Descent of Man [ 1871]

[Bullseye]

Every naturalist who has had the misfortune to undertake the
description of a group of highly varying organisms, has encountered
cases (I speak after experience) precisely like that of man; and if of
a cautious disposition, he will end by uniting all the forms which
graduate into each other, under a single species; for he will say to
himself that he has no right to give names to objects which he
cannot define. Cases of this kind occur in the Order which include
man, namely in certain genera of monkeys; whilst in other genera, as
in Cercopithecus, most of the species can be determined with
certainty. In the American genus Cebus, the various forms are ranked
by some naturalists as species, by others as mere geographical
races. Now if numerous specimens of Cebus were collected from all
parts of South America, and those forms which at present appear to
be specifically distinct, were found to graduate into each other by
close steps, they would usually be ranked as mere varieties or
races; and this course has been followed by most naturalists with
respect to the races of man. Nevertheless, it must be confessed that
there are forms, at least in the vegetable kingdom,* which we cannot
avoid naming as species, but which are connected together by
numberless gradations, independently of intercrossing.

  * Prof. Nageli has carefully described several striking cases in his
Botanische Mittheilungen, B. ii., 1866, ss. 294-369. Prof. Asa Gray
has made analogous remarks on some intermediate forms in the
Compositae of N. America.

  Some naturalists have lately employed the term "sub-species" to
designate forms which possess many of the characteristics of true
species, but which hardly deserve so high a rank. Now if we reflect on
the weighty arguments above given, for raising the races of man to the
dignity of species, and the insuperable difficulties on the other side
in defining them, it seems that the term "sub-species" might here be
used with propriety. But from long habit the term "race" will
perhaps always be employed. The choice of terms is only so far
important in that it is desirable to use, as far as possible, the same
terms for the same degrees of difference. Unfortunately this can
rarely be done: for the larger genera generally include closely-allied
forms, which can be distinguished only with much difficulty, whilst
the smaller genera within the same family include forms that are
perfectly distinct; yet all must be ranked equally as species. So
again, species within the same large genus by no means resemble each
other to the same degree: on the contrary, some of them can
generally be arranged in little groups round other species, like
satellites round planets.*

  * Origin of Species. (OOS)

  The question whether mankind consists of one or several species
has of late years been much discussed by anthropologists, who are
divided into the two schools of monogenists and polygenists. Those who
do not admit the principle of evolution, must look at species as
separate creations, or in some manner as distinct entities; and they
must decide what forms of man they will consider as species by the
analogy of the method commonly pursued in ranking other organic beings
as species. But it is a hopeless endeavour to decide this point, until
some definition of the term "species" is generally accepted; and the
definition must not include an indeterminate element such as an act of
creation. We might as well attempt without any definition to decide
whether a certain number of houses should be called a village, town,
or city. We have a practical illustration of the difficulty in the
never-ending doubts whether many closely-allied mammals, birds,
insects, and plants, which represent each other respectively in
North America and Europe, should be ranked as species or
geographical races; and the like holds true of the productions of many
islands situated at some little distance from the nearest continent.
  Those naturalists, on the other hand, who admit the principle of
evolution, and this is now admitted by the majority of rising men,
will feel no doubt that all the races of man are descended from a
single primitive stock; whether or not they may think fit to designate
the races as distinct species, for the sake of expressing their amount
of difference.* With our domestic animals the question whether the
various races have arisen from one or more species is somewhat
different. Although it may be admitted that all the races, as well
as all the natural species within the same genus, have sprung from the
same primitive stock, yet it is a fit subject for discussion,
whether all the domestic races of the dog, for instance, have acquired
their present amount of difference since some one species was first
domesticated by man; or whether they owe some of their characters to
inheritance from distinct species, which had already been
differentiated in a state of nature. With man no such question can
arise, for he cannot be said to have been domesticated at any
particular period.

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

  During an early stage in the divergence of the races of man from a
common stock, the differences between the races and their number
must have been small; consequently as far as their distinguishing
characters are concerned, they then had less claim to rank as distinct
species than the existing so-called races. Nevertheless, so
arbitrary is the term of species, that such early races would
perhaps have been ranked by some naturalists as distinct species, if
their differences, although extremely slight, had been more constant
than they are at present, and had not graduated into each other.
  It is however possible, though far from probable, that the early
progenitors of man might formerly have diverged much in character,
until they became more unlike each other than any now existing
races; but that subsequently, as suggested by Vogt,* they converged in
character. When man selects the offspring of two distinct species
for the same object, he sometimes induces a considerable amount of
convergence, as far as general appearance is concerned. This is the
case, as shown by von Nathusius,*(2) with the improved breeds of the
pig, which are descended from two distinct species; and in a less
marked manner with the improved breeds of cattle. A great anatomist,
Gratiolet, maintains that the anthropomorphous apes do not form a
natural sub-group; but that the orang is a highly developed gibbon
or Semnopithecus, the chimpanzee a highly developed Macacus, and the
gorilla a highly developed mandrill. If this conclusion, which rests
almost exclusively on brain-characters, be admitted, we should have
a case of convergence at least in external characters, for the
anthropomorphous apes are certainly more like each other in many
points, than they are to other apes. All analogical resemblances, as
of a whale to a fish, may indeed be said to be cases of convergence;
but this term has never been applied to superficial and adaptive
resemblances. It would, however be extremely rash to attribute to
convergence close similarity of character in many points of
structure amongst the modified descendants of widely distinct
beings. The form of a crystal is determined solely by the molecular
forces, and it is not surprising that dissimilar substances should
sometimes assume the same form; but with organic beings we should bear
in mind that the form of each depends on an infinity of complex
relations, namely on variations, due to causes far too intricate to be
followed,- on the nature of the variations preserved, these
depending on the physical conditions, and still more on the
surrounding organisms which compete with each,- and lastly, on
inheritance (in itself a fluctuating element) from innumerable
progenitors, all of which have had their forms determined through
equally complex relations. It appears incredible that the modified
descendants of two organisms, if these differed from each other in a
marked manner, should ever afterwards converge so closely as to lead
to a near approach to identity throughout their whole organisation. In
the case of the convergent races of pigs above referred to, evidence
of their descent from two primitive stock is, according to von
Nathusius, still plainly retained, in certain bones of their skulls.
If the races of man had descended, as is supposed by some naturalists,
from two or more species, which differed from each other as much, or
nearly as much, as does the orang from the gorilla, it can hardly be
doubted that marked differences in the structure of certain bones
would still be discoverable in man as he now exists.

[Bullseye]

* Lectures on Man, Eng. translat., 1864, p. 468.
  *(2) Die Rassen des Schweines, 1860, s. 46. Vorstudien fur
Geschichte, &c., "Schweinesschadel," 1864, s. 104. With respect to
cattle, see M. de Quatrefages, Unite de l'Espece Humaine, 1861, p.
119.

  Although the existing races of man differ in many respects, as in
colour, hair, shape of skull, proportions of the body, &c., yet if
their whole structure be taken into consideration they are found to
resemble each other closely in a multitude of points. Many of these
are of so unimportant or of so singular a nature, that it is extremely
improbable that they should have been independently acquired by
aboriginally distinct species or races. The same remark holds good
with equal or greater force with respect to the numerous points of
mental similarity between the most distinct races of man. The American
aborigines, Negroes and Europeans are as different from each other
in mind as any three races that can be named; yet I was incessantly
struck, whilst living with the Feugians on board the Beagle, with
the many little traits of character, shewing how similar their minds
were to ours; and so it was with a full-blooded negro with whom I
happened once to be intimate.
  He who will read Mr. Tylor's and Sir J. Lubbock's interesting works*
can hardly fail to be deeply impressed with the close similarity
between the men of all races in tastes, dispositions and habits.
This is shown by the pleasure which they all take in dancing, rude
music, acting, painting, tattooing, and otherwise decorating
themselves; in their mutual comprehension of gesture-language, by
the same expression in their features, and by the same inarticulate
cries, when excited by the same emotions. This similarity, or rather
identity, is striking, when contrasted with the different
expressions and cries made by distinct species of monkeys. There is
good evidence that the art of shooting with bows and arrows has not
been handed down from any common progenitor of mankind, yet as
Westropp and Nilsson have remarked,*(2) the stone arrow-heads, brought
from the most distant parts of the world, and manufactured at the most
remote periods, are almost identical; and this fact can only be
accounted for by the various races having similar inventive or
mental powers. The same observation has been made by
archaeologists*(3) with respect to certain widely-prevalent ornaments,
such as zig-zags, &c.; and with respect to various simple beliefs
and customs, such as the burying of the dead under megalithic
structures. I remember observing in South America,*(4) that there,
as in so many other parts of the world, men have generally chosen
the summits of lofty hills, to throw up piles of stones, either as a
record of some remarkable event, or for burying their dead.

  * Tylor's Early History of Mankind, 1865: with respect to
gesture-language, see p. 54. Lubbock's Prehistoric Times, 2nd ed.,
1869.
  *(2) "On Analogous Forms of Implements," in Memoirs of
Anthropological Society by H. M. Westropp. The Primitive Inhabitants
of Scandinavia, Eng. translat., edited by Sir J. Lubbock, 1868, p.
104.
  *(3) Westropp "On Cromlechs," &c., Journal of Ethnological Soc.,
as given in Scientific Opinion, June 2, 1869, p. 3.
  *(4) Journal of Researches: Voyage of the Beagle, p. 46.

  Now when naturalists observe a close agreement in numerous small
details of habits, tastes, and dispositions between two or more
domestic races, or between nearly-allied natural forms, they use
this fact as an argument that they are descended from a common
progenitor who was thus endowed; and consequently that all should be
classed under the same species. The same argument may be applied
with much force to the races of man.
  As it is improbable that the numerous and unimportant points of
resemblance between the several races of man in bodily structure and
mental faculties (I do not here refer to similar customs) should all
have been independently acquired, they must have been inherited from
progenitors who had these same characters. We thus gain some insight
into the early state of man, before he had spread step by step over
the face of the earth. The spreading of man to regions widely
separated by the sea, no doubt, preceded any great amount of
divergence of character in the several races; for otherwise we
should sometimes meet with the same race in distinct continents; and
this is never the case. Sir J. Lubbock, after comparing the arts now
practised by savages in all parts of the world, specifies those
which man could not have known, when he first wandered from his
original birthplace; for if once learnt they would never have been
forgotten.* He thus shews that "the spear, which is but a
development of the knife-point, and the club, which is but a long
hammer, are the only things left." He admits, however, that the art of
making fire probably had been already discovered, for it is common
to all the races now existing, and was known to the ancient
cave-inhabitants of Europe. Perhaps the art of making rude canoes or
rafts was likewise known; but as man existed at a remote epoch, when
the land in many places stood at a very different level to what it
does now, he would have been able, without the aid of canoes, to
have spread widely. Sir J. Lubbock further remarks how improbable it
is that our earliest ancestors could have "counted as high as ten,
considering that so many races now in existence cannot get beyond
four." Nevertheless, at this early period, the intellectual and social
faculties of man could hardly have been inferior in any extreme degree
to those possessed at present by the lowest savages; otherwise
primeval man could not have been so eminently successful in the
struggle for life, as proved by his early and wide diffusion.

  * Prehistoric Times, 1869, p. 574.

  From the fundamental differences between certain languages, some
philologists have inferred that when man first became widely diffused,
he was not a speaking animal; but it may be suspected that
languages, far less perfect than any now spoken, aided by gestures,
might have been used, and yet have left no traces on subsequent and
more highly-developed tongues. Without the use of some language,
however imperfect, it appears doubtful whether man's intellect could
have risen to the standard implied by his dominant position at an
early period.
  Whether primeval man, when he possessed but few arts, and those of
the rudest kind, and when his power of language was extremely
imperfect, would have deserved to be called man, must depend on the
definition which we employ. In a series of forms graduating insensibly
from some ape-like creature to man as he now exists, it would be
impossible to fix on any definite point where the term "man" ought
to be used. But this is a matter of very little importance. So
again, it is almost a matter of indifference whether the so-called
races of man are thus designated, or are ranked as species or
sub-species; but the latter term appears the more appropriate.
Finally, we may conclude that when the principle of evolution is
generally accepted, as it surely will be before long, the dispute
between the monogenists and the polygenists will die a silent and
unobserved death.

