 120; on 
the canine teith in man." i. 121 ; on the 
walking of the chimpanzee and orang. i. 
134; on the mastoid processes in the 
higher apes, i. 13S; on the hairiness of 
elephants in elevated districts, i. 143; on 
the caudal vertebrse of monkeys, i. 144; 
classification of mammaha, i. IsO; on 
the hair in monkeys, i. ISO; on the pis- 
cine affinities of the Ichthyosaurians, i, 
196 ; on polygamy and monogamy among 
the antelopes, i. 25S: on the horns of 
Antilocdpra Americana, i. 230 ; on the 
musky odor of crocodiles during the 
breeding-season, ii. 27; on the secnt- 
glands of snakes, ii. 29 ; on the Dugong, 
Cachalot, and OrnitAor/ii/ncAiis, ii. 23i ; 
on tke antlers of the red-deer. ii. 241 ; on 
the dentition of the Camelida', ii. 246; 
on the tusks of the Mammoth, ii. 247; 
on the horns of the Irish elk, ii. 247 : on 
the voice in the giraffe, porcupine, and 
stag. ii. 261 ; on the laryngeal sac of the 
gorilla and orang, ii. 2(W ; on the oiiorifer- 
ous glonds of mammals, ii. 2t)6. 267 : on 
the effects of emasculation on the vocal 
organs of men. ii. 314; on the voice of 
Jlylobatix ay it is, ii. 316; on Aiiicrican 
monogamous monkeys, ii. 845. 

Owls, white, new mates found by, ii. 100. 

Oje)/notit«. difference of the females of two 
species of; ii. 1S4. 



INDEX. 



421 



p. 

Pachtdermata, i. 259. 

Paget, on the abnormal development of 
hairs in man, i. 24 ; on the thickness of 
the skin on the soles of the feet of in- 
fants, i. 113. 

Painting, i. 224. 

Pa!(xmo7i, chelae of a species o£ i. 321. 

Palceornis, sexual differences of color in, 
ii. 221. 

Palceornis Javanioiis, color of beak of, ii. 
171. 

Puloeornis rosa, young of, ii. ISO. 

Palamedea cornuta, spurs on the wings 
of, ii. 44. 

Paieolithic period, i. 176. 

Palestine, habits of the chaffinch in, i. 
298. 

Pallas, on the perfection of the senses in 
the Mongolians, i. 114; on the want of 
connection between climate and the color 
of the skin, 1. 232 ; on the polygamous 
habits of A?itilope saiga, i. 258; on the 
lighter color of horses and cattle in win- 
ter in Siberia, i. 273 ; on the tusks of the 
musk-deer, ii. 245, 24<y; on the odorifer- 
ous glands of mammals, ii. 266 ; on the 
odoriferous glands of the musk-deer, ii. 
267 ; on winter changes of color in mam- 
mals, ii. 284 ; on the ideal of female beau- 
ty in North China, ii. 823. 

Pabnaris awessorius nmscle, variations 
of the, i. 105. 

Pampas, horses of the, i. 227. 

Pangenesis, hypothesis of, i. 271, 275. 

Panniculus carnosus, i. 19. 

Papilio, sexual differences of coloring in 
species of, i. 377; proportion of the sexes 
in North American species of, i. 301 ; 
coloration of the wings in species of, i. 
383. 

Papilio aitcaniu.% i. 377. 

Papilio Sesoxfris and Children's, varia- 
biUtv of. i. 389. 

Papilio Turniis, i. 301. 

Papilionidje, variability in the, i. 389. 

Papuans, line of separation between the, 
and the Malavs, i. 210 ; beards of the, ii. 
307 ; hair of, ii. 324. 

Papuans and Malays, contrast in char- 
acters of, i. 208. 

Paradise, Bu-ds of, ii. 96, 173; supposed 
by Lesson to be polygamous, i. 260 ; rat- 
tling of their quills by, ii. 58; racket- 
shaped feathers in, ii. 70 ; sexual differ- 
ences in color of, ii. 71 : decomposed feath- 
ers in, ii. 70, 93 ; display of plumage by 
the male, ii. 85. 

Paradisea apoda, barbless feathers in the 
tail ot, ii. 70; plumage of, ii. 72; and P. 
Papxiaiia, divergence of the females of, 
ii. 184. 

Paradisea rubra, ii. 71, 72. 

Paraguay, Indians ot, eradication of ej-e- 
brows and eyelashes by, ii. 332. 

Parakeet, Australian, variation in the col- 
or of the thighs of a male, ii. 121. 



Parallelism of development of species 
and languages, i. 57. 

Parasites on man and anim.als, i. 12; as 
e\ddence of specific identity or distinct- 
ness, i. 211 ; immunity from, correlated 
with color, i. 233. 

Parental affection, partly a result of natu- 
ral selection, i. 77. 

Parents, age of, influence upon sex of off- 
spring, i. 293. 

Parin.e, sexual difference of color in, ii. 166. 

Park, Mungo, negro women teaching their 
children to love the truth, i. 91 ; his treat- 
ment hy the negro women, i. 91, ii. 311 ; 
on negro opinions of the appearance of 
white men, ii. 330. 

Parrot, racket-shaped feathers in the tail 
of a. ii. 70; instance of benevolence in a, 
ii. 105. 

Parrots, imitative faculties of, i. 43 ; change 
of color in. i. 146 ; living in triplets, ii. 102 ; 
affection of ii. 104 ; colors of, ii. 213 ; se.x- 
ual differences of color in, ii. 221 ; colors 
and nidiflcation of the. ii. 163, 166, 168; 
immature plumage of the, ii. 180 ; musi- 
cal powers of, ii. 319. 

Parthenogenesis in the Tenthredin^, i. 
305 ; in Cynipidae, i. 305 ; in Crustacea, i. 
306. 

Partridge, monogamous, i. 261 ; propor- 
tion of the sexes in the, i. 297 ; female, ii. 
186. 

'• Partridge-dances.'' ii. 65. 

Partridges. Uving in triplets, ii. 102 ; spring 
coveys of male, ii. 103; distinguishing 
persons, ii. 106. 

Pat^us coeruleu.% ii. 166. 

Passer, sexes and young of, ii. 203. 

Passer braehydactylus, ii. 203. 

Passer domeslicus. ii. 162, 203. 

Passer montanus. ii. 162, 203. 

Patagonians, self-sacrifice by, i. 84. 

Patterson, Mr., on the Afirionid<E, 1.351. 

P.AULIBTA8 of Brazil, i. 216. 

Paro cristatits, i. 281, ii. 130. 

Pa 10 miiticus, i. 290, ii. 130; possession of 
spurs by the female, ii. 44, 155. 

Paro nigripenni-s, ii. 115. 

Pataguas Indians, thin legs and thick arms 
of the, 1.112. 

Patan, Mr., on the proportion of the sexes 
in sheep, i. 295. 

PE.4.C0CK, polygamous, i. 261 ; sexual char- 
acters of i. 281 ; pugnacity of the, ii. 44 ; 
rattUng of the quiUs by, ii. 58 ; elongated 
tail-coverts of the, ii. 69, 93 ; love of dis- 
play of the, ii. 130, 65, S3 ; oeellated spots 
of the, ii. 130 ; inconvenience of long tail 
of the, to the female, ii. 147, 157. 158; 
continued increase of beauty of the, il. 
206. 

Peacock-eutterflt, i. 380. 

Peafowl, preference of females for a partic- 
ular male, ii. 116 ; first advances made by 
the female, ii. 116. 

Pediculi of domestic animals and man, i. 
211. 

Pedigree of man, 1. 205. 



422 



INDEX. 



Peilionomns torquntaK, sexes of, ii. 192. 
I'kewit, wlng-tubcrcles of the male, 11. 

44. 
Pf,i..\gic animals, transparency o£ 1. 314. 
/'e/ecaniix eryihrorlujnrlnut, horny crest 

on the beak of the male, during the breed- 

Infr-season, ii. "(>. 
Pel era nun oiiocrotdlitu, spring plumage o^ 

ii. 81. 
Pelelk, ii. .S'25. 
I'euc.vs, blind, fed by his companions. 1. 

74; youni,', guided by olil birds, 1. 74; 

j)ugnacity of the male' ii. 41. 
Pelicans, fishing in concert, 1. 72. 
J't/ohiiis I/ermdnni, slridulatlon, of, 1. 86S, 

;{70. 
Pelvis, alteration of, to suit the erect atti- 
tude of man, 1. 137 ; difiereuces of the, in 

the sexes in man, ii. 3(12. 
Penelope nigra, sound jiroduced by the 

male, ii. 61. 
Pesn AST. on the battles of seals, ii. 229 ; on 

the bladder-nose seal, ji. 205. 
Pentlit^ anteunal cushions of the male, 1. 

a«. 

Perch, brightness of male, during breeding- 
season, ii. 13. 

Peregrine Falcon, new mate found by, ii. 
100. 

Period of variability, relation of, to sexual 
selection, i. 2S7. 

Periodicitt, vital. Dr. Laycock on, i. 12. 

Periods, lunar, followed by functions in 
man and animals, i. 12, 204. 

Periods of life, inheritance at correspond- 
ing, i. 271, 276. 

Perisoreua Canadensis, young of, ii. 
200. 

Peritrirhia. difference of color in the se.xes 
of a species of, 1. 356. 

pERlWINKl.E, i. 815. 

Pernin cristata, ii. 121. 

Perseverance, a characteristic of man, ii. 
312. 

Persians, said to be improved by intermix- 
ture with Georgians and Circassians, ii. 
341. 

Personnat, M., on Bombijx Yamamai, i. 
301. 

Peruvians, civilization of the, not foreign, 
i. 176. 

Petrels, colors of, ii. 220. 

Petrocincla cijnnea, young of, ii. 210. 

yv^ronJrt, ii. 20;3. 

Pfeiffer, Ida, on Javanese ideas of beauty, 
ii. 331. 

P/iiieochtvrus .^Jiiopiciis, tusks and pads 
ot, ii. 253. 

PiiALANOER, Vulpine, black varieties of the, 
ii. 2MI. 

J'hnliiroprui fidicarins, ii. 194. 

/'/u//,iropu8'/ii/per(joreus, ii. 194. 

P/nnntiiK, 1. 361. 

PhiDuviin carnifer, variation of the horns 
of the male, i. 369. 

Pliiin4Xii« fauniig, sexual difteronoes of. i. 

Phanceiu lanei/er, I. 359. 



Phangrmiirn riridi«8ima, stridulatton ot, 
i. 344. 345. 

P/tattiuiiim Svinmerringii, ii. 150. 

PlKminiins remicolor, ii. 85. 

P/ianiaiiiiM Wollichii. ii. 89, 1S7. 

PiiASMiD.f, mimicry of leaves by the, 1.401. 

Pheasant, polygamous, i. 261 ; "production 
of hybrid.'* with the common fbwl, ii. 117 ; 
and black groiL^e, hybrids of. ii. 109; im- 
mature plumage of the, ii. 1^0. 

Pheasant, Argu.s, ii. 69, 173; display of 
plumage by the male, ii. &S; ocellatcd 
spots of the, ii. 128, 135; gradation of 
characters in the, ii. 135. 

Pheasant, Blood-, ii. 42. 

Pheasant, t'hecr, ii. 89. 1S7. 

Pheasant, Eared, i. 290; ii. 89. 1S7; eexcs 
alike in the, ii. 170; length of the tail in 
the. ii. 15S. 

Pheasant, Golden, display of plumage by 
the male. ii. S5; sc.x of j-oung. ascer- 
tained by pulling out head-feathers, ii. 
205; age of mature plumage in the, ii. 
204. 

Pheasant, Kalij, drumming of the male, 
ii. 59. 

Pheasant, Reeves, length of the tail in, ii. 
15S. 

Pheasant. Silver, se.xual coloration of the, 
ii. 218; triunifihant male, deposed on ac- 
count of si)oikd plumage, ii. 115. 

Pheasant, b^iemmerring's, ii. 149. 15S. 

Pheasant, Tragopan, ii. 6S: display of 
plumage by the male, ii. 87; markings 
of the sexes of the. ii. 12S. 

Pheasants, period of acquisition of male 
characters in the family of the, i. 2S0; 
proportion of sexes in chicks o£ i. 297 ; 
length of the fciil in, ii. 149, 157, 153. 

Philodromus. i. 82S. 

Philters, worn by wjmen, ii. 328. 

Phoca (irvenlandicu, se.xual diflfercncc in 
the coloration of. ii. 273. 

P/itxiiiciira rtitici/la. ii. 101. 

PnosrHOREScESCE of insects, i. S4!). 

Phryganid-e, copulation of distinct spe- 
cies of, i. 332. 

Phr>/ni«cu« nigricans, ii. 24. 

Physical inferiority, supposed, of man, i. 
149. 

Pickering, on the nmnber of species of 
man, i. 218, 

PiCTON, J. A., on the soul of man, ii. 878. 

Picus aurntu.i. ii. 41. 

PiERiDJi, mimicry bv female, i. 399. 

Pieri^, i. 380. 

Pigeon, carrier, late development of the 
wattle in, i. 284; domestic, breeds and 
subbreeds of, ii. 170; pouter, late de- 
velopment of the crop in, i. 2S4 ; female, 
deserting a weakened mate., i. 254. 

Pigeons, nestlinir. fed by the secretion of 
the crop of both parents, i. 202: ch.ingea 
of plunLige in. i. 272; transmission of 
sexual peculiarities in. i. 274; changing 
color after several moultings. i. 2>4 ; nu- 
merical proportion of the sexes in, 1.296; 
cooing ot; ii. 6S; variations in plumage 



INDEX. 



423 



o£ ii. 71 ; display of plumage by male, li. 
92; local memory of, ii. 105; antipathy 
of female, to certain males, ii. 114; pair- 
ing of, ii. lib; profligate male and. 
female, ii. 114; wng-bars and tail-feath- 
ers of, ii. 125 ; supposititious breed of, ii. 
148; pouter and carrier, peculiarities of 
predominant in males, ii. 150; nidifica- 
tion of, ii. 160; immature plumage of the, 
ii. ISO; Australian, ii. 167; Belgian, wth 
black-streaked males, 1. 2S5, 293; li. 150. 

Pigs, origin of the improved breeds of, 1. 
222 ; numerical proportion of the sexes 
in, i. 295; stripes of young, ii. 176, 288; 
sexual preference shown by, ii. 260. 

Pike, American, brilliant colors of the 
male, during the breeding-season, ii. 14. 

Peke, male, devoured by females, i. 299. 

Pike, L. O., on the psychical elements of 
religion, i. 66. 

Pimetia striata, sounds produced by tho 
female, i. 373. 

Pintail Drake, plumage of, ii. 81 ; pairing 
\rith a wild-duck, ii. 110. 

Pintail Duck, paii-ing with a Widgeon, ii. 
109. 

Pipe-fish, filamentous, ii. IS; marsupial 
receptacles of the male, ii. 20. 

Pipits, moulting of the. ii. 79. 

Pijrra, modified secondary wing-feathers 
of male, ii. 62. 

Pipra deliciosa, ii. 62, 63. 

Pirates stridulus, stridulation of, i. 340. 

Pithecia leucoeephala, sexual difl'erences 
of color in, ii. 277. 

Pithecia Sata7tas, beard of. ii. 269, 272 ; 
resemblance of; to a negro, ii. 365. 

Pits, suborbital, of Euminants, ii. 267. 

PiTTiD^, nidiflcation of, ii. 160. 

Placentata, i. 194. 

Plagiostomous fishes, ii. 1. 

Plain-wanderer, Australian, 11. 192. 

Planarim, bright colors of some, i. 313. 

Plantain-eaters, colors and nidiflcation 
of the, ii. 16;?; both sexes of, equally 
brilliant, ii. 169. 

