Many Lamellicorns have the power of stridulating, and the organs differ

greatly in position. Some species stridulate very loudly, so that when

Mr. F. Smith caught a _Trox sabulosus_, a gamekeeper who stood by

thought that he had caught a mouse; but I failed to discover the proper

organs in this beetle. In Geotrupes and Typhaeus a narrow ridge runs

obliquely across (_r_, fig. 25) the coxa of each hind-leg, having in

_G. stercorarius_ 84 ribs, which are scraped by a specially-projecting

part of one of the abdominal segments. In the nearly allied _Copris

lunaris_, an excessively narrow fine rasp runs along the sutural margin

of the elytra, with another short rasp near the basal outer margin; but

in some other Coprini the rasp is seated, according to Leconte,[499] on

the dorsal surface of the abdomen. In Oryctes it is seated on the

pro-pygidium, and in some other Dynastini, according to the same

entomologist, on the under surface of the elytra. Lastly, Westring

states that in _Omaloplia brunnea_ the rasp is placed on the

pro-sternum, and the scraper on the meta-sternum, the parts thus

occupying the under surface of the body, instead of the upper surface as

in the Longicorns.

We thus see that the stridulating organs in the different coleopterous

families are wonderfully diversified in position, but not much in

structure. Within the same family some species are provided with these

organs, and some are quite destitute of them. This diversity is

intelligible, if we suppose that originally various species made a

shuffling or hissing noise by the rubbing together of the hard and rough

parts of their bodies which were in contact; and that from the noise

thus produced being in some way useful, the rough surfaces were

gradually developed into regular stridulating organs. Some beetles as

they move, now produce, either intentionally or unintentionally, a

shuffling noise, without possessing any proper organs for the purpose.

Mr. Wallace informs me that the _Euchirus longimanus_ (a Lamellicorn,

with the anterior legs wonderfully elongated in the male) "makes, whilst

moving, a low hissing sound by the protrusion and contraction of the

abdomen; and when seized it produces a grating sound by rubbing its

hind-legs against the edges of the elytra." The hissing sound is clearly

due to a narrow rasp running along the sutural margin of each elytron;

and I could likewise make the grating sound by rubbing the shagreened

surface of the femur against the granulated margin of the corresponding

elytron; but I could not here detect any proper rasp; nor is it likely

that I could have overlooked it in so large an insect. After examining

Cychrus and reading what Westring has written in his two papers about

this beetle, it seems very doubtful whether it possesses any true rasp,

though it has the power of emitting a sound.

From the analogy of the Orthoptera and Homoptera, I expected to find

that the stridulating organs in the Coleoptera differed according to

sex; but Landois, who has carefully examined several species, observed

no such difference; nor did Westring; nor did Mr. G. R. Crotch in

preparing the numerous specimens which he had the kindness to send me

for examination. Any slight sexual difference, however, would be

difficult to detect, on account of the great variability of these

organs. Thus in the first pair of the _Necrophorus humator_ and of the

_Pelobius_ which I examined, the rasp was considerably larger in the

male than in the female; but not so with succeeding specimens. In

_Geotrupes stercorarius_ the rasp appeared to me thicker, opaquer, and

more prominent in three males than in the same number of females;

consequently my son, Mr. F. Darwin, in order to discover whether the

sexes differed in their power of stridulating, collected 57 living

specimens, which he separated into two lots, according as they made,

when held in the same manner, a greater or lesser noise. He then

examined their sexes, but found that the males were very nearly in the

same proportion to the females in both lots. Mr. F. Smith has kept alive

numerous specimens of _Mononychus pseudacori_ (Curculionidae), and is

satisfied that both sexes stridulate, and apparently in an equal degree.

Nevertheless the power of stridulating is certainly a sexual character

in some few Coleoptera. Mr. Crotch has discovered that the males alone

of two species of Heliopathes (Tenebrionidae) possess stridulating

organs. I examined five males of _H. gibbus_, and in all these there was

a well-developed rasp, partially divided into two, on the dorsal surface

of the terminal abdominal segment; whilst in the same number of females

there was not even a rudiment of the rasp, the membrane of this segment

being transparent and much thinner than in the male. In _H.

cribratostriatus_ the male has a similar rasp, excepting that it is not

partially divided into two portions, and the female is completely

destitute of this organ; but in addition the male has on the apical

margins of the elytra, on each side of the suture, three or four short

longitudinal ridges, which are crossed by extremely fine ribs, parallel

to and resembling those on the abdominal rasp; whether these ridges

serve as an independent rasp, or as a scraper for the abdominal rasp, I

could not decide: the female exhibits no trace of this latter structure.

Again, in three species of the Lamellicorn genus Oryctes, we have a

nearly parallel case. In the females of _O. gryphus_ and _nasicornis_

the ribs on the rasp of the pro-pygidium are less continuous and less

distinct than in the males; but the chief difference is that the whole

upper surface of this segment, when held in the proper light, is seen to

be clothed with hairs, which are absent or are represented by

excessively fine down in the males. It should be noticed that in all

Coleoptera the effective part of the rasp is destitute of hairs. In _O.

senegalensis_ the difference between the sexes is more strongly marked,

and this is best seen when the proper segment is cleaned and viewed as a

transparent object. In the female the whole surface is covered with

little separate crests, bearing spines; whilst in the male these crests

become, in proceeding towards the apex, more and more confluent,

regular, and naked; so that three-fourths of the segment is covered with

extremely fine parallel ribs, which are quite absent in the female. In

the females, however, of all three species of Oryctes, when the abdomen

of a softened specimen is pushed backwards and forwards, a slight

grating or stridulating sound can be produced.

In the case of the Heliopathes and Oryctes there can hardly be a doubt

that the males stridulate in order to call or to excite the females; but

with most beetles the stridulation apparently serves both sexes as a

mutual call. This view is not rendered improbable from beetles

stridulating under various emotions; we know that birds use their voices

for many purposes besides singing to their mates. The great

Chiasognathus stridulates in anger or defiance; many species do the same

from distress or fear, when held so that they cannot escape; Messrs.

Wollaston and Crotch were able, by striking the hollow stems of trees in

the Canary Islands, to discover the presence of beetles belonging to the

genus Acalles by their stridulation. Lastly the male Ateuchus

stridulates to encourage the female in her work, and from distress when

she is removed.[500] Some naturalists believe that beetles make this

noise to frighten away their enemies; but I cannot think that the

quadrupeds and birds which are able to devour the larger beetles with

their extremely hard coats, would be frightened by so slight a grating

sound. The belief that the stridulation serves as a sexual call is

supported by the fact that death-ticks (_Anobium tessellatum_) are well

known to answer each other's ticking, or, as I have myself observed, a

tapping noise artificially made; and Mr. Doubleday informs me that he

has twice or thrice observed a female ticking,[501] and in the course of

an hour or two has found her united with a male, and on one occasion

surrounded by several males. Finally, it seems probable that the two

sexes of many kinds of beetles were at first enabled to find each other

by the slight shuffling noise produced by the rubbing together of the

adjoining parts of their hard bodies; and that as the males or females

which made the greatest noise succeeded best in finding partners, the

rugosities on various parts of their bodies were gradually developed by

means of sexual selection into true stridulating organs.

CHAPTER XI.

INSECTS, _continued_.--ORDER LEPIDOPTERA.

Courtship of butterflies--Battles--Ticking noise--Colours

common to both sexes, or more brilliant in the

males--Examples--Not due to the direct action of the conditions

of life--Colours adapted for protection--Colours of

moths--Display--Perceptive powers of the

Lepidoptera--Variability--Causes of the difference in colour

between the males and females--Mimickry, female butterflies

more brilliantly coloured than the males--Bright colours of

caterpillars--Summary and concluding remarks on the secondary

sexual characters of insects--Birds and insects compared.

In this great Order the most interesting point for us is the difference

in colour between the sexes of the same species, and between the

distinct species of the same genus. Nearly the whole of the following

chapter will be devoted to this subject; but I will first make a few

remarks on one or two other points. Several males may often be seen

pursuing and crowding round the same female. Their courtship appears to

be a prolonged affair, for I have frequently watched one or more males

pirouetting round a female until I became tired, without seeing the end

of the courtship. Although butterflies are such weak and fragile

creatures, they are pugnacious, and an Emperor butterfly[502] has been

captured with the tips of its wings broken from a conflict with another

male. Mr. Collingwood in speaking of the frequent battles between the

butterflies of Borneo says, "They whirl round each other with the

greatest rapidity, and appear to be incited by the greatest ferocity."

One case is known of a butterfly, namely the _Ageronia feronia_, which

makes a noise like that produced by a toothed wheel passing under a

spring catch, and which could be heard at the distance of several yards.

At Rio de Janeiro this sound was noticed by me, only when two were

chasing each other in an irregular course, so that it is probably made

during the courtship of the sexes; but I neglected to attend to this

point.[503]

Every one has admired the extreme beauty of many butterflies and of some

moths; and we are led to ask, how has this beauty been acquired? Have

their colours and diversified patterns simply resulted from the direct

action of the physical conditions to which these insects have been

exposed, without any benefit being thus derived? Or have successive

variations been accumulated and determined either as a protection or for

some unknown purpose, or that one sex might be rendered attractive to

the other? And, again, what is the meaning of the colours being widely

different in the males and females of certain species, and alike in the

two sexes of other species? Before attempting to answer these questions

a body of facts must be given.

With most of our English butterflies, both those which are beautiful,

such as the admiral, peacock, and painted lady (Vanessae), and those

which are plain-coloured, such as the meadow-browns (Hipparchiae), the

sexes are alike. This is also the case with the magnificent Heliconidae

and Danaidae of the tropics. But in certain other tropical groups, and

with some of our English butterflies, as the purple emperor, orange-tip,

&c. (_Apatura Iris_ and _Anthocharis cardamines_), the sexes differ

either greatly or slightly in colour. No language suffices to describe

the splendour of the males of some tropical species. Even within the

same genus we often find species presenting an extraordinary difference

between the sexes, whilst others have their sexes closely alike. Thus in

the South American genus Epicalia, Mr. Bates, to whom I am much indebted

for most of the following facts and for looking over this whole

discussion, informs me that he knows twelve species, the two sexes of

which haunt the same stations (and this is not always the case with

butterflies), and therefore cannot have been differently affected by

external conditions[504]. In nine of these species the males rank

amongst the most brilliant of all butterflies, and differ so greatly

from the comparatively plain females that they were formerly placed in

distinct genera. The females of these nine species resemble each other

in their general type of coloration, and likewise resemble both sexes in

several allied genera, found in various parts of the world. Hence in

accordance with the descent-theory we may infer that these nine species,

and probably all the others of the genus, are descended from an

ancestral form which was coloured in nearly the same manner. In the

tenth species the female still retains the same general colouring, but

the male resembles her, so that he is coloured in a much less gaudy and

contrasted manner than the males of the previous species. In the

eleventh and twelfth species, the females depart from the type of

colouring which is usual with their sex in this genus, for they are

gaily decorated in nearly the same manner as the males, but in a

somewhat less degree. Hence in these two species the bright colours of

the males seem to have been transferred to the females; whilst the male

of the tenth species has either retained or recovered the plain colours

of the female as well as of the parent-form of the genus; the two sexes

being thus rendered in both cases, though in an opposite manner, nearly

alike. In the allied genus Eubagis, both sexes of some of the species

are plain-coloured and nearly alike; whilst with the greater number the

males are decorated with beautiful metallic tints, in a diversified

manner, and differ much from their females. The females throughout the

genus retain the same general style of colouring, so that they commonly

resemble each other much more closely than they resemble their own

proper males.

In the genus Papilio, all the species of the AEneas group are remarkable

for their conspicuous and strongly contrasted colours, and they

illustrate the frequent tendency to gradation in the amount of

difference between the sexes. In a few species, for instance in _P.

ascanius_, the males and females are alike; in others the males are a

little or very much more superbly coloured than the females. The genus

Junonia allied to our Vanessae offers a nearly parallel case, for

although the sexes of most of the species resemble each other and are

destitute of rich colours, yet in certain species, as in _J. oenone_,

the male is rather more brightly coloured than the female, and in a few

(for instance _J. andremiaja_) the male is so different from the female

that he might be mistaken for an entirely distinct species.

Another striking case was pointed out to me in the British museum by Mr.

A. Butler, namely one of the Tropical American Theclae, in which both

sexes are nearly alike and wonderfully splendid; in another, the male

is coloured in a similarly gorgeous manner, whilst the whole upper

surface of the female is of a dull uniform brown. Our common little

English blue butterflies of the genus Lycaena, illustrate the various

differences in colour between the sexes, almost as well, though not in

so striking a manner, as the above exotic genera. In _Lycaena agestis_

both sexes have wings of a brown colour, bordered with small ocellated

orange spots, and are consequently alike. In _L. oegon_ the wings of

the male are of a fine blue, bordered with black; whilst the wings of

the female are brown, with a similar border, and closely resemble those

of _L. agestis_. Lastly, in _L. arion_ both sexes are of a blue colour

and nearly alike, though in the female the edges of the wings are rather

duskier, with the black spots plainer; and in a bright blue Indian

species both sexes are still more closely alike.