[Bullseye]

One other question ought not to be passed over without notice,
namely, whether, as is sometimes assumed, each sub-species or race
of man has sprung from a single pair of progenitors. With our domestic
animals a new race can readily be formed by carefully matching the
varying offspring from a single pair, or even from a single individual
possessing some new character; but most of our races have been formed,
not intentionally from a selected pair, but unconsciously by the
preservation of many individuals which have varied, however
slightly, in some useful or desired manner. If in one country stronger
and heavier horses, and in another country lighter and fleeter ones,
were habitually preferred, we may feel sure that two distinct
sub-breeds would be produced in the course of time, without any one
pair having been separated and bred from, in either country. Many
races have been thus formed, and their manner of formation is
closely analogous to that of natural species. We know, also, that
the horses taken to the Falkland Islands have, during successive
generations, become smaller and weaker, whilst those which have run
wild on the Pampas have acquired larger and coarser heads; and such
changes are manifestly due, not to any one pair, but to all the
individuals having been subjected to the same conditions, aided,
perhaps, by the principle of reversion. The new sub-breeds in such
cases are not descended from any single pair, but from many
individuals which have varied in different degrees, but in the same
general manner; and we may conclude that the races of man have been
similarly produced, the modifications being either the direct result
of exposure to different conditions, or the indirect result of some
form of selection. But to this latter subject we shall presently
return.
  On the Extinction of the Races of Man.- The partial or complete
extinction of many races and sub-races of man is historically known.
Humboldt saw in South America a parrot which was the sole living
creature that could speak a word of the language of a lost tribe.
Ancient monuments and stone implements found in all parts of the
world, about which no tradition has been preserved by the present
inhabitants, indicate much extinction. Some small and broken tribes,
remnants of former races, still survive in isolated and generally
mountainous districts. In Europe the ancient races were all, according
to Shaaffhausen,* "lower in the scale than the rudest living savages";
they must therefore have differed, to a certain extent, from any
existing race. The remains described by Professor Broca from Les
Eyzies, though they unfortunately appear to have belonged to a
single family, indicate a race with a most singular combination of low
or simious, and of high characteristics. This race is "entirely
different from any other, ancient or modern, that we have heard
of."*(2) It differed, therefore, from the quaternary race of the
caverns of Belgium.

  * Translation in Anthropological Review, Oct., 1868, p. 431.
  *(2) Transactions, International Congress of Prehistoric Archaeology
1868, pp. 172-175. See also Broca (tr.) in Anthropological Review,
Oct., 1868, p. 410.

  Man can long resist conditions which appear extremely unfavourable
for his existence.* He has long lived in the extreme regions of the
North, with no wood for his canoes or implements, and with only
blubber as fuel, and melted snow as drink. In the southern extremity
of America the Fuegians survive without the protection of clothes,
or of any building worthy to be called a hovel. In South Africa the
aborigines wander over arid plains, where dangerous beasts abound. Man
can withstand the deadly influence of the Terai at the foot of the
Himalaya, and the pestilential shores of tropical Africa.

  * Dr. Gerland, Uber das Aussterben der Naturvolker 1868, s. 82.

  Extinction follows chiefly from the competition of tribe with tribe,
and race with race. Various checks are always in action, serving to
keep down the numbers of each savage tribe,- such as periodical
famines, nomadic habits and the consequent deaths of infants,
prolonged suckling, wars, accidents, sickness, licentiousness, the
stealing of women, infanticide, and especially lessened fertility.
If any one of these checks increases in power, even slightly, the
tribe thus affected tends to decrease; and when of two adjoining
tribes one becomes less numerous and less powerful than the other, the
contest is soon settled by war, slaughter, cannibalism, slavery, and
absorption. Even when a weaker tribe is not thus abruptly swept
away, if it once begins to decrease, it generally goes on decreasing
until it becomes extinct.*

[Bullseye]

* Gerland, ibid., s. 12, gives facts in support of this statement.

  When civilised nations come into contact with barbarians the
struggle is short, except where a deadly climate gives its aid to
the native race. Of the causes which lead to the victory of
civilised nations, some are plain and simple, others complex and
obscure. We can see that the cultivation of the land will be fatal
in many ways to savages, for they cannot, or will not, change their
habits. New diseases and vices have in some cases proved highly
destructive; and it appears that a new disease often causes much
death, until those who are most susceptible to its destructive
influence are gradually weeded out;* and so it may be with the evil
effects from spirituous liquors, as well as with the unconquerably
strong taste for them shewn by so many savages. It further appears,
mysterious as is the fact, that the first meeting of distinct and
separated people generates disease.*(2) Mr. Sproat, who in Vancouver
Island closely attended to the subject of extinction, believed that
changed habits of life, consequent on the advent of Europeans, induces
much ill health. He lays, also, great stress on the apparently
trifling cause that the natives become "bewildered and dull by the new
life around them; they lose the motives for exertion, and get no new
ones in their place."*(3)

  * See remarks to this effect in Sir H. Holland's Medical Notes and
Reflections, 1839, p. 390.
  *(2) I have collected (Journal of Researches: Voyage of the
Beagle, p. 435) a good many cases bearing on this subject; see also
Gerland, ibid., s. 8. Poeppig speaks of the "breath of civilisation as
poisonous to savages."
  *(3) Sproat, Scenes and Studies of Savage Life, 1868, p. 284.

  The grade of their civilisation seems to be a most important element
in the success of competing nations. A few centuries ago Europe feared
the inroads of Eastern barbarians; now any such fear would be
ridiculous. It is a more curious fact, as Mr. Bagehot has remarked,
that savages did not formerly waste away before the classical nations,
as they now do before modern civilised nations; had they done so,
the old moralists would have mused over the event; but there is no
lament in any writer of that period over the perishing barbarians.*
The most potent of all the causes of extinction, appears in many cases
to be lessened fertility and ill-health, especially amongst the
children, arising from changed conditions of life, notwithstanding
that the new conditions may not be injurious in themselves. I am
much indebted to Mr. H. H.  Howorth for having called my attention
to this subject, and for having given me information respecting it.
I have collected the following cases.

  * Bagehot, "Physics and Politics," Fortnightly Review, April 1,
1868, p. 455.

  When Tasmania was first colonised the natives were roughly estimated
by some at 7000 and by others at 20,000. Their number was soon greatly
reduced, chiefly by fighting with the English and with each other.
After the famous hunt by all the colonists, when the remaining natives
delivered themselves up to the government, they consisted only of
120 individuals,* who were in 1832 transported to Flinders Island.
This island, situated between Tasmania and Australia, is forty miles
long, and from twelve to eighteen miles broad: it seems healthy, and
the natives were well treated. Nevertheless, they suffered greatly
in health. In 1834 they consisted (Bonwick, p. 250) of forty-seven
adult males, forty-eight adult females, and sixteen children, or in
all of 111 souls. In 1835 only one hundred were left. As they
continued rapidly to decrease, and as they themselves thought that
they should not perish so quickly elsewhere, they were removed in 1847
to Oyster Cove in the southern part of Tasmania. They then consisted
(Dec. 20th, 1847) of fourteen men, twenty-two women and ten
children.*(2) But the change of site did no good. Disease and death
still pursued them, and in 1864 one man (who died in 1869), and
three elderly women alone survived. The infertility of the women is
even a more remarkable fact than the liability of all to ill-health
and death. At the time when only nine women were left at Oyster
Cove, they told Mr. Bonwick (p. 386), that only two had ever borne
children: and these two had together produced only three children!

  * All the statements here given are taken from The Last of the
Tasmanians, by J. Bonwick, 1870.
  *(2) This is the statement of the Governor of Tasmania, Sir W.
Denison, Varieties of Vice-Regal Life, 1870, vol. i., p. 67.

  With respect to the cause of this extraordinary state of things, Dr.
Story remarks that death followed the attempts to civilise the
natives. "If left to themselves to roam as they were wont and
undisturbed, they would have reared more children, and there would
have been less mortality." Another careful observer of the natives,
Mr. Davis, remarks, "The births have been few and the deaths numerous.
This may have been in a great measure owing to their change of
living and food; but more so to their banishment from the mainland
of Van Diemen's Land, and consequent depression of spirits"
(Bonwick, pp. 388, 390).
  Similar facts have been observed in two widely different parts of
Australia. The celebrated explorer, Mr. Gregory, told Mr. Bonwick,
that in Queensland "the want of reproduction was being already felt
with the blacks, even in the most recently settled parts, and that
decay would set in." Of thirteen aborigines from Shark's Bay who
visited Murchison River, twelve died of consumption within three
months.*

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

  The decrease of the Maories of New Zealand has been carefully
investigated by Mr. Fenton, in an admirable report, from which all the
following statements, with one exception, are taken.* The decrease
in number since 1830 is admitted by every one, including the natives
themselves, and is still steadily progressing. Although it has
hitherto been found impossible to take an actual census of the
natives, their numbers were carefully estimated by residents in many
districts. The result seems trustworthy, and shows that during the
fourteen years, previous to 1858, the decrease was 19.42 per cent.
Some of the tribes, thus carefully examined, lived above a hundred
miles apart, some on the coast, some inland; and their means of
subsistence and habits differed to a certain extent (p. 28). The total
number in 1858 was believed to be 53,700, and in 1872, after a
second interval of fourteen years, another census was taken, and the
number is given as only 36,359, shewing a decrease of 32.29 per
cent!*(2) Mr. Fenton, after shewing in detail the insufficiency of the
various causes, usually assigned in explanation of this
extraordinary decrease, such as new diseases, the profligacy of the
women, drunkenness, wars, &c., concludes on weighty grounds that it
depends chiefly on the unproductiveness of the women, and on the
extraordinary mortality of the young children (pp. 31, 34). In proof
of this he shews (p. 33) that in 1844 there was one non-adult for
every 2.57 adults; whereas in 1858 there was only one non-adult for
every 3.27 adults. The mortality of the adults is also great. He
adduces as a further cause of the decrease the inequality of the
sexes; for fewer females are born than males. To this latter point,
depending perhaps on a widely distinct cause, I shall return in a
future chapter. Mr. Fenton contrasts with astonishment the decrease in
New Zealand with the increase in Ireland; countries not very
dissimilar in climate, and where the inhabitants now follow nearly
similar habits. The Maories themselves (p. 35) "attribute their
decadence, in some measure, to the introduction of new food and
clothing, and the attendant change of habits"; and it will be seen,
when we consider the influence of changed conditions on fertility,
that they are probably right. The diminution began between the years
1830 and 1840; and Mr. Fenton shews (p. 40) that about 1830, the art
of manufacturing putrid corn (maize), by long steeping in water, was
discovered and largely practised; and this proves that a change of
habits was beginning amongst the natives, even when New Zealand was
only thinly inhabited by Europeans. When I visited the Bay of
Islands in 1835, the dress and food of the inhabitants had already
been much modified: they raised potatoes, maize, and other
agricultural produce, and exchanged them for English manufactured
goods and tobacco.

  * Observations on the Aboriginal Inhabitants of New Zealand,
published by the Government, 1859.
  *(2) New Zealand, by Alex. Kennedy, 1873, p. 47.

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

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

[Bullseye]

The decrease of the native population of the Sandwich Islands is
as notorious as that of New Zealand. It has been roughly estimated
by those best capable of judging, that when Cook discovered the
islands in 1779, the population amounted to about 300,000. According
to a loose census in 1823, the numbers then were 142,050. In 1832, and
at several subsequent periods, an accurate census was officially
taken, but I have been able to obtain only the following returns:

                Native Population          Annual rate of decrease
                                           per cent, assuming it to
              (Except during 1832 and      have been uniform between
              1836, when the few           the successive censuses;
              foreigners in the islands    these censuses being taken
  Year        were included.)              at irregular intervals.

