II

ON THE RELATIONS OF MAN TO THE

LOWER ANIMALS.

Multis videri poterit, majorem esse differentiam Simiæ et

Hominis, quam diei et noctis; verum tamen hi,

comparatione instituta inter summos Europæ Heroës et

Hottentottos ad Caput bonæ spei degentes, difficillime

sibi persuadebunt, has eosdem habere natales; vel si

virginem nobilem aulicam, maxime comtam et humanissimam,

conferre vellent cum homine sylvestri et sibi relicto,

vix augurari possent, hunc et illam ejusdem esse

speciei.--_Linnæi Amoenitates Acad. "Anthropomorpha."_

The question of questions for mankind--the problem which underlies all

others, and is more deeply interesting than any other--is the

ascertainment of the place which Man occupies in nature and of his

relations to the universe of things. Whence our race has come; what are

the limits of our power over nature, and of nature's power over us; to

what goal we are tending; are the problems which present themselves anew

and with undiminished interest to every man born into the world. Most of

us, shrinking from the difficulties and dangers which beset the seeker

after original answers to these riddles, are contented to ignore them

altogether, or to smother the investigating spirit under the featherbed

of respected and respectable tradition. But, in every age, one or two

restless spirits, blessed with that constructive genius, which can only

build on a secure foundation, or cursed with the mere spirit of

scepticism, are unable to follow in the well-worn and comfortable track

of their forefathers and contemporaries, and unmindful of thorns and

stumbling-blocks, strike out into paths of their own. The sceptics end

in the infidelity which asserts the problem to be insoluble, or in the

atheism which denies the existence of any orderly progress and

governance of things: the men of genius propound solutions which grow

into systems of Theology or of Philosophy, or veiled in musical language

which suggests more than it asserts, take the shape of the Poetry of an

epoch.

Each such answer to the great question, invariably asserted by the

followers of its propounder, if not by himself, to be complete and

final, remains in high authority and esteem, it may be for one century,

or it may be for twenty: but, as invariably, Time proves each reply to

have been a mere approximation to the truth--tolerable chiefly on

account of the ignorance of those by whom it was accepted, and wholly

intolerable when tested by the larger knowledge of their successors.

In a well-worn metaphor, a parallel is drawn between the life of man and

the metamorphosis of the caterpillar into the butterfly; but the

comparison may be more just as well as more novel, if for its former

term we take the mental progress of the race. History shows that the

human mind, fed by constant accessions of knowledge, periodically grows

too large for its theoretical coverings, and bursts them asunder to

appear in new habiliments, as the feeding and growing grub, at

intervals, casts its too narrow skin and assumes another, itself but

temporary. Truly the imago state of Man seems to be terribly distant,

but every moult is a step gained, and of such there have been many.

Since the revival of learning, whereby the Western races of Europe were

enabled to enter upon that progress towards true knowledge, which was

commenced by the philosophers of Greece, but was almost arrested in

subsequent long ages of intellectual stagnation, or, at most, gyration,

the human larva has been feeding vigorously, and moulting in proportion.

A skin of some dimension was cast in the 16th century, and another

towards the end of the 18th, while, within the last fifty years, the

extraordinary growth of every department of physical science has spread

among us mental food of so nutritious and stimulating a character that a

new ecdysis seems imminent. But this is a process not unusually

accompanied by many throes and some sickness and debility, or, it may

be, by graver disturbances; so that every good citizen must feel bound

to facilitate the process, and even if he have nothing but a scalpel to

work withal, to ease the cracking integument to the best of his ability.

In this duty lies my excuse for the publication of these essays. For it

will be admitted that some knowledge of man's position in the animate

world is an indispensable preliminary to the proper understanding of his

relations to the universe--and this again resolves itself, in the long

run, into an inquiry into the nature and the closeness of the ties which

connect him with those singular creatures whose history[25] has been

sketched in the preceding pages.

The importance of such an inquiry is indeed intuitively manifest.

Brought face to face with these blurred copies of himself, the least

thoughtful of men is conscious of a certain shock, due perhaps, not so

much to disgust at the aspect of what looks like an insulting

caricature, as to the awakening of a sudden and profound mistrust of

time-honoured theories and strongly-rooted prejudices regarding his own

position in nature, and his relations to the under-world of life; while

that which remains a dim suspicion for the unthinking, becomes a vast

argument, fraught with the deepest consequences, for all who are

acquainted with the recent progress of the anatomical and physiological

sciences.

I now propose briefly to unfold that argument, and to set forth, in a

form intelligible to those who possess no special acquaintance with

anatomical science, the chief facts upon which all conclusions

respecting the nature and the extent of the bonds which connect man with

the brute world must be based: I shall then indicate the one immediate

conclusion which, in my judgment, is justified by those facts, and I

shall finally discuss the bearing of that conclusion upon the hypotheses

which have been entertained respecting the Origin of Man.

The facts to which I would first direct the reader's attention, though

ignored by many of the professed instructors of the public mind, are

easy of demonstration and are universally agreed to by men of science;

while their significance is so great, that whoso has duly pondered over

them will, I think, find little to startle him in the other revelations

of Biology. I refer to those facts which have been made known by the

study of Development.

It is a truth of very wide, if not of universal, application, that every

living creature commences its existence under a form different from, and

simpler than, that which it eventually attains.

The oak is a more complex thing than the little rudimentary plant

contained in the acorn; the caterpillar is more complex than the egg;

the butterfly than the caterpillar; and each of these beings, in passing

from its rudimentary to its perfect condition, runs through a series of

changes, the sum of which is called its Development. In the higher

animals these changes are extremely complicated; but, within the last

half-century, the labours of such men as Von Baer, Rathke, Reichert,

Bischof, and Remak have almost completely unravelled them, so that the

successive stages of development which are exhibited by a Dog, for

example, are now as well known to the embryologist as are the steps of

the metamorphosis of the silkworm moth to the school-boy. It will be

useful to consider with attention the nature and the order of the stages

of canine development, as an example of the process in the higher

animals generally.

The Dog, like all animals, save the very lowest (and further inquiries

may not improbably remove the apparent exception), commences its

existence as an egg: as a body which is, in every sense, as much an egg

as that of a hen, but is devoid of that accumulation of nutritive matter

which confers upon the bird's egg its exceptional size and domestic

utility; and wants the shell, which would not only be useless to an

animal incubated within the body of its parent, but would cut it off

from access to the source of that nutriment which the young creature

requires, but which the minute egg of the mammal does not contain within

itself.

The Dog's egg is, in fact, a little spheroidal bag (Fig. 12), formed of

a delicate transparent membrane called the _vitelline membrane_, and

about 1/130 to 1/120th an inch in diameter. It contains a mass of viscid

nutritive matter--the "_yelk_"--within which is inclosed a second much

more delicate spheroidal bag, called the "_germinal vesicle_" (_a_). In

this, lastly, lies a more solid rounded body, termed the "_germinal

spot_" (_b_).

[Illustration: FIG. 12.--A. Egg of the Dog, with the vitelline membrane

burst, so as to give exit to the yelk, the germinal vesicle (_a_), and

its included spot (_b_). B. C. D. E. F. Successive changes of the yelk

indicated in the text. After Bischoff.]

The egg, or "Ovum," is originally formed within a gland, from which, in

due season, it becomes detached, and passes into the living chamber

fitted for its protection and maintenance during the protracted process

of gestation. Here, when subjected to the required conditions, this

minute and apparently insignificant particle of living matter becomes

animated by a new and mysterious activity. The germinal vesicle and spot

cease to be discernible (their precise fate being one of the yet

unsolved problems of embryology), but the yelk becomes circumferentially

indented, as if an invisible knife had been drawn round it, and thus

appears divided into two hemispheres (Fig. 12, C).

By the repetition of this process in various planes, these hemispheres

become subdivided, so that four segments are produced (D); and these, in

like manner, divide and subdivide again, until the whole yelk is

converted into a mass of granules, each of which consists of a minute

spheroid of yelk-substance, inclosing a central particle, the so-called

"_nucleus_" (F). Nature, by this process, has attained much the same

result as that at which a human artificer arrives by his operations in a

brickfield. She takes the rough plastic material of the yelk and breaks

it up into well-shaped, tolerably even-sized masses, handy for building

up into any part of the living edifice.

Next, the mass of organic bricks, or "_cells_" as they are technically

called, thus formed, acquires an orderly arrangement, becoming converted

into a hollow spheroid with double walls. Then, upon one side of this

spheroid, appears a thickening, and, by and bye, in the centre of the

area of thickening, a straight shallow groove (Fig. 13, A) marks the

central line of the edifice which is to be raised, or, in other words,

indicates the position of the middle line of the body of the future dog.

The substance bounding the groove on each side next rises up into a

fold, the rudiment of the side wall of that long cavity, which will

eventually lodge the spinal marrow and the brain; and in the floor of

this chamber appears a solid cellular cord, the so-called "_notochord_."

One end of the inclosed cavity dilates to form the head (Fig. 13, B),

the other remains narrow, and eventually becomes the tail; the side

walls of the body are fashioned out of the downward continuation of the

walls of the groove; and from them, by and bye, grow out little buds

which, by degrees, assume the shape of limbs. Watching the fashioning

process stage by stage, one is forcibly reminded of the modeller in

clay. Every part, every organ, is at first, as it were, pinched up

rudely, and sketched out in the rough; then shaped more accurately; and

only, at last, receives the touches which stamp its final character.

Thus, at length, the young puppy assumes such a form as is shown in Fig.

13, C. In this condition it has a disproportionately large head, as

dissimilar to that of a dog as the bud-like limbs are unlike his legs.

The remains of the yelk, which have not yet been applied to the

nutrition and growth of the young animal, are contained in a sac

attached to the rudimentary intestine, and termed the yelk-sac, or

"_umbilical vesicle_." Two membranous bags, intended to subserve

respectively the protection and nutrition of the young creature, have

been developed from the skin and from the under and hinder surface of

the body; the former, the so-called "_amnion_," is a sac filled with

fluid, which invests the whole body of the embryo, and plays the part of

a sort of water-bed for it; the other, termed the "_allantois_," grows

out, loaded with blood-vessels, from the ventral region, and eventually

applying itself to the walls of the cavity, in which the developing

organism is contained, enables these vessels to become the channel by

which the stream of nutriment, required to supply the wants of the

offspring, is furnished to it by the parent.

[Illustration: FIG. 13.--A. Earliest rudiment of the Dog. B. Rudiment

further advanced, showing the foundations of the head, tail, and

vertebral column. C. The very young puppy, with attached ends of the

yelk-sac and allantois, and invested in the amnion.]

The structure which is developed by the interlacement of the vessels of

the offspring with those of the parent, and by means of which the former

is enabled to receive nourishment and to get rid of effete matters, is

termed the "_Placenta_."

It would be tedious, and it is unnecessary for my present purpose, to

trace the process of development further; suffice it to say, that, by a

long and gradual series of changes, the rudiment here depicted and

described becomes a puppy, is born, and then, by still slower and less

perceptible steps, passes into the adult Dog.

There is not much apparent resemblance between a barndoor Fowl and the

Dog who protects the farm-yard. Nevertheless the student of development

finds, not only that the chick commences its existence as an egg,

primarily identical, in all essential respects, with that of the Dog,

but that the yelk of this egg undergoes division--that the primitive

groove arises, and that the contiguous parts of the germ are fashioned,

by precisely similar methods, into a young chick, which, at one stage of

its existence, is so like the nascent Dog, that ordinary inspection

would hardly distinguish the two.