I have given the foregoing cases in some detail in order to shew, in the

first place, that when the sexes of butterflies differ, the male as a

general rule is the most beautiful, and departs most from the usual type

of colouring of the group to which the species belongs. Hence in most

groups the females of the several species resemble each other much more

closely than do the males. In some exceptional cases, however, to which

I shall hereafter allude, the females are coloured more splendidly than

the males. In the second place these cases have been given to bring

clearly before the mind that within the same genus, the two sexes

frequently present every gradation from no difference in colour to so

great a difference that it was long before the two were placed by

entomologists in the same genus. In the third place, we have seen that

when the sexes nearly resemble each other, this apparently may be due

either to the male having transferred his colours to the female, or to

the male having retained, or perhaps recovered, the primordial colours

of the genus to which the species belongs. It also deserves notice that

in those groups in which the sexes present any difference of colour, the

females usually resemble the males to a certain extent, so that when the

males are beautiful to an extraordinary degree, the females almost

invariably exhibit some degree of beauty. From the numerous cases of

gradation in the amount of difference between the sexes, and from the

prevalence of the same general type of coloration throughout the whole

of the same group, we may conclude that the causes, whatever they may

be, which have determined the brilliant colouring of the males alone of

some species, and of both sexes in a more or less equal degree of other

species, have generally been the same.

As so many gorgeous butterflies inhabit the tropics, it has often been

supposed that they owe their colours to the great heat and moisture of

these zones; but Mr. Bates[505] has shewn by the comparison of various

closely-allied groups of insects from the temperate and tropical

regions, that this view cannot be maintained; and the evidence becomes

conclusive when brilliantly-coloured males and plain-coloured females of

the same species inhabit the same district, feed on the same food, and

follow exactly the same habits of life. Even when the sexes resemble

each other, we can hardly believe that their brilliant and

beautifully-arranged colours are the purposeless result of the nature of

the tissues, and the action of the surrounding conditions.

With animals of all kinds, whenever colour has been modified for some

special purpose, this has been, as far as we can judge, either for

protection or as an attraction between the sexes. With many species of

butterflies the upper surfaces of the wings are obscurely coloured, and

this in all probability leads to their escaping observation and danger.

But butterflies when at rest would be particularly liable to be attacked

by their enemies; and almost all the kinds when resting raise their

wings vertically over their backs, so that the lower sides alone are

exposed to view. Hence it is this side which in many cases is obviously

coloured so as to imitate the surfaces on which these insects commonly

rest. Dr. Roessler, I believe, first noticed the similarity of the closed

wings of certain Vanessae and other butterflies to the bark of trees.

Many analogous and striking facts could be given. The most interesting

one is that recorded by Mr. Wallace[506] of a common Indian and Sumatran

butterfly (Kallima), which disappears like magic when it settles in a

bush; for it hides its head and antennae between its closed wings, and

these in form, colour, and veining cannot be distinguished from a

withered leaf together with the footstalk. In some other cases the lower

surfaces of the wings are brilliantly coloured, and yet are protective;

thus in _Thecla rubi_ the wings when closed are of an emerald green and

resemble the young leaves of the bramble, on which this butterfly in the

spring may often be seen seated.

Although the obscure tints of the upper or under surface of many

butterflies no doubt serve to conceal them, yet we cannot possibly

extend this view to the brilliant and conspicuous colours of many kinds,

such as our admiral and peacock Vanessae, our white cabbage-butterflies

(Pieris), or the great swallow-tail Papilio which haunts the open

fens--for these butterflies are thus rendered visible to every living

creature. With these species both sexes are alike; but in the common

brimstone butterfly (_Gonepteryx rhamni_), the male is of an intense

yellow, whilst the female is much paler; and in the orange-tip

(_Anthocharis cardamines_) the males alone have the bright orange tips

to their wings. In these cases the males and females are equally

conspicuous, and it is not credible that their difference in colour

stands in any relation to ordinary protection. Nevertheless it is

possible that the conspicuous colours of many species may be in an

indirect manner beneficial, as will hereafter be explained, by leading

their enemies at once to recognise them as unpalatable. Even in this

case it does not certainly follow that their bright colours and

beautiful patterns were acquired for this special purpose. In some other

remarkable cases, beauty has been gained for the sake of protection,

through the imitation of other beautiful species, which inhabit the same

district and enjoy an immunity from attack by being in some way

offensive to their enemies.

The female of our orange-tip butterfly, above referred to, and of an

American species (_Anth. genutia_) probably shew us, as Mr. Walsh has

remarked to me, the primordial colours of the parent-species of the

genus; for both sexes of four or five widely-distributed species are

coloured in nearly the same manner. We may infer here, as in several

previous cases, that it is the males of _Anth. cardamines_ and _genutia_

which have departed from the usual type of colouring of their genus. In

the _Anth. sara_ from California, the orange-tips have become partially

developed in the female; for her wings are tipped with reddish-orange,

but paler than in the male, and slightly different in some other

respects. In an allied Indian form, the _Iphias glaucippe_, the

orange-tips are fully developed in both sexes. In this Iphias the under

surface of the wings marvellously resembles, as pointed out to me by Mr.

A. Butler, a pale-coloured leaf; and in our English orange-tip, the

under surface resembles the flower-head of the wild parsley, on which it

may be seen going to rest at night.[507] The same reasoning power which

compels us to believe that the lower surfaces have here been coloured

for the sake of protection, leads us to deny that the wings have been

tipped, especially when this character is confined to the males, with

bright orange for the same purpose.

Turning now to Moths: most of these rest motionless with their wings

depressed during the whole or greater part of the day; and the upper

surfaces of their wings are often shaded and coloured in an admirable

manner, as Mr. Wallace has remarked, for escaping detection. With most

of the Bombycidae and Noctuidae,[508] when at rest, the front-wings

overlap and conceal the hind-wings; so that the latter might be brightly

coloured without much risk; and they are thus coloured in many species

of both families. During the act of flight, moths would often be able to

escape from their enemies; nevertheless, as the hind-wings are then

fully exposed to view, their bright colours must generally have been

acquired at the cost of some little risk. But the following fact shews

us how cautious we ought to be in drawing conclusions on this head. The

common yellow under-wings (Triphaena) often fly about during the day or

early evening, and are then conspicuous from the colour of their

hind-wings. It would naturally be thought that this would be a source of

danger; but Mr. J. Jenner Weir believes that it actually serves them as

a means of escape, for birds strike at these brightly coloured and

fragile surfaces, instead of at the body. For instance, Mr. Weir turned

into his aviary a vigorous specimen of _Triphaena pronuba_, which was

instantly pursued by a robin; but the bird's attention being caught by

the coloured wings, the moth was not captured until after about fifty

attempts, and small portions of the wings were repeatedly broken off. He

tried the same experiment, in the open air, with a _T. fimbria_ and

swallow; but the large size of this moth probably interfered with its

capture.[509] We are thus reminded of a statement made by Mr.

Wallace,[510] namely, that in the Brazilian forests and Malayan islands,

many common and highly-decorated butterflies are weak flyers, though

furnished with a broad expanse of wings; and they "are often captured

with pierced and broken wings, as if they had been seized by birds, from

which they had escaped: if the wings had been much smaller in proportion

to the body, it seems probable that the insect would more frequently

have been struck or pierced in a vital part, and thus the increased

expanse of the wings may have been indirectly beneficial."

_Display._--The bright colours of butterflies and of some moths are

specially arranged for display, whether or not they serve in addition as

a protection. Bright colours would not be visible during the night; and

there can be no doubt that moths, taken as a body, are much less gaily

decorated than butterflies, all of which are diurnal in their habits.

But the moths in certain families, such as the Zygaenidae, various

Sphingidae, Uraniidae, some Arctiidae and Saturniidae, fly about during the

day or early evening, and many of these are extremely beautiful, being

far more brightly coloured than the strictly nocturnal kinds. A few

exceptional cases, however, of brightly-coloured nocturnal species have

been recorded.[511]

There is evidence of another kind in regard to display. Butterflies, as

before remarked, elevate their wings when at rest, and whilst basking in

the sunshine often alternately raise and depress them, thus exposing to

full view both surfaces; and although the lower surface is often

coloured in an obscure manner as a protection, yet in many species it is

as highly coloured as the upper surface, and sometimes in a very

different manner. In some tropical species the lower surface is even

more brilliantly coloured than the upper.[512] In one English

fritillary, the _Argynnis aglaia_, the lower surface alone is ornamented

with shining silver discs. Nevertheless, as a general rule, the upper

surface, which is probably the most fully exposed, is coloured more

brightly and in a more diversified manner than the lower. Hence the

lower surface generally affords to entomologists the most useful

character for detecting the affinities of the various species.

Now if we turn to the enormous group of moths, which do not habitually

expose to full view the under surface of their wings, this side is very

rarely, as I hear from Mr. Stainton, coloured more brightly than the

upper side, or even with equal brightness. Some exceptions to the rule,

either real or apparent, must be noticed, as that of Hypopyra, specified

by Mr. Wormald.[513] Mr. R. Trimen informs me that in Guenee's great

work, three moths are figured, in which the under surface is much the

most brilliant. For instance, in the Australian Gastrophora the upper

surface of the fore-wing is pale greyish-ochreous, while the lower

surface is magnificently ornamented by an ocellus of cobalt-blue, placed

in the midst of a black mark, surrounded by orange-yellow, and this by

bluish-white. But the habits of these three moths are unknown; so that

no explanation can be given of their unusual style of colouring. Mr.

Trimen also informs me that the lower surface of the wings in certain

other Geometrae[514] and quadrifid Noctuae are either more variegated or

more brightly-coloured than the upper surface; but some of these species

have the habit of "holding their wings quite erect over their backs,

retaining them in this position for a considerable time," and thus

exposing to view the under surface. Other species when settled on the

ground or herbage have the habit of now and then suddenly and slightly

lifting up their wings. Hence the lower surface of the wings being more

brightly-coloured than the upper surface in certain moths is not so

anomalous a circumstance as it at first appears. The Saturniidae include

some of the most beautiful of all moths, their wings being decorated, as

in our British Emperor moth, with fine ocelli; and Mr. T. W. Wood[515]

observes that they resemble butterflies in some of their movements; "for

instance, in the gentle waving up and down of the wings, as if for

display, which is more characteristic of diurnal than of nocturnal

Lepidoptera."

It is a singular fact that no British moths, nor as far as I can

discover hardly any foreign species, which are brilliantly coloured,

differ much in colour according to sex; though this is the case with

many brilliant butterflies. The male, however, of one American moth, the

_Saturnia Io_, is described as having its fore-wings deep yellow,

curiously marked with purplish-red spots; whilst the wings of the female

are purple-brown, marked with grey lines.[516] The British moths which

differ sexually in colour are all brown, or various tints of dull

yellow, or nearly white. In several species the males are much darker

than the females,[517] and these belong to groups which generally fly

about during the afternoon. On the other hand, in many genera, as Mr.

Stainton informs me, the males have the hind-wings whiter than those of

the female--of which, fact _Agrotis exclamationis_ offers a good

instance. The males are thus rendered more conspicuous than the females,

whilst flying about in the dusk. In the Ghost Moth (_Hepialus humuli_)

the difference is more strongly marked; the males being white and the

females yellow with darker markings. It is difficult to conjecture what

the meaning can be of these differences between the sexes in the shades

of darkness or lightness; but we can hardly suppose that they are the

result of mere variability with sexually-limited inheritance,

independently of any benefit thus derived.

From the foregoing statements it is impossible to admit that the

brilliant colours of butterflies and of some few moths, have commonly

been acquired for the sake of protection. We have seen that their

colours and elegant patterns are arranged and exhibited as if for

display. Hence I am led to suppose that the females generally prefer, or

are most excited by the more brilliant males; for on any other

supposition the males would be ornamented, as far as we can see, for no

purpose. We know that ants and certain lamellicorn beetles are capable

of feeling an attachment for each other, and that ants recognise their

fellows after an interval of several months. Hence there is no abstract

improbability in the Lepidoptera, which probably stand nearly or quite

as high in the scale as these insects, having sufficient mental capacity

to admire bright colours. They certainly discover flowers by colour,

and, as I have elsewhere shewn, the plants which are fertilised

exclusively by the wind never have a conspicuously-coloured corolla. The

Humming-bird Sphinx may often be seen to swoop down from a distance on a

bunch of flowers in the midst of green foliage; and I have been assured

by a friend, that these moths repeatedly visited flowers painted on the

walls of a room in the South of France. The common white butterfly, as I

hear from Mr. Doubleday, often flies down to a bit of paper on the

ground, no doubt mistaking it for one of its own species. Mr.

