AND AFFINITIES OF THE GORILLA. 253 



Monkeys are more anthropoid than it ; they have a proportionally larger and more 

 human-shaped cranium, much less prominent jaws, with more equable teeth. 



In the skeletons of the adult males of the Gorilla, Chimpanzee, Orang, and Gibbon, 

 it may be remarked that the globular cranium of the last, and its superior size com- 

 pared with the jaws and teeth, seem to show the Gibbons to be more nearly akin to 

 Man than are the larger tailless Apes ; and this conclusion has been adopted by a 

 distinguished French palaeontologist, M. Lartet, and accepted by a geological authority 

 at home'. They cite the experienced Professor of Human Anatomy at Amsterdam as 

 supporting this view ; but I have failed to find any statement of the grounds upon 

 which it was sustained. In the article " Quadrumana " of Todd's ' Cyclopaedia of Ana- 

 tomy,' cited by Lartet^, Prof. Vrolik briefly treats of the osteology of the Quadrumana 

 according to their natural families. In " a first genus, Simia proper, or Ape," he in- 

 cludes the Chimpanzee or Orang, noticing some of the chief points by which these 

 Apes approach the nearest to Man. He next goes to " the second genus, the Gibbons " 

 (Hylobates) ; he notices their ischial callosities, and the nearer approach of their molars, 

 in their rounded form, to the teeth of Carnivora than the molars of the genus Simia. 

 Then, comparing the Siamang with other species of Hylobates, Vrolik says, "its skeleton 

 approaches most to that of Man " — which may be true in comparison with other Gibbons, 

 but certainly is not so as respects the higher Simia. No details are given to illustrate 

 the proposition even in its more limited application ; but the minor length of the arms 

 in the Siamang, as compared with Hylobates lar, was probably the character in 

 point. 



The appearance of superior cerebral development in the Siamang and other long- 

 armed Apes is due to their small size and the concomitant feeble development of their 

 jaws and teeth. The same appearance makes the small platyrrhine Monkeys of South 

 America equally anthropoid in their facial physiognomy, and much more human-like 

 than are the great Orangs and Chimpanzees. It is an appearance which depends upon 

 the precocious growth of the brain as dependent on the law of its development. In all 

 Quadrumana the brain has reached its full size before the second set of teeth is acquired 

 — almost before the first set is shed. If, however, a young Gorilla, Chimpanzee, or 

 Orang be compared with a young Siamang of corresponding age, the absolutely larger 

 size and better shape of the brain, the deeper and more numerous convolutions of the 

 cerebrum, and the more completely covered cerebellum in the former, unequivocally 

 demonstrate the higher organization of the shorter-armed Apes. " In the structure of the 

 brain," writes Vrolik'^, in accordance with all other comparative anatomists, " they " 

 (Chimpanzee and Orang-utan) " approach the nearest to Man." The degree to which 

 the Chimpanzee and Orang so resemble the Human type seemed much closer to Cuvier, 



' Sir C. Lyell, ' Supplement to the Fifth Edition of a Manual of Elementary Geology,' 1859, p. 15. 

 ' Comptes Rendus de I'Acad^mie des Sciences, Juillet 28, 1856. 

 ' Art. Quadrumana, 'Cyclopaedia of Anatomy,' vol. iv. p. 195. 



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