Plants, cultivated, more fertile than wild, 
i. 127; Nageli, on natural selection in, i. 
146 ; male flowers of, mature before tho 
female, i. 252 ; phenomena of fertilization 
in, i. 265 ; relation between number and 
size of seeds in, i. 309. 

Platalea, ii. 57 ; change of plumage in, ii. 
171. 

PlatyMemnus, i. 850. 

PlatycercxM, young of; ii. 200. 

Platyphylhim concamim, i. 342, 345. 

Platyrrhine monkeys, i. 188. 

Platysma myoicles, i. 19. 

Pleoostomus, head-tentacles of the male of 
a species of, ii. 10. 

Plecostomiis harbatus, peculiar beard of 
the male, ii. 10. 

Plectropteriis gamhensis, spurred ■wings 
of; ii. 44. 

Ploceus, ii. 52. 

Plovers, wing-spurs of, ii. 44 ; double 
moult in, ii. 79. 



Plitmage, changes of, inheritance of, by 
fowls, i. 272 ; tendency to analogous 
variation in, ii. 70 ; display of; by male 
birds, ii. 82, 92 ; changes of, in relation to 
season, ii. 172; immature, of birds, ii. 
175,179; color of, in relation to protec- 
tion, ii. 213. 

Plumes on the head in birds, difference of, 
in the sexes, ii. 156. 

l^neumora, structure of, i. 346. 

Podica, sexual difterence in the color of 
the irides of ii. 123. 

PoEPPiG, on the contact of civilized and 
savage races, i. 230. 

Poison, avoidance of, by animals, i. 48. 

PoiBONocs fruits and herbs avoided by 
animals, i. 35. 

Poisons, immunity from, correlated -with 
color, i. 233. 

Polish fowls, origin of the crest in, i. 275. 

Pollen and VanDam, on the colors of Le- 
mur macaco, ii. 276. 

Polyandry, ii. 349 ; in certain c^-prinidEe, 
i. 306 ; among the elateridie, 1. 305. 

Polydactylism in man, i. 120. 

Polygamy, influence of, upon sexual selec- 
tion, i. 257 ; superinduced by domesti- 
cation, i. 262 ; supposed increase of fe- 
male bu-ths by, i. 293 ; in the stickleback, 
ii.2. ■^ 

Polygenists, i. 220. 

Polynesia, prevalence of infanticide in, ii. 
347. 

Polynesians, aversion of, to hairs on the 
flice, ii, 332 ; wide geographical range of, 
i. lOS ; difference of stature among the, i. 
110; crosses of, i. 217; variability of, i. 
217 ; heterogeneit}' of the, i. 232. 

Polyplectron, display of plumage by the 
male, ii. 86 ; number of spurs in, ii. 43 ; 
gradation of characters in, ii. 131 ; female 
ot; ii. 185. 

Polyplectron ehinquis, ii. 86, 132, 133. 

Po/yp/ecfron, Ilardu-icJcii, ii. 132, 133. 

Polyplectron, Malaccense, ii. 133, 184. 

Polyplectron Ndpoleonis, ii. 132, 134. 

POLYZOA, i. 315. 

Pontoporeia affinis, i. 819. 

Porcupine, mute, except in the ruttmg- 
season, ii. 261. 

Pores, excretory, numerical relation of; to 
the haii-s in sheep, i. 239. 

Porpitm, bright colors of some, i. 313. 

Portax picta, dorsal crest and throat-tuft 
of, ii. 268 ; sexual differences of color in, 
ii. 274, 286. 

Portunus puber, pugnacity of, i. 823. 

Potamochoerii-s penicillatus, tusks and 
facial knobs of the, ii. 254. 

PouciiET, G., on the ratio of instinct and 
intelligence, i. 36; on the instincts of 
ants, i. ISO; on the caves of Abou-Sim- 
bel, i. 209 ; on the immunity of negroes 
from j'ellow fever, i 234. 

Pouter pigeon, late development of the 
large crop in, i. 2S4. 

Power, Dr., on the different colors of tha 
sexes in a species of Squilla, i. 826. 



424 



INDEX. 



PowTfi, Mr., on ths habits of the chaffinch 
In Corfu, 1. 29S. 

PREKMINENrF. of m.in, i. 131. 

I'REKERENfK for iiinles by femnlc liiixl.s. ii. 
l"'*, 117; shown by iiiainmals, in p.ilr- 
inc. ii. 25(;. 

rRKiiENRiLE orpnns. i. 24**. 

PrexoijtU entellus, fljfhtinp of the mnic, ii. 
309. 

Preyer, Dr., on supernuinornr)' mammiE 
in women, i. 120. 

I'ltiniARD, on the difference of stature 
among: the Polynesians, i. 110; on the 
connertion lietwcen the l)rea(llh of the 
slviill in the Monfjolians and the ]>erfec- 
tion of their sense.s, i. 114; on the ca- 
pacity' of British skulls of different ajres, 
i. 140 ; on the flattened hciuls of the 
Colombian savafres. ii. 324; on Siamese 
notions of beautv. ii. 329 ; on the bcard- 
lessness of the Siamese, ii. 3.32 ; on the 
deformation of the head amonfj Ameri- 
can tribes and the natives of Arakhan, ii. 
335. 

Pklmary sexual organs, i. 246. 

Primates, i. 183; se.xual differences of 
color in, ii. 277. 

PKi.MdGENiTrnE, evils of, i. 163. 

Primula, relation between number and 
size of seeds in, i. 309. 

Prioxidx, difference of the sc.xes in color, 
i. •At^(^. 

Provtdtretux mvltimaculnttifi, ii, 24, 85. 

Prortotretux tenuis, sexual diflerence in 
the color of, ii. 3.5. 

PROFLIGArY, i. 16(5. 

Procenitors. early, of man, i. 198. 

Pro(;re.s8. not the" normal rule in human 
society, i. IGO; element.s of. i. 170. 

Prong-horm, boms of i. 2S0. 

PRoroRTioNs, dilferenco of, in distinct 
races, i. 208. 

Protective coloring in butterflies, i. 392 ; 
in hzanls, ii. 3.'); in bu-ds, ii. ISS, 214; in 
mammals, ii. 2s3, 2S4. 

Protkitive n.aturc of the dull coloring of 
feu)ale Lepidoptera, i. 390. 392. 401. 

Protective rcsembla:ices in fishes, ii. IS. 

Protozoa, absence of secondaiy sexual 
characters in, i. 812. 

PRrNER-BEV, on the occurrence of the 
supra-condyloid foramen in the humerus 
of man, i. 28 ; on the color of negro in- 
fants, ii. 803. 

Prtssia. numerical proportion of male and 
female births in, i. 292. 

Pnoctig, proiiortions of the sexes in, i. 
806. 

Ptarmigan, monogamous, 1. 261 ; summer 
and winter jiluiiiage of the, ii. 78, 79; 
uu]itlnl assemblages of Ii. 97 ; trii)le 
moult of the, ii. 173; protective colora- 
tion of, ii. 189. 

PfFF-iiiRDs, colors and nidiflcation of the, 
ii. 163. 

PrcsAciry of flne-plumaged male birds, 
ii. 89. 

PvMAs, Stripes of young,' ii. \"). 



Puppies learning from cats to clean tlielr 
faces, i. 43. 

Pi/cnoiiofuH fitrworfhoun, pugnacity of 
the male. ii. 39; disiilay of under-tail 
coverts by the male, ii. 91. 

Pi/ranfin (Fxtiva, male aiding in Incuba- 
tion, ii. l.W. 

Pi/rorles, difference of the sexes in color, 
i. 856. 

QfADRi-.MAN.v hands of, i. 134; differences 
between man and the, i. 188; dependence 
of. on climate, i. 210; sexual differences 
of color in, ii. 276; ornament'd charac- 
ters of ii, 291 ; analogj- of sexual differ- 
ences of. with tho.se of man, ii. -So:? ; fight- 
ing of males for the females, ii. 3o9 ; mo- 
nogamous habits of ii. .345; beards of the, 
ii. 3G1. 

QfAiN. R.. on the variation of the muscles 
in man. i. 105. 

QuATREF.VGEs, A. de. on the occun-ence of 
a rudimentary tiiil in man. i. 2> : on the 
moral sense as a distinction between 
man and animals, i. 67; on variability, i. 
108; on the fertiUty of -Vustralian women 
with white men, i.'213; on the Paulistas 
of Brazil, i. 216; on the evolution of the 
breeds of cattle, i. 222 ; on the Jews, i. 
2;33 ; on the liability of negroes to tropi- 
cal fevers after residence in a cold cli- 
mate, i. 284; on the difference between 
field- and house-slaves, i. 237 ; on the in- 
fluence of climate on color, i. 237 ; on the 
Ainos, ii. 3iiG; on the women of San 
Giuliano. ii. 341. 

QvEcnrA Indi.ans. i. 114; loc.il variation of 
color in the, i. 237 ; no gray hair among 
the. ii. 820 ; hairlessness of the, ii. 307 ; 
long hair of the, ii. 831. 

Quenjui'/^/uld acuta, ii. 100. 

Qui.icaluK timjor. proportions of the sexes 
of, in Florid.i and Honduras, i. 298. 



a. 

Rabbit, white tail of the. ii. 284. 

Rabbits, danger-signals of, i. 71 ; domestic 
elongation of the skull in. i. 142; modifi- 
cation of the skull in. by the lopping of 
the ear. i. 142; numerical proportion of 
the sexes in, i. 295. 

Races, distinctive characters of, i. 208; or 
species of man, i. 210; crossed, fertility 
or sterility of, i. 212 ; of man. variability 
of the. i. 217; of man. resemblance of in 
mental characters, i. 223 ; formation of, i. 
225; of man, extinction of i. 226; efl'ects 
of the crossing of i. 281 ; of innn. forma- 
tion of the, i. 231 ; of man, children of 
the, ii. 803; beardless, aversion of; to 
hairs on the ftice. ii. 33:?. 

RAFF1.E.S, Sir S., on the Banteng. ii. 276. 

Kavts. use of i. 132, 22f>. 

Kage, manifested by animals, i. 89. 



INDEX. 



435 



Eaia batis, teeth of, ii. 6. 

Baia clavata, female spined on the back, 
ii. 2 : sexual difference in the teeth otj 
ii. 6. 

Raia maculafa, teeth of, ii. 6. 

Rails, spur-wing-ed, ii. 44. 

Eam, mode of fighting of the, ii. 2.33 ; Afri- 
can, mane of an, ii. 271 ; fat-tailed, ii. 271. 

Eameses II., i. 209. 

Eamsat, Mr., on the Australian Musk- 
duck, ii. 30; on the Regent-bird, ii. 108; 
on the incubation of Meniira guperba, 
ii. 157. 

liOna esculerita, vocal sacs of, ii. 26. 

Eat, common, general dispersion of a 
consequence of superior cunning, i. 49 ; 
supplantation of the native, in New 
Zealand, by the European rat, i. 231; 
common, said to he polygamous, i. 259 ; 
numerical proportion of the sexes in, i. 
296. 

Eats, enticed by essential oils, ii. 267. 

Eationality of birds, -ii. 104. 

Rattlesnakes, difference of the sexes in 
the, ii. 2S ; said to use their rattles as a 
sexu.al call, ii. 2S. 

Raven, vocal organs of the. ii. 52 ; steahng 
bright objects, ii. 107; pied, of the Feroe 
Islands, ii. 121. 

Rays, prehensile organs of male, ii. 1. 

Razor-bill, young of the, ii. 208. 

Reade, Winwood, on the Guinea sheep, i. 
280; non-development of horns in cas- 
trated male Guinea-sheep, ii. 236; on the 
occurrence of a mane in an African ram, 
ii. 271 ; on the negroes' appreciation of 
the beauty of their women, ii. 323; on 
the admiration of negroes for a black 
skin, ii. 330 ; on the idea of beauty 
among negroes, ii. 334; on the Jollofs, 
ii. 341 ; on the marriage-customs of the 
negroes, ii. 357. 

Reason, in animals, i. 45. 

Redstart, American, breeding in imma- 
ture plumage, ii. 205. 

Redstarts, new mates found by, ii. 101. 

Redl'vid.e, stridulation of, i. 340. 

Reed-cunting, head-feathers of the male, 
ii. 91 ; attacked by a bullfinch, ii. 106. 

Reefs, fishes frequenting, ii. 17. 

Regeneration, partial, of lost parts in 
m.an, i. 13. 

Regent-bird, ii. 108. 

Reindeer, antlers of, with numerous 
points, ii. 241 ; sexual preferences shown 
by, ii. 260; horns of the, i. 279; winter 
change of the, ii. 284 ; battles of, ii. 229 ; 
horns of the female, ii. 232. 

Relationship, terms of, ii. 344. 

Religion, deficiency o^ among certain 
races, i. 62 ; psychical elements of, i. 65. 

Remorse, i. 87; deficiency oi, among sav- 
ages, i. 158. 

Renggeb, on the diseases of Cebtis Azane, 
i. 11 ; on maternal affection in a Cef/us, i. 
39 ; revenge taken by monkeys, i. 39 ; on 
the reasoning powers of American mon- 
keys, i. 45; on the use of stones by mon- 



keys for cracking hard nuts, i. 49; on 
the sounds uttered by Cebus Azara, i. 
52 ; on the signal-cries of monkeys, i. 55 ; 
on the diversity of the mental "faculties 
of monkeys, i. i06 ; on the P.ayaguas In- 
dians, i. 112; on the inferiority of Euro- 
peans to savages in their senses, i. 114; 
on the polygamous habits of Mi/ce/e.s 
earaya, i. 253 ; on the voice of the howl- 
ing monkeys, ii. 264; on the odor of 
Cervus campestris, ii. 266 ; on the beards 
of Mycetea caraya and PWiecia Sa- 
tana.% ii. 269; on the colors of Fells 
mitU. ii. 274; on the colors of Cervus 
pa/udosiis, ii. 276; on sexual differences 
of color in Myeetes, ii. 277 ; on the color 
of the infant Guaranys, ii. 303 ; on the 
early matui-ity of the female of Cehus 
Azarm, ii. 303; on the beards of the 
Guaranys, ii. 307 ; on the emotional notes 
employed by monkeys, ii. 320 ; on Ameri- 
can polygamous monkeys, ii. 346. 

Representative species, of birds, ii. 182, 
18.3. 

Reproduction, unity of phenomena ofj 
throughout the mammalia, i. 13 ; period 
of, in birds, ii. 205. 

Reproductive system, rudimentary 
structures in the, i. 29; accessory parts 
of, i. 199. 

Reptiles, ii. 26. 

Reptiles and birds, alliance of, i. 204. 

Rese.mblances, sniaU, between man and 
the apes, i. 184. 

Retrievers, exercise of reasoning faculties 
by, i. 46. 

Revenge, manifested by animals, i. 39. 

Reversion, i. 117; perhaps the cause of 
some bad dispositions, i. 166. 

lihagium, difference of color in the sexe.s 
of a species o^ i. 356. 

EampluKtos carinatiis, ii. 217. 

RniNOCEROs, nakedness of, i. 143; horns 
of ii. 236 ; horns of, used defensively, ii. 
251 ; attacking white or gray horses, ii. 
281. 

Jthyneham, sexes and young of, ii. 193. 

RhyncJuue Au^tralis, ii. 193. 

RhynichcEa Bengalenms, ii. 193. 

Bhynchcea capensis, ii. 193. 

Rhythm, perception of, by animals, ii. 317. 

Richard, M., on rudimentary muscles in 
man, i. 19. 

Richardson, Sir J., on the pairing of 
Tetrao ^^mbellull/n. i()\ on Tetrao uro- 
pha»ianus, ii. 56 ; on the drumming of 
grouse, ii. 60 ; on the dances of Tetrao 
jyhasianeUiw. ii. 66; on assemblages of 
grouse, ii. 97; on the battles of male 
deer, ii. 229 ; on the reindeer, ii. 233 ; on 
the horns of the musk-ox, ii. 236; on 
antlers of the reindeer, with numerous 
points, ii. 241 ; on the moose, ii. 247^ 

Richardson, on the Scotch deer-hound, ii. 
250. 