Collingwood[518] in speaking of the difficulty of collecting certain

butterflies in the Malay Archipelago, states that "a dead specimen

pinned upon a conspicuous twig will often arrest an insect of the same

species in its headlong flight, and bring it down within easy reach of

the net, especially if it be of the opposite sex."

The courtship of butterflies is a prolonged affair. The males sometimes

fight together in rivalry; and many may be seen pursuing or crowding

round the same female. If, then, the females do not prefer one male to

another, the pairing must be left to mere chance, and this does not

appear to me a probable event. If, on the other hand, the females

habitually, or even occasionally, prefer the more beautiful males, the

colours of the latter will have been rendered brighter by degrees, and

will have been transmitted to both sexes or to one sex, according to

which law of inheritance prevailed. The process of sexual selection will

have been much facilitated, if the conclusions arrived at from various

kinds of evidence in the supplement to the ninth chapter can be trusted;

namely that the males of many Lepidoptera, at least in the imago state,

greatly exceed in number the females.

Some facts, however, are opposed to the belief that female butterflies

prefer the more beautiful males; thus, as I have been assured by several

observers, fresh females may frequently be seen paired with battered,

faded or dingy males; but this is a circumstance which could hardly

fail often to follow from the males emerging from their cocoons earlier

than the females. With moths of the family of the Bombycidae, the sexes

pair immediately after assuming the imago state; for they cannot feed,

owing to the rudimentary condition of their mouths. The females, as

several entomologists have remarked to me, lie in an almost torpid

state, and appear not to evince the least choice in regard to their

partners, This is the case with the common silk-moth (_B. mori_), as I

have been told by some continental and English breeders. Dr. Wallace,

who has had such immense experience in breeding _Bombyx cynthia_, is

convinced that the females evince no choice or preference. He has kept

above 300 of these moths living together, and has often found the most

vigorous females mated with stunted males. The reverse apparently seldom

occurs; for, as he believes, the more vigorous males pass over the

weakly females, being attracted by those endowed with most vitality.

Although we have been indirectly induced to believe that the females of

many species prefer the more beautiful males, I have no reason to

suspect, either with moths or butterflies, that the males are attracted

by the beauty of the females. If the more beautiful females had been

continually preferred, it is almost certain, from the colours of

butterflies being so frequently transmitted to one sex alone, that the

females would often have been rendered more beautiful than their male

partners. But this does not occur except in a few instances; and these

can be explained, as we shall presently see, on the principle of

mimickry and protection.

As sexual selection primarily depends on variability, a few words must

be added on this subject. In respect to colour there is no difficulty,

as any number of highly variable Lepidoptera could be named. One good

instance will suffice. Mr. Bates shewed me a whole series of specimens

of _Papilio sesostris_ and _childrenae_; in the latter the males varied

much in the extent of the beautifully enamelled green patch on the

fore-wings, and in the size of the white mark, as well as of the

splendid crimson stripe on the hind-wings; so that there was a great

contrast between the most and least gaudy males. The male of _Papilio

sesostris_, though a beautiful insect, is much less so than _P.

childrenae_. It likewise varies a little in the size of the green patch

on the fore-wings, and in the occasional appearance of a small crimson

stripe on the hind-wings, borrowed, as it would seem, from its own

female; for the females of this and of many other species in the AEneas

group possess this crimson stripe. Hence between the brightest specimens

of _P. sesostris_ and the least bright of _P. childrenae_, there was but

a small interval; and it was evident that as far as mere variability is

concerned, there would be no difficulty in permanently increasing by

means of selection the beauty of either species. The variability is here

almost confined to the male sex; but Mr. Wallace and Mr. Bates have

shewn[519] that the females of some other species are extremely

variable, the males being nearly constant. As I have before mentioned

the Ghost Moth (_Hepialus humuli_) as one of the best instances in

Britain of a difference in colour between the sexes of moths, it may be

worth adding[520] that in the Shetland Islands, males are frequently

found which closely resemble the females. In a future chapter I shall

have occasion to shew that the beautiful eye-like spots or ocelli, so

common on the wings of many Lepidoptera, are eminently variable.

On the whole, although many serious objections may be urged, it seems

probable that most of the species of Lepidoptera which are brilliantly

coloured, owe their colours to sexual selection, excepting in certain

cases, presently to be mentioned, in which conspicuous colours are

beneficial as a protection. From the ardour of the male throughout the

animal kingdom, he is generally willing to accept any female; and it is

the female which usually exerts a choice. Hence if sexual selection has

here acted, the male, when the sexes differ, ought to be the most

brilliantly coloured; and this undoubtedly is the ordinary rule. When

the sexes are brilliantly coloured and resemble each other, the

characters acquired by the males appear to have been transmitted to both

sexes. But will this explanation of the similarity and dissimilarity in

colour between the sexes suffice?

The males and females of the same species of butterfly are known[521] in

several cases to inhabit different stations, the former commonly basking

in the sunshine, the latter haunting gloomy forests. It is therefore

possible that different conditions of life may have acted directly on

the two sexes; but this is not probable,[522] as in the adult state they

are exposed during a very short period to different conditions; and the

larvae of both are exposed to the same conditions. Mr. Wallace believes

that the less brilliant colours of the female have been specially

gained in all or almost all cases for the sake of protection. On the

contrary it seems to me more probable that the males alone, in the large

majority of cases, have acquired their bright colours through sexual

selection, the females having been but little modified. Consequently the

females of distinct but allied species ought to resemble each other much

more closely than do the males of the same species; and this is the

general rule. The females thus approximately show us the primordial

colouring of the parent-species of the group to which they belong. They

have, however, almost always been modified to a certain extent by some

of the successive steps of variation, through the accumulation of which

the males were rendered beautiful, having been transferred to them. The

males and females of allied though distinct species will also generally

have been exposed during their prolonged larval state to different

conditions, and may have been thus indirectly affected; though with the

males any slight change of colour thus caused will often have been

completely masked by the brilliant tints gained through sexual

selection. When we treat of Birds, I shall have to discuss the whole

question whether the differences in colour between the males and females

have been in part specially gained by the latter as a protection; so

that I will here only give unavoidable details.

In all cases when the more common form of equal inheritance by both

sexes has prevailed, the selection of bright-coloured males would tend

to make the females bright-coloured; and the selection of dull-coloured

females would tend to make the males dull. If both processes were

carried on simultaneously, they would tend to neutralise each other. As

far as I can see, it would be extremely difficult to change through

selection the one form of inheritance into the other. But by the

selection of successive variations, which were from the first sexually

limited in their transmission, there would not be the slightest

difficulty in giving bright colours to the males alone, and at the same

time or subsequently, dull colours to the females alone. In this latter

manner female butterflies and moths may, as I fully admit, have been

rendered inconspicuous for the sake of protection, and widely different

from their males.

Mr. Wallace[523] has argued with much force in favour of his view that

when the sexes differ, the female has been specially modified for the

sake of protection; and that this has been effected by one form of

inheritance, namely, the transmission of characters to both sexes,

having been changed through the agency of natural selection into the

other form, namely, transmission to one sex. I was at first strongly

inclined to accept this view; but the more I have studied the various

classes throughout the animal kingdom, the less probable it has

appeared. Mr. Wallace urges that both sexes of the _Heliconidae_,

_Danaidae_, _Acroeidae_ are equally brilliant because both are protected

from the attacks of birds and other enemies, by their offensive odour;

but that in other groups, which do not possess this immunity, the

females have been rendered inconspicuous, from having more need of

protection than the males. This supposed difference in the "need of

protection by the two sexes" is rather deceptive, and requires some

discussion. It is obvious that brightly-coloured individuals, whether

males or females, would equally attract, and obscurely-coloured

individuals equally escape, the attention of their enemies. But we are

concerned with the effects of the destruction or preservation of certain

individuals of either sex, on the character of the race. With insects,

after the male has fertilised the female, and after the latter has laid

her eggs, the greater or less immunity from danger of either sex could

not possibly have any effect on the offspring. Before the sexes have

performed their proper functions, if they existed in equal numbers and

if they strictly paired (all other circumstances being the same), the

preservation of the males and females would be equally important for the

existence of the species and for the character of the offspring. But

with most animals, as is known to be the case with the domestic

silk-moth, the male can fertilise two or three females; so that the

destruction of the males would not be so injurious to the species as

that of the females. On the other hand, Dr. Wallace believes that with

moths the progeny from a second or third fertilisation is apt to be

weakly, and therefore would not have so good chance of surviving. When

the males exist in much greater numbers than the females, no doubt many

males might be destroyed with impunity to the species; but I cannot see

that the results of ordinary selection for the sake of protection would

be influenced by the sexes existing in unequal numbers; for the same

proportion of the more conspicuous individuals, whether males or

females, would probably be destroyed. If indeed the males presented a

greater range of variation in colour, the result would be different; but

we need not here follow out such complex details. On the whole I cannot

perceive that an inequality in the numbers of the two sexes would

influence in any marked manner the effects of ordinary selection on the

character of the offspring.

Female Lepidoptera require, as Mr. Wallace insists, some days to

deposit their fertilised ova and to search for a proper place; during

this period (whilst the life of the male was of no importance) the

brighter-coloured females would be exposed to danger and would be liable

to be destroyed. The duller-coloured females on the other hand would

survive, and thus would influence, it might be thought, in a marked

manner the character of the species,--either of both sexes or of one

sex, according to which form of inheritance prevailed. But it must not

be forgotten that the males emerge from the cocoon-state some days

before the females, and during this period, whilst the unborn females

were safe, the brighter-coloured males would be exposed to danger; so

that ultimately both sexes would probably be exposed during a nearly

equal length of time to danger, and the elimination of conspicuous

colours would not be much more effective in the one than the other sex.

It is a more important consideration that female Lepidoptera, as Mr.

Wallace remarks, and as is known to every collector, are generally

slower flyers than the males. Consequently the latter, if exposed to

greater danger from being conspicuously coloured, might be able to

escape from their enemies, whilst the similarly-coloured females would

be destroyed; and thus the females would have the most influence in

modifying the colour of their progeny.

There is one other consideration: bright colours, as far as sexual

selection is concerned, are commonly of no service to the females; so

that if the latter varied in brightness, and the variations were

sexually limited in their transmission, it would depend on mere chance

whether the females had their bright colours increased; and this would

tend throughout the Order to diminish the number of species with

brightly-coloured females in comparison with the species having

brightly-coloured males. On the other hand, as bright colours are

supposed to be highly serviceable to the males in their love-struggles,

the brighter males (as we shall see in the chapter on Birds) although

exposed to rather greater danger, would on an average procreate a

greater number of offspring than the duller males. In this case, if the

variations were limited in their transmission to the male sex, the males

alone would be rendered more brilliantly coloured; but if the variations

were not thus limited, the preservation and augmentation of such

variations would depend on whether more evil was caused to the species

by the females being rendered conspicuous, than good to the males by

certain individuals being successful over their rivals.

As there can hardly be a doubt that both sexes of many butterflies and

moths have been rendered dull-coloured for the sake of protection, so

it may have been with the females alone of some species in which

successive variations towards dullness first appeared in the female sex

and were from the first limited in their transmission to the same sex.

If not thus limited, both sexes would become dull-coloured. We shall

immediately see, when we treat of mimickry, that the females alone of

certain butterflies have been rendered extremely beautiful for the sake

of protection, without any of the successive protective variations

having been transferred to the male, to whom they could not possibly

have been in the least degree injurious, and therefore could not have

been eliminated through natural selection. Whether in each particular

species, in which the sexes differ in colour, it is the female which has

been specially modified for the sake of protection; or whether it is the

male which has been specially modified for the sake of sexual

attraction, the female having retained her primordial colouring only

slightly changed through the agencies before alluded to; or whether

again both sexes have been modified, the female for protection and the

male for sexual attraction, can only be definitely decided when we know

the life-history of each species.

Without distinct evidence, I am unwilling to admit that a double process

of selection has long been going on with a multitude of species,--the

males having been rendered more brilliant by beating their rivals; and

the females more dull-coloured by having escaped from their enemies. We

may take as an instance the common brimstone butterfly (Gonepteryx),

which appears early in the spring before any other kind. The male of

this species is of a far more intense yellow than the female, though she

is almost equally conspicuous; and in this case it does not seem

probable that she specially acquired her pale tints as a protection,

though it is probable that the male acquired his bright colours as a

sexual attraction. The female of _Anthocharis cardamines_ does not

possess the beautiful orange tips to her wings with which the male is

ornamented; consequently she closely resembles the white butterflies

(Pieris) so common in our gardens; but we have no evidence that this

resemblance is beneficial. On the contrary, as she resembles both sexes

of several species of the same genus inhabiting various quarters of the

world, it is more probable that she has simply retained to a large

extent her primordial colours.

