The Antiquity of Man Part 43

(* The late Archbishop of Canterbury, Dr. Sumner.)

[Ill.u.s.tration: Figure 54, 55 and 56. Brain Of Chimpanzee]

(FIGURE 54. UPPER SURFACE OF BRAIN OF CHIMPANZEE, DISTORTED (FROM SCHROEDER VAN DER KOLK AND VROLIK.) Scale half the diameter of the natural size.

A. Left cerebral hemisphere.

B. Right cerebral hemisphere.

C. Cerebellum displaced.)

(FIGURE 55. SIDE VIEW OF BRAIN OF CHIMPANZEE, DISTORTED (FROM SCHROEDER VAN DER KOLK AND VROLIK.) Scale half the diameter of the natural size.

e. The extension of the displaced cerebellum beyond the cerebrum at d.)

(FIGURE 56. CORRECT SIDE VIEW OF CHIMPANZEE'S BRAIN (FROM GRATIOLET).

Scale half the diameter of the natural size.

d. Backward extension of the cerebrum, beyond the cerebellum at e.

f. Fissure of Sylvius.)

[Ill.u.s.tration: Figure 57 and 58. Chimpanzee and Human Brain]

(FIGURE 57. CORRECT VIEW OF UPPER SURFACE OF CHIMPANZEE'S BRAIN (FROM GRATIOLET), in which the cerebrum covers and conceals the cerebellum.

Scale half the diameter of the natural size.)

(FIGURE 58. SIDE VIEW OF HUMAN BRAIN (FROM GRATIOLET), NAMELY, THAT OF THE BUSHWOMAN CALLED THE HOTTENTOT VENUS.

Scale half the diameter of the natural size.

A. Left cerebral hemisphere.

C. Cerebellum.

ff. Fissure of Sylvius.)

To ill.u.s.trate the difference between the human and Simian brain, Professor Owen gave figures of the negro's brain as represented by Tiedemann, an original one of a South American monkey, Midas rufima.n.u.s, and one of the chimpanzee (Figure 54), from a memoir published in 1849 by MM. Schroeder van der Kolk and M. Vrolik.*

(* "Comptes rendus de l'Academie Royale des Sciences"

Amsterdam volume 13.)

The selection of Figure 54 was most unfortunate, for three years before, M. Gratiolet, the highest authority in cerebral anatomy of our age, had, in his splendid work on "The Convolutions of the Brain in Man and the Primates" (Paris, 1854), pointed out that, though this engraving faithfully expressed the cerebral foldings as seen on the surface, it gave a very false idea of the relative position of the several parts of the brain, which, as very commonly happens in such preparations, had shrunk and greatly sunk down by their own weight.*

(* Gratiolet's words are: "Les plis cerebraux du chimpanze y sont fort bien etudies, malheureus.e.m.e.nt le cerveau qui leur a servi de modele etait profondement affaisse, aussi la forme generale du cerveau est-elle rendue, dans leurs planches, d'une maniere tout-a-fait fausse." Ibid. page 18.)

Antic.i.p.ating the serious mistakes which would arise from this inaccurate representation of the brain of the ape, published under the auspices of men so deserving of trust as the two above-named Dutch anatomists, M.

Gratiolet thought it expedient, by way of warning to his readers, to repeat their incorrect figures (Figures 54 and 55), and to place by the side of them two correct views (Figures 56 and 57) of the brain of the same ape. By reference to these ill.u.s.trations, as well as to Figure 58, the reader will see not only the contrast of the relative position of the cerebrum and cerebellum, as delineated in the natural as well as in the distorted state, but also the remarkable general correspondence between the chimpanzee brain and that of the human subject in everything save in size. The human brain (Figure 58) here given, by Gratiolet, is that of an African bushwoman, called the Hottentot Venus, who was exhibited formerly in London, and who died in Paris.

Respecting this striking a.n.a.logy of cerebral structure in Man and the apes, Gratiolet says, in the work above cited: "The convoluted brain of Man and the smooth brain of the marmoset resemble each other by the quadruple character of a rudimentary olfactory lobe, a posterior lobe COMPLETELY COVERING THE CEREBELLUM, a well-defined fissure of Sylvius (ff, Figure 56), and lastly a posterior horn in the lateral ventricle.

These characters are not met with together except in Man and the apes."*

(* Gratiolet, ibid. Avant-propos page 2 1854.)

In reference to the other figure of a monkey given by Professor Owen, namely, that of the Midas, one of the marmosets, he states, in 1857 as he had done in 1837, that the posterior part of the cerebral hemispheres "extends, as in most of the quadrumana, over the greater part of the cerebellum."*

(* "Proceedings of the Linnaean Society" 1857 page 18 note, and "Philosophical Transactions" 1837 page 93.)

