The Antiquity of Man Part 42

Grounds on which Man has been referred to a distinct Kingdom of Nature.

Immaterial Principle common to Man and Animals.

Non-discovery of intermediate Links among Fossil Anthropomorphous Species.

Hallam on the compound Nature of Man, and his Place in the Creation.

Great Inequality of mental Endowment in different Human Races and Individuals developed by Variation and ordinary Generation.

How far a corresponding Divergence in physical Structure may result from the Working of the same Causes.

Concluding remarks.

Some of the opponents of trans.m.u.tation, who are well versed in Natural History, admit that though that doctrine is untenable, it is not without its practical advantages as a "useful working hypothesis," often suggesting good experiments and observations and aiding us to retain in the memory a mult.i.tude of facts respecting the geographical distribution of genera and species, both of animals and plants, the succession in time of organic remains, and many other phenomena which, but for such a theory, would be wholly without a common bond of relations.h.i.+p.

It is in fact conceded by many eminent zoologists and botanists, as before explained, that whatever may be the nature of the species-making power or law, its effects are of such a character as to imitate the results which variation, guided by natural selection, would produce, if only we could a.s.sume with certainty that there are no limits to the variability of species. But as the anti-trans.m.u.tationists are persuaded that such limits do exist, they regard the hypothesis as simply a provisional one, and expect that it will one day be superseded by another cognate theory, which will not require us to a.s.sume the former continuousness of the links which have connected the past and present states of the organic world, or the outgoing with the incoming species.

In like manner, many of those who hesitate to give in their full adhesion to the doctrine of progression, the other twin branch of the development theory, and who even object to it, as frequently tending to r.e.t.a.r.d the reception of new facts supposed to militate against opinions solely founded on negative evidence, are nevertheless agreed that on the whole it is of great service in guiding our speculations. Indeed it cannot be denied that a theory which establishes a connection between the absence of all relics of vertebrata in the oldest fossiliferous rocks, and the presence of man's remains in the newest, which affords a more than plausible explanation of the successive appearance in strata of intermediate age of the fish, reptile, bird, and mammal, has no ordinary claims to our favour as comprehending the largest number of positive and negative facts gathered from all parts of the globe, and extending over countless ages, that science has perhaps ever attempted to embrace in one grand generalisation.

But will not trans.m.u.tation, if adopted, require us to include the human race in the same continuous series of developments, so that we must hold that Man himself has been derived by an unbroken line of descent from some one of the inferior animals? We certainly cannot escape from such a conclusion without abandoning many of the weightiest arguments which have been urged in support of variation and natural selection considered as the subordinate causes by which new types have been gradually introduced into the earth. Many of the gaps which separate the most nearly allied genera and orders of mammalia are, in a physical point of view, as wide as those which divide Man from the mammalia most nearly akin to him, and the extent of his isolation, whether we regard his whole nature or simply his corporeal attributes, must be considered before we can discuss the bearing of trans.m.u.tation upon his origin and place in the creation.

SYSTEMS OF CLa.s.sIFICATION.

In order to qualify ourselves to judge of the degree of affinity in physical organisation between Man and the lower animals, we cannot do better than study those systems of cla.s.sification which have been proposed by the most eminent teachers of natural history. Of these an elaborate and faithful summary has recently been drawn up by the late Isidore Geoffroy St. Hilaire, which the reader will do well to consult.*

(* "Histoire Naturale Generale des Regnes organiques" Paris volume 2 1856.)

He begins by pa.s.sing in review numerous schemes of cla.s.sification, each of them having some merit, and most of them having been invented with a view of a.s.signing to Man a separate place in the system of Nature, as, for example, by dividing animals into rational and irrational, or the whole organic world into three kingdoms, the human, the animal, and the vegetable--an arrangement defended on the ground that Man is raised as much by his intelligence above the animals as are these by their sensibility above plants. Admitting that these schemes are not unphilosophical, as duly recognising the double nature of Man (his moral and intellectual, as well as his physical attributes), Isidore G. St.

Hilaire observes that little knowledge has been imparted by them. We have gained, he says, much more from those masters of the science who have not attempted any compromise between two distinct orders of ideas, the physical and psychological, and who have confined their attention strictly to Man's physical relation to the lower animals.

Linnaeus led the way in this field of inquiry by comparing Man and the apes, in the same manner as he compared these last with the carnivores, ruminants, rodents, or any other division of warm-blooded quadrupeds.

