The Descent of Man and Selection in Relation to Sex
by
Charles Darwin
Part 2 out of 17
project largely; and in the Naulette jaw they are spoken of as enormous.
(45. C. Carter Blake, on a jaw from La Naulette, 'Anthropological Review,'
1867, p. 295. Schaaffhausen, ibid. 1868, p. 426.)
Of the anthropomorphous apes the males alone have their canines fully
developed; but in the female gorilla, and in a less degree in the female
orang, these teeth project considerably beyond the others; therefore the
fact, of which I have been assured, that women sometimes have considerably
projecting canines, is no serious objection to the belief that their
occasional great development in man is a case of reversion to an ape-like
progenitor. He who rejects with scorn the belief that the shape of his own
canines, and their occasional great development in other men, are due to
our early forefathers having been provided with these formidable weapons,
will probably reveal, by sneering, the line of his descent. For though he
no longer intends, nor has the power, to use these teeth as weapons, he
will unconsciously retract his "snarling muscles" (thus named by Sir C.
Bell) (46. The Anatomy of Expression, 1844, pp. 110, 131.), so as to
expose them ready for action, like a dog prepared to fight.
Many muscles are occasionally developed in man, which are proper to the
Quadrumana or other mammals. Professor Vlacovich (47. Quoted by Prof.
Canestrini in the 'Annuario della Soc. dei Naturalisti,' 1867, p. 90.)
examined forty male subjects, and found a muscle, called by him the ischio-
pubic, in nineteen of them; in three others there was a ligament which
represented this muscle; and in the remaining eighteen no trace of it. In
only two out of thirty female subjects was this muscle developed on both
sides, but in three others the rudimentary ligament was present. This
muscle, therefore, appears to be much more common in the male than in the
female sex; and on the belief in the descent of man from some lower form,
the fact is intelligible; for it has been detected in several of the lower
animals, and in all of these it serves exclusively to aid the male in the
act of reproduction.
Mr. J. Wood, in his valuable series of papers (48. These papers deserve
careful study by any one who desires to learn how frequently our muscles
vary, and in varying come to resemble those of the Quadrumana. The
following references relate to the few points touched on in my text:
'Proc. Royal Soc.' vol. xiv. 1865, pp. 379-384; vol. xv. 1866, pp. 241,
242; vol. xv. 1867, p. 544; vol. xvi. 1868, p. 524. I may here add that
Dr. Murie and Mr. St. George Mivart have shewn in their Memoir on the
Lemuroidea ('Transactions, Zoological Society,' vol. vii. 1869, p. 96), how
extraordinarily variable some of the muscles are in these animals, the
lowest members of the Primates. Gradations, also, in the muscles leading
to structures found in animals still lower in the scale, are numerous in
the Lemuroidea.), has minutely described a vast number of muscular
variations in man, which resemble normal structures in the lower animals.
The muscles which closely resemble those regularly present in our nearest
allies, the Quadrumana, are too numerous to be here even specified. In a
single male subject, having a strong bodily frame, and well-formed skull,
no less than seven muscular variations were observed, all of which plainly
represented muscles proper to various kinds of apes. This man, for
instance, had on both sides of his neck a true and powerful "levator
claviculae," such as is found in all kinds of apes, and which is said to
occur in about one out of sixty human subjects. (49. See also Prof.
Macalister in 'Proceedings, Royal Irish Academy,' vol. x. 1868, p. 124.)
Again, this man had "a special abductor of the metatarsal bone of the fifth
digit, such as Professor Huxley and Mr. Flower have shewn to exist
uniformly in the higher and lower apes." I will give only two additional
cases; the acromio-basilar muscle is found in all mammals below man, and
seems to be correlated with a quadrupedal gait, (50. Mr. Champneys in
'Journal of Anatomy and Physiology,' Nov. 1871, p. 178.) and it occurs in
about one out of sixty human subjects. In the lower extremities Mr.
Bradley (51. Ibid. May 1872, p. 421.) found an abductor ossis metatarsi
quinti in both feet of man; this muscle had not up to that time been
recorded in mankind, but is always present in the anthropomorphous apes.
The muscles of the hands and arms--parts which are so eminently
characteristic of man--are extremely liable to vary, so as to resemble the
corresponding muscles in the lower animals. (52. Prof. Macalister (ibid.
p. 121) has tabulated his observations, and finds that muscular
abnormalities are most frequent in the fore-arms, secondly, in the face,
thirdly, in the foot, etc.) Such resemblances are either perfect or
imperfect; yet in the latter case they are manifestly of a transitional
nature. Certain variations are more common in man, and others in woman,
without our being able to assign any reason. Mr. Wood, after describing
numerous variations, makes the following pregnant remark. "Notable
departures from the ordinary type of the muscular structures run in grooves
or directions, which must be taken to indicate some unknown factor, of much
importance to a comprehensive knowledge of general and scientific anatomy."
(53. The Rev. Dr. Haughton, after giving ('Proc. R. Irish Academy,' June
27, 1864, p. 715) a remarkable case of variation in the human flexor
pollicis longus, adds, "This remarkable example shews that man may
sometimes possess the arrangement of tendons of thumb and fingers
characteristic of the macaque; but whether such a case should be regarded
as a macaque passing upwards into a man, or a man passing downwards into a
macaque, or as a congenital freak of nature, I cannot undertake to say."
It is satisfactory to hear so capable an anatomist, and so embittered an
opponent of evolutionism, admitting even the possibility of either of his
first propositions. Prof. Macalister has also described ('Proceedings
Royal Irish Academy,' vol. x. 1864, p. 138) variations in the flexor
pollicis longus, remarkable from their relations to the same muscle in the
Quadrumana.)
That this unknown factor is reversion to a former state of existence may be
admitted as in the highest degree probable. (54. Since the first edition
of this book appeared, Mr. Wood has published another memoir in the
Philosophical Transactions, 1870, p. 83, on the varieties of the muscles of
the human neck, shoulder, and chest. He here shews how extremely variable
these muscles are, and how often and how closely the variations resemble
the normal muscles of the lower animals. He sums up by remarking, "It will
be enough for my purpose if I have succeeded in shewing the more important
forms which, when occurring as varieties in the human subject, tend to
exhibit in a sufficiently marked manner what may be considered as proofs
and examples of the Darwinian principle of reversion, or law of
inheritance, in this department of anatomical science.") It is quite
incredible that a man should through mere accident abnormally resemble
certain apes in no less than seven of his muscles, if there had been no
genetic connection between them. On the other hand, if man is descended
from some ape-like creature, no valid reason can be assigned why certain
muscles should not suddenly reappear after an interval of many thousand
generations, in the same manner as with horses, asses, and mules, dark-
coloured stripes suddenly reappear on the legs, and shoulders, after an
interval of hundreds, or more probably of thousands of generations.
These various cases of reversion are so closely related to those of
rudimentary organs given in the first chapter, that many of them might have
been indifferently introduced either there or here. Thus a human uterus
furnished with cornua may be said to represent, in a rudimentary condition,
the same organ in its normal state in certain mammals. Some parts which
are rudimentary in man, as the os coccyx in both sexes, and the mammae in
the male sex, are always present; whilst others, such as the supracondyloid
foramen, only occasionally appear, and therefore might have been introduced
under the head of reversion. These several reversionary structures, as
well as the strictly rudimentary ones, reveal the descent of man from some
lower form in an unmistakable manner.
CORRELATED VARIATION.
In man, as in the lower animals, many structures are so intimately related,
that when one part varies so does another, without our being able, in most
cases, to assign any reason. We cannot say whether the one part governs
the other, or whether both are governed by some earlier developed part.
Various monstrosities, as I. Geoffroy repeatedly insists, are thus
intimately connected. Homologous structures are particularly liable to
change together, as we see on the opposite sides of the body, and in the
upper and lower extremities. Meckel long ago remarked, that when the
muscles of the arm depart from their proper type, they almost always
imitate those of the leg; and so, conversely, with the muscles of the legs.
The organs of sight and hearing, the teeth and hair, the colour of the skin
and of the hair, colour and constitution, are more or less correlated.
(55. The authorities for these several statements are given in my
'Variation of Animals under Domestication,' vol. ii. pp. 320-335.)
Professor Schaaffhausen first drew attention to the relation apparently
existing between a muscular frame and the strongly-pronounced supra-orbital
ridges, which are so characteristic of the lower races of man.
Besides the variations which can be grouped with more or less probability
under the foregoing heads, there is a large class of variations which may
be provisionally called spontaneous, for to our ignorance they appear to
arise without any exciting cause. It can, however, be shewn that such
variations, whether consisting of slight individual differences, or of
strongly-marked and abrupt deviations of structure, depend much more on the
constitution of the organism than on the nature of the conditions to which
it has been subjected. (56. This whole subject has been discussed in
chap. xxiii. vol. ii. of my 'Variation of Animals and Plants under
Domestication.')
RATE OF INCREASE.
Civilised populations have been known under favourable conditions, as in
the United States, to double their numbers in twenty-five years; and,
according to a calculation, by Euler, this might occur in a little over
twelve years. (57. See the ever memorable 'Essay on the Principle of
Population,' by the Rev. T. Malthus, vol. i. 1826. pp. 6, 517.) At the
former rate, the present population of the United States (thirty millions),
would in 657 years cover the whole terraqueous globe so thickly, that four
men would have to stand on each square yard of surface. The primary or
fundamental check to the continued increase of man is the difficulty of
gaining subsistence, and of living in comfort. We may infer that this is
the case from what we see, for instance, in the United States, where
subsistence is easy, and there is plenty of room. If such means were
suddenly doubled in Great Britain, our number would be quickly doubled.
With civilised nations this primary check acts chiefly by restraining
marriages. The greater death-rate of infants in the poorest classes is
also very important; as well as the greater mortality, from various
diseases, of the inhabitants of crowded and miserable houses, at all ages.
The effects of severe epidemics and wars are soon counterbalanced, and more
than counterbalanced, in nations placed under favourable conditions.
Emigration also comes in aid as a temporary check, but, with the extremely
poor classes, not to any great extent.
There is reason to suspect, as Malthus has remarked, that the reproductive
power is actually less in barbarous, than in civilised races. We know
nothing positively on this head, for with savages no census has been taken;
but from the concurrent testimony of missionaries, and of others who have
long resided with such people, it appears that their families are usually
small, and large ones rare. This may be partly accounted for, as it is
believed, by the women suckling their infants during a long time; but it is
highly probable that savages, who often suffer much hardship, and who do
not obtain so much nutritious food as civilised men, would be actually less
prolific. I have shewn in a former work (58. 'Variation of Animals and
Plants under Domestication,' vol ii. pp. 111-113, 163.), that all our
domesticated quadrupeds and birds, and all our cultivated plants, are more
fertile than the corresponding species in a state of nature. It is no
valid objection to this conclusion that animals suddenly supplied with an
excess of food, or when grown very fat; and that most plants on sudden
removal from very poor to very rich soil, are rendered more or less
sterile. We might, therefore, expect that civilised men, who in one sense
are highly domesticated, would be more prolific than wild men. It is also
probable that the increased fertility of civilised nations would become, as
with our domestic animals, an inherited character: it is at least known
that with mankind a tendency to produce twins runs in families. (59. Mr.
Sedgwick, 'British and Foreign Medico-Chirurgical Review,' July 1863, p.
170.)
Notwithstanding that savages appear to be less prolific than civilised
people, they would no doubt rapidly increase if their numbers were not by
some means rigidly kept down. The Santali, or hill-tribes of India, have
recently afforded a good illustration of this fact; for, as shewn by Mr.
Hunter (60. 'The Annals of Rural Bengal,' by W.W. Hunter, 1868, p. 259.),
they have increased at an extraordinary rate since vaccination has been
introduced, other pestilences mitigated, and war sternly repressed. This
increase, however, would not have been possible had not these rude people
spread into the adjoining districts, and worked for hire. Savages almost
always marry; yet there is some prudential restraint, for they do not
commonly marry at the earliest possible age. The young men are often
required to shew that they can support a wife; and they generally have
first to earn the price with which to purchase her from her parents. With
savages the difficulty of obtaining subsistence occasionally limits their
number in a much more direct manner than with civilised people, for all
tribes periodically suffer from severe famines. At such times savages are
forced to devour much bad food, and their health can hardly fail to be
injured. Many accounts have been published of their protruding stomachs
and emaciated limbs after and during famines. They are then, also,
compelled to wander much, and, as I was assured in Australia, their infants
perish in large numbers. As famines are periodical, depending chiefly on
extreme seasons, all tribes must fluctuate in number. They cannot steadily
and regularly increase, as there is no artificial increase in the supply of
food. Savages, when hard pressed, encroach on each other's territories,
and war is the result; but they are indeed almost always at war with their
neighbours. They are liable to many accidents on land and water in their
search for food; and in some countries they suffer much from the larger
beasts of prey. Even in India, districts have been depopulated by the
ravages of tigers.
Malthus has discussed these several checks, but he does not lay stress
enough on what is probably the most important of all, namely infanticide,
especially of female infants, and the habit of procuring abortion. These
practices now prevail in many quarters of the world; and infanticide seems
formerly to have prevailed, as Mr. M'Lennan (61. 'Primitive Marriage,'
1865.) has shewn, on a still more extensive scale. These practices appear
to have originated in savages recognising the difficulty, or rather the
impossibility of supporting all the infants that are born. Licentiousness
may also be added to the foregoing checks; but this does not follow from
failing means of subsistence; though there is reason to believe that in
some cases (as in Japan) it has been intentionally encouraged as a means of
keeping down the population.