* * * * *

The history of the development of any other vertebrate animal, Lizard,

Snake, Frog, or Fish, tells the same story. There is always, to begin

with, an egg having the same essential structure as that of the

Dog:--the yelk of that egg always undergoes division, or

"_segmentation_" as it is often called: the ultimate products of that

segmentation constitute the building materials for the body of the young

animal; and this is built up round a primitive groove, in the floor of

which a notochord is developed. Furthermore, there is a period in which

the young of all these animals resemble one another, not merely in

outward form, but in all essentials of structure, so closely, that the

differences between them are inconsiderable, while, in their subsequent

course, they diverge more and more widely from one another. And it is a

general law, that, the more closely any animals resemble one another in

adult structure, the longer and the more intimately do their embryos

resemble one another: so that, for example, the embryos of a Snake and

of a Lizard remain like one another longer than do those of a Snake and

of a Bird; and the embryo of a Dog and of a Cat remain like one another

for a far longer period than do those of a Dog and a Bird; or of a Dog

and an Opossum; or even than those of a Dog and a Monkey.

Thus the study of development affords a clear test of closeness of

structural affinity, and one turns with impatience to inquire what

results are yielded by the study of the development of Man. Is he

something apart? Does he originate in a totally different way from Dog,

Bird, Frog, and Fish, thus justifying those who assert him to have no

place in nature and no real affinity with the lower world of animal

life? Or does he originate in a similar germ, pass through the same slow

and gradually progressive modifications,--depend on the same

contrivances for protection and nutrition, and finally enter the world

by the help of the same mechanism? The reply is not doubtful for a

moment, and has not been doubtful any time these thirty years. Without

question, the mode of origin and the early stages of the development of

man are identical with those of the animals immediately below him in the

scale:--without a doubt, in these respects, he is far nearer the Apes,

than the Apes are to the Dog.

The Human ovum is about 1/125 of an inch in diameter, and might be

described in the same terms as that of the Dog, so that I need only

refer to the figure illustrative (14 A.) of its structure. It leaves the

organ in which it is formed in a similar fashion and enters the organic

chamber prepared for its reception in the same way, the conditions of

its development being in all respects the same. It has not yet been

possible (and only by some rare chance can it ever be possible) to study

the human ovum in so early a developmental stage as that of yelk

division, but there is every reason to conclude that the changes it

undergoes are identical with those exhibited by the ova of other

vertebrated animals; for the formative materials of which the

rudimentary human body is composed, in the earliest conditions in which

it has been observed, are the same as those of other animals. Some of

these earliest stages are figured below and, as will be seen, they are

strictly comparable to the very early states of the Dog; the marvellous

correspondence between the two which is kept up, even for some time, as

development advances, becoming apparent by the simple comparison of the

figures with those on page 58.

Indeed, it is very long before the body of the young human being can be

readily discriminated from that of the young puppy; but, at a tolerably

early period, the two become distinguishable by the different form of

their adjuncts, the yelk-sac and the allantois. The former, in the Dog,

becomes long and spindle-shaped, while in Man it remains spherical; the

latter, in the Dog, attains an extremely large size, and the vascular

processes which are developed from it and eventually give rise to the

formation of the placenta (taking root, as it were, in the parental

organism, so as to draw nourishment therefrom, as the root of a tree

extracts it from the soil) are arranged in an encircling zone, while in

Man, the allantois remains comparatively small, and its vascular

rootlets are eventually restricted to one disk-like spot. Hence, while

the placenta of the Dog is like a girdle, that of Man has the cake-like

form, indicated by the name of the organ.

[Illustration: FIG. 14.--A. Human ovum (after Kölliker). a. germinal

vesicle. b. germinal spot. B. A very early condition of Man, with

yelk-sac, allantois, and amnion (original). C. A more advanced stage

(after Kölliker), compare FIG. 13, C.]

But, exactly in those respects in which the developing Man differs from

the Dog, he resembles the ape, which, like man, has a spheroidal

yelk-sac and a discoidal--sometimes partially lobed--placenta.

So that it is only quite in the later stages of development that the

young human being presents marked differences from the young ape, while

the latter departs as much from the dog in its development, as the man

does.

Startling as the last assertion may appear to be, it is demonstrably

true, and it alone appears to me sufficient to place beyond all doubt

the structural unity of man with the rest of the animal world, and more

particularly and closely with the apes.

* * * * *

Thus, identical in the physical processes by which he

originates--identical in the early stages of his formation--identical in

the mode of his nutrition before and after birth, with the animals which

lie immediately below him in the scale--Man, if his adult and perfect

structure be compared with theirs, exhibits, as might be expected, a

marvellous likeness of organization. He resembles them as they resemble

one another--he differs from them as they differ from one another.--And,

though these differences and resemblances cannot be weighed and

measured, their value may be readily estimated; the scale or standard of

judgment, touching that value, being afforded and expressed by the

system of classification of animals now current among zoologists.

A careful study of the resemblances and differences presented by animals

has, in fact, led naturalists to arrange them into groups, or

assemblages, all the members of each group presenting a certain amount

of definable resemblance, and the number of points of similarity being

smaller as the group is larger and _vice versâ_. Thus, all creatures

which agree only in presenting the few distinctive marks of animality

form the "Kingdom" ANIMALIA. The numerous animals which agree only in

possessing the special characters of Vertebrates form one "Sub-kingdom"

of this Kingdom. Then the Sub-kingdom VERTEBRATA is subdivided into the

five "Classes," Fishes, Amphibians, Reptiles, Birds, and Mammals, and

these into smaller groups called "Orders"; these into "Families" and

"Genera"; while the last are finally broken up into the smallest

assemblages, which are distinguished by the possession of constant,

not-sexual, characters. These ultimate groups are Species.

Every year tends to bring about a greater uniformity of opinion

throughout the zoological world as to the limits and characters of these

groups, great and small. At present, for example, no one has the least

doubt regarding the characters of the classes Mammalia, Aves, or

Reptilia; nor does the question arise whether any thoroughly well-known

animal should be placed in one class or the other. Again, there is a

very general agreement respecting the characters and limits of the

orders of Mammals, and as to the animals which are structurally

necessitated to take a place in one or another order.

No one doubts, for example, that the Sloth and the Ant-eater, the

Kangaroo and the Opossum, the Tiger and the Badger, the Tapir and the

Rhinoceros, are respectively members of the same orders. These

successive pairs of animals may, and some do, differ from one another

immensely, in such matters as the proportions and structure of their

limbs; the number of their dorsal and lumbar vertebræ; the adaptation of

their frames to climbing, leaping, or running; the number and form of

their teeth; and the characters of their skulls and of the contained

brain. But, with all these differences, they are so closely connected in

all the more important and fundamental characters of their organization,

and so distinctly separated by these same characters from other animals,

that zoologists find it necessary to group them together as members of

one order. And if any new animal were discovered, and were found to

present no greater difference from the Kangaroo and the Opossum, for

example, than these animals do from one another, the zoologist would not

only be logically compelled to rank it in the same order with these, but

he would not think of doing otherwise.

Bearing this obvious course of zoological reasoning in mind, let us

endeavour for a moment to disconnect our thinking selves from the mask

of humanity; let us imagine ourselves scientific Saturnians, if you

will, fairly acquainted with such animals as now inhabit the Earth, and

employed in discussing the relations they bear to a new and singular

"erect and featherless biped," which some enterprising traveller,

overcoming the difficulties of space and gravitation, has brought from

that distant planet for our inspection, well preserved, may be, in a

cask of rum. We should all, at once, agree upon placing him among the

mammalian vertebrates; and his lower jaw, his molars, and his brain,

would leave no room for doubting the systematic position of the new

genus among those mammals, whose young are nourished during gestation by

means of a placenta, or what are called the "placental mammals."

Further, the most superficial study would at once convince us that,

among the orders of placental mammals, neither the Whales nor the hoofed

creatures, nor the Sloths and Ant-eaters, nor the carnivorous Cats,

Dogs, and Bears, still less the Rodent Rats and Rabbits, or the

Insectivorous Moles and Hedgehogs, or the Bats, could claim our "_Homo_"

as one of themselves.

There would remain then, but one order for comparison, that of the Apes

(using that word in its broadest sense), and the question for discussion

would narrow itself to this--is Man so different from any of these Apes

that he must form an order by himself? Or does he differ less from them

than they differ from one another, and hence must take his place in the

same order with them?

Being happily free from all real, or imaginary, personal interest in the

results of the inquiry thus set afoot, we should proceed to weigh the

arguments on one side and on the other, with as much judicial calmness

as if the question related to a new Opossum. We should endeavour to

ascertain, without seeking either to magnify or diminish them, all the

characters by which our new Mammal differed from the Apes; and if we

found that these were of less structural value, than those which

distinguish certain members of the Ape order from others universally

admitted to be of the same order, we should undoubtedly place the newly

discovered tellurian genus with them.

I now proceed to detail the facts which seem to me to leave us no

choice but to adopt the last mentioned course.

* * * * *

It is quite certain that the Ape which most nearly approaches man, in

the totality of its organization, is either the Chimpanzee or the

Gorilla; and as it makes no practical difference, for the purposes of my

present argument, which is selected for comparison, on the one hand,

with Man, and on the other hand, with the rest of the Primates,[26] I

shall select the latter (so far as its organization is known)--as a

brute now so celebrated in prose and verse, that all must have heard of

him, and have formed some conception of his appearance. I shall take up

as many of the most important points of difference between man and this

remarkable creature, as the space at my disposal will allow me to

discuss, and the necessities of the argument demand; and I shall inquire

into the value and magnitude of these differences, when placed side by

side with those which separate the Gorilla from other animals of the

same order.

In the general proportions of the body and limbs there is a remarkable

difference between the Gorilla and Man, which at once strikes the eye.

The Gorilla's brain-case is smaller, its trunk larger, its lower limbs

shorter, its upper limbs longer in proportion than those of Man.

I find that the vertebral column of a full-grown Gorilla, in the Museum

of the Royal College of Surgeons, measures 27 inches along its anterior

curvature, from the upper edge of the atlas, or first vertebra of the

neck, to the lower extremity of the sacrum; that the arm, without the

hand, is 31-1/2 inches long; that the leg, without the foot, is 26-1/2

inches long; that the hand is 9-3/4 inches long; the foot 11-1/4 inches

long.

In other words, taking the length of the spinal column as 100, the arm

equals 115, the leg 96, the hand 36, and the foot 41.

In the skeleton of a male Bosjesman, in the same collection, the

proportions, by the same measurement, to the spinal column, taken as

100, are--the arm 78, the leg 110, the hand 26, and the foot 32. In a

woman of the same race the arm is 83, and the leg 120, the hand and foot

remaining the same. In a European skeleton I find the arm to be 80, the

leg 117, the hand 26, the foot 35.

Thus the leg is not so different as it looks at first sight, in its

proportions to the spine in the Gorilla and in the Man--being very

slightly shorter than the spine in the former, and between 1/10 and 1/5

longer than the spine in the latter. The foot is longer and the hand

much longer in the Gorilla; but the great difference is caused by the

arms, which are very much longer than the spine in the Gorilla, very

much shorter than the spine in the Man.