  1832              130,313
                                                   4.46
  1836              108,579
                                                   2.47
  1853               71,019
                                                   0.81
  1860               67,084
                                                   2.18
  1866               58,765
                                                   2.17
  1872               51,531

  We here see that in the interval of forty years, between 1832 and
1872, the population has decreased no less than sixty-eight per
cent! This has been attributed by most writers to the profligacy of
the women, to former bloody wars, and to the severe labour imposed
on conquered tribes and to newly introduced diseases, which have
been on several occasions extremely destructive. No doubt these and
other such causes have been highly efficient, and may account for
the extraordinary rate of decrease between the years 1832 and 1836;
but the most potent of all the causes seems to be lessened
fertility. According to Dr. Ruschenberger of the U. S. Navy, who
visited these islands between 1835 and 1837, in one district of
Hawaii, only twenty-five men out of 1134, and in another district only
ten out of 637, had a family with as many as three children. Of eighty
married women, only thirty-nine had ever borne children; and "the
official report gives an average of half a child to each married
couple in the whole island." This is almost exactly the same average
as with the Tasmanians at Oyster Cove. Jarves, who published his
History in 1843, says that "families who have three children are freed
from all taxes; those having more, are rewarded by gifts of land and
other encouragements." This unparalleled enactment by the government
well shews how infertile the race had become. The Rev. A. Bishop
stated in the Hawaiian Spectator in 1839, that a large proportion of
the children die at early ages, and Bishop Staley informs me that this
is still the case, just as in New Zealand. This has been attributed to
the neglect of the children by the women, but it is probably in
large part due to innate weakness of constitution in the children,
in relation to the lessened fertility of their parents. There is,
moreover, a further resemblance to the case of New Zealand, in the
fact that there is a large excess of male over female births: the
census of 1872 gives 31,650 males to 25,247 females of all ages,
that is 125.36 males for every 100 females; whereas in all civilised
countries the females exceed the males. No doubt the profligacy of the
women may in part account for their small fertility; but their changed
habits of life is a much more probable cause, and which will at the
same time account for the increased mortality, especially of the
children. The islands were visited by Cook in 1779, Vancouver in 1794,
and often subsequently by whalers. In 1819 missionaries arrived, and
found that idolatry had been already abolished and other changes
effected by the king. After this period there was a rapid change in
almost all the habits of life of the natives, and they soon became
"the most civilised of the Pacific Islanders." One of my informants,
Mr. Coan, who was born on the islands, remarks that the natives have
undergone a greater change in their habits of life in the course of
fifty years than Englishmen during a thousand years. From
information received from Bishop Staley, it does not appear that the
poorer classes have ever much changed their diet, although many new
kinds of fruit have been introduced, and the sugar-cane is in
universal use. Owing, however, to their passion for imitating
Europeans, they altered their manner of dressing at an early period,
and the use of alcoholic drinks became very general. Although these
changes appear inconsiderable, I can well believe, from what is
known with respect to animals, that they might suffice to lessen the
fertility of the natives.*

[Bullseye]

* The foregoing statements are taken chiefly from the following
works: Jarves' History of the Hawaiian Islands, 1843, pp. 400-407.
Cheever, Life in the Sandwich Islands, 1851, p. 277. Ruschenberger
is quoted by Bonwick, Last of the Tasmanians, 1870, p. 378. Bishop
is quoted by Sir E. Belcher, Voyage Round the World, 1843, vol. i., p.
272. I owe the census of the several years to the kindness of Mr.
Coan, at the request of Dr. Youmans of New York; and in most cases I
have compared the Youmans figures with those given in several of the
above-named works. I have omitted the census for 1850, as I have
seen two widely different numbers given.

  Lastly, Mr. Macnamara states* that the low and degraded
inhabitants of the Andaman Islands, on the eastern side of the Gulf of
Bengal, are "eminently susceptible to any change of climate: in
fact, take them away from their island homes, and they are almost
certain to die, and that independently of diet or extraneous
influences." He further states that the inhabitants of the Valley of
Nepal, which is extremely hot in summer, and also the various
hill-tribes of India, suffer from dysentery and fever when on the
plains; and they die if they attempt to pass the whole year there.

  * The Indian Medical Gazette, Nov. 1, 1871, p. 240.

  We thus see that many of the wilder races of man are apt to suffer
much in health when subjected to changed conditions or habits of life,
and not exclusively from being transported to a new climate. Mere
alterations in habits, which do not appear injurious in themselves,
seem to have this same effect; and in several cases the children are
particularly liable to suffer. It has often been said, as Mr.
Macnamara remarks, that man can resist with impunity the greatest
diversities of climate and other changes; but this is true only of the
civilised races. Man in his wild condition seems to be in this respect
almost as susceptible as his nearest allies, the anthropoid apes,
which have never yet survived long, when removed from their native
country.
  Lessened fertility from changed conditions, as in the case of the
Tasmanians, Maories, Sandwich Islanders, and apparently the
Australians, is still more interesting than their liability to
ill-health and death; for even a slight degree of infertility,
combined with those other causes which tend to check the increase of
every population, would sooner or later lead to extinction. The
diminution of fertility may be explained in some cases by the
profligacy of the women (as until lately with the Tahitians), but
Mr. Fenton has shewn that this explanation by no means suffices with
the New Zealanders, nor does it with the Tasmanians.
  In the paper above quoted, Mr. Macnamara gives reasons for believing
that the inhabitants of districts subject to malaria are apt to be
sterile; but this cannot apply in several of the above cases. Some
writers have suggested that the aborigines of islands have suffered in
fertility and health from long continued interbreeding; but in the
above cases infertility has coincided too closely with the arrival
of Europeans for us to admit this explanation. Nor have we at
present any reason to believe that man is highly sensitive to the evil
effects of inter-breeding, especially in areas so large as New
Zealand, and the Sandwich archipelago with its diversified stations.
On the contrary, it is known that the present inhabitants of Norfolk
Island are nearly all cousins or near relations, as are the Todas in
India, and the inhabitants of some of the Western Islands of Scotland;
and yet they seem not to have suffered in fertility.*

  * On the close relationship of the Norfolk Islanders, Sir W.
Denison, Varieties of Vice-Regal Life: vol. i., 1870, p. 410. For
the Todas, see Col. Marshall's work 1873, p. 110. For the Western
Islands of Scotland, Dr. Mitchell, Edinburgh Medical Journal, March to
June, 1865.

  A much more probable view is suggested by the analogy of the lower
animals. The reproductive system can be shewn to be susceptible to
an extraordinary degree (though why we know not) to changed conditions
of life; and this susceptibility leads both to beneficial and to
evil results. A large collection of facts on this subject is given
in chap. xviii. of vol. ii. of my Variation of Animals and Plants
under Domestication, I can here give only the briefest abstract; and
every one interested in the subject may consult the above work. Very
slight changes increase the health, vigour, and fertility of most or
all organic beings, whilst other changes are known to render a large
number of animals sterile. One of the most familiar cases, is that
of tamed elephants not breeding in India; though they often breed in
Ava, where the females are allowed to roam about the forests to some
extent, and are thus placed under more natural conditions. The case of
various American monkeys, both sexes of which have been kept for
many years together in their own countries, and yet have very rarely
or never bred, is a more apposite instance, because of their
relationship to man. It is remarkable how slight a change in the
conditions often induces sterility in a wild animal when captured; and
this is the more strange as all our domesticated animals have become
more fertile than they were in a state of nature; and some of them can
resist the most unnatural conditions with undiminished fertility.*
Certain groups of animals are much more liable than others to be
affected by captivity; and generally all the species of the same group
are affected in the same manner. But sometimes a single species in a
group is rendered sterile, whilst the others are not so; on the
other hand, a single species may retain its fertility whilst most of
the others fail to breed. The males and females of some species when
confined, or when allowed to live almost, but not quite free, in their
native country, never unite; others thus circumstanced frequently
unite but never produce offspring; others again produce some
offspring, but fewer than in a state of nature; and as bearing on
the above cases of man, it is important to remark that the young are
apt to be weak and sickly, or malformed, and to perish at an early
age.

  * For the evidence on this head, see Variation of Animals, &c., vol.
ii., p. 111.

[Bullseye]

Seeing how general is this law of the susceptibility of the
reproductive system to changed conditions of life, and that it holds
good with our nearest allies, the Quadrumana, I can hardly doubt
that it applies to man in his primeval state. Hence if savages of
any race are induced suddenly to change their habits of life, they
become more or less sterile, and their young offspring suffer in
health, in the same manner and from the same cause, as do the elephant
and hunting-leopard in India, many monkeys in America, and a host of
animals of all kinds, on removal from their natural conditions.
  We can see why it is that aborigines, who have long inhabited
islands, and who must have been long exposed to nearly uniform
conditions, should be specially affected by any change in their
habits, as seems to be the case. Civilised races can certainly
resist changes of all kinds far better than savages; and in this
respect they resemble domesticated animals, for though the latter
sometimes suffer in health (for instance European dogs in India),
yet they are rarely rendered sterile, though a few such instances have
been recorded.* The immunity of civilised races and domesticated
animals is probably due to their having been subjected to a greater
extent, and therefore having grown somewhat more accustomed, to
diversified or varying conditions, than the majority of wild
animals; and to their having formerly immigrated or been carried
from country to country, and to different families or subraces
having inter-crossed. It appears that a cross with civilised races
at once gives to an aboriginal race an immunity from the evil
consequences of changed conditions. Thus the crossed offspring from
the Tahitians and English, when settled in Pitcairn Island,
increased so rapidly that the island was soon overstocked; and in June
1856 they were removed to Norfolk Island. They then consisted of 60
married persons and 134 children, making a total of 194. Here they
likewise increased so rapidly, that although sixteen of them
returned to Pitcairn Island in 1859, they numbered in January 1868,
300 souls; the males and females being in exactly equal numbers.
What a contrast does this case present with that of the Tasmanians;
the Norfolk Islanders increased in only twelve and a half years from
194 to 300; whereas the Tasmanians decreased during fifteen years from
120 to 46, of which latter number only ten were children.*(2)

  * Variation of Animals, &c., vol. ii., p. 16.
  *(2) These details are taken from The Mutineers of the Bounty, by
Lady Belcher, 1870; and from Pitcairn Island, ordered to be printed by
the House of Commons, May 29, 1863. The following statements about the
Sandwich Islanders are from the Honolulu Gazette, and from Mr. Coan.

  So again in the interval between the census of 1866 and 1872 the
natives of full blood in the Sandwich Islands decreased by 8081,
whilst the half-castes, who are believed to be healthier, increased by
847; but I do not know whether the latter number includes the
offspring from the half-castes, or only the half-castes of the first
generation.
  The cases which I have here given all relate to aborigines, who have
been subjected to new conditions as the result of the immigration of
civilised men. But sterility and ill-health would probably follow,
if savages were compelled by any cause, such as the inroad of a
conquering tribe, to desert their homes and to change their habits. It
is an interesting circumstance that the chief check to wild animals
becoming domesticated, which implies the power of their breeding
freely when first captured, and one chief check to wild men, when
brought into contact with civilisation, surviving to form a
civilised race, is the same, namely, sterility from changed conditions
of life.
  Finally, although the gradual decrease and ultimate extinction of
the races of man is a highly complex problem, depending on many causes
which differ in different places and at different times; it is the
same problem as that presented by the extinction of one of the
higher animals- of the fossil horse, for instance, which disappeared
from South America, soon afterwards to be replaced, within the same
districts, by countless troups of the Spanish horse. The New Zealander
seems conscious of this parallelism, for he compares his future fate
with that of the native rat now almost exterminated by the European
rat. Though the difficulty is great to our imagination, and really
great, if we wish to ascertain the precise causes and their manner
of action, it ought not to be so to our reason, as long as we keep
steadily in mind that the increase of each species and each race is
constantly checked in various ways; so that if any new check, even a
slight one, be superadded, the race will surely decrease in number;
and decreasing numbers will sooner or later lead to extinction; the
end, in most cases, being promptly determined by the inroads of
conquering tribes.
  On the Formation of the Races of Man.- In some cases the crossing of
distinct races has led to the formation of a new race. The singular
fact that the Europeans and Hindoos, who belong to the same Aryan
stock, and speak a language fundamentally the same, differ widely in
appearance, whilst Europeans differ but little from Jews, who belong
to the Semitic stock, and speak quite another language, has been
accounted for by Broca,* through certain Aryan branches having been
largely crossed by indigenous tribes during their wide diffusion. When
two races in close contact cross, the first result is a
heterogeneous mixture: thus Mr. Hunter, in describing the Santali orhill-tribes of India, says that hundreds of imperceptible gradations
may be traced "from the black, squat tribes of the mountains to the
tall olive-coloured Brahman, with his intellectual brow, calm eyes,
and high but narrow head"; so that it is necessary in courts of
justice to ask the witnesses whether they are Santalis or Hindoos.*(2)
Whether a heterogeneous people, such as the inhabitants of some of the
Polynesian islands, formed by the crossing of two distinct races, with
few or no pure members left, would ever become homogeneous, is not
known from direct evidence. But as with our domesticated animals, a
cross-breed can certainly be fixed and made uniform by careful
selection*(3) in the course of a few generations, we may infer that
the free inter-crossing of a heterogeneous mixture during a long
descent would supply the place of selection, and overcome any tendency
to reversion; so that the crossed race would ultimately become
homogeneous, though it might not partake in an equal degree of the
characters of the two parent-races.

  * "On Anthropology," translation, Anthropological Review, Jan.,
1868, p. 38.
  *(2) The Animals of Rural Bengal, 1868, p. 134.
  *(3) The Variation of Animals and Plants under Domestication vol.
ii., p. 95.