Richter, Jean Paul, on imagination, i. 44. 

Riedel, on profligate femalg pigeons, ii. 
114. 



426 



INDEX. 



RiNG-orzEL, colors and niJirioation of the, 
ii. 102. 

ItiPA, Katlior, on the (lifTiculty of distin- 
(JTiiishin;; the racos of the Chinese, i. 2(1". 

EivAi.RT, ill singing, between male birds, 
ii. M. 

KivEK-uoo, African, tiislcs and knobs of 
tlie. ii. 2">4. 

EivER-s, analogj- of, to i.slands. i. 196. 

KoAcii, bri;rlitness of male during breeding- 
season, ii. 13. 

EonBERV, of strangers, considered honor- 
able, i. yo. 

EoBERTSOX. Mr., remarks on the develop- 
ment of the horns in the roebuck and 
red-deer, i. 279. 

Robin, pugnacity of the male, ii. 38 ; au- 
tumn song of the, ii. 51 ; female, singing 
of the, ii. 51 ; attacking other birds with 
red in theu- plum.ige, ii. 106; young of 
the, il. 199. 

RouisET, on the difference of size of the 
male and female cocoons of the silk- 
moth, i. 335. 

Rodents, uterus in the. i. 118; absence of 
secondary se.xual characters in, i. 259; 
sexual ditferenees in the colors of, ii. 272. 

Roe, winter change of the, ii. 2i4. 

RoLLE, F., on the origin of m.in, i. 4 ; on a 
change in German famiUes settled in 
Georgiii, i. 237. 

Roller, ii. 53. 

Romans, ancient, gladiatorial exhibitions of 
the, i. 97. 

Rook, voic? of the, ii. 58. 

RossLER, Dr., on the resemblance of the 
lower surface of buttei-llies to the bark of 
trees, i. 3S0. 

RosTRU.M, sexual difference in the length 
of^ in some weevils, i. 247. 

RcDiMENTARV Organs, i. 17; origin oC i. 
31. 

Rudiments, presence of, in languages, i. 
58. 

RrDOLPin, on the want of connection be- 
tween climate and the color of tlie skin, 
i. 232. 

Ruff, supposed to be polygamous, i. 261 ; 
proportion of the sexes in the, i. 297; 
pugnacity of the, ii. 39, 44; double 
moult in, ii. 78, 80; duration of dances of, 
ii. 96 ; attraction of the, to bright objects, 
ii. 107. 

RfMiNANTS, m-ile, disappearance of cinine 
teeth in, i. 139; ii. 311 ; generally polyg- 
amous, 1. 258; analogy of Laniellicbrn 
beetles to, i. 362; suborbital pits ot^ ii. 
267; sexual differences of color in, ii. 
274. 

liiipicola crocfa, disi)lay of plum.nge by 
the male, ii. 88. 

RCri'ELL, on o.inino teeth in deer and an- 
telopes, il. 246. 

Russia, numerical proportion of male and 
female births in, i. 291. 

linticilla, ii. 172. 

RCtlmeyer, VxoU on the sexual differences 
of monkeys, ii. 30lj. 



RuTLANDsiinsE, numerical proportion of 
mole and female births in, i. 291. 



S. 



Sachs, Prof., on the behavior of the male 
and female elements la fertilization, i. 
26.'>. 

SArRiFiCE.s. Human, i. 175. 

Sagittal crest in male apes and Austra- 
lians, ii. 304. 

Sahara, birds of the. ii. 161; animal in- 
habiUints of the. ii. 214. 

Sailors, growth oC delayed by conditions 
of hie. i. 110; long-slirhted, i. 113. 

Sailors and soldiers, dilfereuce In the pro- 
portions of. i. 112. 

St. John, Mr., on the attachment of mated 
birds, fi. 104. 

St. Kilda, beards of the inhabitants of; ii. 
306. 

Sahno eriox. and S. vmbla, coloring of the 
male, durin:.' the breeding-season, ii. 14. 

Sii/i/io !)/caoi/(»^\. 4. 

/fki/ino sd/tir, ii. 9l 

Salmon, leaping out of fresh water, i. 80; 
male, ready to breed liefore the female, 
i. 2.')2 ; proportion of the sexes in, i. 299 ; 
male, i>ugnacity of the. ii. 3 : male, char- 
acters ot; during the breeding-season, ii. 
3. 14; spawning of the. ii. 18; breeding 
of immature male. ii. 2o6. 

Salvin, O., on the Humming-bii-ds, i. 260; 
ii. 161 ; on the numerical proportion of 
the sexes in Humming-birds, i. 298, ii. 
212; on C/umxrpetes and Penelope, ii. 
61; on Selattplioru.'i phiti/c^rcun, ii. 62; 
on Pipra ileliciona, ii. &3 ; on C/ui«mo- 
rhijiifhun. ii. 70. 

Samoa Islands, beardlessness of the natives 
of, u. 307, 3*3. 

Sand-skipper, i. 323. 

Sandwich Islands, variation in the skulls ' 
of the natives of the, i. 105; superiority 
of the nobles in the. ii. 340. 

Sandwich Islanders, lice o£ i. 211. 

San Giuliano, women of, ii. 341. 

Sant.\ll recent rapid increase of the, i. 
128; Mr. Hunter on the. i. 232. 

Sap/iirina, characters of the males oi; i. 
326. 

Sarl'idiomU melanonotus, characters of 
the young, ii. 177. 

Sars, O.. on Po)itoporeia offlnU. i. 319. 

Sat urn in carpini, attraction of males by 
the female, i. 303. 

Saturn id lo. difference of coloration in the 
sexes of, i. 38.'). 

Satuniiittee, coloration of the, 1. 38.3, 885. 

Savagf., Dr.. on the lighting of the male 
gorillas, ii. 309 ; on the habits of the go- 
rilla, ii. 346. 

Savage and Wjiuan, on the polygamous 
h-ibits of the gorilb, i. 258. 

Sav.\ges, imitative faculties of i. 5,"). 1,V); 
causes of low moraUtj- of. 1. 9:3 ; uniform- 
ity oi; exjiggorated, i. 107; long-sighted, 



IxVDEX. 



437 



1. 113; rate of increase among:, usually- 
small, i. 117; retention of the prehensile 
power of the feet by, i. 136; tribes of, 
supplanting one another, i. 154 ; improve- 
ments in the arts among, 1. 175; arts of, 
i. 225; fondness of, for rough music, ii. 
64; attention paid by, to personal ap- 
pearance, ii. 322; relation of the sexes 
among, ii. 347. 

Saw-fly, pugnacity of a male, i. 358. 

Saw-flles, proportions of the sexes in, i. 
305. 

Saxicola rubicola, young o^ ii 210. 

Scalp, motion of the, i. 20. 

Scent-glands in snakes, ii. 2S. 

Schaaffhausen, Prof., on the develop- 
ment ot the posterior molars ua ditfereut 
races of man, i. 2G ; on the jaw from La 
Naulette, i. 122; on the correlation be- 
tween muscularity and prominent supra- 
orbital ridges, i. 126 ; on the mastoid pro- 
cesses of man, i. 13S; on modifications 
of the cranial bones, i. 141 ; on human 
sacrifices, i. 175 ; on the probable speedy 
extermination of the anthropomorphous 
apes, 1. 193; on the ancient inhabitants 
of Europe, i. 228 ; on the effects of use 
and disuse of parts, i. 238 ; on the super- 
ciliary ridge in man, ii. 301 ; on the ab- 
sence of race-difierences in the infant 
skull in man, ii. 303 ; on ugliness, ii. 387. 

Schaum, H., on the elyti-a of DyiisciM and 
//i/droporu,% i. 333. 

ScHELVER, on dragon-flies, i. 352. 

ScmoDTE, on the stridulation of JTetero- 
cern,% i. 368. 

ScHLEGEL, F. von, on the complexitj' of 
the languages of uncivilized peoples, i. 
59. 

SciiLEGEL, Prof., on Tanysiptera, ii. 1S2. 

Schleicher, Prof, on the origin of lan- 
guage, i. 54. 

ScHLEiDEN, Prof., On the rattlesnake, ii. 28. 

SoHoxiBURGK, Sir K., on the pugnacity of 
the male musk-duck of Guiana, ii. 40; 
on the com-tship of Rupicola crocea, ii. 
S3. 

Scuoolckaft, Mr., on the difiiculty of fash- 
ioning stone implements, i. 133. 

ScLATER, P. L., on modified secondary 
\ving-feathers in the males of Pipnt, ii. 
62 ; on elongated feathers in night-jars, ii. 
69; on the species of Cha>f)norhi/nchn-8, 
ii. 76; on the phnnage of Pelecanus 
onocrotatuii, ii. 62 ; on the plaintain- 
eaters, ii. 169 ; on tlie sexes and young 
of Tadorna variegata, ii. 197; on the 
colors of Lemur inacaco^ ii. 277 ; on the 
stripes in asses, ii. 291. 

ScoLECiDA, absence of secondary sexual 
characters in, i. 312. 

Scolopax frenata, tail-feathers of ii. 61. 

Scolopax gallinago, drumming of, ii. 60. 

Scolopax Javensis, tail-feathers of, ii. 61. 

Scolopax major, assembUes of ii. 97. 

Scnlopax Wiko/iii, sound produced b}', ii. 

Scoltjtus, stridulation of, i. 368, 



ScOTER-DtrcK, black, sexual difference in 
coloration of the, ii. 216; bright beak of 
male, ii. 217. 

Scott, J., on the color of the beard in man, 
ii. 304. 

ScROPE, on the pugnacity of the male salm- 
on, ii. 3 ; on the battle's of stags, ii. 229. 

ScuDDER, S. II., imitation of the stridu- 
lation of the Orthoptera, i. 343; on the 
stridulation of the Acridiida\ i. 846 ; on 
a Devonian insect, i. 349 ; on stridulation, 
ii. 315. 

ScuLPTCKE. expression of the ideal of beau- 
ty by, ii. 383. 

Sea-ane.mones, bright colors of, i. 313. 

Sea-bear, polygamous, i. 260. 

Sea-elephant, male, structure of the nose 
of the, ii. 264 ; polygamous, i. 260. 

SEA-LiOfT, polygamous, i. 200. 

Seal, bladder-nose, ii. 265. 

Seals, their sentinels generally females, i. 
71 ; e\'idence fm-nished by, on classifica- 
tion, i. 183 ; sexual differences in the col- 
oration of, ii. 278 ; appreciation of music 
by. ii. 317 ; battles of male, ii. 229 ; ca- 
nine teeth of male, ii. 230 ; polygamous 
habits of, i. 260 ; pau-lng of, ii. 257 ; sex- 
ual peculiarities of ii. 264. 

Sea-scorpion, sexual differences in, ii. 9. 

Season, changes of color in birds, in ac- 
cordance with the, ii. 77; changes of plu- 
mage of birds in relation to, ii. 172. 

Seasons, inheritance at corresponding, i. 
273. 

Sebititani, ii. .324. 

Sebright Bantam, i. 2S5. 

Secondary sexual characters, i. 245 ; rela- 
tions of polygamy to, i. 257 ; gradation 
of, in birds, ii. 129 ; transmitted through 
both sexes, i. 270. 

Sedgwick, "W., on hereditary' tendency to 
produce twins, i. 128. 

Seemann, Dr., on the different appreciation 
of music by different peoples, ii. 318 ; on 
the effects of music, ii. 320. 

Selasphorus platycercus, acuminate first 
primary of the male, ii. 62. 

Selby, p. J., on the habits of the black 
and red grouse, i. 260. 

Selection, double, i. 267. 

Selection of male by female bh-ds, ii. 95, 
117. 

Selection, methodical, of Prussian grena- 
diers, i. 108. 

Selection, sexual, influence of, on the col- 
oring of Lepidoptera, i. 390 ; explanation 
of i. 248, 252, 262. 

Selection, sexual and natural, contrasted, 
i. 270. 

Self-command, habit of, inherited, i. 88; 
estimation of i. 91. 

SELF-CONSCIOrSNESS, 1. 60. 

Self-preserv.ition, instinct of, i. 85. 

Self-saceifice, by savages, i. 84; estima- 
tion of i. 91. 

Semilunar fold, i. 23. 

Semnopithecus, i. 189; long hair on the 
heads of species of, i. 184, ii. 363. 



428 



INDEX. 



SemnopiViecus chrmomelas, sexual dlffer- 
encos of color in, 11. 277. 

Seiiiiiopif/ieciiJt comatus, ornamental hair 
on the head oi; 11. 291. 

Semiiopithtcii« frotitatus, beard, etc., of, 
ii. 2!U. 

."i-m/topithecio natiica, nose of, 1. 1S>4. 

Sfmiiopit/iecm nemxua, coloring of, ii. 
296. 

Semnopiiliecun riihicxnrluft, ornamental 
hair on tlio head of, ii. 291. 

Se.nses, infiTiority of Eurojieans to savages 
intho, i. 114. 

Sentinels, i. 71, 79. 

Serpents, instinctively dreaded by apes 
and monkeys. 1. 30, 41. 

Sirmnii.'i. horiimpliroditism in, J. 200. 

Sex, inhoritaiKT liiiiitt'il tiy. i. 273. 

Sexes, rcliilivo pnijiortions of, in man, 1. 
291, ii. 3(!,") ; iiroliablc relation of the, in 
primeval man, ii. 346. 

Sexual characters, secondary, i. 245; rela- 
tions of polvgamy to, 1. 2r)9 ; transmitted 
throuirli both sc.xcs, i. 270; gradation of; 
in birds, ii. 129. 

Sexual and natural selection, contrasted, 
i. 269. 

Sexual characters, effects of the loss of, i. 
275; hniitation of. i. 275. 

Sexual dItVerenccs in man. i. 14. 

Sexual selection, expl.ination of, i. 24S, 
252. 262 ; inllucncc of, on the coloring of 
Lopidoptcra, i. 390; action of, in man- 
kind, ii. 3.V2. 

Sexual similarity, i. 263. 

Sharks, prehensile organs of male, ii. 1. 

SiiABi'E, K. 15., on Tain/Kiptera mj/via. ii. 
157; on Ceri/le, ii. 165; on the young 
male of Dact/o Gaudichaiuli, ii. ISO. 

SuAW, Mr., on tlie pugnacity of the male 
salmon, ii. 3. 

Shaw, J., on the decorations of birds, 
ii. CS. 

Sheep, danger-signals of. i. 74 ; sexual dif- 
ferences in the horns of, i. 274 ; horns of; 
i. 2S0 ; ii. 235, 247 ; domestic, sexual dif- 
ferences of, late developed, i. 2S3; nu- 
merical ])rop.>rtion of the sexes in, i. 295; 
mode of tigliting of, ii. 28S ; arched fore- 
heads of SDHic. ii. 271. 

Sheep, Merino, loss of horns in females of, 
1. 275 ; horns o£ 1. 2S0. 

Shells, ditference in form of, in male and 
female Gasteropoda, i. 315 ; beautiful 
colors and shai)es of, i. 316. 
SniELP-DRAKE, pairing with a common 
duck, ii. 109 ; New Zealand, sexes and 
young of, ii. 197. 
SuooTEK, J., on the Kaffres, ii. 331 ; on the 
mamage-custoinsof tlie Kaffros, ii. 357. 
SnKEW-MicF, odor of. ii. 265. 
Shrike, Drongo. ii. 171. 
Shrike-S chai-.utcrs of young, ii. 177. 
Shuckard, W. K., on sixual ililVcrences in 

the wings of llyincjioptenu i. •i^J4. 
SHYNE.S8 of adorned male birds, ii. 93. 
SifiOoniiim, proportions of the sexes in, i. 
305 ; dimorphism in males of, i. 363. 