If we look back to an extremely remote epoch, before man had arrived at the
dignity of manhood, he would have been guided more by instinct and less by
reason than are the lowest savages at the present time. Our early semi-
human progenitors would not have practised infanticide or polyandry; for
the instincts of the lower animals are never so perverted (62. A writer in
the 'Spectator' (March 12, 1871, p. 320) comments as follows on this
passage:--"Mr. Darwin finds himself compelled to reintroduce a new doctrine
of the fall of man. He shews that the instincts of the higher animals are
far nobler than the habits of savage races of men, and he finds himself,
therefore, compelled to re-introduce,--in a form of the substantial
orthodoxy of which he appears to be quite unconscious,--and to introduce as
a scientific hypothesis the doctrine that man's gain of KNOWLEDGE was the
cause of a temporary but long-enduring moral deterioration as indicated by
the many foul customs, especially as to marriage, of savage tribes. What
does the Jewish tradition of the moral degeneration of man through his
snatching at a knowledge forbidden him by his highest instinct assert
beyond this?") as to lead them regularly to destroy their own offspring, or
to be quite devoid of jealousy. There would have been no prudential
restraint from marriage, and the sexes would have freely united at an early
age. Hence the progenitors of man would have tended to increase rapidly;
but checks of some kind, either periodical or constant, must have kept down
their numbers, even more severely than with existing savages. What the
precise nature of these checks were, we cannot say, any more than with most
other animals. We know that horses and cattle, which are not extremely
prolific animals, when first turned loose in South America, increased at an
enormous rate. The elephant, the slowest breeder of all known animals,
would in a few thousand years stock the whole world. The increase of every
species of monkey must be checked by some means; but not, as Brehm remarks,
by the attacks of beasts of prey. No one will assume that the actual power
of reproduction in the wild horses and cattle of America, was at first in
any sensible degree increased; or that, as each district became fully
stocked, this same power was diminished. No doubt, in this case, and in
all others, many checks concur, and different checks under different
circumstances; periodical dearths, depending on unfavourable seasons, being
probably the most important of all. So it will have been with the early
progenitors of man.
NATURAL SELECTION.
We have now seen that man is variable in body and mind; and that the
variations are induced, either directly or indirectly, by the same general
causes, and obey the same general laws, as with the lower animals. Man has
spread widely over the face of the earth, and must have been exposed,
during his incessant migrations (63. See some good remarks to this effect
by W. Stanley Jevons, "A Deduction from Darwin's Theory," 'Nature,' 1869,
p. 231.), to the most diversified conditions. The inhabitants of Tierra
del Fuego, the Cape of Good Hope, and Tasmania in the one hemisphere, and
of the arctic regions in the other, must have passed through many climates,
and changed their habits many times, before they reached their present
homes. (64. Latham, 'Man and his Migrations,' 1851, p. 135.) The early
progenitors of man must also have tended, like all other animals, to have
increased beyond their means of subsistence; they must, therefore,
occasionally have been exposed to a struggle for existence, and
consequently to the rigid law of natural selection. Beneficial variations
of all kinds will thus, either occasionally or habitually, have been
preserved and injurious ones eliminated. I do not refer to strongly-marked
deviations of structure, which occur only at long intervals of time, but to
mere individual differences. We know, for instance, that the muscles of
our hands and feet, which determine our powers of movement, are liable,
like those of the lower animals, (65. Messrs. Murie and Mivart in their
'Anatomy of the Lemuroidea' ('Transact. Zoolog. Soc.' vol. vii. 1869, pp.
96-98) say, "some muscles are so irregular in their distribution that they
cannot be well classed in any of the above groups." These muscles differ
even on the opposite sides of the same individual.) to incessant
variability. If then the progenitors of man inhabiting any district,
especially one undergoing some change in its conditions, were divided into
two equal bodies, the one half which included all the individuals best
adapted by their powers of movement for gaining subsistence, or for
defending themselves, would on an average survive in greater numbers, and
procreate more offspring than the other and less well endowed half.
Man in the rudest state in which he now exists is the most dominant animal
that has ever appeared on this earth. He has spread more widely than any
other highly organised form: and all others have yielded before him. He
manifestly owes this immense superiority to his intellectual faculties, to
his social habits, which lead him to aid and defend his fellows, and to his
corporeal structure. The supreme importance of these characters has been
proved by the final arbitrament of the battle for life. Through his powers
of intellect, articulate language has been evolved; and on this his
wonderful advancement has mainly depended. As Mr. Chauncey Wright remarks
(66. Limits of Natural Selection, 'North American Review,' Oct. 1870, p.
295.): "a psychological analysis of the faculty of language shews, that
even the smallest proficiency in it might require more brain power than the
greatest proficiency in any other direction." He has invented and is able
to use various weapons, tools, traps, etc., with which he defends himself,
kills or catches prey, and otherwise obtains food. He has made rafts or
canoes for fishing or crossing over to neighbouring fertile islands. He
has discovered the art of making fire, by which hard and stringy roots can
be rendered digestible, and poisonous roots or herbs innocuous. This
discovery of fire, probably the greatest ever made by man, excepting
language, dates from before the dawn of history. These several inventions,
by which man in the rudest state has become so pre-eminent, are the direct
results of the development of his powers of observation, memory, curiosity,
imagination, and reason. I cannot, therefore, understand how it is that
Mr. Wallace (67. 'Quarterly Review,' April 1869, p. 392. This subject is
more fully discussed in Mr. Wallace's 'Contributions to the Theory of
Natural Selection,' 1870, in which all the essays referred to in this work
are re-published. The 'Essay on Man,' has been ably criticised by Prof.
Claparede, one of the most distinguished zoologists in Europe, in an
article published in the 'Bibliotheque Universelle,' June 1870. The remark
quoted in my text will surprise every one who has read Mr. Wallace's
celebrated paper on 'The Origin of Human Races Deduced from the Theory of
Natural Selection,' originally published in the 'Anthropological Review,'
May 1864, p. clviii. I cannot here resist quoting a most just remark by
Sir J. Lubbock ('Prehistoric Times,' 1865, p. 479) in reference to this
paper, namely, that Mr. Wallace, "with characteristic unselfishness,
ascribes it (i.e. the idea of natural selection) unreservedly to Mr.
Darwin, although, as is well known, he struck out the idea independently,
and published it, though not with the same elaboration, at the same time.")
maintains, that "natural selection could only have endowed the savage with
a brain a little superior to that of an ape."
Although the intellectual powers and social habits of man are of paramount
importance to him, we must not underrate the importance of his bodily
structure, to which subject the remainder of this chapter will be devoted;
the development of the intellectual and social or moral faculties being
discussed in a later chapter.
Even to hammer with precision is no easy matter, as every one who has tried
to learn carpentry will admit. To throw a stone with as true an aim as a
Fuegian in defending himself, or in killing birds, requires the most
consummate perfection in the correlated action of the muscles of the hand,
arm, and shoulder, and, further, a fine sense of touch. In throwing a
stone or spear, and in many other actions, a man must stand firmly on his
feet; and this again demands the perfect co-adaptation of numerous muscles.
To chip a flint into the rudest tool, or to form a barbed spear or hook
from a bone, demands the use of a perfect hand; for, as a most capable
judge, Mr. Schoolcraft (68. Quoted by Mr. Lawson Tait in his 'Law of
Natural Selection,' 'Dublin Quarterly Journal of Medical Science,' Feb.
1869. Dr. Keller is likewise quoted to the same effect.), remarks, the
shaping fragments of stone into knives, lances, or arrow-heads, shews
"extraordinary ability and long practice." This is to a great extent
proved by the fact that primeval men practised a division of labour; each
man did not manufacture his own flint tools or rude pottery, but certain
individuals appear to have devoted themselves to such work, no doubt
receiving in exchange the produce of the chase. Archaeologists are
convinced that an enormous interval of time elapsed before our ancestors
thought of grinding chipped flints into smooth tools. One can hardly
doubt, that a man-like animal who possessed a hand and arm sufficiently
perfect to throw a stone with precision, or to form a flint into a rude
tool, could, with sufficient practice, as far as mechanical skill alone is
concerned, make almost anything which a civilised man can make. The
structure of the hand in this respect may be compared with that of the
vocal organs, which in the apes are used for uttering various signal-cries,
or, as in one genus, musical cadences; but in man the closely similar vocal
organs have become adapted through the inherited effects of use for the
utterance of articulate language.
Turning now to the nearest allies of men, and therefore to the best
representatives of our early progenitors, we find that the hands of the
Quadrumana are constructed on the same general pattern as our own, but are
far less perfectly adapted for diversified uses. Their hands do not serve
for locomotion so well as the feet of a dog; as may be seen in such monkeys
as the chimpanzee and orang, which walk on the outer margins of the palms,
or on the knuckles. (69. Owen, 'Anatomy of Vertebrates,' vol. iii. p.
71.) Their hands, however, are admirably adapted for climbing trees.
Monkeys seize thin branches or ropes, with the thumb on one side and the
fingers and palm on the other, in the same manner as we do. They can thus
also lift rather large objects, such as the neck of a bottle, to their
mouths. Baboons turn over stones, and scratch up roots with their hands.
They seize nuts, insects, or other small objects with the thumb in
opposition to the fingers, and no doubt they thus extract eggs and young
from the nests of birds. American monkeys beat the wild oranges on the
branches until the rind is cracked, and then tear it off with the fingers
of the two hands. In a wild state they break open hard fruits with stones.
Other monkeys open mussel-shells with the two thumbs. With their fingers
they pull out thorns and burs, and hunt for each other's parasites. They
roll down stones, or throw them at their enemies: nevertheless, they are
clumsy in these various actions, and, as I have myself seen, are quite
unable to throw a stone with precision.
It seems to me far from true that because "objects are grasped clumsily" by
monkeys, "a much less specialised organ of prehension" would have served
them (70. 'Quarterly Review,' April 1869, p. 392.) equally well with their
present hands. On the contrary, I see no reason to doubt that more
perfectly constructed hands would have been an advantage to them, provided
that they were not thus rendered less fitted for climbing trees. We may
suspect that a hand as perfect as that of man would have been
disadvantageous for climbing; for the most arboreal monkeys in the world,
namely, Ateles in America, Colobus in Africa, and Hylobates in Asia, are
either thumbless, or their toes partially cohere, so that their limbs are
converted into mere grasping hooks. (71. In Hylobates syndactylus, as the
name expresses, two of the toes regularly cohere; and this, as Mr. Blyth
informs me, is occasionally the case with the toes of H. agilis, lar, and
leuciscus. Colobus is strictly arboreal and extraordinarily active (Brehm,
'Thierleben,' B. i. s. 50), but whether a better climber than the species
of the allied genera, I do not know. It deserves notice that the feet of
the sloths, the most arboreal animals in the world, are wonderfully hook-
like.
As soon as some ancient member in the great series of the Primates came to
be less arboreal, owing to a change in its manner of procuring subsistence,
or to some change in the surrounding conditions, its habitual manner of
progression would have been modified: and thus it would have been rendered
more strictly quadrupedal or bipedal. Baboons frequent hilly and rocky
districts, and only from necessity climb high trees (72. Brehm,
'Thierleben,' B. i. s. 80.); and they have acquired almost the gait of a
dog. Man alone has become a biped; and we can, I think, partly see how he
has come to assume his erect attitude, which forms one of his most
conspicuous characters. Man could not have attained his present dominant
position in the world without the use of his hands, which are so admirably
adapted to act in obedience to his will. Sir C. Bell (73. 'The Hand,'
etc., 'Bridgewater Treatise,' 1833, p. 38.) insists that "the hand supplies
all instruments, and by its correspondence with the intellect gives him
universal dominion." But the hands and arms could hardly have become
perfect enough to have manufactured weapons, or to have hurled stones and
spears with a true aim, as long as they were habitually used for locomotion
and for supporting the whole weight of the body, or, as before remarked, so
long as they were especially fitted for climbing trees. Such rough
treatment would also have blunted the sense of touch, on which their
delicate use largely depends. From these causes alone it would have been
an advantage to man to become a biped; but for many actions it is
indispensable that the arms and whole upper part of the body should be
free; and he must for this end stand firmly on his feet. To gain this
great advantage, the feet have been rendered flat; and the great toe has
been peculiarly modified, though this has entailed the almost complete loss
of its power of prehension. It accords with the principle of the division
of physiological labour, prevailing throughout the animal kingdom, that as
the hands became perfected for prehension, the feet should have become
perfected for support and locomotion. With some savages, however, the foot
has not altogether lost its prehensile power, as shewn by their manner of
climbing trees, and of using them in other ways. (74. Haeckel has an
excellent discussion on the steps by which man became a biped: 'Naturliche
Schopfungsgeschicte,' 1868, s. 507. Dr. Buchner ('Conferences sur la
Theorie Darwinienne,' 1869, p. 135) has given good cases of the use of the
foot as a prehensile organ by man; and has also written on the manner of
progression of the higher apes, to which I allude in the following
paragraph: see also Owen ('Anatomy of Vertebrates,' vol. iii. p. 71) on
this latter subject.
If it be an advantage to man to stand firmly on his feet and to have his
hands and arms free, of which, from his pre-eminent success in the battle
of life there can be no doubt, then I can see no reason why it should not
have been advantageous to the progenitors of man to have become more and
more erect or bipedal. They would thus have been better able to defend
themselves with stones or clubs, to attack their prey, or otherwise to
obtain food. The best built individuals would in the long run have
succeeded best, and have survived in larger numbers. If the gorilla and a
few allied forms had become extinct, it might have been argued, with great
force and apparent truth, that an animal could not have been gradually
converted from a quadruped into a biped, as all the individuals in an
intermediate condition would have been miserably ill-fitted for
progression. But we know (and this is well worthy of reflection) that the
anthropomorphous apes are now actually in an intermediate condition; and no
one doubts that they are on the whole well adapted for their conditions of
life. Thus the gorilla runs with a sidelong shambling gait, but more
commonly progresses by resting on its bent hands. The long-armed apes
occasionally use their arms like crutches, swinging their bodies forward
between them, and some kinds of Hylobates, without having been taught, can
walk or run upright with tolerable quickness; yet they move awkwardly, and
much less securely than man. We see, in short, in existing monkeys a
manner of progression intermediate between that of a quadruped and a biped;
but, as an unprejudiced judge (75. Prof. Broca, La Constitution des
Vertebres caudales; 'La Revue d'Anthropologie,' 1872, p. 26, (separate
copy).) insists, the anthropomorphous apes approach in structure more
nearly to the bipedal than to the quadrupedal type.