The question now arises how are the other Apes related to the Gorilla in

these respects--taking the length of the spine, measured in the same

way, at 100. In an adult Chimpanzee, the arm is only 96, the leg 90, the

hand 43, the foot 39--so that the hand and the leg depart more from the

human proportion and the arm less, while the foot is about the same as

in the Gorilla.

In the Orang, the arms are very much longer than in the Gorilla (122),

while the legs are shorter (88); the foot is longer than the hand (52

and 48), and both are much longer in proportion to the spine.

In the other man-like Apes again, the Gibbons, these proportions are

still further altered; the length of the arms being to that of the

spinal column as 19 to 11; while the legs are also a third longer than

the spinal column, so as to be longer than in Man, instead of shorter.

The hand is half as long as the spinal column, and the foot, shorter

than the hand, is about 5/11ths of the length of the spinal column.

Thus _Hylobates_ is as much longer in the arms than the Gorilla, as the

Gorilla is longer in the arms than Man; while, on the other hand, it is

as much longer in the legs than the Man, as the Man is longer in the

legs than the Gorilla, so that it contains within itself the extremest

deviations from the average length of both pairs of limbs (see the

Frontispiece).

The Mandrill presents a middle condition, the arms and legs being nearly

equal in length, and both being shorter than the spinal column; while

hand and foot have nearly the same proportions to one another and to the

spine, as in Man.

In the Spider monkey (_Ateles_) the leg is longer than the spine, and

the arm than the leg; and, finally, in that remarkable Lemurine form,

the Indri (_Lichanotus_), the leg is about as long as the spinal column,

while the arm is not more than 11/18ths of its length; the hand having

rather less and the foot rather more, than one-third the length of the

spinal column.

These examples might be greatly multiplied, but they suffice to show

that, in whatever proportion of its limbs the Gorilla differs from Man,

the other Apes depart still more widely from the Gorilla, and that,

consequently, such differences of proportion can have no ordinal value.

* * * * *

We may next consider the differences presented by the trunk, consisting

of the vertebral column, or backbone, and the ribs and pelvis, or bony

hip-basin, which are connected with it, in Man and in the Gorilla

respectively.

In Man, in consequence partly of the disposition of the articular

surfaces of the vertebræ, and largely of the elastic tension of some of

the fibrous bands, or ligaments, which connect these vertebræ together,

the spinal column, as a whole, has an elegant S-like curvature, being

convex forwards in the neck, concave in the back, convex in the loins,

or lumbar region, and concave again in the sacral region; an arrangement

which gives much elasticity to the whole backbone, and diminishes the

jar communicated to the spine, and through it to the head, by locomotion

in the erect position.

Furthermore, under ordinary circumstances, Man has seven vertebræ in his

neck, which are called _cervical_; twelve succeed these, bearing ribs

and forming the upper part of the back, whence they are termed _dorsal_;

five lie in the loins, bearing no distinct, or free, ribs, and are

called _lumbar_; five, united together into a great bone, excavated in

front, solidly wedged in between the hip bones, to form the back of the

pelvis, and known by the name of the _sacrum_, succeed these; and

finally, three or four little more or less moveable bones, so small as

to be insignificant, constitute the _coccyx_ or rudimentary tail.

In the Gorilla, the vertebral column is similarly divided into cervical,

dorsal, lumbar, sacral and coccygeal vertebræ, and the total number of

cervical and dorsal vertebræ, taken together, is the same as in Man; but

the development of a pair of ribs to the first lumbar vertebra, which is

an exceptional occurrence in Man, is the rule in the Gorilla; and hence,

as lumbar are distinguished from dorsal vertebræ only by the presence or

absence of free ribs, the seventeen "dorso-lumbar" vertebræ of the

Gorilla are divided into thirteen dorsal and four lumbar, while in Man

they are twelve dorsal and five lumbar.

Not only, however, does Man occasionally possess thirteen pair of

ribs,[27] but the Gorilla sometimes has fourteen pairs, while an

Orang-Utan skeleton in the Museum of the Royal College of Surgeons has

twelve dorsal and five lumbar vertebræ, as in Man. Cuvier notes the same

number in a _Hylobates_. On the other hand, among the lower Apes, many

possess twelve dorsal and six or seven lumbar vertebræ; the Douroucouli

has fourteen dorsal and eight lumbar, and a Lemur (_Stenops

tardigradus_) has fifteen dorsal and nine lumbar vertebræ.

The vertebral column of the Gorilla, as a whole, differs from that of

Man in the less marked character of its curves, especially in the

slighter convexity of the lumbar region. Nevertheless, the curves are

present, and are quite obvious in young skeletons of the Gorilla and

Chimpanzee which have been prepared without removal of the ligaments. In

young Orangs similarly preserved, on the other hand, the spinal column

is either straight, or even concave forwards, throughout the lumbar

region.

Whether we take these characters then, or such minor ones as those which

are derivable from the proportional length of the spines of the

cervical vertebræ, and the like, there is no doubt whatsoever as to the

marked difference between Man and the Gorilla; but there is as little,

that equally marked differences, of the very same order, obtain between

the Gorilla and the lower apes.

[Illustration: FIG. 15.--Front and side views of the bony pelvis of Man,

the Gorilla and Gibbon: reduced from drawings made from nature, of the

same absolute length, by Mr. Waterhouse Hawkins.]

The Pelvis, or bony girdle of the hips, of Man is a strikingly human

part of his organization; the expanded haunch bones affording support

for his viscera during his habitually erect posture, and giving space

for the attachment of the great muscles which enable him to assume and

to preserve that attitude. In these respects the pelvis of the Gorilla

differs very considerably from his (Fig. 15). But go no lower than the

Gibbon, and see how vastly more he differs from the Gorilla than the

latter does from Man, even in this structure. Look at the flat, narrow

haunch bones--the long and narrow passage--the coarse, outwardly curved,

ischiatic prominences on which the Gibbon habitually rests, and which

are coated by the so-called "callosities," dense patches of skin, wholly

absent in the Gorilla, in the Chimpanzee, and in the Orang, as in Man!

In the lower Monkeys and in the Lemurs the difference becomes more

striking still, the pelvis acquiring an altogether quadrupedal

character.

But now let us turn to a nobler and more characteristic organ--that by

which the human frame seems to be, and indeed is, so strongly

distinguished from all others,--I mean the skull. The differences

between a Gorilla's skull and a Man's are truly immense (Fig. 16). In

the former, the face, formed largely by the massive jaw-bones,

predominates over the brain case, or cranium proper: in the latter, the

proportions of the two are reversed. In the Man, the occipital foramen,

through which passes the great nervous cord connecting the brain with

the nerves of the body, is placed just behind the centre of the base of

the skull, which thus becomes evenly balanced in the erect posture; in

the Gorilla, it lies in the posterior third of that base. In the Man,

the surface of the skull is comparatively smooth, and the supraciliary

ridges or brow prominences usually project but little--while, in the

Gorilla, vast crests are developed upon the skull, and the brow ridges

overhang the cavernous orbits, like great penthouses.

Sections of the skulls, however, show that some of the apparent defects

of the Gorilla's cranium arise, in fact, not so much from deficiency of

brain case as from excessive development of the parts of the face. The

cranial cavity is not ill-shaped, and the forehead is not truly

flattened or very retreating, its really well-formed curve being simply

disguised by the mass of bone which is built up against it (Fig. 16).

But the roofs of the orbits rise more obliquely into the cranial cavity,

thus diminishing the space for the lower part of the anterior lobes of

the brain, and the absolute capacity of the cranium is far less than

that of Man. So far as I am aware, no human cranium belonging to an

adult man has yet been observed with a less cubical capacity than 62

cubic inches, the smallest cranium observed in any race of men by

Morton, measuring 63 cubic inches; while, on the other hand, the most

capacious Gorilla skull yet measured has a content of not more than

34-1/2 cubic inches. Let us assume, for simplicity's sake, that the

lowest Man's skull has twice the capacity of that of the highest

Gorilla.[28]

No doubt, this is a very striking difference, but it loses much of its

apparent systematic value, when viewed by the light of certain other

equally indubitable facts respecting cranial capacities.

The first of these is, that the difference in the volume of the cranial

cavity of different races of mankind is far greater, absolutely, than

that between the lowest Man and the highest Ape, while, relatively, it

is about the same. For the largest human skull measured by Morton

contained 114 cubic inches, that is to say, had very nearly double the

capacity of the smallest; while its absolute preponderance, of 52 cubic

inches--is far greater than that by which the lowest adult male human

cranium surpasses the largest of the Gorillas (62-34-1/2 = 27-1/2).

Secondly, the adult crania of Gorillas which have as yet been measured

differ among themselves by nearly one-third, the maximum capacity being

34.5 cubic inches, the minimum 24 cubic inches; and, thirdly, after

making all due allowance for difference of size, the cranial capacities

of some of the lower Apes fall nearly as much, relatively, below those

of the higher Apes as the latter fall below Man.

Thus, even in the important matter of cranial capacity, Men differ more

widely from one another than they do from the Apes; while the lowest

Apes differ as much, in proportion, from the highest, as the latter does

from Man. The last proposition is still better illustrated by the study

of the modifications which other parts of the cranium undergo in the

Simian series.

It is the large proportional size of the facial bones and the great

projection of the jaws which confers upon the Gorilla's skull its small

facial angle and brutal character.

But if we consider the proportional size of the facial bones to the

skull proper only, the little _Chrysothrix_ (Fig. 16) differs very

widely from the Gorilla, and in the same way as Man does; while the

Baboons (_Cynocephalus_, Fig. 16) exaggerate the gross proportions of

the muzzle of the great Anthropoid, so that its visage looks mild and

human by comparison with theirs. The difference between the Gorilla

and the Baboon is even greater than it appears at first sight; for the

great facial mass of the former is largely due to a downward development

of the jaws; an essentially human character, superadded upon that almost

purely forward, essentially brutal, development of the same parts which

characterizes the Baboon, and yet more remarkably distinguishes the

Lemur.

[Illustration:

FIG. 16.--Sections of the skulls of Man and various Apes, drawn so as to

give the cerebral cavity the same length in each case, thereby

displaying the varying proportions of the facial bones. The line _b_

indicates the plane of the tentorium, which separates the cerebrum from

the cerebellum; _d_, the axis of the occipital outlet of the skull. The

extent of cerebral cavity behind _c_, which is a perpendicular erected

on _b_ at the point where the tentorium is attached posteriorly,

indicates the degree to which the cerebrum overlaps the cerebellum--the

space occupied by which is roughly indicated by the dark shading. In

comparing these diagrams, it must be recollected, that figures on so

small a scale as these simply exemplify the statements in the text, the

proof of which is to be found in the objects themselves.]

Similarly, the occipital foramen of _Mycetes_ (Fig. 16), and still more

of the Lemurs, is situated completely in the posterior face of the

skull, or as much further back than that of the Gorilla, as that of the

Gorilla is further back than that of Man; while, as if to render patent

the futility of the attempt to base any broad classificatory distinction

on such a character, the same group of Platyrhine, or American monkeys,

to which the _Mycetes_ belongs, contains the _Chrysothrix_, whose

occipital foramen is situated far more forward than in any other ape,

and nearly approaches the position it holds in Man.

Again, the Orang's skull is as devoid of excessively developed

supraciliary prominences as a Man's, though some varieties exhibit great

crests elsewhere (see p. 39); and in some of the Cebine Apes and in the

_Chrysothrix_, the cranium is as smooth and rounded as that of Man

himself.