SlAM, proportion of male and female births 

in, i. 29.3. 
Siamese, general beardlessness of the, 11. 

306; notions of beauty of the, ii. 829; 

hairy fainilv of, ii. 361. 
Sir.uoLn, C. 'f., von, on the auditory ap 

Iiaratus of the stridulant orthoptera, 1. 

SifliiT, inheritance of long and short, i. 114. 

Signal-cries of monkeys, i. 5.5. 

SiLK-MDTH, ditference of size of the male 
and female cocoons of the. i. 3:}6 ; pairing 
of the, i. 3SS: male, fertilizing two or 
three females, i. 393 ; proi)ortion of the 
sexes in, i. 300, 302 ; Ailantus, Prof. Ca- 
nestrini, on the destruction of its larvas 
bv wasps, i. 302. 

Sim"iad,e, i. 187; their origin and di\Tslons. 
i. 204. 

SiMiLABrrY. sexual i. 26S. 

Singing of the Cicada and FulgoridiB, 1 
351 ; of tree-frogs, ii. 25; of birds, object 
of the, ii. 50. 

Sirenia, nakedness of, i. 142. 

Sirex jurenctts, i. 354. 

SiRiciD.E, difference of the sexes in, 1. 354. 

Siskin, ii. 81 ; pauing with a canarj-, ii. 
110. 

Sitana. throat-pouch of the males of; Ii 
31, 35. 

Size, relative, of the sexes of insects, i. 335. 

Skin, movement of the. i. 19 ; nakedness 
of, in man, i. 142; color of the, i. 2-32. 

Skin and hair, correlation of color of; 1. 
2;}9. 

Skull, variation of. in man. 1.104; cubic 
contents of. no absolute test of intellect, 
i. 140; Keanderthal, capacity of the. i, 
140; causes of inoditjcation ofthe, i. 141 ; 
difference of, in form and capacity, in dif- 
ferent races of men. i. 2oS ; variability of 
the shape ofthe, i. 218; ditferences of; in 
the sexes in man, ii. 302 ; artificial modi- 
fications of the shape o£ ii. 324. _ 

Skunk, odor emitted by the, ii. 265. 

Slavery, prevalence of, i. 90 ; of women, 
u. 350. 

Slaves, differenice between those of field 
and house, i. 357. 

S.MELL, sense of, in m.in and animals, 1. 23. 

Smith, Adam, on the basis of sympathy, 
i. 7S. 

Smith, Sir A., on the recognition of women 
by male Ci/tiocep/tali. i. 13; on an in- 
sUince of memory in a baboon, i. 48; on 
the retention of their color by the Dutch 
in South .Vfrica, i. 233; on tlie polygamy 
ofthe South African antelopes, i. 258; 
on the proportion of the sexes in Kobua 
el/ij/xijiri/i/iiiuM.i. 296; on Biicep/ialtia 
aijieiiKin'.Vt. 2s; on South African lizartls, 
ii. 35; on fighting gnus, ii. 229; on the 
horns of rhinoceroses, ii. 237; on the 
fighting of lions, ii. 254 ; on the colors of 
the Cape Eland, ii. 274; on the colors of 
the gnu, ii. 275; on Hottentot notions of 
beautv, ii. 829. 

Smith, i\, on the Cyniplda; and Tenthredl- 



INDEX. 



429 



Didffl, i. 805 ; on the relative size of the 
sexes of Aculeate Hymenoptera, i. 337 ; 
on the difference between the sexes of 
ants and bees, i. 354 ; on the stridulation 
of Trcm sabulosns, i. 369 ; on the strid- 
ulation of Mononychiis pseudacofi, i. 
371. 

Smynthnrus hifev.% courtship o£ i. 338. 

Snakes, sexual differences of, ii. 2S ; male, 
ardency of, ii. 29. 

" Snaeling JicscLEs," i. 122. 

Snipe, drumming of the, ii. 60 ; coloration 
ofthe, Ii. 216. 

Snipe, painted, sexes and young of, ii. 
193. 

Snipe, solitary, assembhes of, ii. 97. 

Snipes, arrival of male before the female, 
i. 251 ; pugnacity of male, ii. 41 ; double 
moult in, ii. 77. 

Snow-goose, whiteness ofthe, ii. 218. 

Social animals, aft'oetiou of, for each other, 
i. 73 ; defence o^ by the males, 1. 79. 

Sociability, the sense of duty connected 
■with, i. 68 ; impulse to, in animals, 1. 76, 
77 ; manifestations o^ in man, i. 81 ; in- 
stinct of, in animals, i. 82, S3. 

SociALixy, probable, of primeval men, i. 
149 ; influence of, on the development of 
the intellectual faculties, i. 154 ; origin o^ 
In man, i. 155. 

SoLDiEEs, American, measurements o^ i. 
108. 

Soldiers and sailors, difference in the pro- 
portions of^ i. 110. 

Solenoatoma, bright colors and marsupial 
sack ofthe females of, ii. 21. 

Song of male birds appreciated by their 
females, i. 61 ; want of, in brilliant- 
plumaged birds, ii. 90 ; of birds, ii. 156. 

Sorex, odor ot; ii. 266. 

Sounds admu-ed alike by man and ani- 
mals, i. 62 ; produced by fishes, ii. 22 ; 
produced by male frogs and toads, ii. 25; 
instrumentally produced by bh-ds, ii. 61, 
et seqq. 

Spain, decadence of, i. 171. 

Sparassus »maragdnliw, difference of 
color in the sexes of, i. 328. 

Spakbow, pugnacity of the male, ii. 38 ; 
acquisition of the Linnefs song by a, ii. 
52 ; coloration of the, ii. ISO ; immature 
plumage of the, ii. ISO. 

Sparrow, white-crowned, young of the, 
ii. 208. 

Sparrows, house- and tree-, ii. 162. 

Sparrows, new mates found by, ii. 101. 

Sparrows, sexes and young of, ii. 203 ; 
learning to sing, ii. 319. 

Spathura Underwoodi, ii. 74. 

Spawning of fishes, ii. 15, IS. 

Spear, origin ofthe, i. 225. 

Species, causes of the advancement of, i. 
165; distinctive characters of, i. 200; or 
races of m.an, i. 209 ; sterility and fertil- 
ity ot, when crossed, i. 214 ; supposed, 
of man, i. 218 ; gradation of, i. 218 ; diffi- 
culty of defining, i. 219 ; representative, 
of bu'ds, ii. 182, 1S3 ; of birds, compara- 



tive differences between the sexes of dis- 
tinct, ii. 184. 

Spectre-insects, mimicry of leaves by, i. 
401. 

/Spectrum femoratum, difference of color 
in the sexes of, i. 350. 

Speech, connection between the brain and 
the feculty of i. 56. 

" Spel " of the black-cock, ii. 58. 

Spencer, Herbert, on the dawn of intelh- 
gence, i. 36 ; on the origin of the behef in 
spiritual agencies, 1. 63 ; on the origin of 
the moral sense, i. 97 ; on the influence 
of food on the size of the jaws, i. 113; on 
the ratio between individuation and gene- 
sis, i. 310; on music, ii. 320. 

Sperm-wuales, battles of male, ii. 229. 

Spihngid.e, coloration ofthe, i. 383. 

Sphinx, Humming-bii-d, i. 387. 

iSphinx, Mr. Bates on the caterpillar of a, 
i. 402. 

Spiders, i. 327 ; male, more active than fe- 
male, i. 263 ; proportion of the sexes in, i. 
306 ; male, small size of, i. 328. 

Spilosoma menthrasti, rejected by tur- 
keys, i. 386. 

Spine, alteration of, to suit the erect atti- 
tude of man, i. 13S. 

Spirits, fondness of monkeys for, i. 12. 

Spiritual agencies, behef in, almost uni- 
versal, i. 62. 

Spoonbill, ii. 57 ; Chinese, change of plu- 
mage in, ii. 171. 

Spots, retained throughout groups of buds, 
ii. 126 ; disappearance ot, in adult mam- 
mals, ii. 288. 

Sprengel, C. K., on the sexuaUty of plants, 
i. 252. .> 1- . 

Spring-boc, horns ofthe, ii. 239. 

Sproat, Mr., on the extinction of savages 
in Vancouver Island, i. 230 ; on the eradi- 
cation of facial hah' by the natives of V:m- 
couver Island, ii. 332 ; on the eradication 
of the beard by the Indians of Vancouver 
Island, ii. 363. 

Spurs, occun-ence of; in female fowls, i. 
271, 275 ; development oi^ in various spe- 
cies of Phasianidaj, i. 281 ; of Gallinaceous 
birds, ii. 41, 43; development ot; in fe- 
male Gallinaceae, ii. 155. 

Squilla, dhfferent colors of the sexes of a 
species ot; i. 326. 

Squirrels, battles of male, ii. 228 ; Afl-ican, 
sexual differences in the coloring ot; ii. 
272 ; black, ii. 280. 

Stag, long hau-s of the throat of, ii. 256; 
horns of the, i. 270, 273 ; battles of, ii. 
229 ; horns ofthe, with numerous bnonch 
es, ii. 241 ; beUo^^'ing of the, ii. 201 ; crest 
of the, ii. 263. 

Stag-beetle, large size of male, i. 836; 
weapons of the male, i. 364; numerical 
proportion of sexes ot; i. 305. 

Stainton, H. T., on the numei-ical propor- 
tion of the sexes in the smaller moths, i. 
302 ; habits of Elachista rufocinerea, i. 
303; on the coloration of moths, i. 384; 
on the rejection of Spilosoma menthroH 



430 



INDEX. 



a, by tiirkcv's, 1. 856; on the sexes of 
Agrotix erclamaiionin. i. 8S6. 

Btallios, mane of tlio. ii. '2ri(). 

Stallions, two, attiukinf; a third, i. 72; 
flphting, li. 230; small canine teeth of; ii. 
246. 

Stansburv, Captain, obserrations on pell- 
cans, i. 74. 

Staphylinid^ bornliko processes in male, 
1. 30:3. 

Starfishes, bripht v-olors of some. i. 313. 

Stark. Dr., on the death-rate in towns and 
rural di.stricts. i. l(Ji»; on the influence of 
marriape on mortality, i. 170 ; on the high- 
er mortality of males in Scotland, i. 292. 

Starlino, American field, pugnacity of 
male, ii. 49. 

Starling, red-winjred, selection of a mate 
by the female, ii. 111. 

Starlings, three, frequentins' the same 
nest, i. 209, ii. 102 ; new mates found bv, 
ii. 101. 

Statues, Greek, Egyptian, Assyrian, etc., 
contrasted, ii. 33;3. 

Stati-re, dependence of, upon local influ- 
ences, i. 110. 

Staudinger, Dr.. his list of Lepidoptera, i. 
304; on breeding Le])idoptera. i. 303. 

Staunton, Sir C, hatred of indecency a 
modern virtue, i. 92. 

Stealing of bright objects by birds, ii. 
107. 

Stebeixg, T. E.. on the nakedness of the 
luiman liody, ii. 859. 

Stemtmitopm, li. 26.5. 

jSienol/ot/inm prutoritm, stridulating or- 
gans of i. 340. 

Sterility, genei-al, of sole daughters, i. 164 ; 
when crossed, a distinctive character of 
species, i. 206. 

Sterna, seasonal change of plumage in, 15. 
21 S. 

STiCKLE-BArK, polvgamous. i. 262 ; male, 
courtship of the. ii. 2 ; male, brilliant col- 
oring of. during the breeding-season, ii. 
14; nidiflcation of the, ii. 19. 

Sticks used as implements and weapons 
bj- monkeys, i. 50. 

Sting in bees. i. 240. 

Stokes, Captain, on the habits of the great 
Bower-bird, ii. 00. 

Stoneciiat. young of the, ii. 211. 

Stone implements, difliculty of making, i. 
138 ; as traces of extinct tribes, i. 22S. 

Stones, used by monkeys for breaking 
hard fruits and as missiles, i. 134 ; piles 
of, i. 224. 

Stork, black, sexual differences in the bron- 
chi of the, li. 57; red beak of the, ii. 217. 

Storks, ii. 216. 220; sexual difl'eronce ia 
The color of the eves of. ii. 123. 

Strange, Mr., on the Satin Bower-bird, ii. 
66. 

Stretch, "Mr., on the numerical proportion 
in the sexes of ehickens. i. 290. 

JStrepsiceros A'lidti, horns of, ii. 243; mark- 
ings of. ii. 2S7. 

Stuibclation, by males of Tfieridion, 1. 



829; of the Orthoptera and Ilomoptera 
discussed, i. 349 ; of beetles, i. 366. 

Stripes, retained throughout groups of 
birds, il. 125; disappeai-ance oli in adult 
mammals, ii. 2ss. 

StrixJIammea, ii. 101. 

Structure, existence of unserviceable 
modifications of. i. 147. 

Struggle for existence, in man, i. 174, 
178. 

Strutiierr. Dr.. on the occurrence of the 
supra-condyloid foramen in the humerus 
of man, i. 27. 

SivmfHa ludoviciana, pugnacity of tho 
male, ii. 48. 

f^tuniuK ndgaris, ii. 101. 

Subspecies, i. 219. 

Suffering, In strangers, indiflTercnce of 
savages to, i. 90. 

Suicide, i. 166; formerly not regarded as a 
crime, i. 90 ; rarely pnictised among the 
lowest savages, i. 90. 

SuiDiF., stripes of young, ii. 176. 

Su.vATRA, compression of the nose by tho 
Malays of, ii. a35. 

Sumner, Archbishop, man aloni? capable of 
progressive improvement, i. 47. 

SuN-niRDs, nidiflcation of, ii. 161. 

Superstitions, i. 175; prevalence of, i. 95. 

SuPEP-STiTious customs, i. 60. 

Superciliary ridge in man. ii. 301, 303. 

Supernumerary digits, more frequent in 
men than in women. 1. 268 ; inheritince 
of, 1. 270 ; early development of i. 2S2. 

Supra-condyloid foramen in the early pro- 
genitors of man. i. 198. 

Suspicion, prevalence ofj among animals, 
i. 38. 

SuLivAN. Sir B. J., on two stallions attack- 
ing a third, ii. 230. 

Swallow-tail Butterfly, i. 381. 

Swallows deserting their young, i. 80, 87. 

Swan, black, red beak of the. ii. 217; black- 
necked, ii. 220 ; white, young o^ 11. 202 ; 
wild, trachea of the. ii. 57. 

Swans, ii. 216, 220 ; young, ii. 199. 

Swaysland, Mr., on the aiTival of migra- 
toiy birds, i. 251. 

SwiNHOE. I*., on the common rat in For- 
mosa and Chinii, i. 49; on the sounds 
produced by the male Hoopoe, ii. CO; on 
IMcruriifi inacrocercits and the Spoon- 
bill ii. 171 ; on the young o( Ardeolti. il. 
182; on the habits of Tiirnix. ii. 193; on 
the habits of Ithi/ncfKra BcngultnsU. ii. 
193; on Orioles breeding in immature 
plumage, ii. 205, 206. 

Si/lria uiricapilla. young of, ii. 210. 

Si//vi(i ciiirrea, aerial love-dance of the 
male, ii. 05. 

Sv.mpathy. i. 102; among animals, 1. 74; its 
supposed basis, i. 78. 

Sympathies, gradual widening of. 1. 96. 

Svngnathous fishes, abdominal pouch in 
male, i. 201. 

Si/pheotides aurifiiii, acuminated prima- 
ries of the male, il. 62 ; ear-tufts of. ii. 
70. 



INDEX. 



431 



T. 

Tabanh)^, habits of; i. 246. 