Various facts support the conclusion that with the greater number of

brilliantly-coloured Lepidoptera, it is the male which has been

modified; the two sexes having come to differ from each other, or to

resemble each other, according to which form of inheritance has

prevailed. Inheritance is governed by so many unknown laws or

conditions, that they seem to us to be most capricious in their

action;[524] and we can so far understand how it is that with

closely-allied species the sexes of some differ to an astonishing

degree, whilst the sexes of others are identical in colour. As the

successive steps in the process of variation are necessarily all

transmitted through the female, a greater or less number of such steps

might readily become developed in her; and thus we can understand the

frequent gradations from an extreme difference to no difference at all

between the sexes of the species within the same group. These cases of

gradation are much too common to favour the supposition that we here see

females actually undergoing the process of transition and losing their

brightness for the sake of protection; for we have every reason to

conclude that at any one time the greater number of species are in a

fixed condition. With respect to the differences between the females of

the species in the same genus or family, we can perceive that they

depend, at least in part, on the females partaking of the colours of

their respective males. This is well illustrated in those groups in

which the males are ornamented to an extraordinary degree; for the

females in these groups generally partake to a certain extent of the

splendour of their male partners. Lastly, we continually find, as

already remarked, that the females of almost all the species in the same

genus, or even family, resemble each other much more closely in colour

than do the males; and this indicates that the males have undergone a

greater amount of modification than the females.

_Mimickry._--This principle was first made clear in an admirable paper

by Mr. Bates,[525] who thus threw a flood of light on many obscure

problems. It had previously been observed that certain butterflies in S.

America belonging to quite distinct families, resembled the Heliconidae

so closely in every stripe and shade of colour that they could not be

distinguished except by an experienced entomologist. As the Heliconidae

are coloured in their usual manner, whilst the others depart from the

usual colouring of the groups to which they belong, it is clear that the

latter are the imitators, and the Heliconidae the imitated. Mr. Bates

further observed that the imitating species are comparatively rare,

whilst the imitated swarm in large numbers; the two sets living mingled

together. From the fact of the Heliconidae being conspicuous and

beautiful insects, yet so numerous in individuals and species, he

concluded that they must be protected from the attacks of birds by some

secretion or odour; and this hypothesis has now been confirmed by a

considerable body of curious evidence.[526] From these considerations

Mr. Bates inferred that the butterflies which imitate the protected

species had acquired their present marvellously deceptive appearance,

through variation and natural selection, in order to be mistaken for the

protected kinds and thus to escape being devoured. No explanation is

here attempted of the brilliant colours of the imitated, but only of the

imitating butterflies. We must account for the colours of the former in

the same general manner, as in the cases previously discussed in this

chapter. Since the publication of Mr. Bates' paper, similar and equally

striking facts have been observed by Mr. Wallace[527] in the Malayan

region, and by Mr. Trimen in South Africa.

As some writers[528] have felt much difficulty in understanding how the

first steps in the process of mimickry could have been effected through

natural selection, it may be well to remark that the process probably

has never commenced with forms widely dissimilar in colour. But with two

species moderately like each other, the closest resemblance if

beneficial to either form could readily be thus gained; and if the

imitated form was subsequently and gradually modified through sexual

selection or any other means, the imitating form would be led along the

same track, and thus be modified to almost any extent, so that it might

ultimately assume an appearance or colouring wholly unlike that of the

other members of the group to which it belonged. As extremely slight

variations in colour would not in many cases suffice to render a species

so like another protected species as to lead to its preservation, it

should be remembered that many species of Lepidoptera are liable to

considerable and abrupt variations in colour. A few instances have been

given in this chapter; but under this point of view Mr. Bates' original

paper on mimickry, as well as Mr. Wallace's papers, should be consulted.

In the foregoing cases both sexes of the imitating species

resemble the imitated; but occasionally the female alone mocks a

brilliantly-coloured and protected species inhabiting the same district.

Consequently the female differs in colour from her own male, and, which

is a rare and anomalous circumstance, is the more brightly-coloured of

the two. In all the few species of Pieridae, in which the female is more

conspicuously coloured than the male, she imitates, as I am informed by

Mr. Wallace, some protected species inhabiting the same region. The

female of _Diadema anomala_ is rich purple-brown with almost the whole

surface glossed with satiny blue, and she closely imitates the

_Euploea midamus_, "one of the commonest butterflies of the East;"

whilst the male is bronzy or olive-brown, with only a slight blue gloss

on the outer parts of the wings.[529] Both sexes of this Diadema and of

_D. bolina_ follow the same habits of life, so that the differences in

colour between the sexes cannot be accounted for by exposure to

different conditions;[530] even if this explanation were admissible in

other instances.[531]

The above cases of female butterflies which are more brightly-coloured

than the males, shew us, firstly, that variations have arisen in a state

of nature in the female sex, and have been transmitted exclusively, or

almost exclusively, to the same sex; and, secondly, that this form of

inheritance has not been determined through natural selection. For if we

assume that the females, before they became brightly coloured in

imitation of some protected kind, were exposed during each season for a

longer period to danger than the males; or if we assume that they could

not escape so swiftly from their enemies, we can understand how they

alone might originally have acquired through natural selection and

sexually-limited inheritance their present protective colours. But

except on the principle of these variations having been transmitted

exclusively to the female offspring, we cannot understand why the males

should have remained dull-coloured; for it would surely not have been in

any way injurious to each individual male to have partaken by

inheritance of the protective colours of the female, and thus to have

had a better chance of escaping destruction. In a group in which

brilliant colours are so common as with butterflies, it cannot be

supposed that the males have been kept dull-coloured through sexual

selection by the females rejecting the individuals which were rendered

as beautiful as themselves. We may, therefore, conclude that in these

cases inheritance by one sex is not due to the modification through

natural selection of a tendency to equal inheritance by both sexes.

It may be well here to give an analogous case in another Order, of

characters acquired only by the female, though not in the least

injurious, as far as we can judge, to the male. Amongst the Phasmidae, or

spectre-insects, Mr. Wallace states that "it is often the females alone

that so strikingly resemble leaves, while the males show only a rude

approximation." Now, whatever may be the habits of these insects, it is

highly improbable that it could be disadvantageous to the males to

escape detection by resembling leaves.[532] Hence we may conclude that

the females alone in this latter as in the previous cases originally

varied in certain characters; these characters having been preserved and

augmented through ordinary selection for the sake of protection and from

the first transmitted to the female offspring alone.

_Bright Colours of Caterpillars._--Whilst reflecting on the beauty of

many butterflies, it occurred to me that some caterpillars were

splendidly coloured, and as sexual selection could not possibly have

here acted, it appeared rash to attribute the beauty of the mature

insect to this agency, unless the bright colours of their larvae could

be in some manner explained. In the first place it may be observed that

the colours of caterpillars do not stand in any close correlation with

those of the mature insect. Secondly, their bright colours do not serve

in any ordinary manner as a protection. As an instance of this, Mr.

Bates informs me that the most conspicuous caterpillar which he ever

beheld (that of a Sphinx) lived on the large green leaves of a tree on

the open llanos of South America; it was about four inches in length,

transversely banded with black and yellow, and with its head, legs, and

tail of a bright red. Hence it caught the eye of any man who passed by

at the distance of many yards, and no doubt of every passing bird.

I then applied to Mr. Wallace, who has an innate genius for solving

difficulties. After some consideration he replied: "Most caterpillars

require protection, as may be inferred from some kinds being furnished

with spines or irritating hairs, and from many being coloured green like

the leaves on which they feed, or curiously like the twigs of the trees

on which they live." I may add as another instance of protection, that

there is a caterpillar of a moth, as I am informed by Mr. J. Mansel

Weale, which lives on the mimosas in South Africa, and fabricates for

itself a case, quite undistinguishable from the surrounding thorns. From

such considerations Mr. Wallace thought it probable that

conspicuously-coloured caterpillars were protected by having a nauseous

taste; but as their skin is extremely tender, and as their intestines

readily protrude from a wound, a slight peck from the beak of a bird

would be as fatal to them as if they had been devoured. Hence, as Mr.

Wallace remarks, "distastefulness alone would be insufficient to protect

a caterpillar unless some outward sign indicated to its would-be

destroyer that its prey was a disgusting morsel." Under these

circumstances it would be highly advantageous to a caterpillar to be

instantaneously and certainly recognised as unpalatable by all birds and

other animals. Thus the most gaudy colours would be serviceable, and

might have been gained by variation and the survival of the most

easily-recognised individuals.

This hypothesis appears at first sight very bold; but when it was

brought before the Entomological Society[533] it was supported by

various statements; and Mr. J. Jenner Weir, who keeps a large number of

birds in an aviary, has made, as he informs me, numerous trials, and

finds no exception to the rule, that all caterpillars of nocturnal and

retiring habits with smooth skins, all of a green colour, and all which

imitate twigs, are greedily devoured by his birds. The hairy and spinose

kinds are invariably rejected, as were four conspicuously-coloured

species. When the birds rejected a caterpillar, they plainly shewed, by

shaking their heads and cleansing their beaks, that they were disgusted

by the taste.[534] Three conspicuous kinds of caterpillars and moths

were also given by Mr. A. Butler to some lizards and frogs, and were

rejected; though other kinds were eagerly eaten. Thus the probable truth

of Mr. Wallace's view is confirmed, namely, that certain caterpillars

have been made conspicuous for their own good, so as to be easily

recognised by their enemies, on nearly the same principle that certain

poisons are coloured by druggists for the good of man. This view will,

it is probable, be hereafter extended to many animals, which are

coloured in a conspicuous manner.

_Summary and Concluding Remarks on Insects._--Looking back to the

several Orders, we have seen that the sexes often differ in various

characters, the meaning of which is not understood. The sexes, also,

often differ in their organs of sense or locomotion, so that the males

may quickly discover or reach the females, and still oftener in the

males possessing diversified contrivances for retaining the females when

found. But we are not here much concerned with sexual differences of

these kinds.

In almost all the Orders, the males of some species, even of weak and

delicate kinds, are known to be highly pugnacious; and some few are

furnished with special weapons for fighting with their rivals. But the

law of battle does not prevail nearly so widely with insects as with the

higher animals. Hence probably it is that the males have not often been

rendered larger and stronger than the females. On the contrary they are

usually smaller, in order that they may be developed within a shorter

time, so as to be ready in large numbers for the emergence of the

females.

In two families of the Homoptera the males alone possess, in an

efficient state, organs which may be called vocal; and in three families

of the Orthoptera the males alone possess stridulating organs. In both

cases these organs are incessantly used during the breeding-season, not

only for calling the females, but for charming or exciting them in

rivalry with other males. No one who admits the agency of natural

selection, will dispute that these musical instruments have been

acquired through sexual selection. In four other Orders the members of

one sex, or more commonly of both sexes, are provided with organs for

producing various sounds, which apparently serve merely as call-notes.

Even when both sexes are thus provided, the individuals which were able

to make the loudest or most continuous noise would gain partners before

those which were less noisy, so that their organs have probably been

gained through sexual selection. It is instructive to reflect on the

wonderful diversity of the means for producing sound, possessed by the

males alone or by both sexes in no less than six Orders, and which were

possessed by at least one insect at an extremely remote geological

epoch. We thus learn how effectual sexual selection has been in leading

to modifications of structure, which sometimes, as with the Homoptera,

are of an important nature.

From the reasons assigned in the last chapter, it is probable that the

great horns of the males of many lamellicorn, and some other beetles,

have been acquired as ornaments. So perhaps it may be with certain other

peculiarities confined to the male sex. From the small size of insects,

we are apt to undervalue their appearance. If we could imagine a male

Chalcosoma (fig. 15) with its polished, bronzed coat of mail, and vast

complex horns, magnified to the size of a horse or even of a dog, it

would be one of the most imposing animals in the world.