  Of all the differences between the races of man, the colour of the
skin is the most conspicuous and one of the best marked. It was
formerly thought that differences of this kind could be accounted
for by long exposure to different climates; but Pallas first shewed
that this is not tenable, and he has since been followed by almost all
anthropologists.* This view has been rejected chiefly because the
distribution of the variously coloured races, most of whom have long
inhabited their present homes, does not coincide with corresponding
differences of climate. Some little weight may be given to such
cases as that of the Dutch families, who, as we hear on excellent
authority,*(2) have not undergone the least change of colour after
residing for three centuries in South Africa. An argument on the
same side may likewise be drawn from the uniform appearance in various
parts of the world of gipsies and Jews, though the uniformity of the
latter has been somewhat exaggerated.*(3) A very damp or a very dry
atmosphere has been supposed to be more influential in modifying the
colour of the skin than mere heat; but as D'Orbigny in South
America, and Livingstone in Africa, arrived at diametrically
opposite conclusions with respect to dampness and dryness, any
conclusion on this head must be considered as very doubtful.*(4)

  * Pallas, Act. Acad. St. Petersburg, 1780, part ii., p. 69. He was
followed by Rudolphi, in his Beitrage zur Anthropologie, 1812. An
excellent summary of the evidence is given by Godron, De l'Espece,
1859, vol. ii., p. 246, &c.
  *(2) Sir Andrew Smith, as quoted by Knox, Races of Man, 1850, p.
473.
  *(3) See De Quatrefages on this head, Revue des Cours Scientifiques,
Oct. 17, 1868, p. 731.
  *(4) Livingstone's Travels and Researches in S. Africa, 1857, pp.
338, 339. D'Orbigny, as quoted by Godron, De l'Espece, vol. ii., p.
266.

[Bullseye]

Various facts, which I have given elsewhere, prove that the colour
of the skin and hair is sometimes correlated in a surprising manner
with a complete immunity from the action of certain vegetable poisons,
and from the attacks of certain parasites. Hence it occurred to me,
that negroes and other dark races might have acquired their dark tints
by the darker individuals escaping from the deadly influence of the
miasma of their native countries, during a long series of generations.
  I afterwards found that this same idea had long ago occurred to
Dr. Wells.* It has long been known that negroes, and even mulattoes
are almost completely exempt from the yellow fever, so destructive
in tropical America.*(2) They likewise escape to a large extent the
fatal intermittent fevers, that prevail along at least 2600 miles of
the shores of Africa, and which annually cause one-fifth of the
white settlers to die, and another fifth to return home invalided.*(3)
This immunity in the negro seems to be partly inherent, depending on
some unknown peculiarity of constitution, and partly the result of
acclimatisation. Pouchet*(4) states that the negro regiments recruited
near the Soudan, and borrowed from the Viceroy of Egypt for the
Mexican war, escaped the yellow fever almost equally with the
negroes originally brought from various parts of Africa and accustomed
to the climate of the West Indies. That acclimatisation plays a
part, is shewn by the many cases in which negroes have become somewhat
liable to tropical fevers, after having resided for some time in a
colder climate.*(5) The nature of the climate under which the white
races have long resided likewise has some influence on them; for
during the fearful epidemic of yellow fever in Demerara during 1837,
Dr. Blair found that the death-rate of the immigrants was proportional
to the latitude of the country whence they had come. With the negro
the immunity, as far as it is the result of acclimatisation, implies
exposure during a prodigious length of time; for the aborigines of
tropical America who have resided there from time immemorial, are
not exempt from yellow fever; and the Rev. H. B. Tristram states, that
there are districts in nothern Africa which the native inhabitants are
compelled annually to leave, though the negroes can remain with
safety.

  * See a paper read before the Royal Soc. in 1813, and published in
his Essays in 1818. I have given an account of Dr. Wells' views in the
"Historical Sketch" (p. 2) to my Origin of Species. Various cases of
colour correlated with constitutional peculiarities are given in my
Variation of Animals and Plants under Domestication, vol. ii., pp.
227, 335.
  *(2) See, for instance, Nott and Gliddon, Types of Mankind, p. 68.
  *(3) Major Tulloch in a paper read before the Statistical Society,
April 20, 1840, and given in the Athenaeum, 1840, p. 353.
  *(4) The Plurality of the Human Race (translat.), 1864, p. 60.
  *(5) Quartrefages, Unite de l'Espece Humaine, 1861, p. 205. Wartz,
Introduction to Anthropology, translat., vol. i., 1863, p. 124.
Livingstone gives analogous cases in his Travels.

  That the immunity of the negro is in any degree correlated with
the colour of his skin is a mere conjecture: it may be correlated with
some difference in his blood, nervous system, or other tissues.
Nevertheless, from the facts above alluded to, and from some
connection apparently existing between complexion and a tendency to
consumption, the conjecture seemed to me not improbable.
Consequently I endeavoured, with but little success,* to ascertain how
far it holds good. The late Dr. Daniell, who had long lived on the
west coast of Africa, told me that he did not believe in any such
relation. He was himself unusually fair, and had withstood the climate
in a wonderful manner. When he first arrived as a boy on the coast, an
old and experienced negro chief predicted from his appearance that
this would prove the case. Dr. Nicholson, of Antigua, after having
attended to this subject, writes to me that dark-coloured Europeans
escape the yellow fever more than those that are light-coloured. Mr.
J. M. Harris altogether denies that Europeans with dark hair withstand
a hot climate better than other men: on the contrary, experience has
taught him in making a selection of men for service on the coast of
Africa, to choose those with red hair.*(2) As far, therefore, as these
slight indications go, there seems no foundation for the hypothesis,
that blackness has resulted from the darker and darker individuals
having survived better during long exposure to fever-generating
miasma.

  * In the spring of 1862 I obtained permission from the
Director-General of the Medical department of the Army, to transmit to
the surgeons of the various regiments on foreign service a blank
table, with the following appended remarks, but I have received no
returns. "As several well-marked cases have been recorded with our
domestic animals of a relation between the colour of the dermal
appendages and the constitution; and it being notorious that there
is some limited degree of relation between the colour of the races
of man and the climate inhabited by them; the following
investigation seems worth consideration. Namely, whether there is
any relation in Europeans between the colour of their hair, and
their liability to the diseases of tropical countries. If the surgeons
of the several regiments, when stationed in unhealthy tropical
districts, would be so good as first to count, as a standard of
comparison, how many men, in the force whence the sick are drawn, have
dark and light-coloured hair, and hair of intermediate or doubtful
tints; and if a similar account were kept by the same medical
gentlemen, of all the men who suffered from malarious and yellow
fevers, or from dysentery, it would soon be apparent, after some
thousand cases had been tabulated, whether there exists any relation
between the colour of the hair and constitutional liability to
tropical diseases. Perhaps no such relation would be discovered, but
the investigation is well worth making. In case any positive result
were obtained, it might be of some practical use in selecting men
for any particular service. Theoretically the result would be of
high interest, as indicating one means by which a race of men
inhabiting from a remote period an unhealthy tropical climate, might
have become dark-coloured by the better preservation of dark-haired or
dark-complexioned individuals during a long succession of
generations."
  *(2) Anthropological Review, Jan., 1866, p. xxi. Dr. Sharpe also
says, with respect to India (Man a Special Creation, 1873, p. 118),
"that it has been noticed by some medical officers that Europeans with
light hair and florid complexions suffer less from diseases of
tropical countries than persons with dark hair and sallow complexions;
and, so far as I know, there appear to be good grounds for this
remark." On the other hand, Mr. Heddle, of Sierra Leone, "who has
had more clerks killed under him than any other man," by the climate
of the west African coast (W. Reade, African Sketch Book, vol. ii., p.
522), holds a directly opposite view, as does Capt. Burton.

[Bullseye]

Dr. Sharpe remarks,* that a tropical sun, which burns and blisters a
white skin, does not injure a black one at all; and, as he adds,
this is not due to habit in the individual, for children only six or
eight months old are often carried about naked, and are not
affected. I have been assured by a medical man, that some years ago
during each summer, but not during the winter, his hands became marked
with light brown patches, like, although larger than freckles, and
that these patches were never affected by sun-burning, whilst the
white parts of his skin have on several occasions been much inflamed
and blistered. With the lower animals there is, also, a constitutional
difference in liability to the action of the sun between those parts
of the skin clothed with white hair and other parts.*(2) Whether the
saving of the skin from being thus burnt is of sufficient importance
to account for a dark tint having been gradually acquired by man
through natural selection, I am unable to judge. If it be so, we
should have to assume that the natives of tropical America have
lived there for a much shorter time than the Negroes in Africa or
the Papuans in the southern parts of the Malay archipelago, just as
the lighter-coloured Hindoos have resided in India for a shorter
time than the darker aborigines of the central and southern parts of
the peninsula.

  * Man a Special Creation, 1873, p. 119.
  *(2) Variation of Animals and Plants under Domestication, vol.
ii., pp. 336, 337.

  Although with our present knowledge we cannot account for the
differences of colour in the races of man, through any advantage
thus gained, or from the direct action of climate; yet we must not
quite ignore the latter agency, for there is good reason to believe
that some inherited effect is thus produced.*

  * See, for instance, Quatrefages (Revue des Cours Scientifiques,
Oct. 10, 1868, p. 724) on the effects of residence in Abyssinia and
Arabia, and other analogous cases. Dr. Rolle (Der Mensch, seine
Abstammung, &c., 1865, s. 99) states, on the authority of Khanikof,
that the greater number of German families settled in Georgia, have
acquired in the course of two generations dark hair and eyes. Mr. D.
Forbes informs me that the Quechuas in the Andes vary greatly in
colour, according to the position of the valleys inhabited by them.

  We have seen in the second chapter that the conditions of life
affect the development of the bodily frame in a direct manner, and
that the effects are transmitted. Thus, as is generally admitted,
the European settlers in the United States undergo a slight but
extraordinary rapid change of appearance. Their bodies and limbs
become elongated; and I hear from Col. Bernys that during the late war
in the United States, good evidence was afforded of this fact by the
ridiculous appearance presented by the German regiments, when
dressed in ready-made clothes manufactured for the American market,
and which were much too long for the men in every way. There is, also,
a considerable body of evidence shewing that in the Southern States
the house-slaves of the third generation present a markedly
different appearance from the field-slaves.*

  * Harlan, Medical Researches, p. 532. Quatrefages (Unite de l'Espece
Humaine, 1861, p. 128) has collected much evidence on this head.

  If, however, we look to the races of man as distributed over the
world, we must infer that their characteristic differences cannot be
accounted for by the direct action of different conditions of life,
even after exposure to them for an enormous period of time. The
Esquimaux live exclusively on animal food; they are clothed in thick
fur, and are exposed to intense cold and to prolonged darkness; yet
they do not differ in any extreme degree from the inhabitants of
southern China, who live entirely on vegetable food, and are exposed
almost naked to a hot, glaring climate. The unclothed Fuegians live on
the marine productions of their inhospitable shores; the Botocudos
of Brazil wander about the hot forests of the interior and live
chiefly on vegetable productions; yet these tribes resemble each other
so closely that the Fuegians on board the "Beagle" were mistaken by
some Brazilians for Botocudos. The Botocudos again, as well as the
other inhabitants of tropical America, are wholly different from the
Negroes who inhabit the opposite shores of the Atlantic, are exposed
to a nearly similar climate, and follow nearly the same habits of
life.
  Nor can the differences between the races of man be accounted for by
the inherited effects of the increased or decreased use of parts,
except to a quite insignificant degree. Men who habitually live in
canoes, may have their legs somewhat stunted; those who inhabit
lofty regions may have their chests enlarged; and those who constantly
use certain sense-organs may have the cavities in which they are
lodged somewhat increased in size, and their features consequently a
little modified. With civilized nations, the reduced size of the
jaws from lessened use- the habitual play of different muscles serving
to express different emotions- and the increased size of the brain
from greater intellectual activity, have together produced a
considerable effect on their general appearance when compared with
savages.* Increased bodily stature, without any corresponding increase
in the size of the brain, may (judging from the previously adduced
case of rabbits), have given to some races an elongated skull of the
dolichocephalic type.

  * See Prof. Schaaffhausen, translat., in Anthropological Review,
Oct., 1868, p. 429.

  Lastly, the little-understood principle of correlated development
has sometimes come into action, as in the case of great muscular
development and strongly projecting supra-orbital ridges. The colour
of the skin and hair are plainly correlated, as is the texture of
the hair with its colour in the Mandans of North America.* The
colour also of the skin, and the odour emitted by it, are likewise
in some manner connected. With the breeds of sheep the number of hairs
within a given space and the number of excretory pores are
related.*(2) If we may judge from the analogy of our domesticated
animals, many modifications of structure in man probably come under
this principle of correlated development.

  * Mr. Catlin states (N. American Indians, 3rd ed., 1842, vol. i., p.
49) that in the whole tribe of the Mandans, about one in ten or twelve
of the members, of all ages and both sexes, have bright silvery grey
hair, which is hereditary. Now this hair is as coarse and harsh as
that of a horse's mane, whilst the hair of other colours is fine and
soft.
  *(2) On the odour of the skin, Godron, De l'Espece, tom. ii., p.
217. On the pores of the skin, Dr. Wilckens, Die Aufgaben der
Landwirth. Zootechnik, 1869, s. 7.