Tadorna t'arieffata, sexes and young o^ 

u. 197. 
Tadorna vnlpanser, ii. 109. 
Tahitians, i. 176 ; compression of the nose 

by the, ii. S35. 
Tail, rudimentary, occurrence of, in man, 
i. 29 ; convoluted body in the extremity 
of the, 1. 29 ; absence of, in man and the 
higher apes, i. 145, 1S7 ; variability of, in 
species of Macacus and in baboons, 1. 
144 ; presence of, in the early progenitors 
of man, i. 198; length of, in pheasants, ii. 
149, 157, 158 ; difference of length of the, 
in the two sexes of birds, ii. 157. 

Tait, Lawson, on the effects of natural se- 
lection on ci\'ilized nations, i. 162. 

Tanagee, scai-let, variation in the male, u. 

121. 
Tanagra ceMiva, ii. 172 ; age of mature 

plumage in, ii. 204. 
Tanagra rubra, h. 121 ; young of, ii. 210. 
Tanais, absence of mouth in the males of 
some species o^ i. 247; rehtions of the 
sexes in, i. 307 ; dimorphic males of a 
species of, i. 319. 

Tankerville, Earl, on the battles of ^vild- 
bulls, ii. 229. 

Tany»iptera, races of, determined fi-om 
adult males, ii. 182. 

Tanymptera sylvia, long tail-feathers o£ 
ii. 157. 

Taphroderes distortiis, enlarged left man- 
dible of the male, i. 334. 

Tapirs, longitudinal stripes of young, ii. 
176, 2SS. 

Tarsi, dilatation of fi'ont, in male beetles, i. 
333. 

Tarsius, i. 192. 

Tasmani.\, half-castes killed by the natives 
o^ i. 212. 

Tattooing, i. 224; tmiversality of; ii. 323. 

Taste, in the Quadrumana, ii."2S2. 

Taylor, G., on Quiscahis major, i. 298. 

Tea, fondness of monkeys for, i. 12. 

Tear-sacs, of Ruminants, u. 267. 

Teebay, Mr., on changes of plumage in 
spangled Hamburg fowls, i. 272. 

Teeth, rudimentary incisor, in Ruminants, 
i. 17 ; posterior molar, in man, i. 25; wis- 
dom, i. 26 ; diversity of, i. 104 ; canine, in 
the early progenitors of man, i. 198; ca- 
nine, of male mammals, ii. 230 ; in man, 
reduced by correlation, ii. 310 ; staining 
of the, ii. 823; front, knocked out or filed 
by some savages, ii. 324. 

Teget.meier, Mr., on the abimdance of 
male pigeons, i. 296; on the wattles of 
game-cocks, ii. 94 ; on the courtship of 
fowls, ii. 112 ; on dyed pigeons, ii. 113. 

Tembeta, ii. 825. 

Temper, in dogs and horses, mherited, i. 
38. 

Tench, proportions of the sexes in the, i. 
299, 800; brightness of male, dm-hig 
breeding-season, ii. 18. 



TENEBRIONID.E, stridulation of, i. 367. 
Tennent, Sir J. E., on the tusks of the 
Ceylon Elephant, ii. 237. 247 ; on the iro- 
quent absence of beard in the natives of 
Ceylon, ii. 306 ; on the Chinese opuiion of 
the aspect of the Cingalese, ii. 328. 
Tennyson, A., on the control of thought, 

i. 91. 
Tentiiredinid.e, proportions of the sexes 
in, i. 305 ; fighting habits of male, i. 853 ; 
difference of the sexes in, 1. 354. 
Tephrodornis, young of, ii. 182. 
Terai, i. 229. 
7'ermite,i, habits of, i. 853. 
Terns, white, ii. 218; and black, ii. 220. 
Terns, seasonal change of plumage in, ii. 

218 
Terror, common action of, upon the lower 

animals and man. i. 3S. 
Tentudo nigra, ii. 27. 
Tetrao cvpido, battles of^ ii. 48; sexual 

difference in the vocal organs of, ii. 53. 
Tetrao p/ta.sia»ellus. dances of, ii. 65; du- 
ration of dances of, ii. 96. 
Tetrao Seoticus, ii. 163, 177. 1S6. 
7'etrao tetria; ii. 163, 177, 186 ; pugnacity 

of the male. ii. 42. 
Tetrao umbellu-s:, pahing of, ii. 46; battles 

of, ii. 48 ; drumming of the male, ii. 59. 
Tetrao iirogalloides, dances of ii. 96. 
Tetrao urogallim, pugnacity of the male, 

ii. 42.. 
Tetrao iirophcwianvs, inflation of the 

oesophagus in the male. ii. 55. 
Thamnobia, young of h. 182. 
Thaumalea picta, display of plumage by 

the male, ii. So. 
Thecla, se.xual differences of coloring in 

species of i. 377. 
Thecla riibi., protective coloring of, i. 380. 
Therldion, i. 829 ; stridulation of males 

of, i. 331. 
Theridion Uneatum, variabihty of i. 828. 
Tfiomisns citreus, and T. Jioricolens, HiU 

ference of color in the sexes of, i. 328. 
Thompson, J. II., on the battles of sperm- 
whales, ii. 230. 
Thompson, W., on the coloring of the male 
char during the breeding-season, ii. 14; 
on the pugnacit}' of the males of Galli- 
niila ch/oropus, ii. 39 ; on the finding of 
new mates by magpies, ii. 99 ; on the 
finding of new mates by Peregrine fal- 
cons, ii. 100. 
Thorax, processes of, in male beetles, i. 

857. 
Thorell, T., on the proportion of the 

sexes in spiders, i. 806. 
Thornback, difference In the teeth of the 

two sexes of the, ii. 6. 
Thoughts, control of i. 97. 
TnEusn, pairing with a blackbird, ii. 109 ; 

colors and nidification of the, ii. 162. 
Thrushes, characters of young, ii. 177, 

257. 
Thug, his regrets, 1. 91. 
Thumb, absence of, in Ateles and llijlo- 
bates, i. 135. 



432 



INDEX. 



TiiuBY, M., on the numerical proportion of 
mail' and female births among the Jews, 
i. 292. 

Thylacinim, possession of tlie marsupial 
sac by the male, i. I'jy. 

TllYSANURA, i. SJS. 

Tim A, dilated, of the male Crahro cri- 
brariim, i. *};?. 

TiniA ami femur, proportions of, In the 
Aymara Indians, i. 115. 

TiKr.RA del Fuejfo, marriage-customs of, 11. 
856. 

Tk'.er, colors and markinffs of the, ii. 2S7. 

TiGEES, depopulation of districts by, in In- 
dia, i. 129. 

Ti/lus elongatus, difference of color in the 
se.xes oC i. 357. 

Tlmidity, variability of, in the same species, 

TiNEiNA, proportion of the sexes in, i. 301. 

Tipidii. i)UL'n;icity of male, i. 339. 

Tits, sexual <litt'iTence of color in, ii. 1G6. 

Toads, ii. 'it ; male, treatment of ova by 
some, i. 202 ; male, ready to breed before 
the female, i. 252. 

Toe. great condition of; in the human em- 
bryo, i. 17. 

Tomtit, blue, sexual difference of color in 
the, ii. 106. 

Tonga Islands, beardlessness of the natives 
of, ii. 307, 83:3. 

TooKE, Ilorne, on language, i. 53. 

Tools, flint, 1. 176; used by monkeys, i. 
49 ; use of, i. 132. 

Topknots, in birds, ii. 71. 

Toniicrm rillosus, proportion of the sexes 
in, i. 805. 

Tortoise, voice of the male, ii. 816. 

ToRTrKES, submitted to by American sav- 
ages, 1. 91. 

ToUiniui, double moult In, ii. 77. 

TorcANS, colors and nidification of the, ii. 
163; beaks and ceres of the, ii. 217. 

Towns, residence in, a cause of diminished 
stature, i. 111. 

TovNBEE, J., on the external shell of the 
ear in man, i. 21. 

Trachea, convoluted and embedded in the 
Kternum. in some birds, ii. 57 ; structure 
of the, in Iili)jm-h(V(i. ii. 198. 

Trades, affectiiig the form of tlie skulL i. 
141. 

TrageUiphvs, sexual differences of color 
in, ii. 274. 

Trofiehiphwi script us. dorsal crest of^ ii. 
268 ; markings of, ii. 286, 287. 

Tragopan, i. 261 ; swelling of the wattles 
of the male, during courtship, ii. 6$ ; dis- 
play of plumage by the male. ii. 87 ; 
markings of the sexes of the, ii. 128. 

Tragops tlUpitr. sexual difference in the 
color of, ii. 28. 

Training, effect of, on the mental differ- 
ence between the sexes of man, ii. 813. 

Transfer of male characters to female 
birds, 11. 1S5. 

Transmission, equ.il, of ornamental char- 
acters, to both sexes in mammals, ii. 2s3. 



Tkaps, avoidance ot bv animals, i. 4S ; use 
of; i. 132. 

Treachery, to comrades, avoidance of; by 
savages, 1. 84. 

Tremer cohimbw. i. S.M. 

Tribes, extinct, i. 154; extinction oC 1.226. 

7'ric/tiiis. difference of color in the se.xes 
of a sjiecies of, i. .'556. 

Trimen, I;., on the proportion of the sexes 
in South African butterflies, i. 301 ; on 
the attraction of males by the female of 
Lasiocampa qutrctis, 1. 303; on I'neii- 
niorti. i. 348; on difference of color in 
the .sexes of beetles, i. 856; on moths 
brilliantly colored beneath, 1. 351; on 
mimicry" in butterflies, i. S&S; on Gyna- 
nisa A-/.K,and on the ocellated spots of 
Lepidoptera, ii. 127 ; on Cyllo Leda, ii. 
128. 

Tiinga. sexes and young of; il. 207. 

'J'rhiga cornutii. ii. 78. 

Trip/uvna, coloration of the species of, 1. 
882. 

Tristram, II. B., on unhealthv districts In 
North Africa, i. 285: on the "habits of the 
chaflineh in Talestine, i. 29S; on the 
birds of the Sahara, ii. 164; on the ani- 
mals inhabiting the Sahara, ii. 214. 

Triton criMtitiis. ii. 23. 

'J'ritini jKilmijirx. ii. 23. 

Triton jiinuiiitns. ii. 23. 

'Troijloilijtex riilgitrix. ii. 189. 

Trogons, colors and nidification of the, Ii. 
16:3. 165. 

Tropic-biuds, white onh- when mature, ii. 
218. 

Tropics, fresh-water fishes of the, ii. 17. 

Tkout, proportion of the sexes in, i. 299 ; 
male, pugn.icity of the. ii. 3. 

Tror saOutosus. stridulation oC i. 369. 

Truth, not rare between members of the 
same tribe, i. 91 ; more highly appre- 
ciated by certain tribes, i. 96. 

TuLLocn.Major. on the immunity of the 
negro from certain fevers, i. 234. 

Tumbler, almond, change of plumage In 
the, i. 2.81. 

Tardus iiiemla, ii. 162; young of, ii. 210. 

Turdus DiiffrntoriiM. ii. 177. 

Turd us muj<icus. ii. 162. 

Turdus polyff/ottuA. young of, ii. 210. 

Turdus torijuatus, ii. 162. 

Turkey, swelling of the wattles of the 
male, ii. 68; variety of, with a topknot, 
ii. 71 ; recognition of a dog by a, ii. 106 ; 
wild, jjugnacity of young male, ii. 46 ; 
wild, notes of "the. if. 58 ; male, wild, ac- 
ceptjible to domesticated females, ii. 114; 
wild, lirst advances made by older fe- 
males, ii. 116; wild, breast-tuft of bristles 
ofthe. ii. 171. 

Turkey-cock, .sci-aping of the wings at, 
upon the gmuud, ii. 59 ; wild, dispby of 
plumage bv, ii. 83 ; fighting habits of; ii. 
94. 

Turner, Prof. "W.. on muscular fasciculi In 
m.-ui referable to the panniculus carno- 
sus, i. 19 ; on the occurrence of the su- 



INDEX. 



433 



pracondyloid foramen in the human hu- 
merus, i. 2V ; on muscles attached to the 
coccyx in man, i. 29 ; on the JUum ter- 
min'ale in man, i. 29 ; on the yariability 
of the muscles, i. 105; on abnormal con- 
ditions of the human uterus, i. 119 ; on 
the development of the manunary glands, 
i. 201 ; on male fishes hatching ova in 
their mouths, i. 202. 

Tiirnix, sexes of some species of; ii. 192, 
198. 

Turtle-dove, cooing of the, ii. 58. 

TuTTLE, H., on the number of species of 
man, i. 218. 

Ttlok, E. B., on emotional cries, gestures, 
etc., of man, i. 52 ; on the origin of the 
belief in spiritual agencies, i. 64 ; on the 
primitive barbarism of civilized nations, 
i. 174 ; on the origin of coimting, i. 174 ; 
on resemblances of the mental characters 
in different races of man, i. 223. 

Type of structure, prevalence o^ i. 203. 

Typhavs, stridulating organs of; i. 366; 
stridulation of, i. 369. 

Twins, tendency to produce, hereditary, 
i. 128. 

Twite, proportion of the sexes in the, L 
297. 

TJ. 

Ugliness, said to consist in an approach to 
the lower animals, ii. 337. 

Umbrella-Bird, ii. 55, 56. 

Vmbrina, sounds produced by, ii. 22. 

United States, rate of increase in, i. 126 ; 
influence of natural selection on the prog- 
ress of; i. 172 ; change undergone by 
Europe.ins in the, i. 287. 

Zfptipa epops, sounds produced by the 
male, ii. 60. 

UBANI1D.E, coloration of the, i. 183. 

Uria traile, variety of (= U. Utcrymans), 
ii. 122. 

Ukodela, ii. 22. 

Uronticte Benjanvini, sexual differences 
in, ii. 145. 

Use and disuse of parts, effects of; i. 112 ; 
influence of; on the races of man, i. 238. 

Uterus, reversion in the, i. 118; more or 
less divided, in the human subject, i. 118, 
125 ; double, in the early progenitors of 
man, i. 198. 

V, 

Vaccination, influence of; 1. 162. 

Vancouver Island, Mr. Sproat on the sav- 
ages of; i. 280 ; natives of; eradication of 
facial hair by the, ii. 331. 

Vanelliis eristatus, wing-tubercles of the 
male, ii. 44. 

Vaiiessce, i. 375 ; resemblance of lower sur- 
face of, to bark of trees, i. 880. 

Variability, causes of; i. 107; in man, 
analogous to that in the lower animals, i. 
108; of the races of man, i. 217; greater 
in men than in women, 1. 267 ; period o^ 

38 



relation of the, to sexual selection, i. 287 ; 
of birds, ii. 119 ; of secondary sexual 
characters in man, ii. 305. 

Variation, correlated, i. 29 ; laws of. i. 
109 ; in man, i. 178 ; analogous, i. 186 ; 
analogous, in plumage of birds, ii. 71. 

Variations, spontaneous, i. 126. 

Varieties, absence of, between two spe- 
cies, eWdence of their distinctness, i. 207. 

Variety, an object in nature, ii. 220. 

Variola, communicable between man and 
the lower animals, i. 11. 

Vaureal, i. 28. 

Veddahs, monogamous habits of ii. 847. 

Veitch, Mr., on the aversion of Japanese 
ladies to whiskers, ii. 332. 

Vengeance, instinct of, i. 85. 

Venus Erycina, priestesses of; ii. 341. 

Vermes, i. 318. 

Vermiform appendage, i. 26. 

Verreaux, M., on the attraction of numer- 
ous males by the female of an Australian 
Bomb I/O', i. '303. 

Vertebr.e. caudal, number of, in macaques 
and b.aboons. i. 144; of monkeys, partly 
embedded in the body, i. 145. 

Vertebrata, ii. 1 ; common origin of the, 
i. 195; most ancient progenitors of i. 
203 ; origin of the voice in air-breatliing, 
ii. 315. 