What is true of these leading characteristics of the skull, holds good,

as may be imagined, of all minor features; so that for every constant

difference between the Gorilla's skull and the Man's, a similar constant

difference of the same order (that is to say, consisting in excess or

defect of the same quality) may be found between the Gorilla's skull and

that of some other ape. So that, for the skull, no less than for the

skeleton in general, the proposition holds good, that the differences

between Man and the Gorilla are of smaller value than those between the

Gorilla and some other Apes.

In connection with the skull, I may speak of the teeth--organs which

have a peculiar classificatory value, and whose resemblances and

differences of number, form, and succession, taken as a whole, are

usually regarded as more trustworthy indicators of affinity than any

others.

Man is provided with two sets of teeth--milk teeth and permanent teeth.

The former consist of four incisors, or cutting teeth; two canines, or

eye-teeth; and four molars, or grinders, in each jaw--making twenty in

all. The latter (Fig. 17) comprise four incisors, two canines, four

small grinders, called premolars or false molars, and six large

grinders, or true molars, in each jaw--making thirty-two in all. The

internal incisors are larger than the external pair, in the upper jaw,

smaller than the external pair, in the lower jaw. The crowns of the

upper molars exhibit four cusps, or blunt-pointed elevations, and a

ridge crosses the crown obliquely, from the inner, anterior, cusp to the

outer, posterior cusp (Fig. 17 _m^2_). The anterior lower molars have

five cusps, three external and two internal. The premolars have two

cusps, one internal and one external, of which the outer is the higher.

In all these respects the dentition of the Gorilla may be described in

the same terms as that of Man; but in other matters it exhibits many and

important differences (Fig. 17).

Thus the teeth of man constitute a regular and even series--without any

break and without any marked projection of one tooth above the level of

the rest; a peculiarity which, as Cuvier long ago showed, is shared by

no other mammal save one--as different a creature from man as can well

be imagined--namely, the long extinct _Anoplotherium_. The teeth of the

Gorilla, on the contrary, exhibit a break, or interval, termed the

_diastema_, in both jaws: in front of the eye-tooth, or between it and

the outer incisor, in the upper jaw; behind the eye-tooth, or between it

and the front false molar, in the lower jaw. Into this break in the

series, in each jaw, fits the canine of the opposite jaw; the size of

the eye-tooth in the Gorilla being so great that it projects, like a

tusk, far beyond the general level of the other teeth. The roots of the

false molar teeth of the Gorilla, again, are more complex than in Man,

and the proportional size of the molars is different. The Gorilla has

the crown of the hindmost grinder of the lower jaw more complex, and the

order of eruption of the permanent teeth is different; the permanent

canines making their appearance before the second and third molars in

Man, and after them in the Gorilla.

Thus, while the teeth of the Gorilla closely resemble those of Man in

number, kind, and in the general pattern of their crowns, they exhibit

marked differences from those of Man in secondary respects, such as

relative size, number of fangs, and order of appearance.

But, if the teeth of the Gorilla be compared with those of an Ape, no

further removed from it than a _Cynocephalus_, or Baboon, it will be

found that differences and resemblances of the same order are easily

observable; but that many of the points in which the Gorilla resembles

Man are those in which it differs from the Baboon; while various

respects in which it differs from Man are exaggerated in the

_Cynocephalus_. The number and the nature of the teeth remain the same

in the Baboon as in the Gorilla and in Man. But the pattern of the

Baboon's upper molars is quite different from that described above (Fig.

17), the canines are proportionally longer and more knife-like; the

anterior premolar in the lower jaw is specially modified; the posterior

molar of the lower jaw is still larger and more complex than in the

Gorilla.

Passing from the old-world Apes to those of the new world, we meet with

a change of much greater importance than any of these. In such a genus

as _Cebus_, for example (Fig. 17), it will be found that while in some

secondary points, such as the projection of the canines and the

diastema, the resemblance to the great ape is preserved; in other and

most important respects, the dentition is extremely different. Instead

of 20 teeth in the milk set, there are 24: instead of 32 teeth in the

permanent set, there are 36, the false molars being increased from eight

to twelve. And in form, the crowns of the molars are very unlike those

of the Gorilla, and differ far more widely from the human pattern.

[Illustration: FIG. 17.--Lateral views, of the same length, of the upper

jaws of various Primates. _i_, incisors; _c_, canines; _pm_, premolars;

_m_, molars. A line is drawn through the first molar of Man, Gorilla,

_Cynocephalus_, and _Cebus_, and the grinding surface of the second

molar is shown in each, its anterior and internal angle being just above

the _m_ of _m^2_.]

The Marmosets, on the other hand, exhibit the same number of teeth as

Man and the Gorilla; but, notwithstanding this, their dentition is very

different, for they have four more false molars, like the other

American monkeys--but as they have four fewer true molars, the total

remains the same. And passing from the American Apes to the Lemurs, the

dentition becomes still more completely and essentially different from

that of the Gorilla. The incisors begin to vary both in number and in

form. The molars acquire, more and more, a many-pointed, insectivorous

character, and in one Genus, the Aye-Aye (_Cheiromys_), the canines

disappear, and the teeth completely simulate those of a Rodent (Fig.

17).

Hence it is obvious that, greatly as the dentition of the highest Ape

differs from that of Man, it differs far more widely from that of the

lower and lowest Apes.

* * * * *

Whatever part of the animal fabric--whatever series of muscles, whatever

viscera might be selected for comparison--the result would be the

same--the lower Apes and the Gorilla would differ more than the Gorilla

and the Man. I cannot attempt in this place to follow out all these

comparisons in detail, and indeed it is unnecessary I should do so. But

certain real, or supposed, structural distinctions between man and the

apes remain, upon which so much stress has been laid, that they require

careful consideration, in order that the true value may be assigned to

those which are real, and the emptiness of those which are fictitious

may be exposed. I refer to the characters of the hand, the foot, and the

brain.

Man has been defined as the only animal possessed of two hands

terminating his fore-limbs, and of two feet ending his hind limbs, while

it has been said that all the apes possess four hands; and he has been

affirmed to differ fundamentally from all the apes in the characters of

his brain, which alone, it has been strangely asserted and re-asserted,

exhibits the structures known to anatomists as the posterior lobe, the

posterior cornu of the lateral ventricle, and the hippocampus minor.

That the former proposition should have gained general acceptance is not

surprising--indeed, at first sight, appearances are much in its favour:

but, as for the second, one can only admire the surpassing courage of

its enunciator, seeing that it is an innovation which is not only

opposed to generally and justly accepted doctrines, but which is

directly negatived by the testimony of all original inquirers, who have

specially investigated the matter: and that it neither has been, nor can

be, supported by a single anatomical preparation. It would, in fact, be

unworthy of serious refutation, except for the general and natural

belief that deliberate and reiterated assertions must have some

foundation.

* * * * *

Before we can discuss the first point with advantage we must consider

with some attention, and compare together, the structure of the human

hand and that of the human foot, so that we may have distinct and clear

ideas of what constitutes a hand and what a foot.

The external form of the human hand is familiar enough to every one. It

consists of a stout wrist followed by a broad palm, formed of flesh, and

tendons, and skin, binding together four bones, and dividing into four

long and flexible digits, or fingers, each of which bears on the back of

its last joint a broad and flattened nail. The longest cleft between any

two digits is rather less than half as long as the hand. From the outer

side of the base of the palm a stout digit goes off, having only two

joints instead of three; so short, that it only reaches to a little

beyond the middle of the first joint of the finger next it; and further

remarkable by its great mobility, in consequence of which it can be

directed outwards, almost at a right angle to the rest. This digit is

called the "_pollex_," or thumb; and, like the others, it bears a flat

nail upon the back of its terminal joint. In consequence of the

proportions and mobility of the thumb, it is what is termed "opposable";

in other words, its extremity can, with the greatest ease, be brought

into contact with the extremities of any of the fingers; a property upon

which the possibility of our carrying into effect the conceptions of the

mind so largely depends.

The external form of the foot differs widely from that of the hand; and

yet, when closely compared, the two present some singular resemblances.

Thus the ankle corresponds in a manner with the wrist; the sole with the

palm; the toes with the fingers; the great toe with the thumb. But the

toes, or digits of the foot, are far shorter in proportion than the

digits of the hand, and are less moveable, the want of mobility being

most striking in the great toe--which, again, is very much larger in

proportion to the other toes than the thumb to the fingers. In

considering this point, however, it must not be forgotten that the

civilized great toe, confined and cramped from childhood upwards, is

seen to a great disadvantage, and that in uncivilized and barefooted

people it retains a great amount of mobility, and even some sort of

opposability. The Chinese boatmen are said to be able to pull an oar,

the artisans of Bengal to weave, and the Carajas to steal fishhooks, by

its help; though, after all, it must be recollected that the structure

of its joints and the arrangement of its bones, necessarily render its

prehensile action far less perfect than that of the thumb.

But to gain a precise conception of the resemblances and differences of

the hand and foot, and of the distinctive characters of each, we must

look below the skin, and compare the bony framework and its motor

apparatus in each (Fig. 18).

The skeleton of the hand exhibits, in the region which we term the

wrist, and which is technically called the _carpus_--two rows of closely

fitted polygonal bones, four in each row, which are tolerably equal in

size. The bones of the first row with the bones of the forearm form the

wrist joint, and are arranged side by side, no one greatly exceeding or

over-lapping the rest.

The four bones of the second row of the carpus bear the four long bones

which support the palm of the hand. The fifth bone of the same character

is articulated in a much more free and moveable manner than the others,

with its carpal bone, and forms the base of the thumb. These are called

_metacarpal_ bones, and they carry the _phalanges_, or bones of the

digits, of which there are two in the thumb, and three in each of the

fingers.

[Illustration: FIG. 18.--The skeleton of the Hand and Foot of Man

reduced from Dr. Carter's drawings in Gray's "Anatomy." The hand is

drawn to a larger scale than the foot. The line _a a_ in the hand

indicates the boundary between the carpus and the metacarpus; _b b_ that

between the latter and the proximal phalanges; _c c_ marks the ends of

the distal phalanges. The line _a´ a´_ in the foot indicates the

boundary between the tarsus and metatarsus; _b´ b´_ marks that between

the metatarsus and the proximal phalanges; and _c´ c´_ bounds the ends

of the distal phalanges; _ca_, the calcaneum; _as_, the astragalus;

_sc_, the scaphoid bone in the tarsus.]

The skeleton of the foot is very like that of the hand in some respects.

Thus there are three phalanges in each of the lesser toes, and only two

in the great toe, which answers to the thumb. There is a long bone,

termed _metatarsal_, answering to the metacarpal, for each digit; and

the _tarsus_, which corresponds with the carpus, presents four short

polygonal bones in a row, which correspond very closely with the four

carpal bones of the second row of the hand. In other respects the foot

differs very widely from the hand. Thus the great toe is the longest

digit but one; and its metatarsal is far less moveably articulated with

the tarsus, than the metacarpal of the thumb with the carpus. But a far

more important distinction lies in the fact that, instead of four more

tarsal bones there are only three; and that these three are not arranged

side by side, or in one row. One of them, the _os calcis_ or heel bone

(_ca_), lies externally, and sends back the large projecting heel;

another, the _astragalus_ (_as_), rests on this by one face, and by

another, forms, with the bones of the leg, the ankle joint; while a

third face, directed forwards, is separated from the three inner tarsal

bones of the row next the metatarsus by a bone called the _scaphoid_

(_sc_).