  We have now seen that the external characteristic differences
between the races of man cannot be accounted for in a satisfactory
manner by the direct action of the conditions of life, nor by the
effects of the continued use of parts, nor through the principle of
correlation. We are therefore led to enquire whether slight individual
differences, to which man is eminently liable, may not have been
preserved and augmented during a long series of generations through
natural selection. But here we are at once met by the objection that
beneficial variations alone can be thus preserved; and as far as we
are enabled to judge, although always liable to err on this head, none
of the differences between the races of man are of any direct or
special service to him. The intellectual and moral or social faculties
must of course be excepted from this remark. The great variability
of all the external differences between the races of man, likewise
indicates that they cannot be of much importance; for if important,
they would long ago have been either fixed and preserved, or
eliminated. In this respect man resembles those forms, called by
naturalists protean or polymorphic, which have remained extremely
variable, owing, as it seems, to such variations being of an
indifferent nature, and to their having thus escaped the action of
natural selection.

[Bullseye]

We have thus far been baffled in all our attempts to account for the
differences between the races of man; but there remains one
important agency, namely Sexual Selection, which appears to have acted
powerfully on man, as on many other animals. I do not intend to assert
that sexual selection will account for all the differences between the
races. An unexplained residuum is left, about which we can only say,
in our ignorance, that as individuals are continually born with, for
instance, heads a little rounder or narrower, and with noses a
little longer or shorter, such slight differences might become fixed
and uniform, if the unknown agencies which induced them were to act in
a more constant manner, aided by long-continued intercrossing. Such
variations come under the provisional class, alluded to in our
second chapter, which for want of a better term are often called
spontaneous. Nor do I pretend that the effects of sexual selection can
be indicated with scientific precision; but it can be shewn that it
would be an inexplicable fact if man had not been modified by this
agency, which appears to have acted powerfully on innumerable animals.
It can further be shewn that the differences between the races of man,
as in colour, hairiness, form of features, &c., are of a kind which
might have been expected to come under the influence of sexual
selection. But in order to treat this subject properly, I have found
it necessary to pass the whole animal kingdom in review. I have
therefore devoted to it the Second Part of this work. At the close I
shall return to man, and, after attempting to shew how far he has been
modified through sexual selection, will give a brief summary of the
chapters in this First Part.

  NOTE ON THE RESEMBLANCES AND DIFFERENCES IN THE STRUCTURE AND THE
DEVELOPMENT OF THE BRAIN IN MAN AND APES. BY PROFESSOR HUXLEY, F. R.
S.

  The controversy respecting the nature and the extent of the
differences in the structure of the brain in man and the apes, which
arose some fifteen years ago, has not yet come to an end, though the
subject matter of the dispute is, at present, totally different from
what it was formerly. It was originally asserted and re-asserted, with
singular pertinacity that the brain of all the apes, even the highest,
differs from that of man, in the absence of such conspicuous
structures as the posterior lobes of the cerebral hemispheres, with
the posterior cornu of the lateral ventricle and the hippocampus
minor, contained in those lobes, which are so obvious in man.
  But the truth that the structures in question are as well
developed in apes' as in human brains, or even better; and that it
is characteristic of all the primates (if we exclude the lemurs) to
have these parts well developed, stands at present on as secure a
basis as any proposition in comparative anatomy. Moreover, it is
admitted by every one of the long series of anatomists who, of late
years, have paid special attention to the arrangement of the
complicated sulci 0and gyri which appear upon the surface of the
cerebral hemispheres in man and the higher apes, that they are
disposed after the very same pattern in him, as in them. Every
principal gyrus and sulcus of a chimpanzee's brain is clearly
represented in that of a man, so that the terminology which applies to
the one answers for the other. On this point there is no difference of
opinion. Some years since, Professor Bischoff published a memoir* on
the cerebral convolutions of man and apes; and as the purpose of my
learned colleague was certainly not to diminish the value of the
differences between apes and men in this respect, I am glad to make
a citation from him.

  * "Die Grosshirnwindungen des Menschen"; Abhandlungen der K.
Bayerischen Akademie, B. x., 1868.

  "That the apes, and especially the orang, chimpanzee and gorilla,
come very close to man in their organisation, much nearer than to
any other animal, is a well known fact, disputed by nobody. Looking at
the matter from the point of view of organisation alone, no one
probably would ever have disputed the view of Linnaeus, that man
should be placed, merely as a peculiar species, at the head of the
mammalia and of those apes. Both shew, in all their organs, so close
an affinity, that the most exact anatomical investigation is needed in
order to demonstrate those differences which really exist. So it is
with the brains. The brains of man, the orang, the chimpanzee, the
gorilla, in spite of all the important differences which they present,
come very close to one another" (loc. cit., p. 101).
  There remains, then, no dispute as to the resemblance in fundamental
characters, between the ape's brain and man's: nor any as to the
wonderfully close similarity between the chimpanzee, orang and man, in
even the details of the arrangement of the gyri and sulci of the
cerebral hemispheres. Nor, turning to the differences between the
brains of the highest apes and that of man, is there any serious
question as to the nature and extent of these differences. It is
admitted that the man's cerebral hemispheres are absolutely and
relatively larger than those of the orang and chimpanzee; that his
frontal lobes are less excavated by the upward protrusion of the
roof of the orbits; that his gyri and sulci are, as a rule, less
symmetrically disposed, and present a greater number of secondary
plications. And it is admitted that, as a rule, in man, the
temporo-occipital or "external perpendicular" fissure, which is
usually so strongly marked a feature of the ape's brain is but faintly
marked. But it is also clear, that none of these differences
constitutes a sharp demarcation between the man's and the ape's brain.
In respect to the external perpendicular fissure of Gratiolet, in
the human brain for instance, Professor Turner remarks:*

  * Convolutions of the Human Cerebrum Topographically Considered,
1866, p. 12.

[Bullseye]

"In some brains it appears simply as an indentation of the margin of
the hemisphere, but, in others, it tends for some distance more or
less transversely outwards. I saw it in the right hemisphere of a
female brain pass more than two inches outwards; and on another
specimen, also the right hemisphere, it proceeded for four-tenths of
an inch outwards, and then extended downwards, as far as the lower
margin of the outer surface of the hemisphere. The imperfect
definition of this fissure in the majority of human brains, as
compared with its remarkable distinctness in the brain of most
Quadrumana, is owing to the presence, in the former, of certain
superficial, well marked, secondary convolutions which bridge it
over and connect the parietal with the occipital lobe. The closer
the first of these bridging gyri lies to the longitudinal fissure, the
shorter is the external parieto-occipital fissure" (loc. cit., p. 12).
  The obliteration of the external perpendicular fissure of Gratiolet,
therefore, is not a constant character of the human brain. On the
other hand, its full development is not a constant character of the
higher ape's brain. For, in the chimpanzee, the more or less extensive
obliteration of the external perpendicular sulcus by "bridging
convolutions," on one side or the other, has been noted over and
over again by Prof. Rolleston, Mr. Marshall, M. Broca and Professor
Turner. At the conclusion of a special paper on this subject the
latter writes:*

  * "Notes more especially on the bridging convolutions in the Brain
of the Chimpanzee," Proceedings of the Royal Society of Edinburgh,
1865-6.

 "The three specimens of the brain of a Chimpanzee," just described,
prove that the generalisation which Gratiolet has attempted to draw of
the complete absence of the first connecting convolution and the
concealment of the second, as essentially characteristic features in
the brain of this animal, is by no means universally applicable. In
only one specimen did the brain, in these particulars, follow the
law which Gratiolet has expressed. As regards the presence of the
superior bridging convolution, I am inclined to think that it has
existed in one hemisphere, at least, in a majority of the brains of
this animal which have, up to this time, been figured or described.
The superficial position of the second bridging convolution is
evidently less frequent, and has as yet, I believe, only been seen
in the brain (A) recorded in this communication. The asymmetrical
arrangement in the convolutions of the two hemispheres, which previous
observers have referred to in their descriptions, is also well
illustrated in these specimens" (pp. 8, 9).
  Even were the presence of the temporo-occipital, or external
perpendicular, sulcus, a mark of distinction between the higher apes
and man, the value of such a distinctive character would be rendered
very doubtful by the structure of the brain in the platyrhine apes. In
fact, while the temporo-occipital is one of the most constant of sulci
in the catarhine, or Old World, apes, it is never very strongly
developed in the New World apes; it is absent in the smaller
platyrhine; rudimentary in Pithecia;* and more or less obliterated
by bridging convolutions in Ateles.

  * FIower, "On the Anatomy of Pithecia Monachus," Proceedings of
the Zoological Society, 1862.

  A character which is thus variable within the limits of a single
group can have no great taxonomic value.
  It is further established, that the degree of asymmetry of the
convolution of the two sides in the human brain is subject to much
individual variation; and that, in those individuals of the bushman
race who have been examined, the gyri and sulci of the two hemispheres
are considerably less complicated and more symmetrical than in theEuropean brain, while, in some individuals of the chimpanzee, their
complexity and asymmetry become notable. This is particularly the case
in the brain of a young male chimpanzee figured by M. Broca.
(L'ordre des Primates, p. 165, fig. 11.)
  Again, as respects the question of absolute size, it is
established that the difference between the largest and the smallest
healthy human brain is greater than the difference between the
smallest healthy human brain and the largest chimpanzee's or orang's
brain.
  Moreover, there is one circumstance in which the orang's and
chimpanzee's brains resemble man's, but in which they differ from
the lower apes, and that is the presence of two corpora candicantia-
the Cynomorpha having but one.
  In view of these facts I do not hesitate in this year 1874, to
repeat and insist upon the proposition which I enunciated in 1863:*

  * Man's Place in Nature, p. 102.

  "So far as cerebral structure goes, therefore, it is clear that
man differs less from the chimpanzee or the orang, than these do
even from the monkeys, and that the difference between the brain of
the chimpanzee and of man is almost insignificant when compared with
that between the chimpanzee brain and that of a lemur."
  In the paper to which I have referred, Professor Bischoff does not
deny the second part of this statement, but he first makes the
irrelevant remark that it is not wonderful if the brains of an orang
and a lemur are very different; and secondly, goes on to assert
that, "If we successively compare the brain of a man with that of an
orang; the brain of this with that of a chimpanzee; of this with
that of a gorilla, and so on of a Hylobates, Semnopithecus,
Cynocephalus, Cercopithecus, Macacus, Cebus, Callithrix, Lemur,
Stenops, Hapale, we shall not meet with a greater, or even as great
a break in the degree of development of the convolutions, as we find
between the brain of a man and that of an orang or chimpanzee."
  To which I reply, firstly, that whether this assertion be true or
false, it has nothing whatever to do with the proposition enunciated
in Man's Place in Nature, which refers not to the development of the
convolutions alone, but to the structure of the whole brain. If
Professor Bischoff had taken the trouble to refer to p. 96 of the work
he criticises, in fact, he would have found the following passage:
"And it is a remarkable circumstance that though, so far as our
present knowledge extends, there is one true structural break in the
series of forms of simian brains, this hiatus does not lie between man
and the manlike apes, but between the lower and the lowest simians, or
in other words, between the Old and New World apes and monkeys and the
lemurs. Every lemur which has yet been examined, in fact, has its
cerebellum partially visible from above; and its posterior lobe,
with the contained posterior cornu and hippocampus minor, more or less
rudimentary. Every marmoset, American monkey, Old World monkey, baboon
or manlike ape, on the contrary, has its cerebellum entirely hidden,
posteriorly, by the cerebral lobes, and possesses a large posterior
cornu with a well-developed hippocampus minor."
  This statement was a strictly accurate account of what was known
when it was made; and it does not appear to me to be more than
apparently weakened by the subsequent discovery of the relatively
small development of the posterior lobes in the siamang and in the
howling monkey. Notwithstanding the exceptional brevity of the
posterior lobes in these two species, no one will pretend that their
brains, in the slightest degree, approach those of the lemurs. And if,
instead of putting Hapale out of its natural place, as Professor
Bischoff most unaccountably does, we write the series of animals he
has chosen to mention as follows: Homo, Pithecus, Troglodytes,
Hylobates, Semnopithecus, Cynocephalus, Cereopithecus, Macacus, Cebus,
Callithrix, Hapale, Lemur, Stenops, I venture to reaffirm that the
great break in this series lies between Hapale and Lemur, and that
this break is considerably greater than that between any other two
terms of that series. Professor Bischoff ignores the fact that long
before he wrote, Gratiolet had suggested the separation of the
lemurs from the other primates on the very ground of the difference in
their cerebral characters; and that Professor Flower had made the
following observations in the course of his description of the brain
of the Javan loris:*

  * Transactions of the Zoological Society, vol. v., 1862.