VeHcula prostdtiea, the homologue of 
the uterus, i. 80, 199. 

V1BRIS8.E, represented by long hairs in the 
eyebrows, i. 24. 

Vidua, ii. 173. 

Vidva amUaris, i. 260. 

Villerme, M., on the influence of plenty 
upon stature, 1. 110. 

Vinson, Aug., on the male of Epeira ni- 
gra, i. 829. 

Viper, difference of the sexes in the, ii. 28. 

VlREY, on the number of species of man, i. 
218. 

Virtues, originally social only, i. 90 ; grad- 
ual appreciation of, i. 159. 

Viscera, variability of, in man, i. 105. 

ViTi Archipelago, population of the, i. 217. 

Vlacovich, Prof, on the ischio-pubio 
muscle, i. 122. 

Vocal music of birds, il. 48. 

Vocal organs of man, i. 56 ; of birds, 1. 
57 ; ii. 156 ; of frogs, ii. 27 ; of the Inses- 
sores, ii. 58 ; difference of, in the sexes of 
birds, ii. 58 ; primarily used in relation to 
the propagation of the species, ii. 814. 

VoGT, Carl, on the origin of species, i. 1 ; 
on the origin of man, i. 4 ; on the semi- 
lunar fold in man, i. 23 ; on the imitative 
faculties of microcephalous idiots, i. 55; 
on microcephalous idiots, i. 116; on 
skulls from Brazilian caves, i. 210; on 
the evolution of the races of man, i. 221 ; 
on the formation of the skull in women, 
ii. 302; on the Ainos and negroes, ii. 
306; on the increased cranial difference 
of the sexes in man with race-develop- 
ment, ii. 814; on the obliquity of the 
eye in the Chinese and Japanese, ii. 028. 



434 



INDEX. 



Voice in mammals, ii. 2C1 ; In monkeys 
and man, ii. !<i)4 ; in man. ii. 819; ori^'in 
ot in alr-broatliinp vortcliruU's, ii. SV>. 

Von Baer, definition of advancement la 
the orf^anio scale, i. 203. 

Vplpian, Prof., on the resemblance be- 
tween the brains of man and of the 
higher ai)es, i. 11. 

Vri.TrRES, selection of a mate by the fe- 
male, U. Ill ; colors ot, U. 219. 

W. 

WADEBa, vounp ot ii. 208. 

■W'AONEii,it., on the occurrence of the dias- 
tema in a Kaffre skull, i. 122; on the 
bronchi of tlie black stork, ii. 57. 

Wagtail, liav's, arrival of the male before 
the female, f, 251. 

■Wagtails, Indian, young of, ii. 182. 

Waist, proportions ot, in soldiers and sail- 
ors, i. 112. 

Waitz, Prof., on the number of species of 
man, i. 21 S; on the color of Australian 
infants, 11. 3l)8 ; on the beardlessness of 
neffroes, ii. 31M5 ; on the fondness of man- 
kind for ornaments, ii. 822 ; on the Ua- 
bility of nef,Toes to tropical fevers after 
residence in a cold chiuate, i, 234; on 
negro ideas* of female beauty, ii. 380 ; on 
Javanese and Cochin-Chinese ideas of 
beauty, ii. 3;}1. 

Walckenaeb and Gervais, on the Myria- 
poda, i. 8;J0. 

"VS ALiiEVEB. M., on the hermaphroditism 
of the vertebrate embrj'o, i. 199. 

Wales, North, numerical proportion of 
male and female births in, i. 291. 

Walkek, Alex., on the large size of the 
hands of laborers' children, i. 113. 

Walker, F.. on sexual differences in the 
diptera, i. 3SS. 

Wallace, Dr. A., on the prehensile nse of 
the tarsi Id male moths, i. 'Ha ; on the 
rearing of the Ailantus silk-moth. i. 
802; on breeding Lenidoptera, 1. 302; 
proportion of sexes of liomiiyx Cynthia, 
B. yitmamai. and B. Pernyi. reared by, 
i. 304; on the development of Bombyx 
Cynthin and B. yaminnai, i. 836; on 
the pairing of Bombyx Cynthia, i. 3S8; 
on the fertilization of moth.s, 398. 

Wallace, A. K., on the origin of man, 
1. 4 ; on the power of imitation in man, 
1. 8S ; on the use of missiles by the 
orang, i. 50; on the varying apprecia- 
tion of truth among dilferent tribes, 
i. 96; on the iimitji of natural selection 
in man, i. 132, 152 ; on the occurrence of 
remorse among savages, i. 159; on the 
effects of natural selection on civilized 
nations, i. 161 ; on the use of the con- 
vergence of the hair at the elbow in 
the orung, 1. 1S5; on the contrast in 
the characters of the Malays and Pa- 
puans, 1. 208 ; on the line of se|>aration 
between tile Papuans and Malays, i. 210; 
on the sexes of Ornithojiterd Creesiw, 
1. 801 ; on protective resemblances, i. 
813 i on the relative sizes of the sexes 



of insects, f 336; on EJaphomyia, i. 
&38; on the Birds of Paradise, i. 260; 
on the pugnacity of the males of Lep- 
torhynchua anffimtatiui, 1. 368: on 
sounds pro<luced by Kuchiruit longi- 
manus, 1. 870; on the colors of IMa- 
dema, i. 876; on Kallima, 1. 380; 
on the protective coloring of moths, 
i. 382; on bright coloration as protec- 
tive in butterllies, i. 888 ; on variability 
In the Papilionida', i. 389 ; on male 
and female butterflies Inhabiting differ- 
ent stations. 1. 391 ; on the protective 
nature of the dull coloring of female 
butterflies, i. 392, 892, 401 ; on mimicry 
in butterflies, i. 39S; on the mimicry 
of leaves by Phasmida-, 1. 401 ; on the 
bright colors of cateri)illars, i. 403; on 
brightly -colored flsbes frequenting reefs, 
ii. 17; on the coral snakes, ii. 30; on 
Paraduiea a pod a, ii. 70. 74; on the 
display of plumage by male Birds of 
Paradise, ii. 85; on assemblies of Birds 
of Paradise, ii. 97; on the instability 
of the ocellated spots in //ipparchia 
Janira, ii. 127; on sexually-limited in- 
heritance, ii. 14S; on the sexual colora- 
tion of birds, ii. 158. 187, 189. 192. 198 ; 
on the relation between the colors 
and nidification of birds, ii. 1.58, 168; 
on the coloration of the Cotingida', iL 
169; on the females of J'aradisea 
apoda and Papuana, ii. li!4; on the 
incubation of the Cassowary, 11. 195; 
on protective coloration in birds, ii. 218; 
on the hair of the Papuans, ii. 329; 
on the Babirusa, it 250; on the mark- 
ings of the tiger, ii. 287 ; on the beards 
of the Papuans, ii. 806 ; on the distribu- 
tion of hair on the human body, ii. 259. 

Walbvs, development of the nictitating 
membrane in the, i. 23; tusks of the, 
U. 231, 287'; use of the tusks by the, ii. 246. 

Walsh, B. D., on the proptirtlon of the 
sexes In Papilio turn i«. i. 301 ; on the 
Cynipidee and Cecidomjidit, i. 305; on 
the jaws of Ammophil<i. i. 832; on 
Corydalis coi~n utu«, L 332 ; on the pre- 
hensile organs of male insects, i. 883; 
on the antennip of Penthf. i. 3;}3; on 
the caudal appendages of dragon-flies, 
i. 884; on Platyphyllum omvarutn, 
J. 845 ; on the se.ves of the Ephemerida», 
1. 350 ; on the difference of color in the 
sexes of Spectrum femoratum. i. 350; 
on sexes of dragon-flies, i. 3,50 ; on the 
ditterence of the sexes in the Ichneu- 
monidfli, i. 354; on the sexes of Orno- 
daena atra, i. 857; on the variation 
of the horns of the male Pkamrus car- 
ni/eof, 1. 359 ; on the coloration of the 
species of AnthocJiaris. t. 881. 

Wapiti, battles of, ii. 229 ; traces of horns 
In tlie female, ii. 234 ; attaj-king a man, 
ii. 241 ; crest of the male, ii. 268 ; sexual 
ditterence in the color of the, ii. 276. 

Warbler, Hedge, il. 189 ; young of the, 
ii. 200. 

Wabbi^ebs, Saporb, nidification o^ U- 161. 



INDEX. 



435 



■Wardtess, acquired by animals, i. 48. 
Warington, R., on the habits of the 

sticklebacks, ii. 2, 20; on the brilliant 

colore of the male stickleback during the 

breedinp-season, ii. 14. 
"Wart-hog, tusks and pads of the, ii. 253. 
Watchmakers, short-sighted, i. 113. 
Waterhen, ii. 38. 
Waterhouse, C. O., on blind beetles, i. 

356 ; on difference of color in the sexes 

of beetles, i. 356. 
Waterhouse, G. E., on the voice of Ifj/lo- 

bates aff-iHs, ii. 816. 
Water -OFZBL, autumn song of the, ii. 51. 
Waterton, C, on the pairing of a Canada 

goose with a Bernicle gander, ii. 109 ; on 

hares fighting, ii. 228 ; on the Bell-bird, 

u. 75. 
Wattles, disadvantageous to male birds 

in fighting, ii. 94. 
Wealth, influence o^ i. 163. 
Wealb, J. Mansel, on a South African 

caterpillar, i. 403. 
Weapons, employed by monkeys, i. 50; 

use o^ i. 132 ; offensive, of males, i. 249 ; 

of mammals, ii. 230, et seq. 
Weaver-bibd, ii. 52. 
Weaver-birds, rattling of the wings o^ 

ii. 59 ; assemblies of, ii. 97. 
Webb, Dr., on the wisdom teeth, i. 26. 
Wedgewood, Hensleigh, on the origin of 

language, i. 54. 
Weevils, sexual difference in length of 

snout in some, i. 247. 
Weir, Harrison, on the numerical propor- 
tion of the sexes in pigs and rabbits, i. 

295 ; on the sexes of young pigeons, i. 

297; on the songs of birds, ii. 50; on 

pigeons, ii. 104; on the dislike of blue 

pigeons to other colored varieties, ii. 113 ; 

on the desertion of their mates by female 

W pigeons, ii. 114. 
EiR, J. Jenner, on the nightingale and 
blackcap, i. 2.57; on the relative sexual 
maturity of male birds, i. 253 ; on female 
pigeons deserting a feeble mate, i. 254 ; 
on three starlings frequenting the same 
. nest, i. 260; on the proportion of the 
sexes in Machetes pugnax and other 
birds, i. 297 ; on the coloration of the 
T7-iphcence, i. 883 ; on the rejection of 
certain caterpillars by birds, i. 403 ; on 
sexual differences of the beak in the 
goldfinch, ii. 88; on a piping bullfinch, ii. 
50; on tlie object of the nightingale's 
song, ii. 49 ; on song-birds, ii. 51 ; on the 
pugnacity of male fine-plumaged birds, 
ii. 89 ; on the courtship of birds, ii. 90 ; 
on the finding of new mates by Pere- 
grine-falcons and Kestrels, ii. 100; on 
the bullfinch and starling, ii. 101 ; on the 
cause of birds remaining unpaired, ii. 
103 ; on starlings and parrots Uving in 
triplets, ii. 103 ; on recognition of color 
by birds, ii. 106 ; on hybrid bu-ds, ii. 109 ; 
on the selection of a greenfinch by a fe- 
male canary, ii. 110 ; on a case of rivahy 
of female bullfinches, ii. 116 ; on the ma- 
turity of the Golden-pheasant, ii. 204. 



Weisbach, Dr., measurement of men of 
different races, i. 208; on the greater 
variability of men than of women, i. 266; 
on the relative proportions of the body 
in the sexes of different races of man, ii. 
305. 

Welcker, M., on Brachycephaly and Do- 
lichocephaly, i. 142 ; on sexual differences 
in the skidl in man, ii. 302. 

Wells, Dr., on the immunity of colored 
races fix)m certain poisons, i. 234. 

Westring, on the stridulation of Ee<iurius 
persanatiis, i. 340; on the stridulating 
organs of the Coleoptera, i. 370 ; on 
sounds produced by Cychrxis, i. 370 ; on 
the stridulation of males of Tlieridicyn, 
i. 330 ; on the stridulation of beetles, i. 
867 ; on the stridulation of OmalopUa 
b>'iinne<i. i. 369. 

Westphalia, greater proportion of female 
illegitimate children in, i. 292. 

Westrop, H. M., on the prevalence of cer- 
tain forms of ornamentation, i. 224. 

Westwood, J. O., on the classification of 
the Hymenoptera, i. 181; on the Culi- 
cidse and Tabanidas, i. 246; on a Hymon- 
opterous parasite with a sedentary male, 
i. 263 ; on the proportions of the sexes 
in Lucanua cerirus and Siagoniwm^ i. 
805 ; on the absence of ocelli in female 
mutillida>, i. 331 ; on the jaws of Am- 
7nophila, i. 832 ; on the copulation of in- 
sects of distinct species, i. 832 ; on the 
male of Crabro cribrariu»y i. 333 ; on 
the pugnacity of male Tip^dcE, i. 339 ; on 
the stridulation of Pirates stridulus, i 
340 ; on the Cicadee, i. 841 ; on the strid- 
ulating organs of the crickets, i. 335 ; on 
Pnewmava, i. 347 ; on Ephipj/iger mti- 
v»i, i. 845, 848 ; on the pugnacity of the 
Mantides, i. 349 ; on P/ati/b/emnits, i. 
350; on difference in the sexes of the 
Aginonidae, i. 351 ; on the pugnacity of 
the males of a species of TentliredinsB, 
i. 852 ; on the pugnacity of the male 
stag-beetle, i. 864; on Bledius tanrua 
and Siaffoiiium, i. 363 ; on lamellicom 
beetles, i. 364 ; on the coloration of Litho- 
sia, i. 883. 

Whale, Sperm-, b.attles of male, ii. 229. 

Whales, n.akedness of, i. 142. 

Whately, Archb., language not peculiar 
to man, i. 52 ; on the primitive civiliza- 
tion of man, i. 174. 

Whewell, Prof., on maternal affection, 
i. 38. 

Whiskers, in monkeys, i. 185. 

White, Gilbert, on the proportion of the 
sexes in the partridge, i. 297; on the 
house-cricket, l 342 ; on the object of 
the song of bu-ds, ii. 50 ; on the finding 
of new mates by white owls, ii. 101 ; on 
spring coveys of male partridges, ii. 103. 

Whiteness, a sexual ornament in some 
birds, ii. 221 ; of mammals inhabiting 
snowy countries, il 284. 

White-throat, aerial love-dance of the 
male, ii. 65. 

Wmow-BiBD, polygamous, i 260 ; breed- 



436 



INDEX. 



\ng pliimn^o of the male, il. SO, 93 ; fe- 
iniilo, rejecting the unaQorued male, ii. 
115. 

■V\'ii><)ws anil widowers, mortjilitv of. i. 170. 

"W'niKoN, pairing with a iiijitaii duck, il. 
109. 

"WiLCKF.NS, Dr., on the modifleation of do- 
mestic anhiials in inountiiinous refrions, 
1. IIG; on a niinierieal relation between 
the hairs and excretory pores in sheep, 
1. 289. 

WiLUKK, Dr. Burt, on the greater fre- 
quency of siipernunierarj' digits in men 
than in women, i. 2t)T. 

Williams, on the marriage-customs of the 
Fijians, ii. 857. 

"Wilson, Dr.. on the conical heads of the 
natives of Northwestern America, ii. *J5; 
on the Fijians, ii. 8;35; on the persLstence 
of the fashion of comprossing the skull, 
ii. 836. 

W'iNo-sprRs, ii. 155. 

WiNfis, differences of. in the two sc.xcs of 
buttirHies and ll\ iiuiiciiilini, i. 835; 
play of, in the courtship of birds, ii. !>!. 