The colouring of insects is a complex and obscure subject. When the male

differs slightly from the female, and neither are brilliantly coloured,

it is probable that the two sexes have varied in a slightly different

manner, with the variations transmitted to the same sex, without any

benefit having been thus derived or evil suffered. When the male is

brilliantly coloured and differs conspicuously from the female, as with

some dragon-flies and many butterflies, it is probable that he alone has

been modified, and that he owes his colours to sexual selection; whilst

the female has retained a primordial or very ancient type of colouring,

slightly modified by the agencies before explained, and has therefore

not been rendered obscure, at least in most cases, for the sake of

protection. But the female alone has sometimes been coloured

brilliantly so as to imitate other protected species inhabiting the same

district. When the sexes resemble each other and both are obscurely

coloured, there is no doubt that they have been in a multitude of cases

coloured for the sake of protection. So it is in some instances when

both are brightly coloured, causing them to resemble surrounding objects

such as flowers, or other protected species, or indirectly by giving

notice to their enemies that they are of an unpalatable nature. In many

other cases in which the sexes resemble each other and are brilliantly

coloured, especially when the colours are arranged for display, we may

conclude that they have been gained by the male sex as an attraction,

and have been transferred to both sexes. We are more especially led to

this conclusion whenever the same type of coloration prevails throughout

a group, and we find that the males of some species differ widely in

colour from the females, whilst both sexes of other species are quite

alike, with intermediate gradations connecting these extreme states.

In the same manner as bright colours have often been partially

transferred from the males to the females, so it has been with the

extraordinary horns of many lamellicorn and some other beetles. So,

again, the vocal or instrumental organs proper to the males of the

Homoptera and Orthoptera have generally been transferred in a

rudimentary, or even in a nearly perfect condition to the females; yet

not sufficiently perfect to be used for producing sound. It is also an

interesting fact, as bearing on sexual selection, that the stridulating

organs of certain male Orthoptera are not fully developed until the last

moult; and that the colours of certain male dragon-flies are not fully

developed until some little time after their emergence from the pupal

state, and when they are ready to breed.

Sexual selection implies that the more attractive individuals are

preferred by the opposite sex; and as with insects, when the sexes

differ, it is the male which, with rare exceptions, is the most

ornamented and departs most from the type to which the species

belongs;--and as it is the male which searches eagerly for the female,

we must suppose that the females habitually or occasionally prefer the

more beautiful males, and that these have thus acquired their beauty.

That in most or all the orders the females have the power of rejecting

any particular male, we may safely infer from the many singular

contrivances possessed by the males, such as great jaws, adhesive

cushions, spines, elongated legs, &c., for seizing the female; for these

contrivances shew that there is some difficulty in the act. In the case

of unions between distinct species, of which many instances have been

recorded, the female must have been a consenting party. Judging from

what we know of the perceptive powers and affections of various insects,

there is no antecedent improbability in sexual selection having come

largely into action; but we have as yet no direct evidence on this head,

and some facts are opposed to the belief. Nevertheless, when we see many

males pursuing the same female, we can hardly believe that the pairing

is left to blind chance--that the female exerts no choice, and is not

influenced by the gorgeous colours or other ornaments, with which the

male alone is decorated.

If we admit that the females of the Homoptera and Orthoptera appreciate

the musical tones emitted by their male partners, and that the various

instruments for this purpose have been perfected through sexual

selection, there is little improbability in the females of other insects

appreciating beauty in form or colour, and consequently in such

characters having been thus gained by the males. But from the

circumstance of colour being so variable, and from its having been so

often modified for the sake of protection, it is extremely difficult to

decide in how large a proportion of cases sexual selection has come into

play. This is more especially difficult in those Orders, such as the

Orthoptera, Hymenoptera, and Coleoptera, in which the two sexes rarely

differ much in colour; for we are thus cut off from our best evidence of

some relation between the reproduction of the species and colour. With

the Coleoptera, however, as before remarked, it is in the great

lamellicorn group, placed by some authors at the head of the Order, and

in which we sometimes see a mutual attachment between the sexes, that we

find the males of some species possessing weapons for sexual strife,

others furnished with wonderful horns, many with stridulating organs,

and others ornamented with splendid metallic tints. Hence it seems

probable that all these characters have been gained through the same

means, namely sexual selection.

When we treat of Birds, we shall see that they present in their

secondary sexual characters the closest analogy with insects. Thus, many

male birds are highly pugnacious, and some are furnished with special

weapons for fighting with their rivals. They possess organs which are

used during the breeding-season for producing vocal and instrumental

music. They are frequently ornamented with combs, horns, wattles and

plumes of the most diversified kinds, and are decorated with beautiful

colours, all evidently for the sake of display. We shall find that, as

with insects, both sexes, in certain groups, are equally beautiful, and

are equally provided with ornaments which are usually confined to the

male sex. In other groups both sexes are equally plain-coloured and

unornamented. Lastly, in some few anomalous cases, the females are more

beautiful than the males. We shall often find, in the same group of

birds, every gradation from no difference between the sexes, to an

extreme difference. In the latter case we shall see that the females,

like female insects, often possess more or less plain traces of the

characters which properly belong to the males. The analogy, indeed, in

all these respects between birds and insects, is curiously close.

Whatever explanation applies to the one class probably applies to the

other; and this explanation, as we shall hereafter attempt to shew, is

almost certainly sexual selection.

FOOTNOTES:

[1] As the works of the first-named authors are so well known,

I need not give the titles; but as those of the latter are less

well known in England, I will give them:--'Sechs Vorlesungen

ueber die Darwin'sche Theorie:' zweite Auflage, 1868, von Dr. L.

Buechner; translated into French under the title 'Conferences

sur la Theorie Darwinienne,' 1869. 'Der Mensch, im Lichte der

Darwin'sche Lehre,' 1865, von Dr. F. Rolle. I will not attempt

to give references to all the authors who have taken the same

side of the question. Thus G. Canestrini has published

('Annuario della Soc. d. Nat.,' Modena, 1867, p. 81) a very

curious paper on rudimentary characters, as bearing on the

origin of man. Another work has (1869) been published by Dr.

Barrago Francesco, bearing in Italian the title of "Man, made

in the image of God, was also made in the image of the ape."

[2] Prof. Haeckel is the sole author who, since the publication

of the 'Origin,' has discussed, in his various works, in a very

able manner, the subject of sexual selection, and has seen its

full importance.

[3] 'Grosshirnwindungen des Menschen,' 1868, s. 96.

[4] 'Lec. sur la Phys.' 1866, p. 890, as quoted by M. Dally,

'L'Ordre des Primates et le Transformisme,' 1868, p. 29.

[5] 'Naturgeschichte der Saeugethiere von Paraguay,' 1830, s.

50.

[6] Brehm, 'Thierleben,' B. i. 1864, s. 75, 86. On the Ateles,

s. 105. For other analogous statements, see s. 25, 107.

[7] With respect to insects see Dr. Laycock 'On a General Law

of Vital Periodicity,' British Association, 1842. Dr.

Macculloch, 'Silliman's North American Journal of Science,'

vol. xvii. p. 305, has seen a dog suffering from tertian ague.

[8] I have given the evidence on this head in my 'Variation of

Animals and Plants under Domestication,' vol. ii. p. 15.

[9] "Mares e diversis generibus Quadrumanorum sine dubio

dignoscunt feminas humanas a maribus. Primum, credo, odoratu,

postea aspectu. Mr. Youatt, qui diu in Hortis Zoologicis

(Bestiariis) medicus animalium erat, vir in rebus observandis

cautus et sagax, hoc mihi certissime probavit, et curatores

ejusdem loci et alii e ministris confirmaverunt. Sir Andrew

Smith et Brehm notabant idem in Cynocephalo. Illustrissimus

Cuvier etiam narrat multa de hac re qua ut opinor nihil turpius

potest indicari inter omnia hominibus et Quadrumanis communia.

Narrat enim Cynocephalum quendam in furorem incidere aspectu

feminarum aliquarum, sed nequaquam accendi tanto furore ab

omnibus. Semper eligebat juniores, et dignoscebat in turba, et

advocabat voce gestuque."

[10] This remark is made with respect to Cynocephalus and the

anthropomorphous apes by Geoffroy Saint-Hilaire and F. Cuvier,

'Hist. Nat. des Mammiferes,' tom. i. 1824.

[11] Huxley, 'Man's Place in Nature,' 1863, p. 34.

[12] 'Man's Place in Nature,' 1863, p. 67.

[13] The human embryo (upper fig.) is from Ecker, 'Icones

Phys.,' 1851-1859, tab. xxx. fig. 2. This embryo was ten lines

in length, so that the drawing is much magnified. The embryo of

the dog is from Bischoff, 'Entwicklungsgeschichte des

Hunde-Eies,' 1845, tab. xi. fig. 42 B. This drawing is five

times magnified, the embryo being 25 days old. The internal

viscera have been omitted, and the uterine appendages in both

drawings removed. I was directed to these figures by Prof.

Huxley, from whose work, 'Man's Place in Nature.' the idea of

giving them was taken. Haeckel has also given analogous drawings

in his 'Schoepfungsgeschichte.'

[14] Prof. Wyman in 'Proc. of American Acad. of Sciences,' vol.

iv. 1860, p. 17.

[15] Owen, 'Anatomy of Vertebrates,' vol. i. p. 533.

[16] 'Die Grosshirnwindungen des Menschen,' 1868, s. 95.

[17] 'Anatomy of Vertebrates,' vol. ii. p. 553.

[18] 'Proc. Soc. Nat. Hist.' Boston, 1863, vol. ix. p. 185.

[19] 'Man's Place in Nature,' p. 65.

[20] I had written a rough copy of this chapter before reading

a valuable paper, "Caratteri rudimentali in ordine all'origine

del uomo" ('Annuario della Soc. d. Nat.,' Modena, 1867, p. 81),

by G. Canestrini, to which paper I am considerably indebted.

Haeckel has given admirable discussions on this whole subject,

under the title of Dysteleology, in his 'Generelle Morphologie'

and 'Schoepfungsgeschichte.'

[21] Some good criticisms on this subject have been given by

Messrs. Murie and Mivart, in 'Transact. Zoolog. Soc.' 1869,

vol. vii. p. 92.

[22] 'Variation of Animals and Plants under Domestication,'

vol. ii. pp. 317 and 397. See also 'Origin of Species,' 5th

edit. p. 535.

[23] For instance M. Richard ('Annales des Sciences Nat.' 3rd

series, Zoolog. 1852, tom. xviii. p. 13) describes and figures

rudiments of what he calls the "muscle pedieux de la main,"

which he says is sometimes "infiniment petit." Another muscle,

called "le tibial posterieur," is generally quite absent in the

hand, but appears from time to time in a more or less

rudimentary condition.

[24] Prof. W. Turner, 'Proc. Royal Soc. Edinburgh,' 1866-67, p.

65.

[25] Canestrini quotes Hyrt. ('Annuario della Soc. dei

Naturalisti,' Modena, 1867, p. 97) to the same effect.

[26] 'The Diseases of the Ear,' by J. Toynbee, F.R.S., 1860, p.

12.

[27] See also some remarks, and the drawings of the ears of the

Lemuroidea, in Messrs. Murie and Mivart's excellent paper in

'Transact. Zoolog. Soc.' vol. vii. 1869, pp. 6 and 90.

[28] Mueller's 'Elements of Physiology,' Eng. translat., 1842,

vol. ii. p. 1117. Owen, 'Anatomy of Vertebrates,' vol. iii. p.

260; ibid. on the Walrus, 'Proc. Zoolog. Soc.' November 8th,

1854. See also R. Knox, 'Great Artists and Anatomists,' p. 106.

This rudiment apparently is somewhat larger in Negroes and

Australians than in Europeans, see Carl Vogt, 'Lectures on

Man,' Eng. translat. p. 129.

[29] 'The Physiology and Pathology of Mind,' 2nd edit. 1868, p.

134.

[30] Eschricht, Ueber die Richtung der Haare am menschlichen

Koerper 'Muellers Archiv fuer Anat. und Phys.' 1837, s. 47. I

shall often have to refer to this very curious paper.

[31] Paget, 'Lectures on Surgical Pathology,' 1853, vol. i. p.

71.

[32] Eschricht, ibid. s. 40, 47.

[33] Dr. Webb, 'Teeth in Man and the Anthropoid Apes,' as

quoted by Dr. C. Carter Blake in 'Anthropological Review,'

July, 1867, p. 299.

[34] Owen, 'Anatomy of Vertebrates,' vol. iii. pp. 320, 321,

and 325.

[35] 'On the Primitive Form of the Skull,' Eng. translat. in

'Anthropological Review,' Oct. 1868, p. 426.

[36] Owen, 'Anatomy of Vertebrates,' vol. iii. pp. 416, 434,

441.

[37] 'Annuario della Soc. d. Nat.' Modena, 1867, p. 94.

[38] M. C. Martins ("De l'Unite Organique," in 'Revue des Deux

Mondes,' June 15, 1862, p. 16), and Haeckel ('Generelle

Morphologie,' B. ii. s. 278), have both remarked on the

singular fact of this rudiment sometimes causing death.