After several modifications of his original scheme, he ended by placing Man as one of the many genera in his order Primates, which embraced not only the apes and lemurs, but the bats also, as he found these last to be nearly allied to some of the lowest forms of the monkeys. But all modern naturalists, who retain the order Primates, agree to exclude from it the bats or Cheiroptera; and most of them cla.s.s Man as one of several families of the order Primates. In this, as in most systems of cla.s.sification, the families of modern zoologists and botanists correspond with the genera of Linnaeus.

Blumenbach, in 1779, proposed to deviate from this course, and to separate Man from the apes as an order apart, under the name of Bimana, or two-handed. In making this innovation he seems at first to have felt that it could not be justified without calling in psychological considerations to his aid, to strengthen those which were purely anatomical; for, in the earliest edition of his "Manual of Natural History," he defined Man to be "animal rationale, loquens, er.e.c.t.u.m, bimanum," whereas in later editions he restricted himself entirely to the two last characters, namely, the erect position and the two hands, or "animal er.e.c.t.u.m, bimanum."

The terms "bimanous" and "quadrumanous" had been already employed by Buffon in 1766, but not applied in a strict zoological cla.s.sification till so used by Blumenbach. Twelve years later, Cuvier adopted the same order Bimana for the human family, while the apes, monkeys, and lemurs const.i.tuted a separate order called Quadrumana.

Respecting this last innovation, Isidore G. St. Hilaire asks, "How could such a division stand, repudiated as it was by the anthropologists in the name of the moral and intellectual supremacy of Man; and by the zoologists, on the ground of its incompatibility with natural affinities and with the true principles of cla.s.sification? Separated as a group of ordinal value, placed at the same distance from the ape as the latter from the carnivore, Man is at once too near and too distant from the higher mammalia--too near if we take into account those elevated faculties, which, raising Man above all other organised beings, accord to him not only the first, but a separate place in the creation--too far if we merely consider the organic affinities which unite him with the quadrumana; with the apes especially, which, in a purely physical point of view, approach Man more nearly than they do the lemurs."

"What, then, is this order of Bimana of Blumenbach and Cuvier? An impracticable compromise between two opposite and irreconcilable systems--between two orders of ideas which are clearly expressed in the language of natural history by these two words: the human KINGDOM and the human FAMILY. It is one of those would-be via media propositions which, once seen through, satisfy no one, precisely because they are intended to please everybody; half-truths, perhaps, but also half-falsehoods; for what, in science, is a half-truth but an error?"

Isidore G. St. Hilaire then proceeds to show how, in spite of the great authority of Blumenbach and Cuvier, a large proportion of modern zoologists of note have rejected the order Bimana, and have regarded Man simply as a family of one and the same order, Primates.

TERM "QUADRUMANOUS," WHY DECEPTIVE.

Even the term "Quadrumanous" has lately been shown by Professor Huxley, in a lecture delivered by him in the spring of 1860-61, which I had the good fortune to hear, to have proved a fertile source of popular delusion, conveying ideas which the great anatomists Blumenbach and Cuvier never entertained themselves, namely, that in the so-called Quadrumana the extremities of the hind-limbs bear a real resemblance to the human hands, instead of corresponding anatomically with the human feet.

As this subject bears very directly on the question, how far Man is ent.i.tled, in a purely zoological cla.s.sification, to rank as an order apart, I shall proceed to cite, in an abridged form, the words of the lecturer above alluded to.*

(* Professor Huxley's third lecture "On the Motor Organs of Man compared with those of other Animals," delivered in the Royal School of Mines, in Jermyn Street (March 1861) has been embodied with the rest of the course in his work ent.i.tled "Evidence as to Man's Place in Nature.")

"To gain," he observes, "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.

"The foot of Man is distinguished from his hand by:--

"1. 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 peronaeus longus.

"And if we desire to ascertain whether the terminal division of a limb in other animals 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 precisely as in Man, or with such minute 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 the lower apes, it is not wonderful that the appellation 'Quadrumana,' or four-handed creatures, adopted from the older anatomists by Blumenbach, and unfortunately rendered current by Cuvier, should have gained such wide acceptance as a name for the ape order. But the most cursory anatomical investigation at once proves that the resemblance of the so-called 'hindhand' 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 circ.u.mstances of number, disposition, and form, resemble those of Man. 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 far more movable 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 peronaeus longus, while the tendons of the long flexors of the great toe and of the other toes are united together and into an accessory fleshy bundle.

"The hind-limb of the Gorilla, therefore, ends in a true foot with a very movable great toe. It is a prehensile foot, if you will, but is in no sense a hand: it is a foot which differs from that of Man in no fundamental character, but in mere proportions--degree of mobility--and secondary arrangement of its parts.

"It must not be supposed, however, that 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; 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."*

(* Professor Huxley, ibid.)