  "And it is especially remarkable that, in the development of the
posterior lobes, there is no approximation to the lemurine, short
hemisphered brain, in those monkeys which are commonly supposed to
approach this family in other respects, viz., the lower members of the
platyrhine group."
  So far as the structure of the adult brain is concerned, then, the
very considerable additions to our knowledge, which have been made
by the researches of so many investigators, during the past ten years,
fully justify the statement which I made in 1863. But it has been
said, that, admitting the similarity between the adult brains of man
and apes, they are nevertheless, in reality, widely different, because
they exhibit fundamental differences in the mode of their development.
No one would be more ready than I to admit the force of this argument,
if such fundamental differences of development really exist. But I
deny that they do exist. On the contrary, there is a fundamental
agreement in the development of the brain in men and apes.
  Gratiolet originated the statement that there is a fundamental
difference in the development of the brains of apes and that of man-
consisting in this; that, in the apes, the sulci which first make
their appearance are situated on the posterior region of the
cerebral hemispheres, while, in the human foetus, the sulci first
become visible on the frontal lobes.*

  * "Chez tous les singes, les plis posterieurs se developpent les
premiers; les plis anterieurs se developpent plus tard, aussi la
vertebre occipitale et la parietale sont-elles relativement
tres-grandes chez le foetus. L'Homme presente une exception
remarquable quant a l'epoque de l'apparition des plis frontaux, qui
sont les premiers indiques; mais le developpement general du lobe
frontal, envisage seulement par rapport a son volume, suit les memes
lois que dans les singes"; Gratiolet, Memoire sur les plis cerebres de
l'Homme et des Primateaux, p. 39, tab. iv, fig. 3.

  This general statement is based upon two observations, the one of
a gibbon almost ready to be born, in which the posterior gyri were
"well developed," while those of the frontal lobes were "hardly
indicated"* (loc. cit., p. 39), and the other of a human foetus at the
22nd or 23rd week of utero-gestation, in which Gratiolet notes that
the insula was uncovered, but that nevertheless "des incisures
sement de lobe anterieur, une scissure peu profonde indique la
separation du lobe occipital, tres-reduit, d'ailleurs des cette
epoque. Le reste de la surface cerebrale est encore absolument lisse."

  * Gratiolet's words are (loc. cit., p. 39): "Dans le foetus dont
il s'agit les plis cerebraux posterieurs sont bien developpes,
tandis que les plis du lobe frontal sont a peine indiques." The
figure, however (pl. iv, fig. 3), shews the fissure of Rolando, and
one of the frontal sulci plainly enough. Nevertheless, M. Alix, in his
"Notice sur les travaux anthropologiques de Gratiolet" (Mem. de la
Societe d'Anthropologie de Paris, 1868, page 32), writes thus:
"Gratiolet a eu entre les mains le cerveau d'un foetus de Gibbon,
singe eminemment superieur, et tellement rapproche de l'orang, que des
naturalistes tres-competents l'ont range parmi les anthropoides. M.
Huxley, par exemple, n'hesite pas sur ce point. Eh bien, c'est sur
le cerveau d'un foetus de Gibbon que Gratiolet a vu les
circonvolutions du lobe temporo-sphenoidal deja developpees
lorsqu'il n'existent pas encore de plis sur le lobe frontal. Il
etait donc bien autorise a dire que, chez l'homme les
circonvolutions apparaissent d' a en w, tandis que chez les singes
elles se developpent d'w en a."

  Three views of this brain are given in plate II, figs. 1, 2, 3, of
the work cited, shewing the upper, lateral and inferior views of the
hemispheres, but not the inner view. It is worthy of note that the
figure by no means bears out Gratiolet's description, inasmuch as
the fissure (antero-temporal) on the posterior half of the face of the
hemisphere is more marked than any of those vaguely indicated in the
anterior half. If the figure is correct, it in no way justifies
Gratiolet's conclusion: "Il y a donc entre ces cerveaux [those of a
Callithrix and of a gibbon] et celui du foetus humain une difference
fondamental. Chez celui-ci, longtemps avant que les plis temporaux
apparaissent, les plis frontaux, essayent d'exister."
  Since Gratiolet's time, however, the development of the gyri and
sulci of the brain has been made the subject of renewed
investigation by Schmidt, Bischoff, Pansch,* and more particularly
by Ecker,*(2) whose work is not only the latest, but by far the most
complete, memoir on the subject.

  * Uber die typische Anordnung der Furchen und Windungen auf den
Grosshirn-Hemispharen des Menschen und der Affen," Archiv fur
Anthropologie, iii., 1868
  *(2) "Zur Entwicklungsgeschichte der Furchen und Windungen der
Grosshirn-Hemispharen im Foetus des Menschen." Archiv fur
Anthropologie, iii., 1868.

  The final results of their inquiries may be summed up as follows:-
  1. In the human foetus, the sylvian fissure is formed in the
course of the third month of utero-gestation. In this, and in the
fourth month, the cerebral hemispheres are smooth and rounded (with
the exception of the sylvian depression), and they project backwards
far beyond the cerebellum.
  2. The sulci, properly so called, begin to appear in the interval
between the end of the fourth and the beginning of the sixth month
of foetal life, but Ecker is careful to point out that, not only the
time, but the order, of their appearance is subject to considerable
individual variation. In no case, however, are either the frontal or
the temporal sulci the earliest.
  The first which appears, in fact, lies on the inner face of the
hemisphere (whence doubtless Gratiolet, who does not seem to have
examined that face in his foetus, overlooked it), and is either the
internal perpendicular (occipito-parietal), or the calcarine sulcus,
these two being close together and eventually running into one
another. As a rule the occipito-parietal is the earlier of the two.
  3. At the latter part of this period, another sulcus, the
"posterio-parietal," or "Fissure of Rolando" is developed, and it is
followed, in the course of the sixth month, by the other principal
sulci of the frontal, parietal, temporal and occipital lobes. There
is, however, no clear evidence that one of these constantly appears
before the other; and it is remarkable that, in the brain at the
period described and figured by Ecker (loc. cit., pp. 212-213 tab. II,
figs. 1, 2, 3, 4), the antero-temporal sulcus (scissure parallele)
so characteristic of the ape's brain, is as well, if not better
developed than the fissure of Rolando, and is much more marked than
the proper frontal sulci.
  Taking the facts as they now stand, it appears to me that the
order of the appearance of the sulci and gyri in the foetal human
brain is in perfect harmony with the general doctrine of evolution,
and with the view that man has been evolved from some ape-like form;
though there can be no doubt that that form was, in many respects,
different from any member of the primates now living.
  Von Baer taught us, half a century ago, that, in the course of their
development, allied animals put on at first, the characters of the
greater groups to which they belong, and, by degrees, assume those
which restrict them within the limits of their family, genus, and
species; and he proved, at the same time, that no developmental
stage of a higher animal is precisely similar to the adult condition
of any lower animal. It is quite correct to say that a frog passes
through the condition of a fish, inasmuch as at one period of its life
the tadpole has all the characters of a fish, and if it went no
further, would have to be grouped among fishes. But it is equally true
that a tadpole is very different from any known fish.
  In like manner, the brain of a human foetus, at the fifth month, may
correctly be said to be, not only the brain of an ape, but that of
an arctopithecine or marmoset-like ape; for its hemispheres, with
their great posterior lobster, and with no sulci but the sylvian and
the calcarine, present the characteristics found only in the group
of the arctopithecine primates. But it is equally true, as Gratiolet
remarks, that, in its widely open sylvian fissure, it differs from the
brain of any actual marmoset. No doubt it would be much more similar
to the brain of an advanced foetus of a marmoset. But we know
nothing whatever of the development of the brain in the marmosets.
In the Platyrhini proper, the only observation with which I am
acquainted is due to Pansch, who found in the brain of a foetal
Cebus apella, in addition to the sylvian fissure and the deep
calcarine fissure, only a very shallow antero-temporal fissure
(scissure parallele of Gratiolet).
  Now this fact, taken together with the circumstance that the
antero-temporal sulcus is present in such Platyrhini as the Saimiri,
which present mere traces of sulci on the anterior half of the
exterior of the cerebral hemispheres, or none at all, undoubtedly,
so far as it goes, affords fair evidence in favour of Gratiolet's
hypothesis, that the posterior sulci appear before the anterior, in
the brains of the Platyrhini. But, it by no means follows, that the
rule which may hold good for the Platyrhini extends to the
Catarhini. We have no information whatever respecting the
development of the brain in the Cynomorphia; and, as regards the
Anthropomorpha, nothing but the account of the brain of the gibbon
near birth, already referred to. At the present moment there is not
a shadow of evidence to show that the sulci of a chimpanzee's, or
orang's, brain do not appear in the same order as a man's.
  Gratiolet opens his preface with the aphorism: "Il est dangereux
dans les sciences de conclure trop vite." I fear he must have
forgotten this sound maxim by the time he had reached the discussion
of the differences between men and apes, in the body of his work. No
doubt, the excellent author of one of the most remarkable
contributions to the just understanding of the mammalian brain which
has ever been made, would have been the first to admit the
insufficiency of his data had he lived to profit by the advance of
inquiry. The misfortune is that his conclusions have been employed
by persons incompetent to appreciate their foundation, as arguments in
favour of obscurantism.*

  * For example, M. l'Abbe Lecomte in his terrible pamphlet, Le
Darwinisme et l'origine de l'homme, 1873.

  But it is important to remark that, whether Gratiolet was right or
wrong in his hypothesis respecting the relative order of appearance of
the temporal and frontal sulci, the fact remains; that. before
either temporal or frontal sulci, appear, the foetal brain of man
presents characters which are found only in the lowest group of the
primates (leaving out the lemurs); and that this is exactly what we
should expect to be the case, if man has resulted from the gradual
modification of the same form as that from which the other primates
have sprung.




--------------------------------------------------------------------------------

[Bullseye]

Part Two - Sexual Selection
Chapter VIII - Principles of Sexual Selection

  WITH animals which have their sexes separated, the males necessarily
differ from the females in their organs of reproduction; and these are
the primary sexual characters. But the sexes often differ in what
Hunter has called secondary sexual characters, which are not
directly connected with the act of reproduction; for instance, the
male possesses certain organs of sense or locomotion, of which the
female is quite destitute, or has them more highly-developed, in order
that he may readily find or reach her; or again the male has special
organs of prehension for holding her securely. These latter organs, of
infinitely diversified kinds, graduate into those which are commonly
ranked as primary, and in some cases can hardly be distinguished
from them; we see instances of this in the complex appendages at the
apex of the abdomen in male insects. Unless indeed we confine the term
"primary" to the reproductive glands, it is scarcely possible to
decide which ought to be called primary and which secondary.
  The female often differs from the male in having organs for the
nourishment or protection of her young, such as the mammary glands
of mammals, and the abdominal sacks of the marsupials. In some few
cases also the male possesses similar organs, which are wanting in the
female, such as the receptacles for the ova in certain male fishes,
and those temporarily developed in certain male frogs. The females
of most bees are provided with a special apparatus for collecting
and carrying pollen, and their ovipositor is modified into a sting for
the defense of the larvae and the community. Many similar cases
could be given, but they do not here concern us. There are, however,
other sexual differences quite unconnected with the primary
reproductive organs, and it is with these that we are more
especially concerned such as the greater size, strength, and pugnacity
of the male, his weapons of offence or means of defence against
rivals, his gaudy colouring and various ornaments, his power of
song, and other such characters.
  Besides the primary and secondary sexual differences, such as the
foregoing, the males and females of some animals differ in
structures related to different habits of life, and not at all, or
only indirectly, to the reproductive functions. Thus the females of
certain flies (Culicidae and Tabanidae) are blood-suckers, whilst
the males, living on flowers, have mouths destitute of mandibles.* The
males of certain moths and of some crustaceans (e. g. Tanais) have
imperfect, closed mouths, and cannot feed. The complemental males of
certain cirripedes live like epiphytic plants either on the female
or the hermaphrodite form, and are destitute of a mouth and of
prehensile limbs. In these cases it is the male which has been
modified, and has lost certain important organs, which the females
possess. In other cases it is the female which has lost such parts;
for instance, the female glow-worm is destitute of wings, as also
are many female moths, some of which never leave their cocoons. Many
female parasitic crustaceans have lost their natatory legs. In some
weevil-beetles (Curculionidae) there is a great difference between the
male and female in the length of the rostrum or snout;*(2) but the
meaning of this and of many analogous differences, is not at all
understood. Differences of structure between the two sexes in relation
to different habits of life are generally confined to the lower
animals; but with some few birds the beak of the male differs from
that of the female. In the Huia of New Zealand the difference is
wonderfully great, and we hear from Dr. Buller*(3) that the male
uses his strong beak in chiselling the larvae of insects out of
decayed wood, whilst the female probes the softer parts with her far
longer, much curved and pliant beak: and thus they mutually aid each
other. In most cases, differences of structure between the sexes are
more or less directly connected with the propagation of the species:
thus a female, which has to nourish a multitude of ova, requires
more food than the male, and consequently requires special means for
procuring it. A male animal, which lives for a very short time,
might lose its organs for procuring food through disuse, without
detriment; but he would retain his locomotive organs in a perfect
state, so that he might reach the female. The female, on the other
hand, might safely lose her organs for flying, swimming, or walking,
if she gradually acquired habits which rendered such powers useless.