[39] 'The Lancet,' Jan. 24, 1863, p. 83. Dr. Knox, 'Great

Artists and Anatomists,' p. 63. See also an important memoir on

this process by Dr. Grube, in the 'Bulletin de l'Acad. Imp. de

St. Petersbourg,' tom. xii. 1867, p. 448.

[40] "On the Caves of Gibraltar," 'Transact. Internat. Congress

of Prehist. Arch.' Third Session, 1869, p. 54.

[41] Quatrefages has lately collected the evidence on this

subject. 'Revue des Cours Scientifiques,' 1867-1868, p. 625.

[42] Owen, 'On the Nature of Limbs,' 1849, p. 114.

[43] Leuckart, in Todd's 'Cyclop. of Anat.' 1849-52, vol. iv.

p. 1415. In man this organ is only from three to six lines in

length, but, like so many other rudimentary parts, it is

variable in development as well as in other characters.

[44] See, on this subject, Owen, 'Anatomy of Vertebrates,' vol.

iii. pp. 675, 676, 706.

[45] See the evidence on these points, as given by Lubbock,

'Prehistoric Times,' p. 354, &c.

[46] 'L'Instinct chez les Insectes.' 'Revue des Deux Mondes,'

Feb. 1870, p. 690.

[47] 'The American Beaver and his Works,' 1868.

[48] 'The Principles of Psychology,' 2nd edit. 1870, pp.

418-443.

[49] 'Contributions to the Theory of Natural Selection,' 1870,

p. 212

[50] 'Recherches sur les Moeurs des Fourmis,' 1810, p. 173.

[51] All the following statements, given on the authority of

these two naturalists, are taken from Rengger's 'Naturges. der

Saeugethiere von Paraguay,' 1830, s. 41-57, and from Brehm's

'Thierleben,' B. i. s. 10-87.

[52] 'Bridgewater Treatise,' p. 263.

[53] W. C. L. Martin, 'Nat. Hist. of Mammalia,' 1841, p. 405.

[54] Quoted by Vogt, 'Memoire sur les Microcephales,' 1867, p.

168.

[55] 'The Variation of Animals and Plants under Domestication,'

vol. i. p. 27.

[56] 'Les Moeurs des Fourmis,' 1810, p. 150.

[57] Quoted in Dr. Maudsley's 'Physiology and Pathology of

Mind,' 1868, pp. 19, 220.

[58] Dr. Jerdon, 'Birds of India,' vol. i. 1862, p. xxi.

[59] Mr. L. H. Morgan's work on 'The American Beaver,' 1868,

offers a good illustration of this remark. I cannot, however,

avoid thinking that he goes too far in underrating the power of

Instinct.

[60] 'The Moor and the Loch,' p. 45. Col. Hutchinson on 'Dog

Breaking,' 1850, p. 46.

[61] 'Personal Narrative,' Eng. translat., vol. iii. p. 106.

[62] Quoted by Sir C. Lyell, 'Antiquity of Man,' p. 497.

[63] 'Journal of Researches during the Voyage of the "Beagle,"'

1845, p. 398. 'Origin of Species,' 5th edit. p. 260.

[64] 'Lettres Phil. sur l'Intelligence des Animaux,' nouvelle

edit. 1802, p. 86.

[65] See the evidence on this head in chap. i. vol. i. 'On the

Variation of Animals and Plants under Domestication.'

[66] 'Proc. Zoolog. Soc.' 1864, p. 186.

[67] Savage and Wyman in 'Boston Journal of Nat. Hist.' vol.

iv. 1843-44, p. 383.

[68] 'Saeugethiere von Paraguay,' 1830, s. 51-56.

[69] 'Thierleben,' B. i. s. 79, 82.

[70] 'The Malay Archipelago,' vol. i. 1869, p. 87.

[71] 'Primeval Man,' 1869, pp. 145, 147.

[72] 'Prehistoric Times,' 1865, p. 473, &c.

[73] Quoted in 'Anthropological Review,' 1864, p. 158.

[74] Rengger, ibid. s. 45.

[75] See my 'Variation of Animals and Plants under

Domestication,' vol. i. p. 27.

[76] See a discussion on this subject in Mr. E. B. Tylor's very

interesting work, 'Researches into the Early History of

Mankind,' 1865, chaps. ii. to iv.

[77] Hon. Daines Barrington in 'Philosoph. Transactions,' 1773,

p. 262. See also Dureau de la Malle, in 'Ann. des Sc. Nat.' 3rd

series, Zoolog. tom. x. p. 119.

[78] 'On the Origin of Language,' by H. Wedgwood, 1866.

'Chapters on Language,' by the Rev. F. W. Farrar, 1865. These

works are most interesting. See also 'De la Phys. et de

Parole,' par Albert Lemoine, 1865, p. 190. The work on this

subject, by the late Prof. Aug. Schleicher, has been translated

by Dr. Bikkers into English, under the title of 'Darwinism

tested by the Science of Language,' 1869.

[79] Vogt, 'Memoire sur les Microcephales,' 1867, p. 169. With

respect to savages, I have given some facts in my 'Journal of

Researches,' &c., 1845, p. 206.

[80] See clear evidence on this head in the two works so often

quoted, by Brehm and Rengger.

[81] See remarks on this head by Dr. Maudsley, 'The Physiology

and Pathology of Mind,' 2nd edit. 1868, p. 199.

[82] Many curious cases have been recorded. See, for instance,

'Inquiries Concerning the Intellectual Powers,' by Dr.

Abercrombie, 1838, p. 150.

[83] 'The Variation of Animals and Plants under Domestication,'

vol. ii. p. 6.

[84] See some good remarks to this effect by Dr. Maudsley, 'The

Physiology and Pathology of Mind,' 1808, p. 199.

[85] Macgillivray, 'Hist. of British Birds,' vol. ii. 1839, p.

29. An excellent observer, Mr. Blackwall, remarks that the

magpie learns to pronounce single words, and even short

sentences, more readily than almost any other British bird;

yet, as he adds, after long and closely investigating its

habits, he has never known it, in a state of nature, display

any unusual capacity for imitation. 'Researches in Zoology,'

1834, p. 158.

[86] See the very interesting parallelism between the

development of species and languages, given by Sir C. Lyell in

'The Geolog. Evidences of the Antiquity of Man,' 1863, chap.

xxiii.

[87] See remarks to this effect by the Rev. F. W. Farrar, in an

interesting article, entitled "Philology and Darwinism" in

'Nature,' March 24th, 1870, p. 528.

[88] 'Nature,' Jan. 6th, 1870, p. 257.

[89] Quoted by C. S. Wake, 'Chapters on Man,' 1868, p. 101.

[90] Buckland, 'Bridgewater Treatise,' p. 411.

[91] See some good remarks on the simplification of languages,

by Sir J. Lubbock, 'Origin of Civilisation,' 1870, p. 278.

[92] 'Conferences sur la Theorie Darwinienne,' French

translat., 1869, p. 132.

[93] The Rev. Dr. J. M'Cann, 'Anti-Darwinism,' 1869, p. 13.

[94] 'The Spectator,' Dec. 4th, 1869, p. 1430.

[95] See an excellent article on this subject by the Rev. F. W.

Farrar, in the 'Anthropological Review,' Aug. 1864, p. ccxvii.

For further facts see Sir J. Lubbock, 'Prehistoric Times,' 2nd

edit. 1869. p. 564; and especially the chapters on Religion in

his 'Origin of Civilisation,' 1870.

[96] The Worship of Animals and Plants, in the 'Fortnightly

Review,' Oct. 1, 1869, p. 422.

[97] Tylor, 'Early History of Mankind,' 1865, p. 6. See also

the three striking chapters on the Development of Religion, in

Lubbock's 'Origin of Civilisation,' 1870. In a like manner Mr.

Herbert Spencer, in his ingenious essay in the 'Fortnightly

Review' (May 1st, 1870, p. 535), accounts for the earliest

forms of religious belief throughout the world, by man being

led through dreams, shadows, and other causes, to look at

himself as a double essence, corporeal and spiritual. As the

spiritual being is supposed to exist after death and to be

powerful, it is propitiated by various gifts and ceremonies,

and its aid invoked. He then further shews that names or

nicknames given from some animal or other object to the early

progenitors or founders of a tribe, are supposed after a long

interval to represent the real progenitor of the tribe; and

such animal or object is then naturally believed still to exist

as a spirit, is held sacred, and worshipped as a god.

Nevertheless I cannot but suspect that there is a still earlier

and ruder stage, when anything which manifests power or

movement is thought to be endowed with some form of life, and

with mental faculties analogous to our own.

[98] See an able article on the Psychical Elements of Religion,

by Mr. L. Owen Pike, in 'Anthropolog. Review,' April, 1870, p.

lxiii.

[99] 'Religion, Moral, &c., der Darwin'schen Art-Lehre,' 1869,

s. 53.

[100] 'Prehistoric Times,' 2nd edit. p. 571. In this work (at

p. 553) there will be found an excellent account of the many

strange and capricious customs of savages.

[101] See, for instance, on this subject, Quatrefages, 'Unite

de l'Espece Humaine,' 1861, p. 21, &c.

[102] 'Dissertation on Ethical Philosophy,' 1837, p. 231, &c.

[103] 'Metaphysics of Ethics,' translated by J. W. Semple,

Edinburgh, 1836, p. 136.

[104] Mr. Bain gives a list ('Mental and Moral Science,' 1868,

p. 543-725) of twenty-six British authors who have written on

this subject, and whose names are familiar to every reader; to

these, Mr. Bain's own name, and those of Mr. Lecky, Mr.

Shadworth Hodgson, and Sir J. Lubbock, as well as of others,

may be added.

[105] Sir B. Brodie, after observing that man is a social

animal ('Psychological Enquiries,' 1854, p. 192), asks the

pregnant question, "ought not this to settle the disputed

question as to the existence of a moral sense?" Similar ideas

have probably occurred to many persons, as they did long ago to

Marcus Aurelius. Mr. J. S. Mill speaks, in his celebrated work,

'Utilitarianism,' (1864, p. 46), of the social feelings as a

"powerful natural sentiment," and as "the natural basis of

sentiment for utilitarian morality;" but on the previous page

he says, "if, as is my own belief, the moral feelings are not

innate, but acquired, they are not for that reason less

natural." It is with hesitation that I venture to differ from

so profound a thinker, but it can hardly be disputed that the

social feelings are instinctive or innate in the lower animals;

and why should they not be so in man? Mr. Bain (see, for

instance, 'The Emotions and the Will,' 1865, p. 481) and others

believe that the moral sense is acquired by each individual

during his lifetime. On the general theory of evolution this is

at least extremely improbable.

[106] 'Die Darwin'sche Theorie,' s. 101.

[107] Mr. R. Brown in 'Proc. Zoolog. Soc.' 1868, p. 409.

[108] Brehm, 'Thierleben,' B. i. 1864, s. 52, 79. For the case

of the monkeys extracting thorns from each other, see s. 54.

With respect to the Hamadryas turning over stones, the fact is

given (s. 76) on the evidence of Alvarez, whose observations

Brehm thinks quite trustworthy. For the cases of the old male

baboons attacking the dogs, see s. 79; and with respect to the

eagle, s. 56.

[109] 'Annals and Mag. of Nat. Hist.' November, 1868, p. 382.

[110] Sir J. Lubbock, 'Prehistoric Times,' 2nd edit. p. 446.

[111] As quoted by Mr. L. H. Morgan, 'The American Beaver,'

1868, p. 272. Capt. Stansbury also gives an interesting account

of the manner in which a very young pelican, carried away by a

strong stream, was guided and encouraged in its attempts to

reach the shore by half a dozen old birds.

[112] As Mr. Bain states, "effective aid to a sufferer springs

from sympathy proper:" 'Mental and Moral Science,' 1868, p.

245.

[113] 'Thierleben,' B. i. s. 85.

[114] 'De l'Espece et de la Class.' 1869, p. 97.

[115] 'Der Darwin'schen Art-Lehre,' 1869, s. 54.

[116] Brehm, 'Thierleben,' B. i. s. 76.

[117] See the first and striking chapter in Adam Smith's

'Theory of Moral Sentiments.' Also Mr. Bain's 'Mental and Moral

Science,' 1868, p. 244, and 275-282. Mr. Bain states, that

"sympathy is, indirectly, a source of pleasure to the

sympathiser;" and he accounts for this through reciprocity. He

remarks that "the person benefited, or others in his stead, may

make up, by sympathy and good offices returned, for all the

sacrifice." But if, as appears to be the case, sympathy is

strictly an instinct, its exercise would give direct pleasure,

in the same manner as the exercise, as before remarked, of

almost every other instinct.