Thus there is a fundamental difference in the structure of the foot and

the hand, observable when the carpus and the tarsus are contrasted; and

there are differences of degree noticeable when the proportions and the

mobility of the metacarpals and metatarsals, with their respective

digits, are compared together.

The same two classes of differences become obvious when the muscles of

the hand are compared with those of the foot.

Three principal sets of muscles, called "flexors," bend the fingers and

thumb, as in clenching the fist, and three sets--the extensors--extend

them, as in straightening the fingers. These muscles are all "long

muscles"; that is to say, the fleshy part of each, lying in and being

fixed to the bones of the arm, is, at the other end, continued into

tendons, or rounded cords, which pass into the hand, and are ultimately

fixed to the bones which are to be moved. Thus, when the fingers are

bent, the fleshy parts of the flexors of the fingers, placed in the arm,

contract, in virtue of their peculiar endowment as muscles; and pulling

the tendinous cords, connected with their ends, cause them to pull down

the bones of the fingers towards the palm.

Not only are the principal flexors of the fingers and of the thumb long

muscles, but they remain quite distinct from one another throughout

their whole length.

In the foot, there are also three principal flexor muscles of the digits

or toes, and three principal extensors; but one extensor and one flexor

are short muscles; that is to say, their fleshy parts are not situated

in the leg (which corresponds with the arm), but in the back and in the

sole of the foot--regions which correspond with the back and the palm of

the hand.

Again, the tendons of the long flexor of the toes, and of the long

flexor of the great toe, when they reach the sole of the foot, do not

remain distinct from one another, as the flexors in the palm of the hand

do, but they become united and commingled in a very curious

manner--while their united tendons receive an accessory muscle connected

with the heel-bone.

But perhaps the most absolutely distinctive character about the muscles

of the foot is the existence of what is termed the _peronæus longus_, a

long muscle fixed to the outer bone of the leg, and sending its tendon

to the outer ankle, behind and below which it passes, and then crosses

the foot obliquely to be attached to the base of the great toe. No

muscle in the hand exactly corresponds with this, which is eminently a

foot muscle.

To resume--the foot of man is distinguished from his hand by the

following absolute anatomical differences:--

1. By the arrangement of the tarsal bones.

2. By having a short flexor and a short extensor muscle of the digits.

3. By possessing the muscle termed _peronæus longus_.

And if we desire to ascertain whether the terminal division of a limb,

in other Primates, is to be called a foot or a hand, it is by the

presence or absence of these characters that we must be guided, and not

by the mere proportions and greater or lesser mobility of the great toe,

which may vary indefinitely without any fundamental alteration in the

structure of the foot.

* * * * *

Keeping these considerations in mind, let us now turn to the limbs of

the Gorilla. The terminal division of the fore-limb presents no

difficulty--bone for bone and muscle for muscle, are found to be

arranged essentially as in man, or with such minor differences as are

found as varieties in man. The Gorilla's hand is clumsier, heavier, and

has a thumb somewhat shorter in proportion than that of man; but no one

has ever doubted its being a true hand.

At first sight, the termination of the hind limb of the Gorilla looks

very hand-like, and as it is still more so in many of the lower apes,

it is not wonderful that the appellation "Quadrumana," or four-handed

creatures, adopted from the older anatomists[29] by Blumenbach, and

unfortunately rendered current by Cuvier, should have gained such wide

acceptance as a name for the Simian group. But the most cursory

anatomical investigation at once proves that the resemblance of the

so-called "hind hand" to a true hand, is only skin deep, and that, in

all essential respects, the hind limb of the Gorilla is as truly

terminated by a foot as that of man. The tarsal bones, in all important

circumstances of number, disposition, and form, resemble those of man

(Fig. 19). The metatarsals and digits, on the other hand, are

proportionally longer and more slender, while the great toe is not only

proportionally shorter and weaker, but its metatarsal bone is united by

a more moveable joint with the tarsus. At the same time, the foot is set

more obliquely upon the leg than in man.

As to the muscles, there is a short flexor, a short extensor, and a

_peronæus longus_, while the tendons of the long flexors of the great

toe and of the other toes are united together and with an accessory

fleshy bundle.

The hind limb of the Gorilla, therefore, ends in a true foot, with a

very moveable great toe. It is a prehensile foot, indeed, but is in no

sense a hand: it is a foot which differs from that of man not in any

fundamental character, but in mere proportions, in the degree of

mobility, and in the secondary arrangement of its parts.

It must not be supposed, however, because I speak of these differences

as not fundamental, that I wish to underrate their value. They are

important enough in their way, the structure of the foot being in strict

correlation with that of the rest of the organism in each case. Nor can

it be doubted that the greater division of physiological labour in Man,

so that the function of support is thrown wholly on the leg and foot, is

an advance in organization of very great moment to him; but, after all,

regarded anatomically, the resemblances between the foot of Man and the

foot of the Gorilla are far more striking and important than the

differences.

[Illustration: FIG. 19.--Foot of Man, Gorilla, and Orang-Utan of the

same absolute length, to show the differences in proportion of each.

Letters as in Fig. 18. Reduced from original drawings by Mr. Waterhouse

Hawkins.]

I have dwelt upon this point at length, because it is one regarding

which much delusion prevails; but I might have passed it over without

detriment to my argument, which only requires me to show that, be the

differences between the hand and foot of Man and those of the Gorilla

what they may--the differences between those of the Gorilla and those

of the lower Apes are much greater.

It is not necessary to descend lower in the scale than the Orang for

conclusive evidence on this head.

The thumb of the Orang differs more from that of the Gorilla than the

thumb of the Gorilla differs from that of Man, not only by its

shortness, but by the absence of any special long flexor muscle. The

carpus of the Orang, like that of most lower apes, contains nine bones,

while in the Gorilla, as in Man and the Chimpanzee, there are only

eight.

The Orang's foot (Fig. 19) is still more aberrant; its very long toes

and short tarsus, short great toe, short and raised heel, great

obliquity of articulation in the leg, and absence of a long flexor

tendon to the great toe, separating it far more widely from the foot of

the Gorilla than the latter is separated from that of Man.

But, in some of the lower apes, the hand and foot diverge still more

from those of the Gorilla, than they do in the Orang. The thumb ceases

to be opposable in the American monkeys; is reduced to a mere rudiment

covered by the skin in the Spider Monkey; and is directed forwards and

armed with a curved claw like the other digits, in the Marmosets--so

that, in all these cases, there can be no doubt but that the hand is

more different from that of the Gorilla than the Gorilla's hand is from

Man's.

And as to the foot, the great toe of the Marmoset is still more

insignificant in proportion than that of the Orang--while in the Lemurs

it is very large, and as completely thumb-like and opposable as in the

Gorilla--but in these animals the second toe is often irregularly

modified, and in some species the two principal bones of the tarsus, the

_astragalus_ and the _os calcis_, are so immensely elongated as to

render the foot, so far, totally unlike that of any other mammal.

So with regard to the muscles. The short flexor of the toes of the

Gorilla differs from that of Man by the circumstance that one slip of

the muscle is attached, not to the heel bone, but to the tendons of the

long flexors. The lower Apes depart from the Gorilla by an exaggeration

of the same character, two, three, or more, slips becoming fixed to the

long flexor tendons--or by a multiplication of the slips.--Again, the

Gorilla differs slightly from Man in the mode of interlacing of the long

flexor tendons: and the lower apes differ from the Gorilla in exhibiting

yet other, sometimes very complex, arrangements of the same parts, and

occasionally in the absence of the accessory fleshy bundle.

Throughout all these modifications it must be recollected that the foot

loses no one of its essential characters. Every Monkey and Lemur

exhibits the characteristic arrangement of tarsal bones, possesses a

short flexor and short extensor muscle, and a _peronæus longus_. Varied

as the proportions and appearance of the organ may be, the terminal

division of the hind limb remains, in plan and principle of

construction, a foot, and never, in those respects, can be confounded

with a hand.

Hardly any part of the bodily frame, then, could be found better

calculated to illustrate the truth that the structural differences

between Man and the highest Ape are of less value than those between the

highest and the lower Apes, than the hand or the foot, and yet, perhaps,

there is one organ the study of which enforces the same conclusion in a

still more striking manner--and that is the Brain.

But before entering upon the precise question of the amount of

difference between the Ape's brain and that of Man, it is necessary that

we should clearly understand what constitutes a great, and what a small

difference in cerebral structure; and we shall be best enabled to do

this by a brief study of the chief modifications which the brain

exhibits in the series of vertebrate animals.

The brain of a fish is very small, compared with the spinal cord into

which it is continued, and with the nerves which come off from it: of

the segments of which it is composed--the olfactory lobes, the cerebral

hemisphere, and the succeeding divisions--no one predominates so much

over the rest as to obscure or cover them; and the so-called optic lobes

are, frequently, the largest masses of all. In Reptiles, the mass of the

brain, relatively to the spinal cord, increases and the cerebral

hemispheres begin to predominate over the other parts; while in Birds

this predominance is still more marked. The brain of the lowest Mammals,

such as the duck-billed Platypus and the Opossums and Kangaroos,

exhibits a still more definite advance in the same direction. The

cerebral hemispheres have now so much increased in size as, more or

less, to hide the representatives of the optic lobes, which remain

comparatively small, so that the brain of a Marsupial is extremely

different from that of a Bird, Reptile, or Fish. A step higher in the

scale, among the placental Mammals, the structure of the brain acquires

a vast modification--not that it appears much altered externally, in a

Rat or in a Rabbit, from what it is in a Marsupial--nor that the

proportions of its parts are much changed, but an apparently new

structure is found between the cerebral hemispheres, connecting them

together, as what is called the "great commissure" or "corpus callosum."

The subject requires careful re-investigation, but if the currently

received statements are correct, the appearance of the "corpus callosum"

in the placental mammals is the greatest and most sudden modification

exhibited by the brain in the whole series of vertebrated animals--it is

the greatest leap anywhere made by Nature in her brain work. For the two

halves of the brain being once thus knit together, the progress of

cerebral complexity is traceable through a complete series of steps from

the lowest Rodent, or Insectivore, to Man; and that complexity consists,

chiefly, in the disproportionate development of the cerebral hemispheres

and of the cerebellum, but especially of the former, in respect to the

other parts of the brain.

In the lower placental mammals, the cerebral hemispheres leave the

proper upper and posterior face of the cerebellum completely visible,

when the brain is viewed from above, but, in the higher forms, the

hinder part of each hemisphere, separated only by the tentorium (p. 92)

from the anterior face of the cerebellum, inclines backwards and

downwards, and grows out, as the so-called "posterior lobe," so as at

length to overlap and hide the cerebellum. In all Mammals, each cerebral

hemisphere contains a cavity which is termed the "ventricle," and as

this ventricle is prolonged, on the one hand, forwards, and on the other

downwards, into the substance of the hemisphere, it is said to have two

horns or "cornua," an "anterior cornu," and a "descending cornu." When

the posterior lobe is well developed, a third prolongation of the

ventricular cavity extends into it, and is called the "posterior cornu."