As the progenitors of man became more and more erect, with their hands and
arms more and more modified for prehension and other purposes, with their
feet and legs at the same time transformed for firm support and
progression, endless other changes of structure would have become
necessary. The pelvis would have to be broadened, the spine peculiarly
curved, and the head fixed in an altered position, all which changes have
been attained by man. Prof. Schaaffhausen (76. 'On the Primitive Form of
the Skull,' translated in 'Anthropological Review,' Oct. 1868, p. 428.
Owen ('Anatomy of Vertebrates,' vol. ii. 1866, p. 551) on the mastoid
processes in the higher apes.) maintains that "the powerful mastoid
processes of the human skull are the result of his erect position;" and
these processes are absent in the orang, chimpanzee, etc., and are smaller
in the gorilla than in man. Various other structures, which appear
connected with man's erect position, might here have been added. It is
very difficult to decide how far these correlated modifications are the
result of natural selection, and how far of the inherited effects of the
increased use of certain parts, or of the action of one part on another.
No doubt these means of change often co-operate: thus when certain
muscles, and the crests of bone to which they are attached, become enlarged
by habitual use, this shews that certain actions are habitually performed
and must be serviceable. Hence the individuals which performed them best,
would tend to survive in greater numbers.
The free use of the arms and hands, partly the cause and partly the result
of man's erect position, appears to have led in an indirect manner to other
modifications of structure. The early male forefathers of man were, as
previously stated, probably furnished with great canine teeth; but as they
gradually acquired the habit of using stones, clubs, or other weapons, for
fighting with their enemies or rivals, they would use their jaws and teeth
less and less. In this case, the jaws, together with the teeth, would
become reduced in size, as we may feel almost sure from innumerable
analogous cases. In a future chapter we shall meet with a closely parallel
case, in the reduction or complete disappearance of the canine teeth in
male ruminants, apparently in relation with the development of their horns;
and in horses, in relation to their habit of fighting with their incisor
teeth and hoofs.
In the adult male anthropomorphous apes, as Rutimeyer (77. 'Die Grenzen
der Thierwelt, eine Betrachtung zu Darwin's Lehre,' 1868, s. 51.), and
others, have insisted, it is the effect on the skull of the great
development of the jaw-muscles that causes it to differ so greatly in many
respects from that of man, and has given to these animals "a truly
frightful physiognomy." Therefore, as the jaws and teeth in man's
progenitors gradually become reduced in size, the adult skull would have
come to resemble more and more that of existing man. As we shall hereafter
see, a great reduction of the canine teeth in the males would almost
certainly affect the teeth of the females through inheritance.
As the various mental faculties gradually developed themselves the brain
would almost certainly become larger. No one, I presume, doubts that the
large proportion which the size of man's brain bears to his body, compared
to the same proportion in the gorilla or orang, is closely connected with
his higher mental powers. We meet with closely analogous facts with
insects, for in ants the cerebral ganglia are of extraordinary dimensions,
and in all the Hymenoptera these ganglia are many times larger than in the
less intelligent orders, such as beetles. (78. Dujardin, 'Annales des
Sciences Nat.' 3rd series, Zoolog., tom. xiv. 1850, p. 203. See also Mr.
Lowne, 'Anatomy and Phys. of the Musca vomitoria,' 1870, p. 14. My son,
Mr. F. Darwin, dissected for me the cerebral ganglia of the Formica rufa.)
On the other hand, no one supposes that the intellect of any two animals or
of any two men can be accurately gauged by the cubic contents of their
skulls. It is certain that there may be extraordinary mental activity with
an extremely small absolute mass of nervous matter: thus the wonderfully
diversified instincts, mental powers, and affections of ants are notorious,
yet their cerebral ganglia are not so large as the quarter of a small pin's
head. Under this point of view, the brain of an ant is one of the most
marvellous atoms of matter in the world, perhaps more so than the brain of
a man.
The belief that there exists in man some close relation between the size of
the brain and the development of the intellectual faculties is supported by
the comparison of the skulls of savage and civilised races, of ancient and
modern people, and by the analogy of the whole vertebrate series. Dr. J.
Barnard Davis has proved (79. 'Philosophical Transactions,' 1869, p.
513.), by many careful measurements, that the mean internal capacity of the
skull in Europeans is 92.3 cubic inches; in Americans 87.5; in Asiatics
87.1; and in Australians only 81.9 cubic inches. Professor Broca (80.
'Les Selections,' M. P. Broca, 'Revue d'Anthropologies,' 1873; see also, as
quoted in C. Vogt's 'Lectures on Man,' Engl. translat., 1864, pp. 88, 90.
Prichard, 'Physical History of Mankind,' vol. i. 1838, p. 305.) found that
the nineteenth century skulls from graves in Paris were larger than those
from vaults of the twelfth century, in the proportion of 1484 to 1426; and
that the increased size, as ascertained by measurements, was exclusively in
the frontal part of the skull--the seat of the intellectual faculties.
Prichard is persuaded that the present inhabitants of Britain have "much
more capacious brain-cases" than the ancient inhabitants. Nevertheless, it
must be admitted that some skulls of very high antiquity, such as the
famous one of Neanderthal, are well developed and capacious. (81. In the
interesting article just referred to, Prof. Broca has well remarked, that
in civilised nations, the average capacity of the skull must be lowered by
the preservation of a considerable number of individuals, weak in mind and
body, who would have been promptly eliminated in the savage state. On the
other hand, with savages, the average includes only the more capable
individuals, who have been able to survive under extremely hard conditions
of life. Broca thus explains the otherwise inexplicable fact, that the
mean capacity of the skull of the ancient Troglodytes of Lozere is greater
than that of modern Frenchmen.) With respect to the lower animals, M.E.
Lartet (82. 'Comptes-rendus des Sciences,' etc., June 1, 1868.), by
comparing the crania of tertiary and recent mammals belonging to the same
groups, has come to the remarkable conclusion that the brain is generally
larger and the convolutions are more complex in the more recent forms. On
the other hand, I have shewn (83. The 'Variation of Animals and Plants
under Domestication,' vol. i. pp. 124-129.) that the brains of domestic
rabbits are considerably reduced in bulk, in comparison with those of the
wild rabbit or hare; and this may be attributed to their having been
closely confined during many generations, so that they have exerted their
intellect, instincts, senses and voluntary movements but little.
The gradually increasing weight of the brain and skull in man must have
influenced the development of the supporting spinal column, more especially
whilst he was becoming erect. As this change of position was being brought
about, the internal pressure of the brain will also have influenced the
form of the skull; for many facts shew how easily the skull is thus
affected. Ethnologists believe that it is modified by the kind of cradle
in which infants sleep. Habitual spasms of the muscles, and a cicatrix
from a severe burn, have permanently modified the facial bones. In young
persons whose heads have become fixed either sideways or backwards, owing
to disease, one of the two eyes has changed its position, and the shape of
the skull has been altered apparently by the pressure of the brain in a new
direction. (84. Schaaffhausen gives from Blumenbach and Busch, the cases
of the spasms and cicatrix, in 'Anthropological Review,' Oct. 1868, p. 420.
Dr. Jarrold ('Anthropologia,' 1808, pp. 115, 116) adduces from Camper and
from his own observations, cases of the modification of the skull from the
head being fixed in an unnatural position. He believes that in certain
trades, such as that of a shoemaker, where the head is habitually held
forward, the forehead becomes more rounded and prominent.) I have shewn
that with long-eared rabbits even so trifling a cause as the lopping
forward of one ear drags forward almost every bone of the skull on that
side; so that the bones on the opposite side no longer strictly correspond.
Lastly, if any animal were to increase or diminish much in general size,
without any change in its mental powers, or if the mental powers were to be
much increased or diminished, without any great change in the size of the
body, the shape of the skull would almost certainly be altered. I infer
this from my observations on domestic rabbits, some kinds of which have
become very much larger than the wild animal, whilst others have retained
nearly the same size, but in both cases the brain has been much reduced
relatively to the size of the body. Now I was at first much surprised on
finding that in all these rabbits the skull had become elongated or
dolichocephalic; for instance, of two skulls of nearly equal breadth, the
one from a wild rabbit and the other from a large domestic kind, the former
was 3.15 and the latter 4.3 inches in length. (85. 'Variation of Animals
and Plants under Domestication,' vol. i. p. 117, on the elongation of the
skull; p. 119, on the effect of the lopping of one ear.) One of the most
marked distinctions in different races of men is that the skull in some is
elongated, and in others rounded; and here the explanation suggested by the
case of the rabbits may hold good; for Welcker finds that short "men
incline more to brachycephaly, and tall men to dolichocephaly" (86. Quoted
by Schaaffhausen, in 'Anthropological Review,' Oct. 1868, p. 419.); and
tall men may be compared with the larger and longer-bodied rabbits, all of
which have elongated skulls or are dolichocephalic.
From these several facts we can understand, to a certain extent, the means
by which the great size and more or less rounded form of the skull have
been acquired by man; and these are characters eminently distinctive of him
in comparison with the lower animals.
Another most conspicuous difference between man and the lower animals is
the nakedness of his skin. Whales and porpoises (Cetacea), dugongs
(Sirenia) and the hippopotamus are naked; and this may be advantageous to
them for gliding through the water; nor would it be injurious to them from
the loss of warmth, as the species, which inhabit the colder regions, are
protected by a thick layer of blubber, serving the same purpose as the fur
of seals and otters. Elephants and rhinoceroses are almost hairless; and
as certain extinct species, which formerly lived under an Arctic climate,
were covered with long wool or hair, it would almost appear as if the
existing species of both genera had lost their hairy covering from exposure
to heat. This appears the more probable, as the elephants in India which
live on elevated and cool districts are more hairy (87. Owen, 'Anatomy of
Vertebrates,' vol. iii. p. 619.) than those on the lowlands. May we then
infer that man became divested of hair from having aboriginally inhabited
some tropical land? That the hair is chiefly retained in the male sex on
the chest and face, and in both sexes at the junction of all four limbs
with the trunk, favours this inference--on the assumption that the hair was
lost before man became erect; for the parts which now retain most hair
would then have been most protected from the heat of the sun. The crown of
the head, however, offers a curious exception, for at all times it must
have been one of the most exposed parts, yet it is thickly clothed with
hair. The fact, however, that the other members of the order of Primates,
to which man belongs, although inhabiting various hot regions, are well
clothed with hair, generally thickest on the upper surface (88. Isidore
Geoffroy St.-Hilaire remarks ('Histoire Nat. Generale,' tom. ii. 1859, pp.
215-217) on the head of man being covered with long hair; also on the upper
surfaces of monkeys and of other mammals being more thickly clothed than
the lower surfaces. This has likewise been observed by various authors.
Prof. P. Gervais ('Histoire Nat. des Mammiferes,' tom. i. 1854, p. 28),
however, states that in the Gorilla the hair is thinner on the back, where
it is partly rubbed off, than on the lower surface.), is opposed to the
supposition that man became naked through the action of the sun. Mr. Belt
believes (89. The 'Naturalist in Nicaragua,' 1874, p. 209. As some
confirmation of Mr. Belt's view, I may quote the following passage from Sir
W. Denison ('Varieties of Vice-Regal Life,' vol. i. 1870, p. 440): "It is
said to be a practice with the Australians, when the vermin get
troublesome, to singe themselves.") that within the tropics it is an
advantage to man to be destitute of hair, as he is thus enabled to free
himself of the multitude of ticks (acari) and other parasites, with which
he is often infested, and which sometimes cause ulceration. But whether
this evil is of sufficient magnitude to have led to the denudation of his
body through natural selection, may be doubted, since none of the many
quadrupeds inhabiting the tropics have, as far as I know, acquired any
specialised means of relief. The view which seems to me the most probable
is that man, or rather primarily woman, became divested of hair for
ornamental purposes, as we shall see under Sexual Selection; and, according
to this belief, it is not surprising that man should differ so greatly in
hairiness from all other Primates, for characters, gained through sexual
selection, often differ to an extraordinary degree in closely related
forms.
According to a popular impression, the absence of a tail is eminently
distinctive of man; but as those apes which come nearest to him are
destitute of this organ, its disappearance does not relate exclusively to
man. The tail often differs remarkably in length within the same genus:
thus in some species of Macacus it is longer than the whole body, and is
formed of twenty-four vertebrae; in others it consists of a scarcely
visible stump, containing only three or four vertebrae. In some kinds of
baboons there are twenty-five, whilst in the mandrill there are ten very
small stunted caudal vertebrae, or, according to Cuvier (90. Mr. St.
George Mivart, 'Proc. Zoolog. Soc.' 1865, pp. 562, 583. Dr. J.E. Gray,
'Cat. Brit. Mus.: 'Skeletons.' Owen, 'Anatomy of Vertebrates,' vol. ii.
p. 517. Isidore Geoffroy, 'Hist. Nat. Gen.' tom. ii. p. 244.), sometimes
only five. The tail, whether it be long or short, almost always tapers
towards the end; and this, I presume, results from the atrophy of the
terminal muscles, together with their arteries and nerves, through disuse,
leading to the atrophy of the terminal bones. But no explanation can at
present be given of the great diversity which often occurs in its length.