[118] This fact, the Rev. L. Jenyns states (see his edition of

'White's Nat. Hist. of Selborne,' 1853, p. 204) was first

recorded by the illustrious Jenner, in 'Phil. Transact.' 1824,

and has since been confirmed by several observers, especially

by Mr. Blackwall. This latter careful observer examined, late

in the autumn, during two years, thirty-six nests; he found

that twelve contained young dead birds, five contained eggs on

the point of being hatched, and three eggs not nearly hatched.

Many birds not yet old enough for a prolonged flight are

likewise deserted and left behind. See Blackwall, 'Researches

in Zoology,' 1834, pp. 108, 118. For some additional evidence,

although this is not wanted, see Leroy, 'Lettres Phil.' 1802,

p. 217.

[119] Hume remarks ('An Enquiry Concerning the Principles of

Morals,' edit. of 1751, p. 132), "there seems a necessity for

confessing that the happiness and misery of others are not

spectacles altogether indifferent to us, but that the view of

the former ... communicates a secret joy; the appearance of the

latter ... throws a melancholy damp over the imagination."

[120] 'Mental and Moral Science,' 1868, p. 254.

[121] I have given one such case, namely of three Patagonian

Indians who preferred being shot, one after the other, to

betraying the plans of their companions in war ('Journal of

Researches,' 1845, p. 103).

[122] Dr. Prosper Despine, in his 'Psychologie Naturelle,' 1868

(tom. i. p. 243; tom ii. p. 169) gives many curious cases of

the worst criminals, who apparently have been entirely

destitute of conscience.

[123] See an able article in the 'North British Review,' 1867,

p. 395. See also Mr. W. Bagehot's articles on the Importance of

Obedience and Coherence to Primitive Man, in the 'Fortnightly

Review,' 1867, p. 529, and 1868, p. 457, &c.

[124] The fullest account which I have met with is by Dr.

Gerland, in his 'Ueber das Aussterben der Naturvoelker,' 1868;

but I shall have to recur to the subject of infanticide in a

future chapter.

[125] See the very interesting discussion on Suicide in Lecky's

'History of European Morals,' vol. i. 1869, p. 223.

[126] See, for instance, Mr. Hamilton's account of the Kaffirs,

'Anthropological Review,' 1870, p. xv.

[127] Mr. M'Lennan has given 'Primitive Marriage,' 1865, p.

176, a good collection of facts on this head.

[128] Lecky, 'History of European Morals,' vol. i. 1869, p.

109.

[129] 'Embassy to China,' vol. ii. p. 348.

[130] See on this subject copious evidence in Chap. vii. of Sir

J. Lubbock, 'Origin of Civilisation,' 1870.

[131] For instance Lecky, 'Hist. European Morals,' vol. i. p.

124.

[132] This term is used in an able article in the 'Westminster

Review,' Oct. 1869, p. 498. For the Greatest Happiness

principle, see J. S. Mill, 'Utilitarianism,' p. 17.

[133] Good instances are given by Mr. Wallace in 'Scientific

Opinion,' Sept. 15, 1869; and more fully in his 'Contributions

to the Theory of Natural Selection,' 1870, p. 353.

[134] Tennyson, 'Idylls of the King,' p. 244.

[135] 'The Thoughts of the Emperor M. Aurelius Antoninus,' Eng.

translat., 2nd edit., 1869, p. 112. Marcus Aurelius was born

A.D. 121.

[136] Letter to Mr. Mill in Bain's 'Mental and Moral Science,'

1868, p. 722.

[137] A writer in the 'North British Review' (July, 1869, p.

531), well capable of forming a sound judgment, expresses

himself strongly to this effect. Mr. Lecky ('Hist. of Morals,'

vol. i. p. 143) seems to a certain extent to coincide.

[138] See his remarkable work on 'Hereditary Genius,' 1869, p.

349. The Duke of Argyll ('Primeval Man,' 1869, p. 188) has some

good remarks on the contest in man's nature between right and

wrong.

[139] 'The Thoughts of Marcus Aurelius,' &c., p. 139.

[140] 'Investigations in Military and Anthropolog. Statistics

of American Soldiers,' by B. A. Gould, 1869, p. 256.

[141] With respect to the "Cranial forms of the American

aborigines," see Dr. Aitken Meigs in 'Proc. Acad. Nat. Sci.'

Philadelphia, May, 1866. On the Australians, see Huxley, in

Lyell's 'Antiquity of Man,' 1863, p. 87. On the Sandwich

Islanders, Prof. J. Wyman, 'Observations on Crania,' Boston,

1868, p. 18.

[142] 'Anatomy of the Arteries,' by R. Quain.

[143] 'Transact. Royal Soc.' Edinburgh, vol. xxiv. p. 175, 189.

[144] 'Proc. Royal Soc.' 1867, p. 544; also 1868, p. 483, 524.

There is a previous paper, 1866, p. 229.

[145] 'Proc. R. Irish Academy,' vol. x. 1868, p. 141.

[146] 'Act. Acad.,' St. Petersburg, 1778, part ii. p. 217.

[147] Brehm, 'Thierleben,' B. i. s. 58, 87. Rengger,

'Saeugethiere von Paraguay,' s. 57.

[148] 'Variation of Animals and Plants under Domestication,'

vol. ii. chap. xii.

[149] 'Hereditary Genius: an Inquiry into its Laws and

Consequences,' 1869.

[150] Mr. Bates remarks ('The Naturalist on the Amazons,' 1863,

vol. ii. p. 159), with respect to the Indians of the same S.

American tribe, "no two of them were at all similar in the

shape of the head; one man had an oval visage with fine

features, and another was quite Mongolian in breadth and

prominence of cheek, spread of nostrils, and obliquity of

eyes."

[151] Blumenbach, 'Treatises on Anthropolog.' Eng. translat.,

1865, p. 205.

[152] Godron, 'De l'Espece,' 1859, tom. ii. livre 3.

Quatrefages, 'Unite de l'Espece Humaine,' 1861. Also Lectures

on Anthropology, given in the 'Revue des Cours Scientifiques,'

1866-1868.

[153] 'Hist. Gen. et Part. des Anomalies de l'Organisation,' in

three volumes, tom. i. 1832.

[154] I have fully discussed these laws in my 'Variation of

Animals and Plants under Domestication,' vol. ii. chap. xxii.

and xxiii. M. J. P. Durand has lately 1868; published a

valuable essay 'De l'Influence des Milieux, &c.' He lays much

stress on the nature of the soil.

[155] 'Investigations in Military and Anthrop. Statistics,' &c.

1869, by B. A. Gould, p. 93, 107, 126, 131, 134.

[156] For the Polynesians, see Prichard's 'Physical Hist. of

Mankind,' vol. v. 1847, p. 145, 283. Also Godron, 'De

l'Espece,' tom. ii. p. 289. There is also a remarkable

difference in appearance between the closely-allied Hindoos

inhabiting the Upper Ganges and Bengal; see Elphinstone's

'History of India,' vol. i. p. 324.

[157] 'Memoirs, Anthropolog. Soc.' vol. iii. 1867-69, p. 561,

565, 567.

[158] Dr. Brakenridge, 'Theory of Diathesis,' 'Medical Times,'

June 19 and July 17, 1869.

[159] I have given authorities for these several statements in

my 'Variation of Animals under Domestication,' vol. ii. p.

297-300. Dr. Jaeger, "Ueber das Laengenwachsthum der Knochen,"

'Jenaischen Zeitschrift,' B. v. Heft i.

[160] 'Investigations,' &c. By B. A. Gould, 1869, p. 288.

[161] 'Saeugethiere von Paraguay,' 1830, s. 4.

[162] 'History of Greenland,' Eng. translat. 1767, vol. i. p.

230.

[163] 'Intermarriage.' By Alex. Walker, 1838. p. 377.

[164] 'The Variation of Animals under Domestication,' vol. i.

p. 173.

[165] 'Principles of Biology,' vol. i. p. 455.

[166] Paget, 'Lectures on Surgical Pathology,' vol. i. 1853, p.

209.

[167] 'The Variation of Animals under Domestication,' vol. ii.

p. 8.

[168] 'Saeugethiere von Paraguay,' s. 8, 10. I have had good

opportunities for observing the extraordinary power of eyesight

in the Fuegians.' See also Lawrence ('Lectures on Physiology,'

&c., 1822, p. 404) on this same subject. M. Giraud-Teulon has

recently collected ('Revue des Cours Scientifiques,' 1870, p.

625) a large and valuable body of evidence proving that the

cause of short-sight, "_C'est le travail assidu, de pres._"

[169] Prichard, 'Phys. Hist. of Mankind,' on the authority of

Blumenbach, vol. i. 1851, p. 311; for the statement by Pallas,

vol. iv. 1844, p. 407.

[170] Quoted by Prichard, 'Researches into the Phys. Hist. of

Mankind,' vol. v. p. 463.

[171] Mr. Forbes' valuable paper is now published in the

'Journal of the Ethnological Soc. of London,' new series, vol.

ii. 1870, p. 193.

[172] Dr. Wilckens ('Landwirthschaft. Wochenblatt,' No. 10,

1869) has lately published an interesting essay shewing how

domestic animals, which live in mountainous regions, have their

frames modified.

[173] 'Memoire sur les Microcephales,' 1867, p. 50, 125, 169,

171, 184-198.

[174] See Dr. A. Farre's well-known article in the 'Cyclop. of

Anat. and Phys.' vol. v. 1859, p. 642. Owen 'Anatomy of

Vertebrates,' vol. iii. 1868, p. 687. Prof. Turner in

'Edinburgh Medical Journal,' Feb. 1865.

[175] 'Annuario della Soc. dei Naturalisti in Modena,' 1867, p.

83. Prof. Canestrini gives extracts on this subject from

various authorities. Laurillard remarks, that as he has found a

complete similarity in the form, proportions, and connexion of

the two malar bones in several human subjects and in certain

apes, he cannot consider this disposition of the parts as

simply accidental.

[176] A whole series of cases is given by Isid. Geoffroy

St.-Hilaire, 'Hist. des Anomalies,' tom. iii. p. 437.

[177] In my 'Variation of Animals under Domestication' (vol.

ii. p. 57) I attributed the not very rare cases of

supernumerary mammae in women to reversion. I was led to this as

a _probable_ conclusion, by the additional mammae being

generally placed symmetrically on the breast, and more

especially from one case, in which a single efficient mamma

occurred in the inguinal region of a woman, the daughter of

another woman with supernumerary mammae. But Prof. Preyer ('Der

Kampf um das Dasein,' 1869, s. 45) states that _mammae erraticae_

have been known to occur in other situations, even on the back;

so that the force of my argument is greatly weakened or perhaps

quite destroyed.

With much hesitation I, in the same work (vol. ii. p. 12),

attributed the frequent cases of polydactylism in men to

reversion. I was partly led to this through Prof. Owen's

statement, that some of the Ichthyopterygia possess more than

five digits, and therefore, as I supposed, had retained a

primordial condition; but after reading Prof. Gegenbaur's paper

('Jenaischen Zeitschrift,' B. v. Heft 3, s. 341), who is the

highest authority in Europe on such a point, and who disputes

Owen's conclusion, I see that it is extremely doubtful whether

supernumerary digits can thus be accounted for. It was the fact

that such digits not only frequently occur and are strongly

inherited, but have the power of regrowth after amputation,

like the normal digits of the lower vertebrata, that chiefly

led me to the above conclusion. This extraordinary fact of

their regrowth remains inexplicable, if the belief in reversion

to some extremely remote progenitor must be rejected. I cannot,

however, follow Prof. Gegenbaur in supposing that additional

digits could not reappear through reversion, without at the

same time other parts of the skeleton being simultaneously and

similarly modified; for single characters often reappear

through reversion.

[178] 'Anatomy of Vertebrates,' vol. iii. 1868, p. 323.

[179] 'Generelle Morphologie,' 1866, B. ii. s. clv.

[180] Carl Vogt's 'Lectures on Man,' Eng. translat. 1864, p.

151.

[181] C. Carter Blake, on a jaw from La Naulette, 'Anthropolog.

Review,' 1867, p. 295. Schaaffhausen, ibid. 1868, p. 426.

[182] 'The Anatomy of Expression,' 1844, p. 110, 131.

[183] Quoted by Prof. Canestrini in the 'Annuario,' &c., 1867,

p. 90.

[184] These papers deserve careful study by any one who desires

to learn how frequently our muscles vary, and in varying come

to resemble those of the Quadrumana. The following references

relate to the few points touched on in my text: Proc. Royal

Soc. vol. xiv. 1865, p. 379-384; vol. xv. 1866, p. 241, 242;

vol. xv. 1867, p. 544; vol. xvi. 1868, p. 524. I may here add

that Dr. Murie and Mr. St. George Mivart have shewn in their

Memoir on the Lemuroidea ('Transact. Zoolog. Soc.' vol. vii.

1869, p. 96), how extraordinarily variable some of the muscles

are in these animals, the lowest members of the Primates.