After dwelling on some points of anatomical detail, highly important, but for which I have not s.p.a.ce here, the Professor continues--"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 peronaeus 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 the least degree approaches a hand."*

(* Ibid.)

For these reasons, Professor Huxley rejects the term "Quadrumana," as leading to serious misconception, and regards Man as one of the families of the Primates. This method of cla.s.sification he shows to be equally borne out by an appeal to another character on which so much reliance has always been placed in cla.s.sification, as affording in the mammalia the most trustworthy indications of affinity, namely, the dent.i.tion.

"The number of teeth in the Gorilla and all the Old World monkeys, except the lemurs, is thirty-two, the same as in Man, and the general pattern of their crowns the same. But besides other distinctions, the canines in all but Man project in the upper or lower jaws almost like tusks. But all the American apes have four more teeth in their permanent set, or thirty-six in all, so that they differ in this respect more from the Old World apes than do these last from Man."

If therefore, by reference to this character, we place Man in a separate order, we must make several orders for the apes, monkeys, and lemurs, and so, in regard to the structure of the hands and feet before alluded to, "the Gorilla differs far more from some of the quadrumana than he differs from Man." Indeed, Professor Huxley contends that there is more difference between the hand and foot of the Gorilla and those of the Orang, one of the anthropomorphous apes, than between those of the Gorilla and Man, for "the thumb of the Orang differs by its shortness and by the absence of any special long flexor muscle from that of the Gorilla more than it differs from that of Man." The carpus also 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." Other characters are also given to show that the Orang's foot separates it more widely from the Gorilla than that of the Gorilla separates that ape from Man. In some of the lower apes, the divergence from the human type of hand and foot, as well as from those of the Gorilla, is still greater, as, for example, in the spider-monkey and marmoset."*

(* Huxley, ibid. page 29.)

If the muscles, viscera, or any other part of the animal fabric, including the brain, be compared, the results are declared to be similar.

WHETHER THE STRUCTURE OF THE HUMAN BRAIN ENt.i.tLES MAN TO FORM A DISTINCT SUB-CLa.s.s OF THE MAMMALIA.

In consequence of these and many other zoological considerations, the order Bimana had already been declared, in 1856, by Isidore G. St.

Hilaire in his history of the science above quoted "to have become obsolete," even though sanctioned by the great names of Blumenbach and Cuvier. But in opposition to the new views Professor Owen announced, the year after the publication of G. St. Hilaire's work, that he had been led by purely anatomical considerations to separate Man from the other Primates and from the mammalia generally as a distinct SUB-CLa.s.s, thus departing farther from the cla.s.sification of Blumenbach and Cuvier than they had ventured to do from that of Linnaeus.

The proposed innovation was based chiefly on three cerebral characters belonging, it was alleged, exclusively to Man and thus described in the following pa.s.sages of a memoir communicated to the Linnaean Society in 1857, in which all the mammalia were divided, according to the structure of the brain, into four sub-cla.s.ses, represented by the kangaroo, the beaver, the ape, and Man respectively:--

"In Man, the brain presents an ascensive step in development, higher and more strongly marked than that by which the preceding sub-cla.s.s 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 farther back than the other. Their posterior development is so marked that anatomists have a.s.signed to that part the character of a third lobe; it is peculiar to the genus h.o.m.o, and equally peculiar is the 'posterior horn of the lateral ventricle' and the 'hippocampus minor' which characterises the hind-lobe of each hemisphere. The superficial grey matter of the cerebrum, through the number and depth of its convolutions, attains its maximum of extent in Man.

"Peculiar mental powers are a.s.sociated with this highest form of brain, and their consequences wonderfully ill.u.s.trate the value of the cerebral character; according to my estimate of which I am led to regard the genus h.o.m.o as not merely a representative of a distinct order, but of a distinct sub-cla.s.s of the mammalia, for which I propose the name of 'Archencephala.'"*

(* Owen, "Proceedings of the Linnaean Society" London volume 8 page 20.)

The above definition is accompanied in the same memoir by the following note:--"Not being able to appreciate, or conceive, of the distinction between the psychical phenomena of a chimpanzee and of a Boschisman, or of an Aztec with arrested brain-growth, as being of a nature so essential as to preclude a comparison between them, or as being other than a difference of degree, I cannot shut my eyes to the significance of that all-pervading similitude of structure--every tooth, every bone, strictly h.o.m.ologous--which makes the determination of the difference between h.o.m.o and Pithecus the anatomist's difficulty; and therefore, with every respect for the author of the Records of Creation,* I follow Linnaeus and Cuvier in regarding mankind as a legitimate subject of zoological comparison and cla.s.sification."