Here, however, we are more specially concerned with the complete external
disappearance of the tail. Professor Broca has recently shewn (91. 'Revue
d'Anthropologie,' 1872; 'La Constitution des vertebres caudales.') that the
tail in all quadrupeds consists of two portions, generally separated
abruptly from each other; the basal portion consists of vertebrae, more or
less perfectly channelled and furnished with apophyses like ordinary
vertebrae; whereas those of the terminal portion are not channelled, are
almost smooth, and scarcely resemble true vertebrae. A tail, though not
externally visible, is really present in man and the anthropomorphous apes,
and is constructed on exactly the same pattern in both. In the terminal
portion the vertabrae, constituting the os coccyx, are quite rudimentary,
being much reduced in size and number. In the basal portion, the vertebrae
are likewise few, are united firmly together, and are arrested in
development; but they have been rendered much broader and flatter than the
corresponding vertebrae in the tails of other animals: they constitute
what Broca calls the accessory sacral vertebrae. These are of functional
importance by supporting certain internal parts and in other ways; and
their modification is directly connected with the erect or semi-erect
attitude of man and the anthropomorphous apes. This conclusion is the more
trustworthy, as Broca formerly held a different view, which he has now
abandoned. The modification, therefore, of the basal caudal vertebrae in
man and the higher apes may have been effected, directly or indirectly,
through natural selection.
But what are we to say about the rudimentary and variable vertebrae of the
terminal portion of the tail, forming the os coccyx? A notion which has
often been, and will no doubt again be ridiculed, namely, that friction has
had something to do with the disappearance of the external portion of the
tail, is not so ridiculous as it at first appears. Dr. Anderson (92.
'Proceedings Zoological Society,' 1872, p. 210.) states that the extremely
short tail of Macacus brunneus is formed of eleven vertebrae, including the
imbedded basal ones. The extremity is tendinous and contains no vertebrae;
this is succeeded by five rudimentary ones, so minute that together they
are only one line and a half in length, and these are permanently bent to
one side in the shape of a hook. The free part of the tail, only a little
above an inch in length, includes only four more small vertebrae. This
short tail is carried erect; but about a quarter of its total length is
doubled on to itself to the left; and this terminal part, which includes
the hook-like portion, serves "to fill up the interspace between the upper
divergent portion of the callosities;" so that the animal sits on it, and
thus renders it rough and callous. Dr. Anderson thus sums up his
observations: "These facts seem to me to have only one explanation; this
tail, from its short size, is in the monkey's way when it sits down, and
frequently becomes placed under the animal while it is in this attitude;
and from the circumstance that it does not extend beyond the extremity of
the ischial tuberosities, it seems as if the tail originally had been bent
round by the will of the animal, into the interspace between the
callosities, to escape being pressed between them and the ground, and that
in time the curvature became permanent, fitting in of itself when the organ
happens to be sat upon." Under these circumstances it is not surprising
that the surface of the tail should have been roughened and rendered
callous, and Dr. Murie (93. 'Proceedings Zoological Society,' 1872, p.
786.), who carefully observed this species in the Zoological Gardens, as
well as three other closely allied forms with slightly longer tails, says
that when the animal sits down, the tail "is necessarily thrust to one side
of the buttocks; and whether long or short its root is consequently liable
to be rubbed or chafed." As we now have evidence that mutilations
occasionally produce an inherited effect (94. I allude to Dr. Brown-
Sequard's observations on the transmitted effect of an operation causing
epilepsy in guinea-pigs, and likewise more recently on the analogous
effects of cutting the sympathetic nerve in the neck. I shall hereafter
have occasion to refer to Mr. Salvin's interesting case of the apparently
inherited effects of mot-mots biting off the barbs of their own tail-
feathers. See also on the general subject 'Variation of Animals and Plants
under Domestication,' vol. ii. pp. 22-24.), it is not very improbable that
in short-tailed monkeys, the projecting part of the tail, being
functionally useless, should after many generations have become rudimentary
and distorted, from being continually rubbed and chafed. We see the
projecting part in this condition in the Macacus brunneus, and absolutely
aborted in the M. ecaudatus and in several of the higher apes. Finally,
then, as far as we can judge, the tail has disappeared in man and the
anthropomorphous apes, owing to the terminal portion having been injured by
friction during a long lapse of time; the basal and embedded portion having
been reduced and modified, so as to become suitable to the erect or semi-
erect position.
I have now endeavoured to shew that some of the most distinctive characters
of man have in all probability been acquired, either directly, or more
commonly indirectly, through natural selection. We should bear in mind
that modifications in structure or constitution which do not serve to adapt
an organism to its habits of life, to the food which it consumes, or
passively to the surrounding conditions, cannot have been thus acquired.
We must not, however, be too confident in deciding what modifications are
of service to each being: we should remember how little we know about the
use of many parts, or what changes in the blood or tissues may serve to fit
an organism for a new climate or new kinds of food. Nor must we forget the
principle of correlation, by which, as Isidore Geoffroy has shewn in the
case of man, many strange deviations of structure are tied together.
Independently of correlation, a change in one part often leads, through the
increased or decreased use of other parts, to other changes of a quite
unexpected nature. It is also well to reflect on such facts, as the
wonderful growth of galls on plants caused by the poison of an insect, and
on the remarkable changes of colour in the plumage of parrots when fed on
certain fishes, or inoculated with the poison of toads (95. The 'Variation
of Animals and Plants under Domestication,' vol. ii. pp. 280, 282.); for we
can thus see that the fluids of the system, if altered for some special
purpose, might induce other changes. We should especially bear in mind
that modifications acquired and continually used during past ages for some
useful purpose, would probably become firmly fixed, and might be long
inherited.
Thus a large yet undefined extension may safely be given to the direct and
indirect results of natural selection; but I now admit, after reading the
essay by Nageli on plants, and the remarks by various authors with respect
to animals, more especially those recently made by Professor Broca, that in
the earlier editions of my 'Origin of Species' I perhaps attributed too
much to the action of natural selection or the survival of the fittest. I
have altered the fifth edition of the 'Origin' so as to confine my remarks
to adaptive changes of structure; but I am convinced, from the light gained
during even the last few years, that very many structures which now appear
to us useless, will hereafter be proved to be useful, and will therefore
come within the range of natural selection. Nevertheless, I did not
formerly consider sufficiently the existence of structures, which, as far
as we can at present judge, are neither beneficial nor injurious; and this
I believe to be one of the greatest oversights as yet detected in my work.
I may be permitted to say, as some excuse, that I had two distinct objects
in view; firstly, to shew that species had not been separately created, and
secondly, that natural selection had been the chief agent of change, though
largely aided by the inherited effects of habit, and slightly by the direct
action of the surrounding conditions. I was not, however, able to annul
the influence of my former belief, then almost universal, that each species
had been purposely created; and this led to my tacit assumption that every
detail of structure, excepting rudiments, was of some special, though
unrecognised, service. Any one with this assumption in his mind would
naturally extend too far the action of natural selection, either during
past or present times. Some of those who admit the principle of evolution,
but reject natural selection, seem to forget, when criticising my book,
that I had the above two objects in view; hence if I have erred in giving
to natural selection great power, which I am very far from admitting, or in
having exaggerated its power, which is in itself probable, I have at least,
as I hope, done good service in aiding to overthrow the dogma of separate
creations.
It is, as I can now see, probable that all organic beings, including man,
possess peculiarities of structure, which neither are now, nor were
formerly of any service to them, and which, therefore, are of no
physiological importance. We know not what produces the numberless slight
differences between the individuals of each species, for reversion only
carries the problem a few steps backwards, but each peculiarity must have
had its efficient cause. If these causes, whatever they may be, were to
act more uniformly and energetically during a lengthened period (and
against this no reason can be assigned), the result would probably be not a
mere slight individual difference, but a well-marked and constant
modification, though one of no physiological importance. Changed
structures, which are in no way beneficial, cannot be kept uniform through
natural selection, though the injurious will be thus eliminated.
Uniformity of character would, however, naturally follow from the assumed
uniformity of the exciting causes, and likewise from the free intercrossing
of many individuals. During successive periods, the same organism might in
this manner acquire successive modifications, which would be transmitted in
a nearly uniform state as long as the exciting causes remained the same and
there was free intercrossing. With respect to the exciting causes we can
only say, as when speaking of so-called spontaneous variations, that they
relate much more closely to the constitution of the varying organism, than
to the nature of the conditions to which it has been subjected.
CONCLUSION.
In this chapter we have seen that as man at the present day is liable, like
every other animal, to multiform individual differences or slight
variations, so no doubt were the early progenitors of man; the variations
being formerly induced by the same general causes, and governed by the same
general and complex laws as at present. As all animals tend to multiply
beyond their means of subsistence, so it must have been with the
progenitors of man; and this would inevitably lead to a struggle for
existence and to natural selection. The latter process would be greatly
aided by the inherited effects of the increased use of parts, and these two
processes would incessantly react on each other. It appears, also, as we
shall hereafter see, that various unimportant characters have been acquired
by man through sexual selection. An unexplained residuum of change must be
left to the assumed uniform action of those unknown agencies, which
occasionally induce strongly marked and abrupt deviations of structure in
our domestic productions.
Judging from the habits of savages and of the greater number of the
Quadrumana, primeval men, and even their ape-like progenitors, probably
lived in society. With strictly social animals, natural selection
sometimes acts on the individual, through the preservation of variations
which are beneficial to the community. A community which includes a large
number of well-endowed individuals increases in number, and is victorious
over other less favoured ones; even although each separate member gains no
advantage over the others of the same community. Associated insects have
thus acquired many remarkable structures, which are of little or no service
to the individual, such as the pollen-collecting apparatus, or the sting of
the worker-bee, or the great jaws of soldier-ants. With the higher social
animals, I am not aware that any structure has been modified solely for the
good of the community, though some are of secondary service to it. For
instance, the horns of ruminants and the great canine teeth of baboons
appear to have been acquired by the males as weapons for sexual strife, but
they are used in defence of the herd or troop. In regard to certain mental
powers the case, as we shall see in the fifth chapter, is wholly different;
for these faculties have been chiefly, or even exclusively, gained for the
benefit of the community, and the individuals thereof have at the same time
gained an advantage indirectly.
It has often been objected to such views as the foregoing, that man is one
of the most helpless and defenceless creatures in the world; and that
during his early and less well-developed condition, he would have been
still more helpless. The Duke of Argyll, for instance, insists (96.
'Primeval Man,' 1869, p. 66.) that "the human frame has diverged from the
structure of brutes, in the direction of greater physical helplessness and
weakness. That is to say, it is a divergence which of all others it is
most impossible to ascribe to mere natural selection." He adduces the
naked and unprotected state of the body, the absence of great teeth or
claws for defence, the small strength and speed of man, and his slight
power of discovering food or of avoiding danger by smell. To these
deficiencies there might be added one still more serious, namely, that he
cannot climb quickly, and so escape from enemies. The loss of hair would
not have been a great injury to the inhabitants of a warm country. For we
know that the unclothed Fuegians can exist under a wretched climate. When
we compare the defenceless state of man with that of apes, we must remember
that the great canine teeth with which the latter are provided, are
possessed in their full development by the males alone, and are chiefly
used by them for fighting with their rivals; yet the females, which are not
thus provided, manage to survive.
In regard to bodily size or strength, we do not know whether man is
descended from some small species, like the chimpanzee, or from one as
powerful as the gorilla; and, therefore, we cannot say whether man has
become larger and stronger, or smaller and weaker, than his ancestors. We
should, however, bear in mind that an animal possessing great size,
strength, and ferocity, and which, like the gorilla, could defend itself
from all enemies, would not perhaps have become social: and this would
most effectually have checked the acquirement of the higher mental
qualities, such as sympathy and the love of his fellows. Hence it might
have been an immense advantage to man to have sprung from some
comparatively weak creature.
The small strength and speed of man, his want of natural weapons, etc., are
more than counterbalanced, firstly, by his intellectual powers, through
which he has formed for himself weapons, tools, etc., though still
remaining in a barbarous state, and, secondly, by his social qualities
which lead him to give and receive aid from his fellow-men. No country in
the world abounds in a greater degree with dangerous beasts than Southern
Africa; no country presents more fearful physical hardships than the Arctic
regions; yet one of the puniest of races, that of the Bushmen, maintains
itself in Southern Africa, as do the dwarfed Esquimaux in the Arctic
regions. The ancestors of man were, no doubt, inferior in intellect, and
probably in social disposition, to the lowest existing savages; but it is
quite conceivable that they might have existed, or even flourished, if
they had advanced in intellect, whilst gradually losing their brute-like
powers, such as that of climbing trees, etc. But these ancestors would not
have been exposed to any special danger, even if far more helpless and
defenceless than any existing savages, had they inhabited some warm
continent or large island, such as Australia, New Guinea, or Borneo, which
is now the home of the orang. And natural selection arising from the
competition of tribe with tribe, in some such large area as one of these,
together with the inherited effects of habit, would, under favourable
conditions, have sufficed to raise man to his present high position in the
organic scale.
CHAPTER III.
COMPARISON OF THE MENTAL POWERS OF MAN AND THE LOWER ANIMALS.
The difference in mental power between the highest ape and the lowest
savage, immense--Certain instincts in common--The emotions--Curiosity--
Imitation--Attention--Memory--Imagination--Reason--Progressive improvement
--Tools and weapons used by animals--Abstraction, Self-consciousness--
Language--Sense of beauty--Belief in God, spiritual agencies,
superstitions.
We have seen in the last two chapters that man bears in his bodily
structure clear traces of his descent from some lower form; but it may be
urged that, as man differs so greatly in his mental power from all other
animals, there must be some error in this conclusion. No doubt the
difference in this respect is enormous, even if we compare the mind of one
of the lowest savages, who has no words to express any number higher than
four, and who uses hardly any abstract terms for common objects or for the
affections (1. See the evidence on those points, as given by Lubbock,
'Prehistoric Times,' p. 354, etc.), with that of the most highly organised
ape. The difference would, no doubt, still remain immense, even if one of
the higher apes had been improved or civilised as much as a dog has been in
comparison with its parent-form, the wolf or jackal. The Fuegians rank
amongst the lowest barbarians; but I was continually struck with surprise
how closely the three natives on board H.M.S. "Beagle," who had lived some
years in England, and could talk a little English, resembled us in
disposition and in most of our mental faculties. If no organic being
excepting man had possessed any mental power, or if his powers had been of
a wholly different nature from those of the lower animals, then we should
never have been able to convince ourselves that our high faculties had been
gradually developed. But it can be shewn that there is no fundamental
difference of this kind. We must also admit that there is a much wider
interval in mental power between one of the lowest fishes, as a lamprey or
lancelet, and one of the higher apes, than between an ape and man; yet this
interval is filled up by numberless gradations.