"WiNTKR, change of color of mammals in, 
ii. 2S4. 

"WiTnicRAFT, i. 66. 

Wives, traces of the forcible capture o£ L 
175. 

Wolf, \vintcr change of the, ii. 2S4. 

Wolff, on the variability of the viscera in 
man, i. 105. 

WoLLASTON, T. v., on Eiirygnathuft, 1. 
834; on musical curculionidie, i. 866 ; on 
the stridulation oi Actilhn, i. 872. 

WoLVKS learning to bark from dogs, i. 42; 
hunting in packs, i. 72. 

WoLVFXs. black, ii. 2S0. 

Wo.MBAT, black varieties of the, ii. 2S0. 

Women distinguislied from men i)y male 
monkevs, i. 13 ; preponderance of, in 
numbers, i. 292 ; effects of seU'Ction ot, 
in aceordaiK-e with different standards 
of beauty, ii. .S:i9 ; jiractiee of capturing, 
ii. 344. .'Us ; early betrothals and slavery 
of. ii. 85(1; selection ot; for beauty, u. 
8.56 ; freedom of selection by, in savage 
tribes, ii. 356. 

Wonder, manifestations of. by animals. i.41. 

WoNFOR. Mr., on sexual peculiarities in the 
wings of buttertlies, i. .835. 

WoOLNER, Mr., observations on the e^r in 
man, i. 22. 

Wood, .1., on muscular variations in man, 
i. 105, 12.3. 124 ; on the greater variability 
of the muscles in men tlian in women, 1 
266. 

Wood. T. W., on the coloring of the orange- 
tip butleitly. 1. 3^1 ; ,,n the habits of the 
Saturniida'. i. 3N^; on the habits of J/e- 
nura Albert i, ii. 53; on Tetrao cupklo, 
ii. .53 ; on the display of plumage by male 
Jihea.sants. ii. 85 ; on the ocellated spots 
of the Argus iiheas.nnt, ii. 1.3S; on the 
habits of the female (."as.'sowary. ii. 195. 

WooiicooK, coloration of the, ii.'2I6. 

WoiiorEi-KER, selection of u mate by the 
female, Ii. 111. 



WooDPErKERS. il. .%3; tapping of Ii. .59; 
colors and nidllication or the, ii. 1(W, 166, 
214; characters of young, ii. 177, 190. 2(MJ. 

Worm ALU. Mr., on the coloration oiilijpo- 
l>!/iii. i. 8s4. 

Wor.SDs. healing o£ i. 13. 

Wren. il. 1S9 ; young of the, ii. 200. 

Wriuht, C. a., on the young of Orocetet 
and J'etrocincki, ii. 210. 

WRKiiiT, Chaimcey, on correlative acquisi- 
tion, ii. 819; on the enlargement of the 
brain in man, ii. 873. 

Wrkmit, Mr., on the Scotch deerhound. ii. 
250 ; on sexual preference in dogs, ii. 259 ; 
on the rejection of a horse by a mare, ii. 
260. 

AVeiciit. W. von, on the protective plu- 
mage of the Ptarmigan, ii. 78. 

Writino, i. 17.5. 

Wyman, Prof, on the prolongation of the 
coccy.x in the human embiyo. i. 16; on 
the condition of the great-tt>o in the hu- 
man embrj'o, i. 17; on variation in the 
skulls of tlie natives of the Sandwich 
Islands, i. 104; on the hatching of the 
eggs in the mouths and branchial ca\itie8 
of male tishes, L 202 ; ii. 19. 



XENARciirs, on the Cicadm, i. 840. 

Xeiiorltinich M.v. se.vual difference in the col- 
or (if tlie i'ves in, ii. 123. 

A'ij'/ioji/)i>riiJi /fel/erii, peculiar anal fin of 
the male. ii. 9. 10. 

Xylocopa, difference of the sexes in, L 354. 

Y. 

Tarreli., W., on the habits of the Cyprl- 
nida>, i. 300; on Itaia cl<tra<a. ii. 2; on 
the characters of the male salmon during 
the breeding-season, ii. 4, 14 ; on the char- 
acters of the rays, ii. 6; on the gemme- 
ous dragonet, ii. 8; on the .<;pawning of 
the salmon, ii. 18; on the incubation of 
tlie Lophobranchii, ii. 20; on rivalry in 
song-birds, ii. 50 ; on the trachea of" the 
swan, ii. 57 ; on th£ moulting of the ana- 
tida". ii. 81 ; on an instance of reasoning 
in a gull, ii. 104; on the young of the 
waders, ii. 208. 

Yellow fever, immunity of negroes and 
inulattoes from, i. 234. 

You ATT, Mr., on the development of the 
horns in cattle, i. 280. 

YfRA-0ABA8, their notioDB of beauty, il. 
831. 

Z. 

Zebra, rejection of an ass by a female, U. 

281 ; stripes of the, ii. 2S3. 
ZEitrs, humps of ii. 271. 
ZiuzAUS, prevalence of as ornaments, i. 224. 
ZiNCKE. Mr., on Kuropeau emigration to 

America, i. 172. 
Zi>oUh-<i riripara^ sexual difference in the 

color of, il. 34. 
ZYQ.SNUJE:, coloration of tbe^ t. 3S3. 



VOEKS OP HEEBEET SPEXCEE, 

PUBLISHED BT 

D. APPLETOlSr AND COMPAlSrY. 

SYSTEM OF PHILOSOPHY. 

I.— FIRST PRINCIPLES. 
{New and Enlarged Edition.) 
Part I. — The Unkxowable. 
Part II.— Laws of the Knowable. 

559 pages. Price, $2.60 

IL— THE PRINCIPLES OF BIOLOGY.— VOL. L 
Part I. — The Data of Biology. 
Part II. — The Inductions of Biology. 
Part III. — The Evolotion of Life. 

475 pages. Price, ...-.--- $2.50 

PRINCIPLES OF BIOLOGY.— VOL. IL 
Part TV. — Morphological Deyelopment. 
Part V. — Physiological Development. 
Part VI. — Laws of Multiplication. 

565 pages. Price, ........ $2.50 

III.— THE PRINCIPLES OF PSYCHOLOGY. 

Part I. — The Data of Psychology. 144 pages. Price, - - $0.75 

Part II. — The Inductions of Psychology. 146 pages. Price, - $().'75 
Part III. — General Synthesis. 100 pages. ) „ . 

Part IV.— Special Synthesis. 112 pages. |- i nee, - . $1.00 

MISCELLANEOUS. 

I.— ILLUSTRATIONS OF UNIVERSAL PROGRESS. 
Thirteen Articles. 451 pages. Price, • - . - - $2.50 

n.— ESSAYS : 

Moral, Political, and .^Esthetic. 

Ten Essays. S86 pages. Price, ...... $2.50 

III.— SOCIAL STATICS: 
Or the Conditions Essential to Human Happiness Specified, and the 
First of them Developed. 
623 pages. Price, - - - $2.50 

TV.— EDUCATION : 

Intellectual, Moral, and Physical. 

283 pages. Price, $1.25 

v.— CLASSIFICATION OF THE SCIENCES. 
60 pages. Price, ... . ..... $0.25 

VL— SPONTANEOUS GENERATION, &c. 
16 pages. Price, $0.25 



THE ORIGIN OF CIVILIZATION; 

OR, THE 

PRIMITIVE CONDITION OF MAN. 
By SIR JOHN LUBBOCK, Bart, M. P., F. R. S. 

3SO Pages. Illustrated. 

This interesting work is the fruit of many years' research 
by an accoraplislied naturalist, and one well trained in mod- 
ern scientific methods, into the mental, moral, and social con- 
dition of the lowest savage races. The want of a work of 
this kind had long been felt, and, as scientific methods are 
being more and more applied to questions of humanity, there 
has been increasing need of a careful and authentic work de- 
scribing the conditions of those tribes of men who are lowest 
in the scale of development. 

" This interesting work — for it is intensely so in its aim, scope, and the 
ability of its author — treats of what the scientists denominate anthropologyy 
or the natural history of the human species; the complete science of man, 
body and soul, including sex, temperament, race, civilization, etc." — Provi- 
dence Press. 

" A work which is most comprehensive in its aim, and most admirable in 
its execution. The patience and judgment bestowed on the book are every- 
where apparent; the mere list of autliorities quoted giving evidence of wide 
and impartial reading. The work, indeed, is not only a valuable one on ac- 
count of the opinions it expresses, but it is also most serviceable as a book 
of reference. It oflFers an able and exhaustive table of a vast array of facts, 
which no single student could well obtain for himself, and it has not been 
made the vehicle for any special pleading on the part of the author."— 
London Atlienwum. 

" The book is no cursory and superficial review ; it goes to the very heart 
of the subject, and embodies the results of all the later investigations. It is 
replete with curious and quaint information presented in a compact, luminous, 
and entertaining form." — AWany Evening Journal. 

" The treatment of the subject is eminently practical, dealing more with 
fact than theory, or perhaps it will be more just to say, dealing only with 
theory amply sustained by fact." — Detroit Free Press. 

" This interesting and valuable volume illustrates, to some extent, the 
way in which the modern scientific spirit manages to extract a considerable 
treasure from the chaff and refuse neglected or thrown aside by former in- 
quirers." — L<yndon Sutnrday Review. 

D. APPLETON & CO., Publishers. 



THE ORIGIN OF SPECIES, 

By CHARLES DARWIN. 



A new American edition of " The Origin of Species," later than the latest 
English edition, has just been published, with the author's most recent cor- 
rections and additions. 

In the whole history of the progress of knowledge there is no case so re- 
markable of a system of doctrines, at first generally condemned as false and 
absurd, coming into general acceptance in the scientific world in a single 
decade. From the following statements, the reader will infer the estimate 
that is now placed upon the man and his works by the highest authorities. 

"Personally and practically exercised in zoology, in minute anatomy, in 
geology ; a student of geographical distribution, not on maps and in museums 
only, but by long voyages and laborious collection ; having largely advanced 
each of these branches of science, and having spent many years in gathering 
and sifting materials for his present work, the store of accurately-registered 
facts upon which the author of the 'Origin of Species' is able to draw at 
will is prodigious." — Prof. T. H. Huxlet. 

" Far abler men than myself may confess that they have not that untiring 
patience in accumulating, and that wonderful skill in using, large masses of 
facts of the most varied kind — that wide and accurate physiological knowl- 
edge — that aeuteness in devising, that skill in carrying out experiments, and 
that admirable style of composition, at once clear, persuasive, and judicial, 
qualities which, in their harmonious combination, mark out Mr. Darwin as 
the man, perhaps of all men now living, best fitted for the great work he 
has undertaken and accomplished." — Alfred Russell Wallace. 

In Germany these views are rapidly extending. Prof. Giekie, a distin- 
guished British geologist, attended the recent Congress of German Natural- 
ists and Physicians, at Innspruck, in which some eight hundred savanta 
were present, and thus writes : 

"What specially struck me was the universal sway which the writings 
of Darwin now exercise over the German mind. You see it on every side, in 
private conversation, in printed papers, in all the many sections into which 
such a meeting as that at Innspruck divides. Darwin's name is often men- 
tioned, and always with the profoundest veneration. But even where no al- 
lusion is specially made to him, nay, even more markedly, where such allusion 
is absent, we see how thoroughly his doctrines have permeated the scientific 
mind, even in those departments of knowledge which might seem at first 
sight to be farthest from natural history. ' You are still discussing in Eng- 
land,' said a German friend to me, ' whether or not the theory of Darwin can 
be true. We have got a long way beyond that here. His theory is now our 
common starting-point.' And, so far as my experience went, I found it t« 
be so." 

D. -A.I»I>I..KTON- & CO.. I»iat»lislier«. 



D. Appleton & Company''8 rvhUcatiovn. 



LAY SEEMO^y, 
ADDRESSES, AND REVIEWS, 

By THOMAS HENRY HUXLEY. 
Cloth, 12mo. 390 pages- Price, $1.76 

This is the latest and most popular of the works of this in- 
trepid and accomplished English thinker. The American edition 
of the work is the latest, and contains, in addition to the English 
edition, Professor lluxley's recent masterly address on " Spon- 
taneous Generation," delivered before the British Association for 
the Advancement of Science, of which he was president. 

The following is from an able article in the Independent : 

The " Lay Sermons, Addresses, and Reviews " is a book to be read 
by every one who would keep up with the advance of truth — as well by 
those who are hostile as those who are IVicudly to his conclusions. In 
it, scientitic and philosophical topics are handled with consummate abil- 
ity. It is remarkable for purity of style and power of expression. No- 
where, in any modern work, is the advancement of the pursuit of that 
natural knowledge, which is of vital importance to bodily and mental 
well-being, so ably handled. 

Professor Iluxley is undoubtedly the representative scientific man of 
the age. His reverence for the right and devotion to truth have estab- 
lished his leadership of modern scientific thought. He leads the beliefs 
and aspirations of the increasingly powerful body of the younger men of 
science. His ability for research is marvellous. There is possible no more 
equipoise of judgment than that to which he brings the phenomena of 
Nature. Besides, he is not a mere scientist. His is a popularized phi- 
losophy ; social ([uestions have been treated by his pen in a manner most 
masterly. In his popular addresses, embracing the widest range of top- 
ics, he treads on ground with which he seems thoroughly familiar. 

There are those wlio hold tlie name of Professor Iluxley as synony- 
mous with irreverence and atlicism. Plato's was so held, and Galileo's, 
and Descartes's, and Newton's, and Faraday'g. There can be no greater 
mistake. No man has greater reverence for the Bible than Huxley. No 
one more acquaintance with the text of Scripture. He believes there is 
definite government of the universe ; that pleasures anJ pains are distrib- 
uted in accordance with law ; and that the certain proportion of evd 
woven up in the life even of worms will help the man n\\o thinks to bear 
his own share with courage. 

In the estimate of Professor Huxley's future influence upon science, 
his youth and health form a large element. He has just pasj^ed his Ibrty- 
fifth year. If God spare his life, truth can hardly fall to be the gainer 
from a mind that is stored with knowledse of the laws of the Creator's 
operations, and that has learned to love all beauty and hitt^* «3 rilcucaii of 
Nature and art. 



BPENGER8 SYSTEM OF PHILOSOPHY. 

THE PHILOSOPHY OF EYOLUTION. 

By HERBERT SPENCER. 



Thia great system of scientiflc thought, the most original and important men- 
tal undertaking of the age, to which Mr. Spencer has devoted his life, is now well 
advanced, the published volumes being; First Principles, The Principles of Bi- 
ology, two volumes, and The Principles of Psychology, vol. i., which will bo 
shortly printed. 

This philosophical system differs from all its predecessors in being solidly 
based on the sciences of observation and induction ; in representing the order 
and course of Nature ; in bringing Nature and man, life, mind, and society, undt^r 
one great law of action ; and in developing a method of thought which may serve 
for practical guidance in dealing with the affairs of life. That Mr. Spencer is the 
man for this great work will be evident from the following statements : 

" The only complete and systematic statement of the doctrine of Evolution 
with whicli I am acquainted is that contained in Mr. Herbert Spencer's ' System 
of Philosophy ; ' a work which should be carefully studied by all who desire to 
know whither scientific thought is tending."— T. H. Huxley. 

" Of all our thinkers, he is the one who has formed to himself the largest new 
scheme of a systematic philosophy." — Prof. Masson. 

" If any individual influence is visibly encroaching on Mills in this country, it 
is his." — Ibid. 

" Mr. Spencer is one of the most vigorons as well as boldest '.tinkers that 
English speculation has yet produced." — John Stuart Mill. 

" One of the acutest metaphysicians of modern times." — Ibid. 

*' One of our deepest thinkers."— Dr. Joseph D. Hookeb. 

It is questionable if any thinker of finer calibre has appearo'l h\ our coun- 
try." — George Henbt Lewes. 