In 1859, in his Rede Lecture, delivered to the University of Cambridge, the same ill.u.s.trations of the ape's brain were given, namely, that of the Midas and the distorted one of the Dutch anatomists already cited (Figure 54).*

(* See Appendix M.)

Two years later, Professor Huxley, in a memoir "On the Zoological Relations of Man with the Lower Animals," took occasion to refer to Gratiolet's warning, and to cite his criticism on the Dutch plates;* but this reminder appears to have been overlooked by Professor Owen, who six months later came out with a new paper on "The Cerebral Character of Man and the Ape," in which he repeated the incorrect representation of Schroeder van der Kolk and Vrolik, a.s.sociating it with Tiedemann's figure of a negro's brain, expressly to show the relative and different extent to which the cerebellum is overlapped by the cerebrum in the two cases respectively.** In the ape's brain as thus depicted, the portion of the cerebellum left uncovered is greater than in the lemurs, the lowest type of Primates, and almost as large as in the rodentia, or some of the lowest grades of the mammalia.

(* Huxley, "Natural History Review" January 7, 1861 page 76.)

(** "Annals and Magazine of Natural History" volume 7 1861 page 456 and Plate 20.)

When the Dutch naturalists above mentioned found their figures so often appealed to as authority, by one the weight of whose opinion on such matters they well knew how to appreciate, they resolved to do their best towards preventing the public from being misled. Accordingly, they addressed to the Royal Academy of Amsterdam a memoir "On the brain of an Orang-outang" which had just died in the Zoological Gardens of that city.*

(* This paper is reprinted in the original French in the "Natural History Review" volume 2 1862 page 111.)

The dissection of this ape, in 1861, fully bore out the general conclusions at which they had previously arrived in 1849, as to the existence both in the human and the simian brain of the three characters, which Professor Owen had represented as exclusively appertaining to Man, namely, the occipital or posterior lobe, the hippocampus minor, and the posterior cornu. These last two features consist of certain cavities and furrows in the posterior lobes, which are caused by the foldings of the brain, and are only visible when it is dissected. MM. Schroeder van der Kolk and Vrolik took this opportunity of candidly confessing that M. Gratiolet's comments on the defects of their two figures (Figures 54 and 55) were perfectly just, and they expressed regret that Professor Owen should have overstated the differences existing between the brain of Man and the Quadrumana, "led astray, as they supposed, by his zeal to combat the Darwinian theory respecting the transformation of species," a doctrine against which they themselves protested strongly, saying that it belongs to a cla.s.s of speculations which are sure to be revived from time to time, and are always "peculiarly seductive to young and sanguine minds."*

(* Ibid. page 114.)

As the two memoirs before alluded to by us, the one by Mr. Darwin on "Natural Selection," and the other by Mr. Wallace "On the Tendency of Varieties to depart indefinitely from the original Type," did not appear till 1858, a year after Professor Owen's cla.s.sification of the mammalia, and as Darwin's "Origin of Species" was not published till another year had elapsed, we cannot accept the explanation above offered to us of the causes which led the founder of the sub-cla.s.s Archencephala to seek for new points of distinction between the human and simian brains; but the Dutch anatomists may have fallen into this anachronism by having just read, in the paper by Professor Owen in the "Annals," some prefatory allusions to "the Vestiges of Creation," "Natural Selection, and the question whether man be or be not a descendant of the ape."

The number of original and important memoirs to which this discussion on the cerebral relations of Man to the Primates has already given rise in less than five years, must render the controversy for ever memorable in the history of Comparative Anatomy.*

(* Rolleston, "Natural History Review" April 1861. Huxley, on "Brain of Ateles" "Proceedings of the Zoological Society"

1861. Flower, "Posterior Lobe in Quadrumana" etc., "Philosophical Transactions" 1862. Id. "Javan Loris"

"Proceedings of the Zoological Society" 1862. Id. on "Anatomy of Pithecia" ibid. 1862.)

In England alone, no less than fifteen genera of the Primates (the subjects having been almost all furnished by that admirable inst.i.tution the Zoological Gardens of London) have been anatomically examined, and they include nearly all the leading types of structure of the Old and New World apes and monkeys, from the most anthropoid form to that farthest removed from Man; in other words, from the Chimpanzee to the Lemur. These are:--

Troglodytes (Chimpanzee).

Pithecus (Orang).

Hylobates (Gibbon).

Semnopithecus.

Cercopithecus.

Macacus.

Cynocephalus (Baboon).

Ateles (Spider Monkey).

Cebus (Capuchin Monkey).

Pithecia (Saki).

Nyctipithecus (Douricouli).

Hapale (Marmoset).

Otolicnus.

Stenops.

Lemur.