Nor is the difference slight in moral disposition between a barbarian, such
as the man described by the old navigator Byron, who dashed his child on
the rocks for dropping a basket of sea-urchins, and a Howard or Clarkson;
and in intellect, between a savage who uses hardly any abstract terms, and
a Newton or Shakspeare. Differences of this kind between the highest men
of the highest races and the lowest savages, are connected by the finest
gradations. Therefore it is possible that they might pass and be developed
into each other.
My object in this chapter is to shew that there is no fundamental
difference between man and the higher mammals in their mental faculties.
Each division of the subject might have been extended into a separate
essay, but must here be treated briefly. As no classification of the
mental powers has been universally accepted, I shall arrange my remarks in
the order most convenient for my purpose; and will select those facts which
have struck me most, with the hope that they may produce some effect on the
reader.
With respect to animals very low in the scale, I shall give some additional
facts under Sexual Selection, shewing that their mental powers are much
higher than might have been expected. The variability of the faculties in
the individuals of the same species is an important point for us, and some
few illustrations will here be given. But it would be superfluous to enter
into many details on this head, for I have found on frequent enquiry, that
it is the unanimous opinion of all those who have long attended to animals
of many kinds, including birds, that the individuals differ greatly in
every mental characteristic. In what manner the mental powers were first
developed in the lowest organisms, is as hopeless an enquiry as how life
itself first originated. These are problems for the distant future, if
they are ever to be solved by man.
As man possesses the same senses as the lower animals, his fundamental
intuitions must be the same. Man has also some few instincts in common, as
that of self-preservation, sexual love, the love of the mother for her new-
born offspring, the desire possessed by the latter to suck, and so forth.
But man, perhaps, has somewhat fewer instincts than those possessed by the
animals which come next to him in the series. The orang in the Eastern
islands, and the chimpanzee in Africa, build platforms on which they sleep;
and, as both species follow the same habit, it might be argued that this
was due to instinct, but we cannot feel sure that it is not the result of
both animals having similar wants, and possessing similar powers of
reasoning. These apes, as we may assume, avoid the many poisonous fruits
of the tropics, and man has no such knowledge: but as our domestic
animals, when taken to foreign lands, and when first turned out in the
spring, often eat poisonous herbs, which they afterwards avoid, we cannot
feel sure that the apes do not learn from their own experience or from that
of their parents what fruits to select. It is, however, certain, as we
shall presently see, that apes have an instinctive dread of serpents, and
probably of other dangerous animals.
The fewness and the comparative simplicity of the instincts in the higher
animals are remarkable in contrast with those of the lower animals. Cuvier
maintained that instinct and intelligence stand in an inverse ratio to each
other; and some have thought that the intellectual faculties of the higher
animals have been gradually developed from their instincts. But Pouchet,
in an interesting essay (2. 'L'Instinct chez les Insectes,' 'Revue des
Deux Mondes,' Feb. 1870, p. 690.), has shewn that no such inverse ratio
really exists. Those insects which possess the most wonderful instincts
are certainly the most intelligent. In the vertebrate series, the least
intelligent members, namely fishes and amphibians, do not possess complex
instincts; and amongst mammals the animal most remarkable for its
instincts, namely the beaver, is highly intelligent, as will be admitted by
every one who has read Mr. Morgan's excellent work. (3. 'The American
Beaver and His Works,' 1868.)
Although the first dawnings of intelligence, according to Mr. Herbert
Spencer (4. 'The Principles of Psychology,' 2nd edit., 1870, pp. 418-
443.), have been developed through the multiplication and co-ordination of
reflex actions, and although many of the simpler instincts graduate into
reflex actions, and can hardly be distinguished from them, as in the case
of young animals sucking, yet the more complex instincts seem to have
originated independently of intelligence. I am, however, very far from
wishing to deny that instinctive actions may lose their fixed and untaught
character, and be replaced by others performed by the aid of the free will.
On the other hand, some intelligent actions, after being performed during
several generations, become converted into instincts and are inherited, as
when birds on oceanic islands learn to avoid man. These actions may then
be said to be degraded in character, for they are no longer performed
through reason or from experience. But the greater number of the more
complex instincts appear to have been gained in a wholly different manner,
through the natural selection of variations of simpler instinctive actions.
Such variations appear to arise from the same unknown causes acting on the
cerebral organisation, which induce slight variations or individual
differences in other parts of the body; and these variations, owing to our
ignorance, are often said to arise spontaneously. We can, I think, come to
no other conclusion with respect to the origin of the more complex
instincts, when we reflect on the marvellous instincts of sterile worker-
ants and bees, which leave no offspring to inherit the effects of
experience and of modified habits.
Although, as we learn from the above-mentioned insects and the beaver, a
high degree of intelligence is certainly compatible with complex instincts,
and although actions, at first learnt voluntarily can soon through habit be
performed with the quickness and certainty of a reflex action, yet it is
not improbable that there is a certain amount of interference between the
development of free intelligence and of instinct,--which latter implies
some inherited modification of the brain. Little is known about the
functions of the brain, but we can perceive that as the intellectual powers
become highly developed, the various parts of the brain must be connected
by very intricate channels of the freest intercommunication; and as a
consequence each separate part would perhaps tend to be less well fitted to
answer to particular sensations or associations in a definite and
inherited--that is instinctive--manner. There seems even to exist some
relation between a low degree of intelligence and a strong tendency to the
formation of fixed, though not inherited habits; for as a sagacious
physician remarked to me, persons who are slightly imbecile tend to act in
everything by routine or habit; and they are rendered much happier if this
is encouraged.
I have thought this digression worth giving, because we may easily
underrate the mental powers of the higher animals, and especially of man,
when we compare their actions founded on the memory of past events, on
foresight, reason, and imagination, with exactly similar actions
instinctively performed by the lower animals; in this latter case the
capacity of performing such actions has been gained, step by step, through
the variability of the mental organs and natural selection, without any
conscious intelligence on the part of the animal during each successive
generation. No doubt, as Mr. Wallace has argued (5. 'Contributions to the
Theory of Natural Selection,' 1870, p. 212.), much of the intelligent work
done by man is due to imitation and not to reason; but there is this great
difference between his actions and many of those performed by the lower
animals, namely, that man cannot, on his first trial, make, for instance, a
stone hatchet or a canoe, through his power of imitation. He has to learn
his work by practice; a beaver, on the other hand, can make its dam or
canal, and a bird its nest, as well, or nearly as well, and a spider its
wonderful web, quite as well (6. For the evidence on this head, see Mr. J.
Traherne Moggridge's most interesting work, 'Harvesting Ants and Trap-Door
Spiders,' 1873, pp. 126, 128.), the first time it tries as when old and
experienced.
To return to our immediate subject: the lower animals, like man,
manifestly feel pleasure and pain, happiness and misery. Happiness is
never better exhibited than by young animals, such as puppies, kittens,
lambs, etc., when playing together, like our own children. Even insects
play together, as has been described by that excellent observer, P. Huber
(7. 'Recherches sur les Moeurs des Fourmis,' 1810, p. 173.), who saw ants
chasing and pretending to bite each other, like so many puppies.
The fact that the lower animals are excited by the same emotions as
ourselves is so well established, that it will not be necessary to weary
the reader by many details. Terror acts in the same manner on them as on
us, causing the muscles to tremble, the heart to palpitate, the sphincters
to be relaxed, and the hair to stand on end. Suspicion, the offspring of
fear, is eminently characteristic of most wild animals. It is, I think,
impossible to read the account given by Sir E. Tennent, of the behaviour of
the female elephants, used as decoys, without admitting that they
intentionally practise deceit, and well know what they are about. Courage
and timidity are extremely variable qualities in the individuals of the
same species, as is plainly seen in our dogs. Some dogs and horses are
ill-tempered, and easily turn sulky; others are good-tempered; and these
qualities are certainly inherited. Every one knows how liable animals are
to furious rage, and how plainly they shew it. Many, and probably true,
anecdotes have been published on the long-delayed and artful revenge of
various animals. The accurate Rengger, and Brehm (8. All the following
statements, given on the authority of these two naturalists, are taken from
Rengger's 'Naturgesch. der Saugethiere von Paraguay,' 1830, s. 41-57, and
from Brehm's 'Thierleben,' B. i. s. 10-87.) state that the American and
African monkeys which they kept tame, certainly revenged themselves. Sir
Andrew Smith, a zoologist whose scrupulous accuracy was known to many
persons, told me the following story of which he was himself an eye-
witness; at the Cape of Good Hope an officer had often plagued a certain
baboon, and the animal, seeing him approaching one Sunday for parade,
poured water into a hole and hastily made some thick mud, which he
skilfully dashed over the officer as he passed by, to the amusement of many
bystanders. For long afterwards the baboon rejoiced and triumphed whenever
he saw his victim.
The love of a dog for his master is notorious; as an old writer quaintly
says (9. Quoted by Dr. Lauder Lindsay, in his 'Physiology of Mind in the
Lower Animals,' 'Journal of Mental Science,' April 1871, p. 38.), "A dog is
the only thing on this earth that luvs you more than he luvs himself."
In the agony of death a dog has been known to caress his master, and every
one has heard of the dog suffering under vivisection, who licked the hand
of the operator; this man, unless the operation was fully justified by an
increase of our knowledge, or unless he had a heart of stone, must have
felt remorse to the last hour of his life.
As Whewell (10. 'Bridgewater Treatise,' p. 263.) has well asked, "who that
reads the touching instances of maternal affection, related so often of the
women of all nations, and of the females of all animals, can doubt that the
principle of action is the same in the two cases?" We see maternal
affection exhibited in the most trifling details; thus Rengger observed an
American monkey (a Cebus) carefully driving away the flies which plagued
her infant; and Duvaucel saw a Hylobates washing the faces of her young
ones in a stream. So intense is the grief of female monkeys for the loss
of their young, that it invariably caused the death of certain kinds kept
under confinement by Brehm in N. Africa. Orphan monkeys were always
adopted and carefully guarded by the other monkeys, both males and females.
One female baboon had so capacious a heart that she not only adopted young
monkeys of other species, but stole young dogs and cats, which she
continually carried about. Her kindness, however, did not go so far as to
share her food with her adopted offspring, at which Brehm was surprised, as
his monkeys always divided everything quite fairly with their own young
ones. An adopted kitten scratched this affectionate baboon, who certainly
had a fine intellect, for she was much astonished at being scratched, and
immediately examined the kitten's feet, and without more ado bit off the
claws. (11. A critic, without any grounds ('Quarterly Review,' July 1871,
p. 72), disputes the possibility of this act as described by Brehm, for the
sake of discrediting my work. Therefore I tried, and found that I could
readily seize with my own teeth the sharp little claws of a kitten nearly
five weeks old.) In the Zoological Gardens, I heard from the keeper that
an old baboon (C. chacma) had adopted a Rhesus monkey; but when a young
drill and mandrill were placed in the cage, she seemed to perceive that
these monkeys, though distinct species, were her nearer relatives, for she
at once rejected the Rhesus and adopted both of them. The young Rhesus, as
I saw, was greatly discontented at being thus rejected, and it would, like
a naughty child, annoy and attack the young drill and mandrill whenever it
could do so with safety; this conduct exciting great indignation in the old
baboon. Monkeys will also, according to Brehm, defend their master when
attacked by any one, as well as dogs to whom they are attached, from the
attacks of other dogs. But we here trench on the subjects of sympathy and
fidelity, to which I shall recur. Some of Brehm's monkeys took much
delight in teasing a certain old dog whom they disliked, as well as other
animals, in various ingenious ways.
Most of the more complex emotions are common to the higher animals and
ourselves. Every one has seen how jealous a dog is of his master's
affection, if lavished on any other creature; and I have observed the same
fact with monkeys. This shews that animals not only love, but have desire
to be loved. Animals manifestly feel emulation. They love approbation or
praise; and a dog carrying a basket for his master exhibits in a high
degree self-complacency or pride. There can, I think, be no doubt that a
dog feels shame, as distinct from fear, and something very like modesty
when begging too often for food. A great dog scorns the snarling of a
little dog, and this may be called magnanimity. Several observers have
stated that monkeys certainly dislike being laughed at; and they sometimes
invent imaginary offences. In the Zoological Gardens I saw a baboon who
always got into a furious rage when his keeper took out a letter or book
and read it aloud to him; and his rage was so violent that, as I witnessed
on one occasion, he bit his own leg till the blood flowed. Dogs shew what
may be fairly called a sense of humour, as distinct from mere play; if a
bit of stick or other such object be thrown to one, he will often carry it
away for a short distance; and then squatting down with it on the ground
close before him, will wait until his master comes quite close to take it
away. The dog will then seize it and rush away in triumph, repeating the
same manoeuvre, and evidently enjoying the practical joke.
We will now turn to the more intellectual emotions and faculties, which are
very important, as forming the basis for the development of the higher
mental powers. Animals manifestly enjoy excitement, and suffer from ennui,
as may be seen with dogs, and, according to Rengger, with monkeys. All
animals feel WONDER, and many exhibit CURIOSITY. They sometimes suffer
from this latter quality, as when the hunter plays antics and thus attracts
them; I have witnessed this with deer, and so it is with the wary chamois,
and with some kinds of wild-ducks. Brehm gives a curious account of the
instinctive dread, which his monkeys exhibited, for snakes; but their
curiosity was so great that they could not desist from occasionally
satiating their horror in a most human fashion, by lifting up the lid of
the box in which the snakes were kept. I was so much surprised at his
account, that I took a stuffed and coiled-up snake into the monkey-house at
the Zoological Gardens, and the excitement thus caused was one of the most
curious spectacles which I ever beheld. Three species of Cercopithecus
were the most alarmed; they dashed about their cages, and uttered sharp
signal cries of danger, which were understood by the other monkeys. A few
young monkeys and one old Anubis baboon alone took no notice of the snake.