"He alone, of all British thinkers, has organized a philosophy."— TT'^fi. 

" He is as keen an analyst as is known In the history of philotiophy ; I do not 
except either Aristotle or Kant." — George Kiplet. 

" If we were to give our own judgment, we should say that, since Newton, 
there has not in England been a philosopher of more remarkable speculative and 
eystematizing talent than (in spite of some errors and some narrowness) Mr. Her- 
bert Spencer."— /^Oftc^cOT Saturday Review. 

" We cannot refrain from offering our tribute of respect to one who, whether 
for the extent of his positive knowledge, or for the profundity of his speculative 
insight, has already achieved a name second to none in the whole rangt, of Eng- 
lish philosophy, and whose vi-orks will worthily sustain the credit of English 
tboaght in the present generation."— fre«<m««<er Review. 



Works of Herbert Spencer publuhed by D. App eton «* Ob. 



ESSAYS: 

MORAL, POLITICAL, AND ESTBETIO. 

In one Voliune. I<aree 12mo. 386 patraa. 

contents: 
L The Philosophy of Style. 
n. Ovcr-Lefrislation. 
in. Morals of Trade. 
IV. Personal Beauty. 
V. Representative Government 
VI. Prison-Ethics. 

VII. Railway Morals and Railway Policy. 
VIIL Gracefulness. 
IX, State Tamperings with Money and Banka. 
X Reform ; the Dangers and the Safeguards. 



" These Essays form a new, and if we are not mistaken, a most popular InstaTlraent 
If the intellectual benefactions of that earnest »Titer and profound philosopher, Her- 
bert Spencer. There is a reinarkalile anion of the speculative and practical tn theM 
papers. They are the fhiit of studies alike economical and psychological; they touch 
the problems of the passing hour, an<l they grasp truths of universal application ; they 
will be founa as instructive to the general reader as interesting to political and social 
students." — Bonton Traivcript. 

•'These Essays exhibit on a. most every i)age the powers of an independent hum&n- 
iUuian thinker. Mr. Spencer's ethics are rigid, his political views liberalistic, and hu 
aim is the production ol the highest earthly good." — Methodist Quarterly Review. 

" It abounds iii the results of the sharp observation, the wide reach of kf^vledga, 
and the capacity to write clearly, forcibly, and pointedly, for which this writei \» pre- 
eminent. The subjects are all suchiat concern us most intimately, and they are treated 
with admirable tact and knowledge. The drat essay on the Philosophy of Style it 
worth the cost of the volume; it would be a deed of charity to print It by itself and 
•end it to the editor of every newspaper In the land." — New Engiander. 

"Spencer is continually g.iining ground with Americans; be makes a book fbr oci 
more serious moods. His remarks npon legislation, npon the nature of political Insti- 
tutions and of tbeir fundamental principles; his elucidation of those foundation truth* 
which control the policy of government, are of peculiar value to the American stu- 
dent"— J?o«ton Pogt. 

"This volume will receive the applause of every serious reader l«r the prorband 
evnestneHS and thoroughness with which its views are elaborated, the inOnitescientlflo 
knowledge brought to bear on every question, and the acute and subtle tbinUng dis- 
played In every ohapter."— A^. W. Christian Advocate. 

"A more Instructive, suggestive, and stimulating volume bas not reaotted us 1» • 
JBf tlma," — Piovidence JoumoK, 



Worit published bv T>. Appldon <£r Co. 



THE CORREUTION AND COKSERVATION 



rORCES. 



A SERIES OF EXPOSITIONS BY GROVE, MAYER, HELMHOLT^ 
FARADAY, LIEBIG, AND CARPENTER. 



AN INTRODUCTION. 

BY K L. T0UMAN8 

The work embraces ; 

L— THE CORKELATIOF OF PHYSICAL FORCES. Bt 
W. R. Gkove. (The complete work.) 

n.— CELESTIAL DYNAMICS. By De. J. R. Mayb*. 

m.— THE INTERACTION OF FORCES. By Peof. Hkuc. 

HOLTZ. 

rV. — THE CONNECTION AND EQIHYALENCE OF 
FORCES. By Peof. Liebig. 

v.— ON THE CONSERVATION OF FORCE. Bt Di^ 
Fabaday. 

VI.— ON THE CORRELATION OF PHYSICAL AND VI 
TAL FORCES. By De. Cabpbntbb. 



Wmks of Herbert Spencer published 6^ J), dppldoti <fc Cb. 



A NEW SYSTEM OF PHILOSOPUY. 

FIRST PRINCIPLES. 

L. VoL L*rsre 12mo. 616 Pages. Price $2 60. 

Contents : 
Part Ferst. — 7%« Uhknotoable. 

Ckiaptei 1. Religion and Science; IL Ultimate Religious Ideas; lU 
Ultimate Scientific ideas; IV. The Relativity of all Knowledge; V Th« 
RecoucUiatiuu. 

Part Second. — Laws of Ow Knomable. 

I. Laws in General; 11. The Law of Evolution; III. The same con- 
tinued ; IV. The Causes of Evolution ; V. Space, Time, Matter, Motion, and 
Force; VI. The Indestructibility of Matter ; VII. The Continuity of Motion ; 
VIII. The Persistence of Force; IX. The Correlation and Equivalence of 
Forces ; X. The Direction of Motion ; XI. The Klinhm of Motion ; XII. The 
Conditions Essential to Evolution; XIII. The Instability of the domoge- 
ueous; XIV. The Multiplication of Eflects; XV. Differentiation -.nd Inte- 
gration ; XVI. Equilibration ; XVII. Summary and Conclusion. 

In the first part of this work Mr. Spencer defines the province, limits, and 
relations of religion and science, and determines the legitimate scope of 
philosophy. 

In part second he unfolds those fundamental principles which have been 
arrived at within the sphere of the knowable ; which are true of all orders 
of phcnonema, and thus constitute the foundation of all philosophy. The 
law of Evolution, Mr. Spencer maintains to be universal, and he has here 
worked it out as the basis of his system. 

These First Principles are the foundation of a system of Philosophy 
bolder, more elaborate, and comprehensive perhaps, than any other wliicb 
Dai beeu hitherto designed in England. — BrUish Quarterly Review. 

A work lofty in aim and remarkable in execution — Corr,hiU Afayadnt. 

In the works of Ilerbert Spencer we have the rudiments of a poeitiTS 
Theology, and an immense step toward the perfection of the science of I'ay- 
ebology. — Christian Examiner. 

If we mintake not, in spite of the very negative character of his own r» 
nits, he has foreshadowed some strong arguments for tUe doctrijie of a pooK 
Mtb Christian Theology. — New Eiiglaiuler. 

As far as the frontiers of knowledge, where the Intellect may go, there li 
•0 living man whose guidance may more safely be trustuiL — A ilt mUt 
IfmOdv. 



Worts of Herbert Spencer published by D. Appleton tit Vo. 
la One Volnme, gvo., Cloth. Price %iM. 



SOCIAL STATICS; 

OR, 

THE CONDITIONS ESSENTIAL TO HUMAN HAPPINESS SPECI. 
TIED, AND THE FIEST OF THEM DEVELOPED. 

BY HEEBEKT SPENCEK. 



OPINIONS OF TEE PRESS. 



Mr. Spencer, in his able and logical work on " Social Statics " . . . . Edin- 
burgh Review, 

It deserves very high praise for the ability, clearness, and force with which 
it is written, and which entitle it to the character, now so rare, of a really sub- 
stantial booli. — North British Review. 

A remarkable work Mr. Spencer exhibits, and exhibits with re- 
markable force and clearness, many social equalizations of a just and right 
species which remain yet to be effected. — British Quarterly Review. 

An inquiry conducted throughout with clearness, good temper, and strict 

logic We shall be mistaken if this book do not assist in organising that 

huge mass of thought which, for want of a more specific name, is now called 
Liberal Opinion. — Athenceum. 

It is the most eloquent, the most interesting, the most clearly-expressed and 
logically-reasoned work, with views the most original, that has appeared in tha 
science of social poVity.— 'Literary Oaaette. 

The author of the present work is no ordinary thinker, and no ordinary wri- 
ter; and he gives us, in language that sparkles with beauties, and in reasoning 
at once novel and elaborate, precise and logical, a very comprehensive and 

complete exposition of the rights of men in society The book will 

mark an epoch in the literature of scientific morality. — Economist. 

We remember no work on ethics since that of Spinoza to be compared with 
It in the simplicity of its premises, and the logical rigour with which a com- 
plete system of scientific ethics is evolved from them A work at once 

so scientific in spirit and method, and so popular in execution, we shall look in 
vain for through libraries of political philosophy. — Leader. 

The careful reading we have given it has both afforded us intense pleasure, 
and rendered it a duty to express, with unusual emphasis, our opinion of ita 
gre»t ability and excellence.— iVb»co«/ormis<. 



New York: D. Appleton and Compant. 



Works of Herbert Spencer puIAiahed by D. AppUton dt Co. 

ILLUSTRATIONS OF UNIVERSAL PROGRESS. 

A SERIES OF DISCUSSIONS. 

1 Vol Larse 12mo. 470 Pa«M. Price $2.50. 



Amencan Notice of Spencer's New System of Philosophy. 

L Progress : its Law and Cause. 

II Manners and P'ashion. 

ni. The Genesis of Science. 

IV. The Physiology of Laughter. 

V. The Origin and Function of Music. 

VL The Nebular Hypothesis. 

VIL Bain on the Emotions and the WilL 

VlIL Illogical Geology. 

IX. The Development Hypothesis. 

X The Social Organism. 

XL Use and Beauty. 

XIL The Sources of Architectural Types. 

Xin. The Use of Anthropomorphism, 

These Essays constitute a body of massive and original thought upon a 
large variety of important topics, and will be read with pleasure by all who 
appreciate a bold and powerful treatment of fVmdamental themes. Tha 
general thought which pervades this book is beyond doubt the most impor- 
tant that the human mind has yet reached. — N. Y. Independent. 

Those who have read the work on Education, will remember the ana- 
lytic tendency of the author's mind — his clear perception and admirable ex- 
position of first principles — his wide grasp of facts — his lucid and vigorou« 
•tyle, and the constant and controlling bearing of the discussion on practical 
results. These traits characterize all Mr. Spencer's writings, and mark, io 
•n eminent degree, the present volume. — N, Y. TVUmm, 

We regard the distinguishing feature of this work to be the peculiarly 
Interesting character of its matter to the general reader. This is a great 
literary as well as philosophic triumph. In the evolution of a system of 
Philosophy which demands serious attention, and a keen exercise of the in- 
tellect to fathom and appreciate, he has mingled much that is really popoUi 
•od entertaining. — Rochester DeniocroL 



Works qf Herbert Spencer published by D. Apphtcn dk Gk 
The Philosophy of Herbert Spencer, 



THE 

PKLtTOIPLES OF BIOLOGY 

VoL I. 475 pagres. (Now in press.) 

CONTENTS: 

Part L — The Data of Biology. 

I Organic Matter. — 11. The actions of Forces on Organic Matter. — IIT. The 
re-actions of Organic Matter on Forces. — IV. Proximate Definition of 
Life. — V. The Correspondence between Life and its Circumstances.— 
VI. The Degree of Life varies as the Degree of Correspondence.— 
VIL The Scope of Biology. 

Part II. — The Inductions of Biology. 

L Growth. — n. Development. — III. Function. — IV. Waste and Repair.— 
V. Adaptation. — VI. Individuality. — Vll. Genesis. — VIII. Heredity. — 

IX. Variation. — X. Genesis, Heredity, and Variation — XI. Classifica- 
tion. — Xn. Distribution. 

Part HI. — The Evolution of Lira. 

L Preliminary. — ^H. General Aspects of the Special-creatiou-hypothesis.^ 
ni. General Aspects of the Evolution-hypothesis. — IV. The Argumenta 
from Classification. — V. The Arguments from Embryology. — VI. The 
Arguments from Morphology. — VII. The Arguments f.'om Distribution. 
— Vip. How is Organic Evolution caused ? — IX. External Factors.- 

X. Internal Factors. — XL Direct Equilibration. — Xll Indirect Equlli 
bration. — XIU. The Cooperation of the Factors. — ^XIV. The Converg 
ence of the Evidences. 



All these works are rich In materials for forming intelligent opinions, even whero 
we are unable to agree with those put forth by the anthor. Much may be learned from 
Jiem in departments in which our common Educational system Is very deficient. The 
active citizen may derive from them accurate systematized information concerning his 
highest duties to society, and the principles on which they are based. He may gain 
dearer notions of the value and bearing of evidence, and be better able to distinguish 
between facts and inferences. He may find common things suggestive of wiser thought 
—nay, we will venture to say of truer emotion — than before. By giving us fuller renll- 
tatioiu of liberty and justice his vritings will tend to increase our self-reliance in the 
great emergenej of civilization to which we have been summoned.— Atlantic Monthly 



D. APPLETON <t CO: a PUBLICATIONS. 



Lockyer's Astronomy. 

AMERICAN EDITION. 

" This is by far the clearest and best manual of Astronomy we 

have ever seen. A child may understand it-and yet 

it contains tniormation which will be new to 

all who have not time to follow the 

latest discoveries." — New 

YM-k Daily Times. 

The opinion of the critic of the Times, given above, 
is tliat of all who have examined this sterling school- 
book, which is winning golden opinions everywhere. 
Out of hosts of letters, we have space for the following 
only :— 

" Lockyer'8 Elements of Astronomy is a work of rare excellence. As a text-book for 
the use of schools it i« unxurpamed by any work on that subject with which I am ac- 
quainted.'— Pkof. Joiis S. Hakt, State Normal School, Trenton, N. J. 

" I think it an excellent work— well calculated for class use by pupils of an academic 
grade. The arrangement and typography are worthy of especial commendation. It is 
a decided success."— S. B. Howe, Supt. of Schooh, Sdteneetady, N. Y. 

" It is the bent school-book on Astronomy that I ever saw. The spectra of the sun, 
stars, and nebukp, are worth the price of the book. The diagrams are excellent I 
deem it superior to all other books on that science with which I am acquainted. Of 
course I shall use it."— W. H. Pnr, A. M., Princ. Friendnhip Academy. 

" I have examined with much satisfaction the admirable elementarj' treatise on As- 
tronomy by I^ckyer. It furnishes the reader with the means of learning in a short 
time the great features of the modern progress of Astronomy. No book (except, pcr- 
hap.s, Youmans's New Chemistr>-) has appeared, which so easily, yet thoroughly, pre- 
pares the reader for the subsequent study of that mighty auxiliarj' to modern science — 
spectrum-analysis. Moreover it presents, in a clear and succinct style, the relations of 
the various parts of the stellar universe, besides inducting the learner into that neglected 
branch of .Vstronomy known as Geography of the Heavens. Its illustrations are genu- 
ine aids to the comprehension of the subject-matter." — David Beattle, Supt. Troy 
(N. r.) City Schools. 

" I have examined it with care, and find it admirably adapted for use in schools. It 
Is so plainly written and so ftilly illustrated as to render it specially suited for beginners 
In the science, and, at the same time, profitable for advanced students." — Peof. C. Sta- 
LET, Union College. 

" It is a clear and beautiftil unfolding of a profound and fitscinating subject It 
seems to me admirably adapted to the academic grade of students. Not attempting to 
discuss those problems and theories of the science for which such pupils have neither 
the time nor the capacity, the author has given an outline of the subject that is clear, 
Bufflciently complete, and thoroughly modem." — Pbof. Bbadlev, Princ. Albany Free 
Academy. 





DATE DUE 




tTA Oi II ^ 








' '^^mmm 










«. 






FEB PR 1 


)flC 








'85 














































































































GAYLORD 






P«,NTtD.NOS.*. 



MW 





-^ 




"" ■■ " ' ' — -■ I I I 11,1 II I. ■