Prof. Owen on the Gorilla, 385 



and accepted by a high geological authority at home*. They cite the 

 experienced Professor of Human Anatomy at Amsterdam as support- 

 ing this view ; but Prof. Owen had failed to find any statement of 

 the grounds upon which it was sustained. In the art. Quadrumana 

 of Todd's " Cyclopaedia of Anatomy," cited by Lartet,f Prof. VroHk 

 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 

 HylobateSf 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 Simice. No details are 

 given to illustrate the proposition even in its more limited appli- 

 cation ; but the minor length of the arms in the Siamang, as com- 

 pared 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 con- 

 comitant 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 ac- 

 quired, 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 

 brain, the deeper and more numerous convolutions of the cerebrum, 

 and the more completely covered cerebellum in the former, unequi- 

 vocally demonstrate the higher organization of the shorter-armed 

 Apes. "In the structure of the brain," writes Vrolik, | in accord- 

 ance with all other comparative anatomists, "they" (Chimpanzee 

 and Orang-utan) "approach the nearest to man." The degree to 

 which the Chimpanzee and Orang so resembled the human type 

 seemed much closer to Cuvier, who knew those great apes only in 

 their immaturity, with their small milk-teeth and precociously de- 

 veloped brain. Accordingly, the anthropoid characters of the Simia 

 satyrus and Simia troglodytes, as deduced from the facial angle and 

 dentition, are proportionally exaggerated in the " Regne Animal." § 

 As growth proceeds, the milk-teeth are shed, the jaws expand, the 

 great canines succeed their diminutive representatives, the temporal 



* Lyell, Sir C. " Supplement to the Fifth Edition of a Manual of Elementary 

 Geology," 1859, p. 15. 



t " Coraptes Rendus de I'Academie des Sciences, Juillet 28, 1856." 

 X Art. Quadrumana, " Cyclopaedia of Anatomy," vol. iv. p. 195. 

 § Ed. 1829, pp. 87, 89. 



Ann, §• Mag, N, Hist. Ser. 3. Vol iv. 35 