I then placed the stuffed specimen on the ground in one of the larger
compartments. After a time all the monkeys collected round it in a large
circle, and staring intently, presented a most ludicrous appearance. They
became extremely nervous; so that when a wooden ball, with which they were
familiar as a plaything, was accidentally moved in the straw, under which
it was partly hidden, they all instantly started away. These monkeys
behaved very differently when a dead fish, a mouse (12. I have given a
short account of their behaviour on this occasion in my 'Expression of the
Emotions in Man and Animals,' p. 43.), a living turtle, and other new
objects were placed in their cages; for though at first frightened, they
soon approached, handled and examined them. I then placed a live snake in
a paper bag, with the mouth loosely closed, in one of the larger
compartments. One of the monkeys immediately approached, cautiously opened
the bag a little, peeped in, and instantly dashed away. Then I witnessed
what Brehm has described, for monkey after monkey, with head raised high
and turned on one side, could not resist taking a momentary peep into the
upright bag, at the dreadful object lying quietly at the bottom. It would
almost appear as if monkeys had some notion of zoological affinities, for
those kept by Brehm exhibited a strange, though mistaken, instinctive dread
of innocent lizards and frogs. An orang, also, has been known to be much
alarmed at the first sight of a turtle. (13. W.C.L. Martin, 'Natural
History of Mammalia,' 1841, p. 405.)
The principle of IMITATION is strong in man, and especially, as I have
myself observed, with savages. In certain morbid states of the brain this
tendency is exaggerated to an extraordinary degree: some hemiplegic
patients and others, at the commencement of inflammatory softening of the
brain, unconsciously imitate every word which is uttered, whether in their
own or in a foreign language, and every gesture or action which is
performed near them. (14. Dr. Bateman, 'On Aphasia,' 1870, p. 110.)
Desor (15. Quoted by Vogt, 'Memoire sur les Microcephales,' 1867, p. 168.)
has remarked that no animal voluntarily imitates an action performed by
man, until in the ascending scale we come to monkeys, which are well known
to be ridiculous mockers. Animals, however, sometimes imitate each other's
actions: thus two species of wolves, which had been reared by dogs,
learned to bark, as does sometimes the jackal (16. The 'Variation of
Animals and Plants under Domestication,' vol. i. p. 27.), but whether this
can be called voluntary imitation is another question. Birds imitate the
songs of their parents, and sometimes of other birds; and parrots are
notorious imitators of any sound which they often hear. Dureau de la Malle
gives an account (17. 'Annales des Sciences Nat.' (1st Series), tom. xxii.
p. 397.) of a dog reared by a cat, who learnt to imitate the well-known
action of a cat licking her paws, and thus washing her ears and face; this
was also witnessed by the celebrated naturalist Audouin. I have received
several confirmatory accounts; in one of these, a dog had not been suckled
by a cat, but had been brought up with one, together with kittens, and had
thus acquired the above habit, which he ever afterwards practised during
his life of thirteen years. Dureau de la Malle's dog likewise learnt from
the kittens to play with a ball by rolling it about with his fore paws, and
springing on it. A correspondent assures me that a cat in his house used
to put her paws into jugs of milk having too narrow a mouth for her head.
A kitten of this cat soon learned the same trick, and practised it ever
afterwards, whenever there was an opportunity.
The parents of many animals, trusting to the principle of imitation in
their young, and more especially to their instinctive or inherited
tendencies, may be said to educate them. We see this when a cat brings a
live mouse to her kittens; and Dureau de la Malle has given a curious
account (in the paper above quoted) of his observations on hawks which
taught their young dexterity, as well as judgment of distances, by first
dropping through the air dead mice and sparrows, which the young generally
failed to catch, and then bringing them live birds and letting them loose.
Hardly any faculty is more important for the intellectual progress of man
than ATTENTION. Animals clearly manifest this power, as when a cat watches
by a hole and prepares to spring on its prey. Wild animals sometimes
become so absorbed when thus engaged, that they may be easily approached.
Mr. Bartlett has given me a curious proof how variable this faculty is in
monkeys. A man who trains monkeys to act in plays, used to purchase common
kinds from the Zoological Society at the price of five pounds for each; but
he offered to give double the price, if he might keep three or four of them
for a few days, in order to select one. When asked how he could possibly
learn so soon, whether a particular monkey would turn out a good actor, he
answered that it all depended on their power of attention. If when he was
talking and explaining anything to a monkey, its attention was easily
distracted, as by a fly on the wall or other trifling object, the case was
hopeless. If he tried by punishment to make an inattentive monkey act, it
turned sulky. On the other hand, a monkey which carefully attended to him
could always be trained.
It is almost superfluous to state that animals have excellent MEMORIES for
persons and places. A baboon at the Cape of Good Hope, as I have been
informed by Sir Andrew Smith, recognised him with joy after an absence of
nine months. I had a dog who was savage and averse to all strangers, and I
purposely tried his memory after an absence of five years and two days. I
went near the stable where he lived, and shouted to him in my old manner;
he shewed no joy, but instantly followed me out walking, and obeyed me,
exactly as if I had parted with him only half an hour before. A train of
old associations, dormant during five years, had thus been instantaneously
awakened in his mind. Even ants, as P. Huber (18. 'Les Moeurs des
Fourmis,' 1810, p. 150.) has clearly shewn, recognised their fellow-ants
belonging to the same community after a separation of four months. Animals
can certainly by some means judge of the intervals of time between
recurrent events.
The IMAGINATION is one of the highest prerogatives of man. By this faculty
he unites former images and ideas, independently of the will, and thus
creates brilliant and novel results. A poet, as Jean Paul Richter remarks
(19. Quoted in Dr. Maudsley's 'Physiology and Pathology of Mind,' 1868,
pp. 19, 220.), "who must reflect whether he shall make a character say yes
or no--to the devil with him; he is only a stupid corpse." Dreaming gives
us the best notion of this power; as Jean Paul again says, "The dream is an
involuntary art of poetry." The value of the products of our imagination
depends of course on the number, accuracy, and clearness of our
impressions, on our judgment and taste in selecting or rejecting the
involuntary combinations, and to a certain extent on our power of
voluntarily combining them. As dogs, cats, horses, and probably all the
higher animals, even birds (20. Dr. Jerdon, 'Birds of India,' vol. i.
1862, p. xxi. Houzeau says that his parokeets and canary-birds dreamt:
'Etudes sur les Facultes Mentales des Animaux,' tom. ii. p. 136.) have
vivid dreams, and this is shewn by their movements and the sounds uttered,
we must admit that they possess some power of imagination. There must be
something special, which causes dogs to howl in the night, and especially
during moonlight, in that remarkable and melancholy manner called baying.
All dogs do not do so; and, according to Houzeau (21. ibid. 1872, tom. ii.
p. 181.), they do not then look at the moon, but at some fixed point near
the horizon. Houzeau thinks that their imaginations are disturbed by the
vague outlines of the surrounding objects, and conjure up before them
fantastic images: if this be so, their feelings may almost be called
superstitious.
Of all the faculties of the human mind, it will, I presume, be admitted
that REASON stands at the summit. Only a few persons now dispute that
animals possess some power of reasoning. Animals may constantly be seen to
pause, deliberate, and resolve. It is a significant fact, that the more
the habits of any particular animal are studied by a naturalist, the more
he attributes to reason and the less to unlearnt instincts. (22. Mr. L.H.
Morgan's work on 'The American Beaver,' 1868, offers a good illustration of
this remark. I cannot help thinking, however, that he goes too far in
underrating the power of instinct.) In future chapters we shall see that
some animals extremely low in the scale apparently display a certain amount
of reason. No doubt it is often difficult to distinguish between the power
of reason and that of instinct. For instance, Dr. Hayes, in his work on
'The Open Polar Sea,' repeatedly remarks that his dogs, instead of
continuing to draw the sledges in a compact body, diverged and separated
when they came to thin ice, so that their weight might be more evenly
distributed. This was often the first warning which the travellers
received that the ice was becoming thin and dangerous. Now, did the dogs
act thus from the experience of each individual, or from the example of the
older and wiser dogs, or from an inherited habit, that is from instinct?
This instinct, may possibly have arisen since the time, long ago, when dogs
were first employed by the natives in drawing their sledges; or the Arctic
wolves, the parent-stock of the Esquimaux dog, may have acquired an
instinct impelling them not to attack their prey in a close pack, when on
thin ice.
We can only judge by the circumstances under which actions are performed,
whether they are due to instinct, or to reason, or to the mere association
of ideas: this latter principle, however, is intimately connected with
reason. A curious case has been given by Prof. Mobius (23. 'Die
Bewegungen der Thiere,' etc., 1873, p. 11.), of a pike, separated by a
plate of glass from an adjoining aquarium stocked with fish, and who often
dashed himself with such violence against the glass in trying to catch the
other fishes, that he was sometimes completely stunned. The pike went on
thus for three months, but at last learnt caution, and ceased to do so.
The plate of glass was then removed, but the pike would not attack these
particular fishes, though he would devour others which were afterwards
introduced; so strongly was the idea of a violent shock associated in his
feeble mind with the attempt on his former neighbours. If a savage, who
had never seen a large plate-glass window, were to dash himself even once
against it, he would for a long time afterwards associate a shock with a
window-frame; but very differently from the pike, he would probably reflect
on the nature of the impediment, and be cautious under analogous
circumstances. Now with monkeys, as we shall presently see, a painful or
merely a disagreeable impression, from an action once performed, is
sometimes sufficient to prevent the animal from repeating it. If we
attribute this difference between the monkey and the pike solely to the
association of ideas being so much stronger and more persistent in the one
than the other, though the pike often received much the more severe injury,
can we maintain in the case of man that a similar difference implies the
possession of a fundamentally different mind?
Houzeau relates (24. 'Etudes sur les Facultes Mentales des Animaux,' 1872,
tom. ii. p. 265.) that, whilst crossing a wide and arid plain in Texas, his
two dogs suffered greatly from thirst, and that between thirty and forty
times they rushed down the hollows to search for water. These hollows were
not valleys, and there were no trees in them, or any other difference in
the vegetation, and as they were absolutely dry there could have been no
smell of damp earth. The dogs behaved as if they knew that a dip in the
ground offered them the best chance of finding water, and Houzeau has often
witnessed the same behaviour in other animals.
I have seen, as I daresay have others, that when a small object is thrown
on the ground beyond the reach of one of the elephants in the Zoological
Gardens, he blows through his trunk on the ground beyond the object, so
that the current reflected on all sides may drive the object within his
reach. Again a well-known ethnologist, Mr. Westropp, informs me that he
observed in Vienna a bear deliberately making with his paw a current in
some water, which was close to the bars of his cage, so as to draw a piece
of floating bread within his reach. These actions of the elephant and bear
can hardly be attributed to instinct or inherited habit, as they would be
of little use to an animal in a state of nature. Now, what is the
difference between such actions, when performed by an uncultivated man, and
by one of the higher animals?
The savage and the dog have often found water at a low level, and the
coincidence under such circumstances has become associated in their minds.
A cultivated man would perhaps make some general proposition on the
subject; but from all that we know of savages it is extremely doubtful
whether they would do so, and a dog certainly would not. But a savage, as
well as a dog, would search in the same way, though frequently
disappointed; and in both it seems to be equally an act of reason, whether
or not any general proposition on the subject is consciously placed before
the mind. (25. Prof. Huxley has analysed with admirable clearness the
mental steps by which a man, as well as a dog, arrives at a conclusion in a
case analogous to that given in my text. See his article, 'Mr. Darwin's
Critics,' in the 'Contemporary Review,' Nov. 1871, p. 462, and in his
'Critiques and Essays,' 1873, p. 279.) The same would apply to the
elephant and the bear making currents in the air or water. The savage
would certainly neither know nor care by what law the desired movements
were effected; yet his act would be guided by a rude process of reasoning,
as surely as would a philosopher in his longest chain of deductions. There
would no doubt be this difference between him and one of the higher
animals, that he would take notice of much slighter circumstances and
conditions, and would observe any connection between them after much less
experience, and this would be of paramount importance. I kept a daily
record of the actions of one of my infants, and when he was about eleven
months old, and before he could speak a single word, I was continually
struck with the greater quickness, with which all sorts of objects and
sounds were associated together in his mind, compared with that of the most
intelligent dogs I ever knew. But the higher animals differ in exactly the
same way in this power of association from those low in the scale, such as
the pike, as well as in that of drawing inferences and of observation.
The promptings of reason, after very short experience, are well shewn by
the following actions of American monkeys, which stand low in their order.
Rengger, a most careful observer, states that when he first gave eggs to
his monkeys in Paraguay, they smashed them, and thus lost much of their
contents; afterwards they gently hit one end against some hard body, and
picked off the bits of shell with their fingers. After cutting themselves
only ONCE with any sharp tool, they would not touch it again, or would
handle it with the greatest caution. Lumps of sugar were often given them
wrapped up in paper; and Rengger sometimes put a live wasp in the paper, so
that in hastily unfolding it they got stung; after this had ONCE happened,
they always first held the packet to their ears to detect any movement
within. (26. Mr. Belt, in his most interesting work, 'The Naturalist in
Nicaragua,' 1874, (p. 119,) likewise describes various actions of a tamed
Cebus, which, I think, clearly shew that this animal possessed some
reasoning power.)