In the lower and smaller forms of placental Mammals the surface of the

cerebral hemispheres is either smooth or evenly rounded, or exhibits a

very few grooves, which are technically termed "sulci," separating

ridges or "convolutions" of the substance of the brain; and the smaller

species of all orders tend to a similar smoothness of brain. But, in the

higher orders, and especially the larger members of these orders, the

grooves, or sulci, become extremely numerous, and the intermediate

convolutions proportionately more complicated in their meanderings,

until, in the Elephant, the Porpoise, the higher Apes, and Man, the

cerebral surface appears a perfect labyrinth of tortuous foldings.

Where a posterior lobe exists and presents its customary cavity--the

posterior cornu--it commonly happens that a particular sulcus appears

upon the inner and under surface of the lobe, parallel with and beneath

the floor of the cornu--which is, as it were, arched over the roof of

the sulcus. It is as if the groove had been formed by indenting the

floor of the posterior horn from without with a blunt instrument, so

that the floor should rise as a convex eminence. Now this eminence is

what has been termed the "Hippocampus minor"; the "Hippocampus major"

being a larger eminence in the floor of the descending cornu. What may

be the functional importance of either of these structures we know not.

* * * * *

As if to demonstrate, by a striking example, the impossibility of

erecting any cerebral barrier between man and the apes, Nature has

provided us, in the latter animals, with an almost complete series of

gradations from brains little higher than that of a Rodent, to brains

little lower than that of Man. And it is a remarkable circumstance that

though, so far as our present knowledge extends, there _is_ one true

structural break in the series of forms of Simian brains, this hiatus

does not lie between Man and the man-like Apes, but between the lower

and the lowest Simians; or, in other words, between the old and new

world apes and monkeys, and the Lemurs. Every Lemur which has yet been

examined, in fact, has its cerebellum partially visible from above, and

its posterior lobe, with the contained posterior cornu and hippocampus

minor, more or less rudimentary. Every Marmoset, American monkey, old

world monkey, Baboon, or Man-like ape, on the contrary, has its

cerebellum entirely hidden, posteriorly, by the cerebral lobes, and

possesses a large posterior cornu, with a well-developed hippocampus

minor.

* * * * *

In many of these creatures, such as the Saimiri (_Chrysothrix_), the

cerebral lobes overlap and extend much further behind the cerebellum, in

proportion, than they do in man (Fig. 16)--and it is quite certain that,

in all, the cerebellum is completely covered behind, by well-developed

posterior lobes. The fact can be verified by every one who possesses the

skull of any old or new world monkey. For, inasmuch as the brain in all

mammals completely fills the cranial cavity, it is obvious that a cast

of the interior of the skull will reproduce the general form of the

brain, at any rate with such minute and, for the present purpose,

utterly unimportant differences as may result from the absence of the

enveloping membranes of the brain in the dry skull. But if such a cast

be made in plaster, and compared with a similar cast of the interior of

a human skull, it will be obvious that the cast of the cerebral chamber,

representing the cerebrum of the ape, as completely covers over and

overlaps the cast of the cerebellar chamber, representing the

cerebellum, as it does in the man (Fig. 20). A careless observer,

forgetting that a soft structure like the brain loses its proper shape

the moment it is taken out of the skull, may indeed mistake the

uncovered condition of the cerebellum of an extracted and distorted

brain for the natural relations of the parts; but his error must become

patent even to himself if he try to replace the brain within the

cranial chamber. To suppose that the cerebellum of an ape is naturally

uncovered behind is a miscomprehension comparable only to that of one

who should imagine that a man's lungs always occupy but a small portion

of the thoracic cavity--because they do so when the chest is opened, and

their elasticity is no longer neutralized by the pressure of the air.

[Illustration: FIG. 20.--Drawings of the internal casts of a Man's and

of a Chimpanzee's skull, of the same absolute length, and placed in

corresponding positions, _A._ Cerebrum; _B._ Cerebellum. The former

drawing is taken from a cast in the Museum of the Royal College of

Surgeons, the latter from the photograph of the cast of a Chimpanzee's

skull, which illustrates the paper by Mr. Marshall "On the Brain of the

Chimpanzee" in the Natural History Review for July, 1861. The sharper

definition of the lower edge of the cast of the cerebral chamber in the

Chimpanzee arises from the circumstance that the tentorium remained in

that skull and not in the Man's. The cast more accurately represents the

brain in Chimpanzee than in the Man; and the great backward projection

of the posterior lobes of the cerebrum of the former, beyond the

cerebellum, is conspicuous.]

And the error is the less excusable, as it must become apparent to every

one who examines a section of the skull of any ape above a Lemur,

without taking the trouble to make a cast of it. For there is a very

marked groove in every such skull, as in the human skull--which

indicates the line of attachment of what is termed the _tentorium_--a

sort of parchment-like shelf, or partition, which, in the recent state,

is interposed between the cerebrum and cerebellum, and prevents the

former from pressing upon the latter (see Fig. 16).

This groove, therefore, indicates the line of separation between that

part of the cranial cavity which contains the cerebrum, and that which

contains the cerebellum; and as the brain exactly fills the cavity of

the skull, it is obvious that the relations of these two parts of the

cranial cavity at once informs us of the relations of their contents.

Now in man, in all the old world, and in all the new world Simiæ, with

one exception, when the face is directed forwards, this line of

attachment of the tentorium, or impression for the lateral sinus, as it

is technically called, is nearly horizontal, and the cerebral chamber

invariably overlaps or projects behind the cerebellar chamber. In the

Howler Monkey or _Mycetes_ (see Fig. 16), the line passes obliquely

upwards and backwards, and the cerebral overlap is almost nil; while in

the Lemurs, as in the lower mammals, the line is much more inclined in

the same direction, and the cerebellar chamber projects considerably

beyond the cerebral.

When the gravest errors respecting points so easily settled as this

question respecting the posterior lobes can be authoritatively

propounded, it is no wonder that matters of observation, of no very

complex character, but still requiring a certain amount of care, should

have fared worse. Any one who cannot see the posterior lobe in an ape's

brain is not likely to give a very valuable opinion respecting the

posterior cornu or the hippocampus minor. If a man cannot see a church,

it is preposterous to take his opinion about its altar-piece or painted

window--so that I do not feel bound to enter upon any discussion of

these points, but content myself with assuring the reader that the

posterior cornu and the hippocampus minor, have now been seen--usually,

at least as well developed as in man, and often better--not only in the

Chimpanzee, the Orang, and the Gibbon, but in all the genera of the old

world baboons and monkeys, and in most of the new world forms, including

the Marmosets.[30]

In fact, all the abundant and trustworthy evidence (consisting of the

results of careful investigations directed to the determination of these

very questions, by skilled anatomists) which we now possess, leads to

the conviction that, so far from the posterior lobe, the posterior

cornu, and the hippocampus minor, being structures peculiar to and

characteristic of man, as they have been over and over again asserted to

be, even after the publication of the clearest demonstration of the

reverse, it is precisely these structures which are the most marked

cerebral characters common to man with the apes. They are among the most

distinctly Simian peculiarities which the human organism exhibits.

As to the convolutions, the brains of the apes exhibit every stage of

progress, from the almost smooth brain of the Marmoset, to the Orang and

the Chimpanzee, which fall but little below Man. And it is most

remarkable that, as soon as all the principal sulci appear, the pattern

according to which they are arranged is identical with that of the

corresponding sulci of man. The surface of the brain of a monkey

exhibits a sort of skeleton map of man's, and in the man-like Apes the

details become more and more filled in, until it is only in minor

characters, such as the greater excavation of the anterior lobes, the

constant presence of fissures usually absent in man, and the different

disposition and proportions of some convolutions, that the

Chimpanzee's or the Orang's brain can be structurally distinguished from

Man's.

[Illustration: FIG. 21.--Drawings of the cerebral hemispheres of a Man

and of a Chimpanzee of the same length, in order to show the relative

proportions of the parts: the former taken from a specimen, which Mr.

Flower, Conservator of the Museum of the Royal College of Surgeons, was

good enough to dissect for me; the latter, from the photograph of a

similarly dissected Chimpanzee's brain, given in Mr. Marshall's paper

above referred to. _a_, posterior lobe; _b_, lateral ventricle; _c_,

posterior cornu; _x_, the hippocampus minor.]

So far as cerebral structure goes, therefore, it is clear that Man

differs less from the Chimpanzee or the Orang, than these do even from

the Monkeys, and that the difference between the brains of the

Chimpanzee and of Man is almost insignificant, when compared with that

between the Chimpanzee brain and that of a Lemur.

It must not be overlooked, however, that there is a very striking

difference in the absolute mass and weight between the lowest human

brain and that of the highest ape--a difference which is all the more

remarkable when we recollect that a full grown Gorilla is probably

pretty nearly twice as heavy as a Bosjes man, or as many an European

woman. It may be doubted whether a healthy human adult brain ever

weighed less than thirty-one or two ounces, or that the heaviest Gorilla

brain has exceeded twenty ounces.

This is a very noteworthy circumstance, and doubtless will one day help

to furnish an explanation of the great gulf which intervenes between the

lowest man and the highest ape in intellectual power;[31] but it has

little systematic value, for the simple reason that, as may be

concluded from what has been already said respecting cranial capacity,

the difference in weight of brain between the highest and the lowest men

is far greater, both relatively and absolutely, than that between the

lowest man and the highest ape. The latter, as has been seen, is

represented by, say twelve, ounces of cerebral substance absolutely, or

by 32: 20 relatively; but as the largest recorded human brain weighed

between 65 and 66 ounces, the former difference is represented by more

than 33 ounces absolutely, or by 65: 32 relatively. Regarded

systematically the cerebral differences, of man and apes, are not of

more than generic value--his Family distinction resting chiefly on his

dentition, his pelvis, and his lower limbs.

* * * * *

Thus, whatever system of organs be studied, the comparison of their

modifications in the ape series leads to one and the same result--that

the structural differences which separate Man from the Gorilla and the

Chimpanzee are not so great as those which separate the Gorilla from the

lower apes.

But in enunciating this important truth I must guard myself against a

form of misunderstanding, which is very prevalent. I find, in fact, that

those who endeavour to teach what nature so clearly shows us in this

matter, are liable to have their opinions misrepresented and their

phraseology garbled, until they seem to say that the structural

differences between man and even the highest apes are small and

insignificant. Let me take this opportunity then of distinctly

asserting, on the contrary, that they are great and significant; that

every bone of a Gorilla bears marks by which it might be distinguished

from the corresponding bone of a Man; and that, in the present creation,

at any rate, no intermediate link bridges over the gap between _Homo_

and _Troglodytes_.

It would be no less wrong than absurd to deny the existence of this

chasm; but it is at least equally wrong and absurd to exaggerate its

magnitude, and, resting on the admitted fact of its existence, to refuse

to inquire whether it is wide or narrow. Remember, if you will, that

there is no existing link between Man and the Gorilla, but do not forget

that there is a no less sharp line of demarcation, a no less complete

absence of any transitional form, between the Gorilla and the Orang, or

the Orang and the Gibbon. I say, not less sharp, though it is somewhat

narrower. The structural differences between Man and the Man-like Apes

certainly justify our regarding him as constituting a family apart from

them; though, inasmuch as he differs less from them than they do from

other families of the same order, there can be no justification for

placing him in a distinct order.