Gradations, also, in the muscles leading to structures found in

animals still lower in the scale, are numerous in the

Lemuroidea.

[185] Prof. Macalister in 'Proc. R. Irish Academy,' vol. x.

1868, p. 124.

[186] Prof. Macalister (ibid. p. 121) has tabulated his

observations, and finds that muscular abnormalities are most

frequent in the fore-arms, secondly in the face, thirdly in the

foot, &c.

[187] The Rev. Dr. Haughton, after giving ('Proc. R. Irish

Academy,' June 27, 1864, p. 715) a remarkable case of variation

in the human _flexor pollicis longus_, adds, "This remarkable

example shews that man may sometimes possess the arrangement of

tendons of thumb and fingers characteristic of the macaque; but

whether such a case should be regarded as a macaque passing

upwards into a man, or a man passing downwards into a macaque,

or as a congenital freak of nature, I cannot undertake to say."

It is satisfactory to hear so capable an anatomist, and so

embittered an opponent of evolutionism, admitting even the

possibility of either of his first propositions. Prof.

Macalister has also described ('Proc. R. Irish Acad.' vol. x.

1864, p. 138) variations in the _flexor pollicis longus_,

remarkable from their relations to the same muscle in the

Quadrumana.

[188] The authorities for these several statements are given in

my 'Variation of Animals under Domestication,' vol. ii. p.

320-335.

[189] This whole subject has been discussed in chap. xxiii.

vol. ii. of my 'Variation of Animals and Plants under

Domestication.'

[190] See the ever memorable 'Essay on the Principle of

Population,' by the Rev. T. Malthus, vol. i. 1826, p. 6, 517.

[191] 'Variation of Animals and Plants under Domestication,'

vol. ii. p. 111-113, 163.

[192] Mr. Sedgwick, 'British and Foreign Medico-Chirurg.

Review,' July, 1863, p. 170.

[193] 'The Annals of Rural Bengal,' by W. W. Hunter, 1868, p.

259.

[194] 'Primitive Marriage,' 1865.

[195] See some good remarks to this effect by W. Stanley

Jevons, "A Deduction from Darwin's Theory," 'Nature,' 1869, p.

231.

[196] Latham, 'Man and his Migrations,' 1851, p. 135.

[197] Messrs. Murie and Mivart in their "Anatomy of the

Lemuroidea" ('Transact. Zoolog. Soc.' vol. vii. 1869, p. 96-98)

say, "some muscles are so irregular in their distribution that

they cannot be well classed in any of the above groups." These

muscles differ even on the opposite sides of the same

individual.

[198] 'Quarterly Review,' April, 1869, p. 392. This subject is

more fully discussed in Mr. Wallace's 'Contributions to the

Theory of Natural Selection,' 1870, in which all the essays

referred to in this work are republished. The 'Essay on Man'

has been ably criticised by Prof. Claparede, one of the most

distinguished zoologists in Europe, in an article published in

the 'Bibliotheque Universelle,' June, 1870. The remark quoted

in my text will surprise every one who has read Mr. Wallace's

celebrated paper on 'The Origin of Human Races deduced from the

Theory of Natural Selection,' originally published in the

'Anthropological Review,' May, 1864, p. clviii. I cannot here

resist quoting a most just remark by Sir J. Lubbock

('Prehistoric Times,' 1865, p. 479) in reference to this paper,

namely, that Mr. Wallace, "with characteristic unselfishness,

ascribes it (_i.e._ the idea of natural selection) unreservedly

to Mr. Darwin, although, as is well known, he struck out the

idea independently, and published it, though not with the same

elaboration, at the same time."

[199] Quoted by Mr. Lawson Tait in his "Law of Natural

Selection,"--'Dublin Quarterly Journal of Medical Science,'

Feb. 1869. Dr. Keller is likewise quoted to the same effect.

[200] Owen, 'Anatomy of Vertebrates,' vol. iii. p. 71.

[201] 'Quarterly Review,' April, 1869, p. 392.

[202] In _Hylobates syndactylus_, as the name expresses, two of

the digits regularly cohere; and this, as Mr. Blyth informs me,

is occasionally the case with the digits of _H. agilis_, _lar_,

and _leuciscus_.

[203] Brehm, 'Thierleben,' B. i. s. 80.

[204] "The Hand, its mechanism," &c. 'Bridgewater Treatise,'

1833, p. 38.

[205] Haeckel has an excellent discussion on the steps by which

man became a biped: 'Natuerliche Schoepfungsgeschichte,' 1868, s.

507. Dr. Buechner ('Conferences sur la Theorie Darwinienne,'

1869, p. 135) has given good cases of the use of the foot as a

prehensile organ by man; also on the manner of progression of

the higher apes to which I allude in the following paragraph:

see also Owen ('Anatomy of Vertebrates,' vol. iii. p. 71) on

this latter subject.

[206] "On the Primitive Form of the Skull," translated in

'Anthropological Review,' Oct. 1868, p. 428. Owen ('Anatomy of

Vertebrates,' vol. ii. 1866, p. 551) on the mastoid processes

in the higher apes.

[207] 'Die Grenzen der Thierwelt, eine Betrachtung zu Darwin's

Lehre,' 1868, s. 51.

[208] Dujardin, 'Annales des Sc. Nat.' 3rd series, Zoolog. tom.

xiv. 1850, p. 203. See also Mr. Lowne, 'Anatomy and Phys. of

the _Musca vomitoria_,' 1870, p. 14. My son, Mr. F. Darwin,

dissected for me the cerebral ganglia of the _Formica rufa_.

[209] 'Philosophical Transactions,' 1869, p. 513.

[210] Quoted in C. Vogt's 'Lectures on Man,' Eng. translat.

1864, p. 88, 90. Prichard, 'Phys. Hist. of Mankind,' vol. i.

1838, p. 305.

[211] 'Comptes Rendus des Seances,' &c. June 1, 1868.

[212] 'The Variation of Animals and Plants under

Domestication,' vol. ii. p. 124-129.

[213] Schaaffhausen gives from Blumenbach and Busch, the cases

of the spasms and cicatrix, in 'Anthropolog. Review,' Oct.

1868, p. 420. Dr. Jarrold ('Anthropologia,' 1808, p. 115, 116)

adduces from Camper and from his own observations, cases of the

modification of the skull from the head being fixed in an

unnatural position. He believes that certain trades, such as

that of a shoemaker, by causing the head to be habitually held

forward, makes the forehead more rounded and prominent.

[214] 'Variation of Animals,' &c., vol. i. p. 117 on the

elongation of the skull; p. 119, on the effect of the lopping

of one ear.

[215] Quoted by Schaaffhausen, in 'Anthropolog. Review,' Oct.

1868, p. 419.

[216] Owen, 'Anatomy of Vertebrates,' vol. iii. p. 619.

[217] Isidore Geoffroy St.-Hilaire remarks ('Hist. Nat.

Generale,' tom. ii. 1859, p. 215-217) on the head of man being

covered with long hair; also on the upper surfaces of monkeys

and of other mammals being more thickly clothed than the lower

surfaces. This has likewise been observed by various authors.

Prof. P. Gervais ('Hist. Nat. des Mammiferes,' tom. i. 1854, p.

28), however, states that in the Gorilla the hair is thinner on

the back, where it is partly rubbed off, than on the lower

surface.

[218] Mr. St. George Mivart, 'Proc. Zoolog. Soc.' 1865, p. 562,

583. Dr. J. E. Gray, 'Cat. Brit. Mus.: Skeletons.' Owen,

'Anatomy of Vertebrates,' vol. ii. p. 517. Isidore Geoffroy,

'Hist. Nat. Gen.' tom. ii. p. 244.

[219] 'The Variation of Animals and Plants under

Domestication,' vol. ii. p. 280, 282.

[220] 'Primeval Man,' 1869, p. 66.

[221] 'Anthropological Review,' May, 1864, p. clviii.

[222] After a time the members or tribes which are absorbed

into another tribe assume, as Mr. Maine remarks ('Ancient Law,'

1861, p. 131), that they are the co-descendants of the same

ancestors.

[223] Morlot, 'Soc. Vaud. Sc. Nat.' 1860, p. 294.

[224] I have given instances in my 'Variation of Animals under

Domestication,' vol. ii. p. 196.

[225] See a remarkable series of articles on Physics and

Politics in the 'Fortnightly Review,' Nov. 1867; April 1, 1868;

July 1, 1869.

[226] 'Origin of Civilisation,' 1870, p. 265.

[227] Mr. Wallace gives cases in his 'Contributions to the

Theory of Natural Selection,' 1870, p. 354.

[228] 'Ancient Law,' 1861, p. 22. For Mr. Bagehot's remarks,

'Fortnightly Review,' April 1, 1868, p. 452.

[229] 'The Variation of Animals and Plants under

Domestication,' vol. i. p. 309.

[230] 'Fraser's Magazine,' Sept. 1868, p. 353. This article

seems to have struck many persons, and has given rise to two

remarkable essays and a rejoinder in the 'Spectator,' Oct. 3rd

and 17th 1868. It has also been discussed in the 'Q. Journal of

Science,' 1869, p. 152, and by Mr. Lawson Tait in the 'Dublin

Q. Journal of Medical Science,' Feb. 1869, and by Mr. E. Ray

Lankester in his 'Comparative Longevity,' 1870, p. 128. Similar

views appeared previously in the 'Australasian,' July 13, 1867.

I have borrowed ideas from several of these writers.

[231] For Mr. Wallace, see 'Anthropolog. Review,' as before

cited. Mr. Galton in 'Macmillan's Magazine,' Aug. 1865, p. 318;

also his great work, 'Hereditary Genius,' 1870.

[232] 'Hereditary Genius,' 1870, p. 132-140.

[233] See the fifth and sixth columns, compiled from good

authorities, in the table given in Mr. E. R. Lankester's

'Comparative Longevity,' 1870, p. 115.

[234] 'Hereditary Genius,' 1870, p. 330.

[235] 'Origin of Species' (fifth edition, 1869), p. 104.

[236] 'Hereditary Genius,' 1870, p. 347.

[237] E. Ray Lankester, 'Comparative Longevity,' 1870, p. 115.

The table of the intemperate is from Nelson's 'Vital

Statistics.' In regard to profligacy, see Dr. Farr, "Influence

of Marriage on Mortality," 'Nat. Assoc. for the Promotion of

Social Science,' 1858.

[238] 'Fraser's Magazine,' Sept. 1868, p. 353. 'Macmillan's

Magazine,' Aug. 1865, p. 318. The Rev. F. W. Farrar ('Fraser's

Mag.,' Aug. 1870, p. 264) takes a different view.

[239] "On the Laws of the Fertility of Women," in 'Transact.

Royal Soc.' Edinburgh, vol. xxiv. p. 287. See, also, Mr.

Galton, 'Hereditary Genius,' p. 352-357, for observations to

the above effect.

[240] 'Tenth Annual Report of Births, Deaths, &c., in

Scotland,' 1867, p. xxix.

[241] These quotations are taken from our highest authority on

such questions, namely, Dr. Farr, in his paper "On the

Influence of Marriage on the Mortality of the French People,"

read before the Nat. Assoc. for the Promotion of Social

Science, 1858.

[242] Dr. Farr, ibid. The quotations given below are extracted

from the same striking paper.

[243] I have taken the mean of the quinquennial means, given in

'The Tenth Annual Report of Births, Deaths, &c., in Scotland,'

1867. The quotation from Dr. Stark is copied from an article in

the 'Daily News,' Oct. 17th, 1868, which Dr. Farr considers

very carefully written.

[244] See the ingenious and original argument on this subject

by Mr. Galton, 'Hereditary Genius,' p. 340-342.

[245] Mr. Greg, 'Fraser's Magazine,' Sept. 1868, p. 357.

[246] 'Hereditary Genius,' 1870, p. 357-359. The Rev. F. H.

Farrar ('Fraser's Mag.' , Aug. 1870, p. 257) advances arguments

on the other side. Sir C. Lyell had already ('Principles of

Geology,' vol. ii. 1868, p. 489) called attention, in a

striking passage, to the evil influence of the Holy Inquisition

in having lowered, through selection, the general standard of

intelligence in Europe.

[247] Mr. Galton, 'Macmillan's Magazine,' August, 1865, p. 325.

See, also, 'Nature,' "On Darwinism and National Life," Dec.

1869, p. 184.

[248] 'Last Winter in the United States,' 1868, p. 29.

[249] 'On the Origin of Civilisation,' 'Proc. Ethnological

Soc.' Nov. 26, 1867.

[250] 'Primeval Man,' 1869.

[251] 'Royal Institution of Great Britain,' March 15, 1867.

Also, 'Researches into the Early History of Mankind,' 1865.