The following cases relate to dogs. Mr. Colquhoun (27. 'The Moor and the
Loch,' p. 45. Col. Hutchinson on 'Dog Breaking,' 1850, p. 46.) winged two
wild-ducks, which fell on the further side of a stream; his retriever tried
to bring over both at once, but could not succeed; she then, though never
before known to ruffle a feather, deliberately killed one, brought over the
other, and returned for the dead bird. Col. Hutchinson relates that two
partridges were shot at once, one being killed, the other wounded; the
latter ran away, and was caught by the retriever, who on her return came
across the dead bird; "she stopped, evidently greatly puzzled, and after
one or two trials, finding she could not take it up without permitting the
escape of the winged bird, she considered a moment, then deliberately
murdered it by giving it a severe crunch, and afterwards brought away both
together. This was the only known instance of her ever having wilfully
injured any game." Here we have reason though not quite perfect, for the
retriever might have brought the wounded bird first and then returned for
the dead one, as in the case of the two wild-ducks. I give the above
cases, as resting on the evidence of two independent witnesses, and because
in both instances the retrievers, after deliberation, broke through a habit
which is inherited by them (that of not killing the game retrieved), and
because they shew how strong their reasoning faculty must have been to
overcome a fixed habit.
I will conclude by quoting a remark by the illustrious Humboldt. (28.
'Personal Narrative,' Eng. translat., vol. iii. p. 106.) "The muleteers in
S. America say, 'I will not give you the mule whose step is easiest, but la
mas racional,--the one that reasons best'"; and; as, he adds, "this popular
expression, dictated by long experience, combats the system of animated
machines, better perhaps than all the arguments of speculative philosophy."
Nevertheless some writers even yet deny that the higher animals possess a
trace of reason; and they endeavour to explain away, by what appears to be
mere verbiage, (29. I am glad to find that so acute a reasoner as Mr.
Leslie Stephen ('Darwinism and Divinity, Essays on Free Thinking,' 1873, p.
80), in speaking of the supposed impassable barrier between the minds of
man and the lower animals, says, "The distinctions, indeed, which have been
drawn, seem to us to rest upon no better foundation than a great many other
metaphysical distinctions; that is, the assumption that because you can
give two things different names, they must therefore have different
natures. It is difficult to understand how anybody who has ever kept a
dog, or seen an elephant, can have any doubt as to an animal's power of
performing the essential processes of reasoning.") all such facts as those
above given.
It has, I think, now been shewn that man and the higher animals, especially
the Primates, have some few instincts in common. All have the same senses,
intuitions, and sensations,--similar passions, affections, and emotions,
even the more complex ones, such as jealousy, suspicion, emulation,
gratitude, and magnanimity; they practise deceit and are revengeful; they
are sometimes susceptible to ridicule, and even have a sense of humour;
they feel wonder and curiosity; they possess the same faculties of
imitation, attention, deliberation, choice, memory, imagination, the
association of ideas, and reason, though in very different degrees. The
individuals of the same species graduate in intellect from absolute
imbecility to high excellence. They are also liable to insanity, though
far less often than in the case of man. (30. See 'Madness in Animals,' by
Dr. W. Lauder Lindsay, in 'Journal of Mental Science,' July 1871.)
Nevertheless, many authors have insisted that man is divided by an
insuperable barrier from all the lower animals in his mental faculties. I
formerly made a collection of above a score of such aphorisms, but they are
almost worthless, as their wide difference and number prove the difficulty,
if not the impossibility, of the attempt. It has been asserted that man
alone is capable of progressive improvement; that he alone makes use of
tools or fire, domesticates other animals, or possesses property; that no
animal has the power of abstraction, or of forming general concepts, is
self-conscious and comprehends itself; that no animal employs language;
that man alone has a sense of beauty, is liable to caprice, has the feeling
of gratitude, mystery, etc.; believes in God, or is endowed with a
conscience. I will hazard a few remarks on the more important and
interesting of these points.
Archbishop Sumner formerly maintained (31. Quoted by Sir C. Lyell,
'Antiquity of Man,' p. 497.) that man alone is capable of progressive
improvement. That he is capable of incomparably greater and more rapid
improvement than is any other animal, admits of no dispute; and this is
mainly due to his power of speaking and handing down his acquired
knowledge. With animals, looking first to the individual, every one who
has had any experience in setting traps, knows that young animals can he
caught much more easily than old ones; and they can be much more easily
approached by an enemy. Even with respect to old animals, it is impossible
to catch many in the same place and in the same kind of trap, or to destroy
them by the same kind of poison; yet it is improbable that all should have
partaken of the poison, and impossible that all should have been caught in
a trap. They must learn caution by seeing their brethren caught or
poisoned. In North America, where the fur-bearing animals have long been
pursued, they exhibit, according to the unanimous testimony of all
observers, an almost incredible amount of sagacity, caution and cunning;
but trapping has been there so long carried on, that inheritance may
possibly have come into play. I have received several accounts that when
telegraphs are first set up in any district, many birds kill themselves by
flying against the wires, but that in the course of a very few years they
learn to avoid this danger, by seeing, as it would appear, their comrades
killed. (32. For additional evidence, with details, see M. Houzeau,
'Etudes sur les Facultes Mentales des Animaux,' tom. ii. 1872, p. 147.)
If we look to successive generations, or to the race, there is no doubt
that birds and other animals gradually both acquire and lose caution in
relation to man or other enemies (33. See, with respect to birds on
oceanic islands, my 'Journal of Researches during the Voyage of the
"Beagle,"' 1845, p. 398. 'Origin of Species,' 5th ed. p. 260.); and this
caution is certainly in chief part an inherited habit or instinct, but in
part the result of individual experience. A good observer, Leroy (34.
'Lettres Phil. sur l'Intelligence des Animaux,' nouvelle edit., 1802, p.
86.), states, that in districts where foxes are much hunted, the young, on
first leaving their burrows, are incontestably much more wary than the old
ones in districts where they are not much disturbed.
Our domestic dogs are descended from wolves and jackals (35. See the
evidence on this head in chap. i. vol. i., 'On the Variation of Animals and
Plants under Domestication.'), and though they may not have gained in
cunning, and may have lost in wariness and suspicion, yet they have
progressed in certain moral qualities, such as in affection, trust-
worthiness, temper, and probably in general intelligence. The common rat
has conquered and beaten several other species throughout Europe, in parts
of North America, New Zealand, and recently in Formosa, as well as on the
mainland of China. Mr. Swinhoe (36. 'Proceedings Zoological Society,'
1864, p. 186.), who describes these two latter cases, attributes the
victory of the common rat over the large Mus coninga to its superior
cunning; and this latter quality may probably be attributed to the habitual
exercise of all its faculties in avoiding extirpation by man, as well as to
nearly all the less cunning or weak-minded rats having been continuously
destroyed by him. It is, however, possible that the success of the common
rat may be due to its having possessed greater cunning than its fellow-
species, before it became associated with man. To maintain, independently
of any direct evidence, that no animal during the course of ages has
progressed in intellect or other mental faculties, is to beg the question
of the evolution of species. We have seen that, according to Lartet,
existing mammals belonging to several orders have larger brains than their
ancient tertiary prototypes.
It has often been said that no animal uses any tool; but the chimpanzee in
a state of nature cracks a native fruit, somewhat like a walnut, with a
stone. (37. Savage and Wyman in 'Boston Journal of Natural History,' vol.
iv. 1843-44, p. 383.) Rengger (38. 'Saugethiere von Paraguay,' 1830, s.
51-56.) easily taught an American monkey thus to break open hard palm-nuts;
and afterwards of its own accord, it used stones to open other kinds of
nuts, as well as boxes. It thus also removed the soft rind of fruit that
had a disagreeable flavour. Another monkey was taught to open the lid of a
large box with a stick, and afterwards it used the stick as a lever to move
heavy bodies; and I have myself seen a young orang put a stick into a
crevice, slip his hand to the other end, and use it in the proper manner as
a lever. The tamed elephants in India are well known to break off branches
of trees and use them to drive away the flies; and this same act has been
observed in an elephant in a state of nature. (39. The Indian Field,
March 4, 1871.) I have seen a young orang, when she thought she was going
to be whipped, cover and protect herself with a blanket or straw. In these
several cases stones and sticks were employed as implements; but they are
likewise used as weapons. Brehm (40. 'Thierleben,' B. i. s. 79, 82.)
states, on the authority of the well-known traveller Schimper, that in
Abyssinia when the baboons belonging to one species (C. gelada) descend in
troops from the mountains to plunder the fields, they sometimes encounter
troops of another species (C. hamadryas), and then a fight ensues. The
Geladas roll down great stones, which the Hamadryas try to avoid, and then
both species, making a great uproar, rush furiously against each other.
Brehm, when accompanying the Duke of Coburg-Gotha, aided in an attack with
fire-arms on a troop of baboons in the pass of Mensa in Abyssinia. The
baboons in return rolled so many stones down the mountain, some as large as
a man's head, that the attackers had to beat a hasty retreat; and the pass
was actually closed for a time against the caravan. It deserves notice
that these baboons thus acted in concert. Mr. Wallace (41. 'The Malay
Archipelago,' vol. i. 1869, p. 87.) on three occasions saw female orangs,
accompanied by their young, "breaking off branches and the great spiny
fruit of the Durian tree, with every appearance of rage; causing such a
shower of missiles as effectually kept us from approaching too near the
tree." As I have repeatedly seen, a chimpanzee will throw any object at
hand at a person who offends him; and the before-mentioned baboon at the
Cape of Good Hope prepared mud for the purpose.
In the Zoological Gardens, a monkey, which had weak teeth, used to break
open nuts with a stone; and I was assured by the keepers that after using
the stone, he hid it in the straw, and would not let any other monkey touch
it. Here, then, we have the idea of property; but this idea is common to
every dog with a bone, and to most or all birds with their nests.
The Duke of Argyll (42. 'Primeval Man,' 1869, pp. 145, 147.) remarks, that
the fashioning of an implement for a special purpose is absolutely peculiar
to man; and he considers that this forms an immeasurable gulf between him
and the brutes. This is no doubt a very important distinction; but there
appears to me much truth in Sir J. Lubbock's suggestion (43. 'Prehistoric
Times,' 1865, p. 473, etc.), that when primeval man first used flint-stones
for any purpose, he would have accidentally splintered them, and would then
have used the sharp fragments. From this step it would be a small one to
break the flints on purpose, and not a very wide step to fashion them
rudely. This latter advance, however, may have taken long ages, if we may
judge by the immense interval of time which elapsed before the men of the
neolithic period took to grinding and polishing their stone tools. In
breaking the flints, as Sir J. Lubbock likewise remarks, sparks would have
been emitted, and in grinding them heat would have been evolved: thus the
two usual methods of "obtaining fire may have originated." The nature of
fire would have been known in the many volcanic regions where lava
occasionally flows through forests. The anthropomorphous apes, guided
probably by instinct, build for themselves temporary platforms; but as many
instincts are largely controlled by reason, the simpler ones, such as this
of building a platform, might readily pass into a voluntary and conscious
act. The orang is known to cover itself at night with the leaves of the
Pandanus; and Brehm states that one of his baboons used to protect itself
from the heat of the sun by throwing a straw-mat over its head. In these
several habits, we probably see the first steps towards some of the simpler
arts, such as rude architecture and dress, as they arose amongst the early
progenitors of man.
ABSTRACTION, GENERAL CONCEPTIONS, SELF-CONSCIOUSNESS, MENTAL INDIVIDUALITY.
It would be very difficult for any one with even much more knowledge than I
possess, to determine how far animals exhibit any traces of these high
mental powers. This difficulty arises from the impossibility of judging
what passes through the mind of an animal; and again, the fact that writers
differ to a great extent in the meaning which they attribute to the above
terms, causes a further difficulty. If one may judge from various articles
which have been published lately, the greatest stress seems to be laid on
the supposed entire absence in animals of the power of abstraction, or of
forming general concepts. But when a dog sees another dog at a distance,
it is often clear that he perceives that it is a dog in the abstract; for
when he gets nearer his whole manner suddenly changes, if the other dog be
a friend. A recent writer remarks, that in all such cases it is a pure
assumption to assert that the mental act is not essentially of the same
nature in the animal as in man. If either refers what he perceives with
his senses to a mental concept, then so do both. (44. Mr. Hookham, in a
letter to Prof. Max Muller, in the 'Birmingham News,' May 1873.) When I
say to my terrier, in an eager voice (and I have made the trial many
times), "Hi, hi, where is it?" she at once takes it as a sign that
something is to be hunted, and generally first looks quickly all around,
and then rushes into the nearest thicket, to scent for any game, but
finding nothing, she looks up into any neighbouring tree for a squirrel.
Now do not these actions clearly shew that she had in her mind a general
idea or concept that some animal is to be discovered and hunted?
It may be freely admitted that no animal is self-conscious, if by this term
it is implied, that he reflects on such points, as whence he comes or
whither he will go, or what is life and death, and so forth. But how can
we feel sure that an old dog with an excellent memory and some power of
imagination, as shewn by his dreams, never reflects on his past pleasures
or pains in the chase? And this would be a form of self-consciousness. On
the other hand, as Buchner (45. 'Conferences sur la Theorie Darwinienne,'
French translat. 1869, p. 132.) has remarked, how little can the hard-
worked wife of a degraded Australian savage, who uses very few abstract
words, and cannot count above four, exert her self-consciousness, or
reflect on the nature of her own existence. It is generally admitted, that
the higher animals possess memory, attention, association, and even some
imagination and reason. If these powers, which differ much in different
animals, are capable of improvement, there seems no great improbability in
more complex faculties, such as the higher forms of abstraction, and self-
consciousness, etc., having been evolved through the development and
combination of the simpler ones. It has been urged against the views here
maintained that it is impossible to say at what point in the ascending
scale animals become capable of abstraction, etc.; but who can say at what
age this occurs in our young children? We see at least that such powers
are developed in children by imperceptible degrees.