And thus the sagacious foresight of the great lawgiver of systematic

zoology, Linnæus, becomes justified, and a century of anatomical

research brings us back to his conclusion, that man is a member of the

same order (for which the Linnæan term PRIMATES ought to be retained) as

the Apes and Lemurs. This order is now divisible into seven families, of

about equal systematic value: the first, the ANTHROPINI, contains Man

alone; the second, the CATARHINI, embraces the old world apes; the

third, the PLATYRHINI, all new world apes, except the Marmosets; the

fourth, the ARCTOPITHECINI, contains the Marmosets; the fifth, the

LEMURINI, the Lemurs--from which _Cheiromys_ should probably be excluded

to form a sixth distinct family, the CHEIROMYINI; while the seventh, the

GALEOPITHECINI, contains only the flying Lemur _Galeopithecus_,--a

strange form which almost touches on the Bats, as the _Cheiromys_ puts

on a rodent clothing, and the Lemurs simulate Insectivora.

Perhaps no order of mammals presents us with so extraordinary a series

of gradations as this--leading us insensibly from the crown and summit

of the animal creation down to creatures, from which there is but a

step, as it seems, to the lowest, smallest, and least intelligent of the

placental Mammalia. It is as if nature herself had foreseen the

arrogance of man, and with Roman severity had provided that his

intellect, by its very triumphs, should call into prominence the slaves,

admonishing the conqueror that he is but dust.

* * * * *

These are the chief facts, this the immediate conclusion from them to

which I adverted in the commencement of this Essay. The facts, I

believe, cannot be disputed; and if so, the conclusion appears to me to

be inevitable.

But if Man be separated by no greater structural barrier from the brutes

than they are from one another--then it seems to follow that if any

process of physical causation can be discovered by which the genera and

families of ordinary animals have been produced, that process of

causation is amply sufficient to account for the origin of Man. In other

words, if it could be shown that the Marmosets, for example, have arisen

by gradual modification of the ordinary Platyrhini, or that both

Marmosets and Platyrhini are modified ramifications of a primitive

stock--then, there would be no rational ground for doubting that man

might have originated, in the one case, by the gradual modification of a

man-like ape; or, in the othercase, as a ramification of the same

primitive stock as those apes.

At the present moment, but one such process of physical causation has

any evidence in its favour; or, in other words, there is but one

hypothesis regarding the origin of species of animals in general which

has any scientific existence--that propounded by Mr. Darwin. For

Lamarck, sagacious as many of his views were, mingled them with so much

that was crude and even absurd, as to neutralize the benefit which his

originality might have effected, had he been a more sober and cautious

thinker; and though I have heard of the announcement of a formula

touching "the ordained continuous becoming of organic forms," it is

obvious that it is the first duty of a hypothesis to be intelligible,

and that a qua-quâ-versal proposition of this kind, which may be read

backwards, or forwards, or sideways, with exactly the same amount of

signification, does not really exist, though it may seem to do so.

At the present moment, therefore, the question of the relation of man to

the lower animals resolves itself, in the end, into the larger question

of the tenability or untenability of Mr. Darwin's views. But here we

enter upon difficult ground, and it behoves us to define our exact

position with the greatest care.

It cannot be doubted, I think, that Mr. Darwin has satisfactorily proved

that what he terms selection, or selective modification, must occur, and

does occur, in nature; and he has also proved to superfluity that such

selection is competent to produce forms as distinct, structurally, as

some genera even are. If the animated world presented us with none but

structural differences, I should have no hesitation in saying that Mr.

Darwin had demonstrated the existence of a true physical cause, amply

competent to account for the origin of living species, and of man among

the rest.

But, in addition to their structural distinctions, the species of

animals and plants, or at least a great number of them, exhibit

physiological characters--what are known as distinct species,

structurally, being for the most part either altogether incompetent to

breed one with another; or if they breed, the resulting mule, or hybrid,

is unable to perpetuate its race with another hybrid of the same kind.

A true physical cause is, however, admitted to be such only on one

condition--that it shall account for all the phenomena which come within

the range of its operation. If it is inconsistent with any one

phenomenon, it must be rejected; if it fails to explain any one

phenomenon, it is so far weak, so far to be suspected; though it may

have a perfect right to claim provisional acceptance.

Now, Mr. Darwin's hypothesis is not, so far as I am aware, inconsistent

with any known biological fact; on the contrary, if admitted, the facts

of Development, of Comparative Anatomy, of Geographical Distribution,

and of Palæontology, become connected together, and exhibit a meaning

such as they never possessed before; and I, for one, am fully convinced,

that if not precisely true, that hypothesis is as near an approximation

to the truth as, for example, the Copernican hypothesis was to the true

theory of the planetary motions.

But, for all this, our acceptance of the Darwinian hypothesis must be

provisional so long as one link in the chain of evidence is wanting; and

so long as all the animals and plants certainly produced by selective

breeding from a common stock are fertile, and their progeny are fertile

with one another, that link will be wanting. For, so long, selective

breeding will not be proved to be competent to do all that is required

of it to produce natural species.

I have put this conclusion as strongly as possible before the reader,

because the last position in which I wish to find myself is that of an

advocate for Mr. Darwin's, or any other views--if by an advocate is

meant one whose business it is to smooth over real difficulties, and to

persuade where he cannot convince.

In justice to Mr. Darwin, however, it must be admitted that the

conditions of fertility and sterility are very ill understood, and that

every day's advance in knowledge leads us to regard the hiatus in his

evidence as of less and less importance, when set against the multitude

of facts which harmonize with, or receive an explanation from, his

doctrines.

I adopt Mr. Darwin's hypothesis, therefore, subject to the production of

proof that physiological species may be produced by selective breeding;

just as a physical philosopher may accept the undulatory theory of

light, subject to the proof of the existence of the hypothetical ether;

or as the chemist adopts the atomic theory, subject to the proof of the

existence of atoms; and for exactly the same reasons, namely, that it

has an immense amount of primâ facie probability; that it is the only

means at present within reach of reducing the chaos of observed facts to

order; and lastly, that it is the most powerful instrument of

investigation which has been presented to naturalists since the

invention of the natural system of classification, and the commencement

of the systematic study of embryology.

But even leaving Mr. Darwin's views aside, the whole analogy of natural

operations furnishes so complete and crushing an argument against the

intervention of any but what are termed secondary causes, in the

production of all the phenomena of the universe; that, in view of the

intimate relations between Man and the rest of the living world; and

between the forces exerted by the latter and all other forces, I can see

no excuse for doubting that all are co-ordinated terms of Nature's great

progression, from the formless to the formed--from the inorganic to the

organic--from blind force to conscious intellect and will.

* * * * *

Science has fulfilled her function when she has ascertained and

enunciated truth; and were these pages addressed to men of science only,

I should now close this essay, knowing that my colleagues have learned

to respect nothing but evidence, and to believe that their highest duty

lies in submitting to it, however it may jar against their inclinations.

But desiring, as I do, to reach the wider circle of the intelligent

public, it would be unworthy cowardice were I to ignore the repugnance

with which the majority of my readers are likely to meet the conclusions

to which the most careful and conscientious study I have been able to

give to this matter, has led me.

On all sides I shall hear the cry--"We are men and women, not a mere

better sort of apes, a little longer in the leg, more compact in the

foot, and bigger in brain than your brutal Chimpanzees and Gorillas. The

power of knowledge--the conscience of good and evil--the pitiful

tenderness of human affections, raise us out of all real fellowship

with the brutes, however closely they may seem to approximate us."

To this I can only reply that the exclamation would be most just and

would have my own entire sympathy, if it were only relevant. But, it is

not I who seek to base Man's dignity upon his great toe, or insinuate

that we are lost if an Ape has a hippocampus minor. On the contrary, I

have done my best to sweep away this vanity. I have endeavoured to show

that no absolute structural line of demarcation, wider than that between

the animals which immediately succeed us in the scale, can be drawn

between the animal world and ourselves; and I may add the expression of

my belief that the attempt to draw a psychical distinction is equally

futile, and that even the highest faculties of feeling and of intellect

begin to germinate in lower forms of life.[32] At the same time, no one

is more strongly convinced than I am of the vastness of the gulf between

civilized man and the brutes; or is more certain that whether _from_

them or not, he is assuredly not _of_ them. No one is less disposed to

think lightly of the present dignity, or despairingly of the future

hopes, of the only consciously intelligent denizen of this world.

We are indeed told by those who assume authority in these matters, that

the two sets of opinions are incompatible, and that the belief in the

unity of origin of man and brutes involves the brutalization and

degradation of the former. But is this really so? Could not a sensible

child confute, by obvious arguments, the shallow rhetoricians who would

force this conclusion upon us? Is it, indeed, true, that the Poet, or

the Philosopher, or the Artist whose genius is the glory of his age, is

degraded from his high estate by the undoubted historical probability,

not to say certainty, that he is the direct descendant of some naked and

bestial savage, whose intelligence was just sufficient to make him a

little more cunning than the Fox, and by so much more dangerous than the

Tiger? Or is he bound to howl and grovel on all fours because of the

wholly unquestionable fact, that he was once an egg, which no ordinary

power of discrimination could distinguish from that of a Dog? Or is the

philanthropist or the saint to give up his endeavours to lead a noble

life, because the simplest study of man's nature reveals, at its

foundations, all the selfish passions and fierce appetites of the merest

quadruped? Is mother-love vile because a hen shows it, or fidelity base

because dogs possess it?

The common sense of the mass of mankind will answer these questions

without a moment's hesitation. Healthy humanity, finding itself hard

pressed to escape from real sin and degradation, will leave the brooding

over speculative pollution to the cynics and the "righteous overmuch"

who, disagreeing in everything else, unite in blind insensibility to the

nobleness of the visible world, and in inability to appreciate the

grandeur of the place Man occupies therein.

Nay more, thoughtful men, once escaped from the blinding influences of

traditional prejudice, will find in the lowly stock whence man has

sprung, the best evidence of the splendour of his capacities; and will

discern in his long progress through the Past, a reasonable ground of

faith in his attainment of a nobler Future.

They will remember that in comparing civilized man with the animal

world, one is as the Alpine traveller, who sees the mountains soaring

into the sky and can hardly discern where the deep shadowed crags and

roseate peaks end, and where the clouds of heaven begin. Surely the

awe-struck voyager may be excused if, at first, he refuses to believe

the geologist, who tells him that these glorious masses are, after all,

the hardened mud of primeval seas, or the cooled slag of subterranean

furnaces--of one substance with the dullest clay, but raised by inward

forces to that place of proud and seemingly inaccessible glory.

But the geologist is right; and due reflection on his teachings, instead

of diminishing our reverence and our wonder, adds all the force of

intellectual sublimity to the mere æsthetic intuition of the

uninstructed beholder.

And after passion and prejudice have died away, the same result will

attend the teachings of the naturalist respecting that great Alps and

Andes of the living world--Man. Our reverence for the nobility of

manhood will not be lessened by the knowledge, that Man is, in substance

and in structure, one with the brutes; for, he alone possesses the

marvellous endowment of intelligible and rational speech, whereby, in

the secular period of his existence, he has slowly accumulated and

organized the experience which is almost wholly lost with the cessation

of every individual life in other animals; so that now he stands raised

upon it as on a mountain top, far above the level of his humble fellows,

and transfigured from his grosser nature by reflecting, here and there,

a ray from the infinite source of truth.

_A succinct History of the Controversy respecting the

Cerebral Structure of Man and the Apes_

Up to the year 1857 all anatomists of authority, who had occupied

themselves with the cerebral structure of the Apes--Cuvier, Tiedemann,

Sandifort, Vrolik, Isidore G. St. Hilaire, Schroeder van der Kolk,

Gratiolet--were agreed that the brain of the Apes possesses a POSTERIOR

LOBE.