  * Westwood, Modern Classification of Insects, vol. ii., 1840, p.
541. For the statement about Tanais, mentioned below, I am indebted to
Fritz Muller.
  *(2) Kirby and Spence, Introduction to Entomology, vol. iii.,
1826, p. 309.
  *(3) Birds of New Zealand, 1872, p. 66.

  We are, however, here concerned only with sexual selection. This
depends on the advantage which certain individuals have over others of
the same sex and species solely in respect of reproduction. When, as
in the cases above mentioned, the two sexes differ in structure in
relation to different habits of life, they have no doubt been modified
through natural selection, and by inheritance, limited to one and
the same sex. So again the primary sexual organs, and those for
nourishing or protecting the young, come under the same influence; for
those individuals which generated or nourished their offspring best,
would leave, ceteris paribus, the greatest number to inherit their
superiority; whilst those which generated or nourished their offspring
badly, would leave but few to inherit their weaker powers. As the male
has to find the female, he requires organs of sense and locomotion,
but if these organs are necessary for the other purposes of life, as
is generally the case, they will have been developed through natural
selection. When the male has found the female, he sometimes absolutely
requires prehensile organs to hold her; thus Dr. Wallace informs me
that the males of certain moths cannot unite with the females if their
tarsi or feet are broken. The males of many oceanic crustaceans,
when adult, have their legs and antennae modified in an
extraordinary manner for the prehension of the female; hence we may
suspect that it is because these animals are washed about by the waves
of the open sea, that they require these organs in order to
propagate their kind, and if so, their development has been the result
of ordinary or natural selection. Some animals extremely low in the
scale have been modified for this same purpose; thus the males of
certain parasitic worms, when fully grown, have the lower surface of
the terminal part of their bodies roughened like a rasp, and with this
they coil round and permanently hold the females.*

  * M. Perrier advances this case (Revue Scientifique, Feb. 1, 1873,
p. 865) as one fatal to the belief in sexual election, inasmuch as
he supposes that I attribute all the differences between the sexes
to sexual selection. This distinguished naturalist, therefore, like so
many other Frenchmen, has not taken the trouble to understand even the
first principles of sexual selection. An English naturalist insists
that the claspers of certain male animals could not have been
developed through the choice of the female! Had I not met with this
remark, I should not have thought it possible for any one to have read
this chapter and to have imagined that I maintain that the choice of
the female had anything to do with the development of the prehensile
organs in the male.

[Bullseye]

When the two sexes follow exactly the same habits of life, and the
male has the sensory or locomotive organs more highly developed than
those of the female, it may be that the perfection of these is
indispensable to the male for finding the female; but in the vast
majority of cases, they serve only to give one male an advantage
over another, for with sufficient time, the less well-endowed males
would succeed in pairing with the females; and judging from the
structure of the female, they would be in all other respects equally
well adapted for their ordinary habits of life. Since in such cases
the males have acquired their present structure, not from being better
fitted to survive in the struggle for existence, but from having
gained an advantage over other males, and from having transmitted this
advantage to their male offspring alone, sexual selection must here
have come into action. It was the importance of this distinction which
led me to designate this form of selection as Sexual Selection. So
again, if the chief service rendered to the male by his prehensile
organs is to prevent the escape of the female before the arrival of
other males, or when assaulted by them, these organs will have been
perfected through sexual selection, that is by the advantage
acquired by certain individuals over their rivals. But in most cases
of this kind it is impossible to distinguish between the effects of
natural and sexual selection. Whole chapters could be filled with
details on the differences between the sexes in their sensory,
locomotive, and prehensile organs. As, however, these structures are
not more interesting than others adapted for the ordinary purposes
of life, I shall pass them over almost entirely, giving only a few
instances under each class.
  There are many other structures and instincts which must have been
developed through sexual selection- such as the weapons of offence and
the means of defence- of the males for fighting with and driving
away their rivals- their courage and pugnacity- their various
ornaments- their contrivances for producing vocal or instrumental
music- and their glands for emitting odours, most of these latter
structures serving only to allure or excite the female. It is clear
that these characters are the result of sexual and not of ordinary
selection, since unarmed, unornamented, or unattractive males would
succeed equally well in the battle for life and in leaving a
numerous progeny, but for the presence of better endowed males. We may
infer that this would be the case, because the females, which are
unarmed and unornamented, are able to survive and procreate their
kind. Secondary sexual characters of the kind just referred to, will
be fully discussed in the following chapters, as being in many
respects interesting, but especially as depending on the will, choice,
and rivalry of the individuals of either sex. When we behold two males
fighting for the possession of the female, or several male birds
displaying their gorgeous plumage, and performing strange antics
before an assembled body of females, we cannot doubt that, though
led by instinct, they know what they are about, and consciously
exert their mental and bodily powers.
  Just as man can improve the breeds of his game-cocks by the
selection of those birds which are victorious in the ****-pit, so it
appears that the strongest and most vigorous males, or those
provided with the best weapons, have prevailed under nature, and
have led to the improvement of the natural breed or species. A
slight degree of variability leading to some advantage, however
slight, in reiterated deadly contests would suffice for the work of
sexual selection; and it is certain that secondary sexual characters
are eminently variable. Just as man can give beauty, according to
his standard of taste, to his male poultry, or more strictly can
modify the beauty originally acquired by the parent species, can
give to the Sebright bantam a new and elegant plumage, an erect and
peculiar carriage- so it appears that female birds in a state of
nature, have by a long selection of the more attractive males, added
to their beauty or other attractive qualities. No doubt this implies
powers of discrimination and taste on the part of the female which
will at first appear extremely improbable; but by the facts to be
adduced hereafter, I hope to be able to shew that the females actually
have these powers. When, however, it is said that the lower animals
have a sense of beauty, it must not be supposed that such sense is
comparable with that of a cultivated man, with his multiform and
complex associated ideas. A more just comparison would be between
the taste for the beautiful in animals, and that in the lowest
savages, who admire and deck themselves with any brilliant,
glittering, or curious object.
  From our ignorance on several points, the precise manner in which
sexual selections acts is somewhat uncertain. Nevertheless if those
naturalists who already believe in the mutability of species, will
read the following chapters, they will, I think, agree with me, that
sexual selection has played an important part in the history of the
organic world. It is certain that amongst almost all animals there
is a struggle between the males for the possession of the female. This
fact is so notorious that it would be superfluous to give instances.
Hence the females have the opportunity of selecting one out of several
males, on the supposition that their mental capacity suffices for
the exertion of a choice. In many cases special circumstances tend
to make the struggle between the males particularly severe. Thus the
males of our migratory birds generally arrive at their places of
breeding before the females, so that many males are ready to contend
for each female. I am informed by Mr. Jenner Weir, that the
bird-catchers assert that this is invariably the case with the
nightingale and blackcap, and with respect to the latter he can
himself confirm the statement.
  Mr. Swaysland of Brighton has been in the habit, during the last
forty years, of catching our migratory birds on their first arrival,
and he has never known the females of any species to arrive before
their males. During one spring he shot thirty-nine males of Ray's
wagtail (Budytes raii) before he saw a single female. Mr. Gould has
ascertained by the dissection of those snipes which arrive the first
in this country, that the males come before the females. And the
like holds good with most of the migratory birds of the United
States.* The majority of the male salmon in our rivers, on coming up
from the sea, are ready to breed before the females. So it appears
to be with frogs and toads. Throughout the great class of insects
the males almost always are the first to emerge from the pupal
state, so that they generally abound for a time before any females can
be seen.*(2) The cause of this difference between the males and
females in their periods of arrival and maturity is sufficiently
obvious. Those males which annually first migrated into any country,
or which in the spring were first ready to breed, or were the most
eager, would leave the largest number of offspring; and these would
tend to inherit similar instincts and constitutions. It must be
borne in mind that it would have been impossible to change very
materially the time of sexual maturity in the females, without at
the same time interfering with the period of the production of the
young- a period which must be determined by the seasons of the year.
On the whole there can be no doubt that with almost all animals, in
which the sexes are separate, there is a constantly recurrent struggle
between the males for the possession of the females.

  * J. A. Allen, on the "Mammals and Winter Birds of Florida,"
Bulletin of Comparative Zoology, Harvard College, p. 268.
  *(2) Even with those plants in which the sexes are separate, the
male flowers are generally mature before the female. As first shewn by
C. K. Sprengel, many hermaphrodite plants are dichogamous; that is,
their male and female organs are not ready at the same time, so that
they cannot be self-fertilised. Now in such flowers, the pollen is
in general matured before the stigma, though there are exceptional
cases in which the female organs are before-hand.

  Our difficulty in regard to sexual selection lies in understanding
how it is that the males which conquer other males, or those which
prove the most attractive to the females, leave a greater number of
offspring to inherit their superiority than their beaten and less
attractive rivals. Unless this result does follow, the characters
which give to certain males an advantage over others, could not be
perfected and augmented through sexual selection. When the sexes exist
in exactly equal numbers, the worst-endowed males will (except where
polygamy prevails), ultimately find females, and leave as many
offspring, as well fitted for their general habits of life, as the
best-endowed males. From various facts and considerations, I
formerly inferred that with most animals, in which secondary sexual
characters are well developed, the males considerably exceeded the
females in number; but this is not by any means always true. If the
males were to the females as two to one, or as three to two, or even
in a somewhat lower ratio, the whole affair would be simple; for the
better-armed or more attractive males would leave the largest number
of offspring. But after investigating, as far as possible, the
numerical proportion of the sexes, I do not believe that any great
inequality in number commonly exists. In most cases sexual selection
appears to have been effective in the following manner.
  Let us take any species, a bird for instance, and divide the females
inhabiting a district into two equal bodies, the one consisting of the
more vigorous and better-nourished individuals, and the other of the
less vigorous and healthy. The former, there can be little doubt,
would be ready to breed in the spring before the others; and this is
the opinion of Mr. Jenner Weir, who has carefully attended to the
habits of birds during many years. There can also be no doubt that the
most vigorous, best-nourished and earliest breeders would on an
average succeed in rearing the largest number of fine offspring.*
The males, as we have seen, are generally ready to breed before the
females; the strongest, and with some species the best armed of the
males, drive away the weaker; and the former would then unite with the
more vigorous and better-nourished females, because they are the first
to breed.*(2) Such vigorous pairs would surely rear a larger number of
offspring than the retarded females, which would be compelled to unite
with the conquered and less powerful males, supposing the sexes to
be numerically equal; and this is all that is wanted to add, in the
course of successive generations, to the size, strength and courage of
the males, or to improve their weapons.

[Bullseye]

* Here is excellent evidence on the character of the offspring
from an experienced ornithologist. Mr. J. A. Allen, in speaking
(Mammals and Winter Birds of E. Florida, p. 229) of the later
broods, after the accidental destruction of the first, says, that
these "are found to be smaller and paler-coloured than those hatched
earlier in the season. In cases where several broods are reared each
year, as a general rule the birds of the earlier broods seem in all
respects the most perfect and vigorous."
  *(2) Hermann Muller has come to this same conclusion with respect to
those female bees which are the first to emerge from the pupa each
year. See his remarkable essay, "Anwendung der Darwin'schen Lehre
auf Bienen," Verh. d. V. Jahrg., xxix., p. 45

  But in very many cases the males which conquer their rivals, do
not obtain possession of the females, independently of the choice of
the latter. The courtship of animals is by no means so simple and
short an affair as might be thought. The females are most excited
by, or prefer pairing with, the more ornamented males, or those
which are the best songsters, or play the best antics; but it is
obviously probable that they would at the same time prefer the more
vigorous and lively males, and this has in some cases been confirmed
by actual observation.* Thus the more vigorous females, which are
the first to breed, will have the choice of many males; and though
they may not always select the strongest or best armed, they will
select those which are vigorous and well armed, and in other
respects the most attractive. Both sexes, therefore, of such early
pairs would as above explained, have an advantage over others in
rearing offspring; and this apparently has sufficed during a long
course of generations to add not only to the strength and fighting
powers of the males, but likewise to their various ornaments or
other attractions.

  * With respect to poultry, I have received information, hereafter to
be given, to this effect. Even birds, such as pigeons, which pair
for life, the female, as I hear from Mr. Jenner Weir, will desert
her mate if he is injured or grows weak.