That animals retain their mental individuality is unquestionable. When my
voice awakened a train of old associations in the mind of the before-
mentioned dog, he must have retained his mental individuality, although
every atom of his brain had probably undergone change more than once during
the interval of five years. This dog might have brought forward the
argument lately advanced to crush all evolutionists, and said, "I abide
amid all mental moods and all material changes...The teaching that atoms
leave their impressions as legacies to other atoms falling into the places
they have vacated is contradictory of the utterance of consciousness, and
is therefore false; but it is the teaching necessitated by evolutionism,
consequently the hypothesis is a false one." (46. The Rev. Dr. J. M'Cann,
'Anti-Darwinism,' 1869, p. 13.)
LANGUAGE.
This faculty has justly been considered as one of the chief distinctions
between man and the lower animals. But man, as a highly competent judge,
Archbishop Whately remarks, "is not the only animal that can make use of
language to express what is passing in his mind, and can understand, more
or less, what is so expressed by another." (47. Quoted in
'Anthropological Review,' 1864, p. 158.) In Paraguay the Cebus azarae when
excited utters at least six distinct sounds, which excite in other monkeys
similar emotions. (48. Rengger, ibid. s. 45.) The movements of the
features and gestures of monkeys are understood by us, and they partly
understand ours, as Rengger and others declare. It is a more remarkable
fact that the dog, since being domesticated, has learnt to bark (49. See
my 'Variation of Animals and Plants under Domestication,' vol. i. p. 27.)
in at least four or five distinct tones. Although barking is a new art, no
doubt the wild parent-species of the dog expressed their feelings by cries
of various kinds. With the domesticated dog we have the bark of eagerness,
as in the chase; that of anger, as well as growling; the yelp or howl of
despair, as when shut up; the baying at night; the bark of joy, as when
starting on a walk with his master; and the very distinct one of demand or
supplication, as when wishing for a door or window to be opened. According
to Houzeau, who paid particular attention to the subject, the domestic fowl
utters at least a dozen significant sounds. (50. 'Facultes Mentales des
Animaux,' tom. ii. 1872, p. 346-349.)
The habitual use of articulate language is, however, peculiar to man; but
he uses, in common with the lower animals, inarticulate cries to express
his meaning, aided by gestures and the movements of the muscles of the
face. (51. See a discussion on this subject in Mr. E.B. Tylor's very
interesting work, 'Researches into the Early History of Mankind,' 1865,
chaps. ii. to iv.) This especially holds good with the more simple and
vivid feelings, which are but little connected with our higher
intelligence. Our cries of pain, fear, surprise, anger, together with
their appropriate actions, and the murmur of a mother to her beloved child
are more expressive than any words. That which distinguishes man from the
lower animals is not the understanding of articulate sounds, for, as every
one knows, dogs understand many words and sentences. In this respect they
are at the same stage of development as infants, between the ages of ten
and twelve months, who understand many words and short sentences, but
cannot yet utter a single word. It is not the mere articulation which is
our distinguishing character, for parrots and other birds possess this
power. Nor is it the mere capacity of connecting definite sounds with
definite ideas; for it is certain that some parrots, which have been taught
to speak, connect unerringly words with things, and persons with events.
(52. I have received several detailed accounts to this effect. Admiral
Sir B.J. Sulivan, whom I know to be a careful observer, assures me that an
African parrot, long kept in his father's house, invariably called certain
persons of the household, as well as visitors, by their names. He said
"good morning" to every one at breakfast, and "good night" to each as they
left the room at night, and never reversed these salutations. To Sir B.J.
Sulivan's father, he used to add to the " good morning" a short sentence,
which was never once repeated after his father's death. He scolded
violently a strange dog which came into the room through the open window;
and he scolded another parrot (saying "you naughty polly") which had got
out of its cage, and was eating apples on the kitchen table. See also, to
the same effect, Houzeau on parrots, 'Facultes Mentales,' tom. ii. p. 309.
Dr. A. Moschkau informs me that he knew a starling which never made a
mistake in saying in German "good morning" to persons arriving, and "good
bye, old fellow," to those departing. I could add several other such
cases.) The lower animals differ from man solely in his almost infinitely
larger power of associating together the most diversified sounds and ideas;
and this obviously depends on the high development of his mental powers.
As Horne Tooke, one of the founders of the noble science of philology,
observes, language is an art, like brewing or baking; but writing would
have been a better simile. It certainly is not a true instinct, for every
language has to be learnt. It differs, however, widely from all ordinary
arts, for man has an instinctive tendency to speak, as we see in the babble
of our young children; whilst no child has an instinctive tendency to brew,
bake, or write. Moreover, no philologist now supposes that any language
has been deliberately invented; it has been slowly and unconsciously
developed by many steps. (53. See some good remarks on this head by Prof.
Whitney, in his 'Oriental and Linguistic Studies,' 1873, p. 354. He
observes that the desire of communication between man is the living force,
which, in the development of language, "works both consciously and
unconsciously; consciously as regards the immediate end to be attained;
unconsciously as regards the further consequences of the act.") The sounds
uttered by birds offer in several respects the nearest analogy to language,
for all the members of the same species utter the same instinctive cries
expressive of their emotions; and all the kinds which sing, exert their
power instinctively; but the actual song, and even the call-notes, are
learnt from their parents or foster-parents. These sounds, as Daines
Barrington (54. Hon. Daines Barrington in 'Philosoph. Transactions,' 1773,
p. 262. See also Dureau de la Malle, in 'Ann. des. Sc. Nat.' 3rd series,
Zoolog., tom. x. p. 119.) has proved, "are no more innate than language is
in man." The first attempts to sing "may be compared to the imperfect
endeavour in a child to babble." The young males continue practising, or
as the bird-catchers say, "recording," for ten or eleven months. Their
first essays shew hardly a rudiment of the future song; but as they grow
older we can perceive what they are aiming at; and at last they are said
"to sing their song round." Nestlings which have learnt the song of a
distinct species, as with the canary-birds educated in the Tyrol, teach and
transmit their new song to their offspring. The slight natural differences
of song in the same species inhabiting different districts may be
appositely compared, as Barrington remarks, "to provincial dialects"; and
the songs of allied, though distinct species may be compared with the
languages of distinct races of man. I have given the foregoing details to
shew that an instinctive tendency to acquire an art is not peculiar to man.
With respect to the origin of articulate language, after having read on the
one side the highly interesting works of Mr. Hensleigh Wedgwood, the Rev.
F. Farrar, and Prof. Schleicher (55. 'On the Origin of Language,' by H.
Wedgwood, 1866. 'Chapters on Language,' by the Rev. F.W. Farrar, 1865.
These works are most interesting. See also 'De la Phys. et de Parole,' par
Albert Lemoine, 1865, p. 190. The work on this subject, by the late Prof.
Aug. Schleicher, has been translated by Dr. Bikkers into English, under the
title of 'Darwinism tested by the Science of Language,' 1869.), and the
celebrated lectures of Prof. Max Muller on the other side, I cannot doubt
that language owes its origin to the imitation and modification of various
natural sounds, the voices of other animals, and man's own instinctive
cries, aided by signs and gestures. When we treat of sexual selection we
shall see that primeval man, or rather some early progenitor of man,
probably first used his voice in producing true musical cadences, that is
in singing, as do some of the gibbon-apes at the present day; and we may
conclude from a widely-spread analogy, that this power would have been
especially exerted during the courtship of the sexes,--would have expressed
various emotions, such as love, jealousy, triumph,--and would have served
as a challenge to rivals. It is, therefore, probable that the imitation of
musical cries by articulate sounds may have given rise to words expressive
of various complex emotions. The strong tendency in our nearest allies,
the monkeys, in microcephalous idiots (56. Vogt, 'Memoire sur les
Microcephales,' 1867, p. 169. With respect to savages, I have given some
facts in my 'Journal of Researches,' etc., 1845, p. 206.), and in the
barbarous races of mankind, to imitate whatever they hear deserves notice,
as bearing on the subject of imitation. Since monkeys certainly understand
much that is said to them by man, and when wild, utter signal-cries of
danger to their fellows (57. See clear evidence on this head in the two
works so often quoted, by Brehm and Rengger.); and since fowls give
distinct warnings for danger on the ground, or in the sky from hawks (both,
as well as a third cry, intelligible to dogs) (58. Houzeau gives a very
curious account of his observations on this subject in his 'Facultes
Mentales des Animaux,' tom. ii. p. 348.), may not some unusually wise ape-
like animal have imitated the growl of a beast of prey, and thus told his
fellow-monkeys the nature of the expected danger? This would have been a
first step in the formation of a language.
As the voice was used more and more, the vocal organs would have been
strengthened and perfected through the principle of the inherited effects
of use; and this would have reacted on the power of speech. But the
relation between the continued use of language and the development of the
brain, has no doubt been far more important. The mental powers in some
early progenitor of man must have been more highly developed than in any
existing ape, before even the most imperfect form of speech could have come
into use; but we may confidently believe that the continued use and
advancement of this power would have reacted on the mind itself, by
enabling and encouraging it to carry on long trains of thought. A complex
train of thought can no more be carried on without the aid of words,
whether spoken or silent, than a long calculation without the use of
figures or algebra. It appears, also, that even an ordinary train of
thought almost requires, or is greatly facilitated by some form of
language, for the dumb, deaf, and blind girl, Laura Bridgman, was observed
to use her fingers whilst dreaming. (59. See remarks on this head by Dr.
Maudsley, 'The Physiology and Pathology of Mind,' 2nd ed., 1868, p. 199.)
Nevertheless, a long succession of vivid and connected ideas may pass
through the mind without the aid of any form of language, as we may infer
from the movements of dogs during their dreams. We have, also, seen that
animals are able to reason to a certain extent, manifestly without the aid
of language. The intimate connection between the brain, as it is now
developed in us, and the faculty of speech, is well shewn by those curious
cases of brain-disease in which speech is specially affected, as when the
power to remember substantives is lost, whilst other words can be correctly
used, or where substantives of a certain class, or all except the initial
letters of substantives and proper names are forgotten. (60. Many curious
cases have been recorded. See, for instance, Dr. Bateman 'On Aphasia,'
1870, pp. 27, 31, 53, 100, etc. Also, 'Inquiries Concerning the
Intellectual Powers,' by Dr. Abercrombie, 1838, p. 150.) There is no more
improbability in the continued use of the mental and vocal organs leading
to inherited changes in their structure and functions, than in the case of
hand-writing, which depends partly on the form of the hand and partly on
the disposition of the mind; and handwriting is certainly inherited. (61.
'The Variation of Animals and Plants under Domestication,' vol. ii. p. 6.'
Several writers, more especially Prof. Max Muller (62. Lectures on 'Mr.
Darwin's Philosophy of Language,' 1873.), have lately insisted that the use
of language implies the power of forming general concepts; and that as no
animals are supposed to possess this power, an impassable barrier is formed
between them and man. (63. The judgment of a distinguished philologist,
such as Prof. Whitney, will have far more weight on this point than
anything that I can say. He remarks ('Oriental and Linguistic Studies,'
1873, p. 297), in speaking of Bleek's views: "Because on the grand scale
language is the necessary auxiliary of thought, indispensable to the
development of the power of thinking, to the distinctness and variety and
complexity of cognitions to the full mastery of consciousness; therefore he
would fain make thought absolutely impossible without speech, identifying
the faculty with its instrument. He might just as reasonably assert that
the human hand cannot act without a tool. With such a doctrine to start
from, he cannot stop short of Max Muller's worst paradoxes, that an infant
(in fans, not speaking) is not a human being, and that deaf-mutes do not
become possessed of reason until they learn to twist their fingers into
imitation of spoken words." Max Muller gives in italics ('Lectures on Mr.
Darwin's Philosophy of Language,' 1873, third lecture) this aphorism:
"There is no thought without words, as little as there are words without
thought." What a strange definition must here be given to the word
thought!) With respect to animals, I have already endeavoured to shew that
they have this power, at least in a rude and incipient degree. As far as
concerns infants of from ten to eleven months old, and deaf-mutes, it seems
to me incredible, that they should be able to connect certain sounds with
certain general ideas as quickly as they do, unless such ideas were already
formed in their minds. The same remark may be extended to the more
intelligent animals; as Mr. Leslie Stephen observes (64. 'Essays on Free
Thinking,' etc., 1873, p. 82.), "A dog frames a general concept of cats or
sheep, and knows the corresponding words as well as a philosopher. And the
capacity to understand is as good a proof of vocal intelligence, though in
an inferior degree, as the capacity to speak."
Why the organs now used for speech should have been originally perfected
for this purpose, rather than any other organs, it is not difficult to see.
Ants have considerable powers of intercommunication by means of their
antennae, as shewn by Huber, who devotes a whole chapter to their language.
We might have used our fingers as efficient instruments, for a person with
practice can report to a deaf man every word of a speech rapidly delivered
at a public meeting; but the loss of our hands, whilst thus employed, would
have been a serious inconvenience. As all the higher mammals possess vocal
organs, constructed on the same general plan as ours, and used as a means
of communication, it was obviously probable that these same organs would be
still further developed if the power of communication had to be improved;
and this has been effected by the aid of adjoining and well adapted parts,
namely the tongue and lips. (65. See some good remarks to this effect by
Dr. Maudsley, 'The Physiology and Pathology of Mind,' 1868, p. 199.) The
fact of the higher apes not using their vocal organs for speech, no doubt
depends on their intelligence not having been sufficiently advanced. The
possession by them of organs, which with long-continued practice might have
been used for speech, although not thus used, is paralleled by the case of
many birds which possess organs fitted for singing, though they never sing.
Thus, the nightingale and crow have vocal organs similarly constructed,
these being used by the former for diversified song, and by the latter only
for croaking. (66. Macgillivray, 'Hist. of British Birds,' vol. ii. 1839,
p. 29. An excellent observer, Mr. Blackwall, remarks that the magpie
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