Tiedemann, in 1825, figured and acknowledged in the text of his

"Icones," the existence of the POSTERIOR CORNU of the lateral ventricle

in the Apes, not only under the title of "Scrobiculus parvus loco cornu

posterioris"--a fact which has been paraded--but as "cornu posterius"

(Icones, p. 54), a circumstance which has been, as sedulously, kept in

the back ground.

Cuvier (Lecons, T. iii. p. 103) says, "the anterior or lateral

ventricles possess a digital cavity [posterior cornu] only in Man and

the Apes.... Its presence depends on that of the posterior lobes."

Schroeder van der Kolk and Vrolik, and Gratiolet, had also figured and

described the posterior cornu in various Apes. As to the HIPPOCAMPUS

MINOR Tiedemann had erroneously asserted its absence in the Apes; but

Schroeder van der Kolk and Vrolik had pointed out the existence of what

they considered a rudimentary one in the Chimpanzee, and Gratiolet had

expressly affirmed its existence in these animals. Such was the state of

our information on these subjects in the year 1856.

In the year 1857, however, Professor Owen, either in ignorance of these

well-known facts or else unjustifiably suppressing them, submitted to

the Linnæan Society a paper "On the Characters, Principles of Division,

and Primary Groups of the Class Mammalia," which was printed in the

Society's Journal, and contains the following passage:--"In Man, the

brain presents an ascensive step in development, higher and more

strongly marked than that by which the preceding subclass was

distinguished from the one below it. Not only do the cerebral

hemispheres overlap the olfactory lobes and cerebellum, but they extend

in advance of the one and further back than the other. The posterior

development is so marked, that anatomists have assigned to that part the

character of a third lobe; _it is peculiar to the genus Homo, and

equally peculiar is the posterior horn of the lateral ventricle and the

'hippocampus minor,' which characterise the hind lobe of each

hemisphere_."--_Journal of the Proceedings of the Linnæan Society_, Vol.

ii. p. 19.

As the essay in which this passage stands had no less ambitious an aim

than the remodelling of the classification of the Mammalia, its author

might be supposed to have written under a sense of peculiar

responsibility, and to have tested, with especial care, the statements

he ventured to promulgate. And even if this be expecting too much,

hastiness, or want of opportunity for due deliberation, cannot now be

pleaded in extenuation of any shortcomings; for the propositions cited

were repeated two years afterwards in the Reade Lecture, delivered

before so grave a body as the University of Cambridge, in 1859.

When the assertions, which I have italicised in the above extract, first

came under my notice, I was not a little astonished at so flat a

contradiction of the doctrines current among well-informed anatomists;

but, not unnaturally imagining that the deliberate statements of a

responsible person must have some foundation in fact, I deemed it my

duty to investigate the subject anew before the time at which it would

be my business to lecture thereupon came round. The result of my

inquiries was to prove that Mr. Owen's three assertions, that "the third

lobe, the posterior horn of the lateral ventricle, and the hippocampus

minor," are "peculiar to the genus _Homo_," are contrary to the plainest

facts. I communicated this conclusion to the students of my class; and

then, having no desire to embark in a controversy which could not

redound to the honour of British science, whatever its issue, I turned

to more congenial occupations.

The time speedily arrived, however, when a persistence in this reticence

would have involved me in an unworthy paltering with truth.

At the meeting of the British Association at Oxford, in 1860, Professor

Owen repeated these assertions in my presence, and, of course, I

immediately gave them a direct and unqualified contradiction, pledging

myself to justify that unusual procedure elsewhere. I redeemed that

pledge by publishing, in the January number of the _Natural History

Review_ for 1861, an article wherein the truth of the three following

propositions was fully demonstrated (l. c. p. 71):--

"1. That the third lobe is neither peculiar to, nor

characteristic of, man seeing that it exists in all the

higher quadrumana."

"2. That the posterior cornu of the lateral ventricle is

neither peculiar to, nor characteristic of, man, inasmuch

as it also exists in the higher quadrumana."

"3. That the _hippocampus minor_ is neither peculiar to,

nor characteristic of, man, as it is found in certain of

the higher quadrumana."

Furthermore, this paper contains the following paragraph (p. 76):

"And lastly, Schroeder van der Kolk and Vrolik (op. cit.

p. 271), though they particularly note that 'the lateral

ventricle is distinguished from that of Man by the very

defective proportions of the posterior cornu, wherein only

a stripe is visible as an indication of the hippocampus

minor;' yet the Figure 4, in their second Plate, shows

that this posterior cornu is a perfectly distinct and

unmistakeable structure, quite as large as it often is in

Man. It is the more remarkable that Professor Owen should

have overlooked the explicit statement and figure of these

authors, as it is quite obvious, on comparison of the

figures, that his woodcut of the brain of a Chimpanzee (l.

c. p. 19) is a reduced copy of the second figure of

Messrs. Schroeder van der Kolk and Vrolik's first Plate.

"As M. Gratiolet (l. c. p. 18), however, is careful to

remark, 'unfortunately the brain which they have taken as

a model was greatly altered (profondément affaissé),

whence the general form of the brain is given in these

plates in a manner which is altogether incorrect.' Indeed,

it is perfectly obvious, from a comparison of a section of

the skull of the Chimpanzee with these figures, that such

is the case; and it is greatly to be regretted that so

inadequate a figure should have been taken as a typical

representation of the Chimpanzee's brain."

From this time forth, the untenability of his position might have been

as apparent to Professor Owen as it was to every one else; but, so far

from retracting the grave errors into which he had fallen, Professor

Owen has persisted in and reiterated them; first, in a lecture delivered

before the Royal Institution on the 19th of March, 1861, which is

admitted to have been accurately reproduced in the "Athenæum" for the

23rd of the same month, in a letter addressed by Professor Owen to that

journal on the 30th of March. The "Athenæum" report was accompanied by a

diagram purporting to represent a Gorilla's brain, but in reality so

extraordinary a misrepresentation, that Professor Owen substantially,

though not explicitly, withdraws it in the letter in question. In

amending this error, however, Professor Owen fell into another of much

graver import, as his communication concludes with the following

paragraph: "For the true proportion in which the cerebrum covers the

cerebellum in the highest Apes, reference should be made to the figure

of the undissected brain of the Chimpanzee in my 'Reade's Lecture on the

Classification, &c. of the Mammalia,' p. 25, fig. 7, 8vo. 1859."

It would not be credible, if it were not unfortunately true, that this

figure, to which the trusting public is referred, without a word of

qualification, "for the true proportion in which the cerebrum covers the

cerebellum in the highest Apes," is exactly that unacknowledged copy of

Schroeder van der Kolk and Vrolik's figure whose utter inaccuracy had

been pointed out years before by Gratiolet, and had been brought to

Professor Owen's knowledge by myself in the passage of my article in the

"Natural History Review" above quoted.

I drew public attention to this circumstance again in my reply to

Professor Owen, published in the "Athenæum" for April 13th, 1861; but

the exploded figure was reproduced once more by Professor Owen, without

the slightest allusion to its inaccuracy, in the "Annals of Natural

History" for June 1861!

This proved too much for the patience of the original authors of the

figure, Messrs. Schroeder van der Kolk and Vrolik, who, in a note

addressed to the Academy of Amsterdam, of which they were members,

declared themselves to be, though decided opponents of all forms of the

doctrine of progressive development, above all things, lovers of truth:

and that, therefore, at whatever risk of seeming to lend support to

views which they disliked, they felt it their duty to take the first

opportunity of publicly repudiating Professor Owen's misuse of their

authority.

In this note they frankly admitted the justice of the criticisms of M.

Gratiolet, quoted above, and they illustrated, by new and careful

figures, the posterior lobe, the posterior cornu, and the hippocampus

minor of the Orang. Furthermore, having demonstrated the parts, at one

of the sittings of the Academy, they add, "la présence des parties

contestées y a été universellement reconnue par les anatomistes présents

à la séance. Le seul doute qui soit resté se rapporte au pes Hippocampi

minor.... A l'état frais l'indice du petit pied d'Hippocampe était plus

prononcé que maintenant."

Professor Owen repeated his erroneous assertions at the meeting of the

British Association in 1861, and again, without any obvious necessity,

and without adducing a single new fact or new argument, or being able in

any way to meet the crushing evidence from original dissections of

numerous Apes' brains, which had in the meanwhile been brought forward

by Prof. Rolleston,[33] F.R.S., Mr. Marshall,[34] F.R.S., Mr.

Flower,[35] Mr. Turner,[36] and myself,[37] revived the subject at the

Cambridge meeting of the same body in 1862. Not content with the

tolerably vigorous repudiation which these unprecedented proceedings met

with in Section D, Professor Owen sanctioned the publication of a

version of his own statements, accompanied by a strange

misrepresentation of mine (as may be seen by comparison of the "Times"

report of the discussion), in the "Medical Times" for October 11th,

1862. I subjoin the conclusion of my reply in the same journal for

October 25th.

"If this were a question of opinion, or a question of

interpretation of parts or of terms,--were it even a

question of observation in which the testimony of my own

senses alone was pitted against that of another person, I

should adopt a very different tone in discussing this

matter. I should, in all humility, admit the likelihood of

having myself erred in judgment, failed in knowledge, or

been blinded by prejudice.

"But no one pretends now, that the controversy is one of

terms or of opinions. Novel and devoid of authority as

some of Professor Owen's proposed definitions may have

been, they might be accepted without changing the great

features of the case. Hence, though special investigations

into these matters have been undertaken during the last

two years by Dr. Allen Thomson, by Dr. Rolleston, by Mr.

Marshall, and by Mr. Flower, all, as you are aware,

anatomists of repute in this country, and by Professors

Schroeder Van der Kolk, and Vrolik (whom Professor Owen

incautiously tried to press into his own service) on the

Continent, all these able and conscientious observers have

with one accord testified to the accuracy of my

statements, and to the utter baselessness of the

assertions of Professor Owen. Even the venerable Rudolph

Wagner, whom no man will accuse of progressionist

proclivities, has raised his voice on the same side; while

not a single anatomist, great or small, has supported

Professor Owen.

"Now, I do not mean to suggest that scientific differences

should be settled by universal suffrage, but I do conceive

that solid proofs must be met by something more than empty

and unsupported assertions. Yet during the two years

through which this preposterous controversy has dragged

its weary length, Professor Owen has not ventured to

bring forward a single preparation in support of his

often-repeated assertions.

"The case stands thus, therefore:--Not only are the

statements made by me in consonance with the doctrines of

the best older authorities, and with those of all recent

investigators, but I am quite ready to demonstrate them on

the first monkey that comes to hand; while Professor

Owen's assertions are not only in diametrical opposition

to both old and new authorities, but he has not produced,

and, I will add, cannot produce, a single preparation

which justifies them."

I now leave this subject, for the present.--For the credit of my calling

I should be glad to be, hereafter, for ever silent upon it. But,

unfortunately, this is a matter upon which, after all that has occurred,

no mistake or confusion of terms is possible--and in affirming that the

posterior lobe, the posterior cornu, and the hippocampus minor exist in

certain Apes, I am stating either that which is true, or that which I

must know to be false. The question has thus become one of personal

veracity. For myself, I will accept no other issue than this, grave as

it is, to the present controversy.