  In the converse and much rarer case of the males selecting
particular females, it is plain that those which were the most
vigorous and had conquered others, would have the freest choice; and
it is almost certain that they would select vigorous as well as
attractive females. Such pairs would have an advantage in rearing
offspring, more especially if the male had the power to defend the
female during the pairing-season as occurs with some of the higher
animals, or aided her in providing for the young. The same
principles would apply if each sex preferred and selected certain
individuals of the opposite sex; supposing that they selected not only
the more attractive, but likewise the more vigorous individuals.

  Numerical Proportion of the Two Sexes.- I have remarked that
sexual selection would be a simple affair if the males were
considerably more numerous than the females. Hence I was led to
investigate, as far as I could, the proportions between the two
sexes of as many animals as possible; but the materials are scanty.
I will here give only a brief abstract of the results, retaining the
details for a supplementary discussion, so as not to interfere with
the course of my argument. Domesticated animals alone afford the means
of ascertaining the proportional numbers at birth; but no records have
been specially kept for this purpose. By indirect means, however, I
have collected a considerable body of statisties, from which it
appears that with most of our domestic animals the sexes are nearly
equal at birth. Thus 25,560 births of race-horses have been recorded
during twenty-one years, and the male births were to the female births
as 99.7 to 100. In greyhounds the inequality is greater than with
any other animal, for out of 6878 births during twelve years, the male
births were to the female as 110.1 to 100. It is, however, in some
degree doubtful whether it is safe to infer that the proportion
would be the same under natural conditions as under domestication; for
slight and unknown differences in the conditions affect the proportion
of the sexes. Thus with mankind, the male births in England are as
104.5, in Russia as 108.9, and with the Jews of Livonia as 120, to 100
female births. But I shall recur to this curious point of the excess
of male births in the supplement to this chapter. At the Cape of
Good Hope, however, male children of European extraction have been
born during several years in the proportion of between 90 and 99 to
100 female children.
  For our present purpose we are concerned with the proportions of the
sexes, not only at birth, but also at maturity, and this adds
another element of doubt; for it is a well-ascertained fact that
with man the number of males dying before or during birth, and
during the first two years of infancy, is considerably larger than
that of females. So it almost certainly is with male lambs, and
probably with some other animals. The males of some species kill one
another by fighting; or they drive one another about until they become
greatly emaciated. They must also be often exposed to various dangers,
whilst wandering about in eager search for the females. In many
kinds of fish the males are much smaller than the females, and they
are believed often to be devoured by the latter, or by other fishes.
The females of some birds appear to die earlier than the males; they
are also liable to be destroyed on their nests, or whilst in charge of
their young. With insects the female larvae are often larger than
those of the males, and would consequently be more likely to be
devoured. In some cases the mature females are less active and less
rapid in their movements than the males, and could not escape so
well from danger. Hence, with animals in a state of nature, we must
rely on mere estimation, in order to judge of the proportions of the
sexes at maturity; and this is but little trustworthy, except when the
inequality is strongly marked. Nevertheless, as far as a judgment
can be formed, we may conclude from the facts given in the supplement,
that the males of some few mammals, of many birds, of some fish and
insects, are considerably more numerous than the females.
  The proportion between the sexes fluctuates slightly during
successive years: thus with race-horses, for every 100 mares born
the stallions varied from 107.1 in one year to 92.6 in another year,
and with greyhounds from 116.3 to 95.3. But had larger numbers been
tabulated throughout an area more extensive than England, these
fluctuations would probably have disappeared; and such as they are,
would hardly suffice to lead to effective sexual selection in a
state of nature. Nevertheless, in the cases of some few wild
animals, as shewn in the supplement, the proportions seem to fluctuate
either during different seasons or in different localities in a
sufficient degree to lead to such selection. For it should be observed
that any advantage, gained during certain years or in certain
localities by those males which were able to conquer their rivals,
or were the most attractive to the females, would probably be
transmitted to the offspring, and would not subsequently be
eliminated. During the succeeding seasons, when, from the equality
of the sexes, every male was able to procure a female, the stronger or
more attractive males previously produced would still have at least as
good a chance of leaving offspring as the weaker or less attractive.

  Polygamy.- The practice of polygamy leads to the same results as
would follow from an actual inequality in the number of the sexes; for
if each male secures two or more females, many males cannot pair;
and the latter assuredly will be the weaker or less attractive
individuals. Many mammals and some few birds are polygamous, but
with animals belonging to the lower classes I have found no evidence
of this habit. The intellectual powers of such animals are, perhaps,
not sufficient to lead them to collect and guard a harem of females.
That some relation exists between polygamy and the development of
secondary sexual characters, appears nearly certain; and this supports
the view that a numerical preponderance of males would be eminently
favourable to the action of sexual selection. Nevertheless many
animals, which are strictly monogamous, especially birds, display
strongly-marked secondary sexual characters; whilst some few
animals, which are polygamous, do not have such characters.
  We will first briefly run through the mammals, and then turn to
birds. The gorilla seems to be polygamous, and the male differs
considerably from the female; so it is with some baboons, which live
in herds containing twice as many adult females as males. In South
America the Mycetes caraya present well-marked sexual differences,
in colour, beard, and vocal organs; and the male generally lives
with two or three wives: the male of the Cebus capucinus differs
somewhat from the female, and appears to be polygamous.* Little is
known on this head with respect to most other monkeys, but some
species are strictly monogamous. The ruminants are eminently
polygamous, and they present sexual differences more frequently than
almost any other group of mammals; this holds good, especially in
their weapons, but also in other characters. Most deer, cattle, and
sheep are polygamous; as are most antelopes, though some are
monogamous. Sir Andrew Smith, in speaking of the antelopes of South
Africa, says that in herds of about a dozen there was rarely more than
one mature male. The Asiatic Antilope saiga appears to be the most
inordinate polygamist in the world; for Pallas*(2) states that the
male drives away all rivals, and collects a herd of about a hundred
females and kids together; the female is hornless and has softer hair,
but does not otherwise differ much from the male. The wild horse of
the Falkland Islands and of the western states of N. America is
polygamous, but, except in his greater size and in the proportions
of his body, differs but little from the mare. The wild boar
presents well-marked sexual characters, in his great tusks and some
other points. In Europe and in India he leads a solitary life,
except during the breeding-season; but as is believed by Sir W.
Elliot, who has had many opportunities in India of observing this
animal, he consorts at this season with several females. Whether
this holds good in Europe is doubtful, but it is supported by some
evidence. The adult male Indian elephant, like the boar, passes much
of his time in solitude; but as Dr. Campbell states, when with others,
"It is rare to find more than one male with a whole herd of
females"; the larger males expelling or killing the smaller and weaker
ones. The male differs from the female in his immense tusks, greater
size, strength, and endurance; so great is the difference in these
respects that the males when caught are valued at one-fifth more
than the females.*(3) The sexes of other pachydermatous animals differ
very little or not at all, and, as far as known, they are not
polygamists. Nor have I heard of any species in the Orders of
Cheiroptera, Edentata, Insectivora and rodents being polygamous,
excepting that amongst the rodents, the common rat, according to
some rat-catchers, lives with several females. Nevertheless the two
sexes of some sloths (Edentata) differ in the character and colour
of certain patches of hair on their shoulders.*(4) And many kinds of
bats (Cheiroptera) present well-marked sexual differences, chiefly
in the males possessing odoriferous glands and pouches, and by their
being of a lighter colour.*(5) In the great order of rodents, as far
as I can learn, the sexes rarely differ, and when they do so, it is
but slightly in the tint of the fur.

[Bullseye]

* On the Gorilla, Savage and Wyman, Boston Journal of Natural
History, vol. v., 1845-47, p. 423. On Cynocephalus, Brehm,
Illustriertes Thierleben, B. i., 1864, s. 77. On Mycetes, Rengger,
Naturgeschichte der Saugethiere von Paraguay, 1830, ss. 14, 20. On
Cebus, Brehm, ibid., s. 108.
  *(2) Pallas, Spicilegia Zoolog., fasc. xii., 1777, p. 29. Sir Andrew
Smith, Illustrations of the Zoology of S. Africa, 1849, pl. 29, on the
Kobus. Owen, in his Anatomy of Vertebrates (vol. iii., 1868, p. 633)
gives a table shewing incidentally which species of antelopes are
gregarious.
  *(3) Dr. Campbell, in Proc., Zoolog. Soc., 1869, p. 138. See also an
interesting paper by Lieut. Johnstone, in Proceedings, Asiatic Society
of Bengal, May, 1868.
  *(4) Dr. Gray, in Annals and Magazine of Natural History, 1871, p.
302.
  *(5) See Dr. Dobson's excellent paper in Proceedings of the
Zoological Society, 1873, p. 241.

  As I hear from Sir Andrew Smith, the lion in South Africa
sometimes lives with a single female, but generally with more, and, in
one case, was found with as many as five females; so that he is
polygamous. As far as I can discover, he is the only polygamist
amongst all the terrestrial Carnivora, and he alone presents
well-marked sexual characters. If, however, we turn to the marine
Carnivora, as we shall hereafter see, the case is widely different;
for many species of seals offer extraordinary sexual differences,
and they are eminently polygamous. Thus, according to Peron, the
male sea-elephant of the southern ocean always possesses several
females, and the sea-lion of Forster is said to be surrounded by
from twenty to thirty females. In the North, the male sea-bear of
Steller is accompanied by even a greater number of females. It is an
interesting fact, as Dr. Gill remarks,* that in the monogamous
species, "or those living in small communities, there is little
difference in size between the males and females; in the social
species, or rather those of which the males have harems, the males are
vastly larger than the females."

  * "The Eared Seals," American Naturalist, vol. iv., Jan. 1871.

  Amongst birds, many species, the sexes of which differ greatly
from each other, are certainly monogamous. In Great Britain we see
well-marked sexual differences, for instance, in the wild-duck which
pairs with a single female, the common blackbird, and the bullfinch
which is said to pair for life. I am informed by Mr. Wallace that
the like is true of chatterers or Cotingidae of South America, and
of many other birds. In several groups I have not been able to
discover whether the species are polygamous or monogamous. Lesson says
that birds of paradise, so remarkable for their sexual differences,
are polygamous, but Mr. Wallace doubts whether he had sufficient
evidence. Mr. Salvin tells me he has been led to believe that
humming-birds are polygamous. The male widow-bird, remarkable for
his caudal plumes, certainly seems to be a polygamist.* I have been
assured by Mr. Jenner Weir and by others, that it is somewhat common
for three starlings to frequent the same nest; but whether this is a
case of polygamy or polyandry has not been ascertained.

  * The Ibis, vol. iii., 1861, p. 133, on the Progne widow-bird. See
also on the Vidua axillaris, ibid., vol. ii., 1860, p. 211. On the
polygamy of the capercailzie and great bustard, see L. Lloyd, Game
Birds of Sweden, 1867, pp. 19, and 182. Montagu and Selby speak of the
black grouse as polygamous and of the red grouse as monogamous.

  The Gallinaceae exhibit almost as strongly marked sexual differences
as birds of paradise or humming-birds, and many of the species are, as
is well know, polygamous; others being strictly monogamous. What a
contrast is presented between the sexes of the polygamous peacock or
pheasant, and the monogamous guinea-fowl or partridge! Many similar
cases could be given, as in the grouse tribe, in which the males of
the polygamous capercailzie and black-**** differ greatly from the
females; whilst the sexes of the monogamous red grouse and ptarmigan
differ very little. In the Cursores, except amongst the bustards,
few species offer strongly-marked sexual differences, and the great
bustard (Otis tarda) is said to be polygamous. With the Grallatores,
extremely few species differ sexually, but the ruff (Machetes
pugnax) affords a marked exception, and this species is believed by
Montagu to be a polygamist. Hence it appears that amongst birds
there often exists a close relation between polygamy and the
development of strongly-marked sexual differences. I asked Mr.
Bartlett, of the Zoological Gardens, who has had very large experience
with birds, whether the male tragopan (one of the Gallinaceae) was
polygamous, and I was struck by his answering, "I do not know, but
should think so from his splendid colours."
  It deserves notice that the instinct of pairing with a single female
is easily lost under domestication. The wild-duck is strictly
monogamous, the domestic-duck highly polygamous. The Rev. W. D. Fox
informs me that out of some half-tamed wild-ducks, on a large pond
in his neighborhood, so many mallards were shot by the game-keeper
that only one was left for every seven or eight females; yet unusually
large broods were reared. The guinea-fowl is strictly monogamous;
but Mr. Fox finds that his birds succeed best when he keeps one ****
to two or three hens. Canary-birds pair in a state of nature, but
the breeders in England successfully put one male to four or five
females. I have noticed these cases, as rendering it probable that
wild monogamous species might readily become either temporarily or
permanently polygamous.