THE GREAT CHIMPANZEE. 383 



and has since generally influenced systematic mammalogists in restoring the genuine 

 Troglodytes to the same relative position in regard to the Pithecus Satyrus which the 

 fabulous Homo Troglodytes occupies in the ' Systema Naturae' of Linnaeus. 



The dental and osteological differences between the Chimpanzee and Orang, coupled 

 with other anatomical distinctions brought to light by dissection of specimens that had 

 died in the Society's menagerie, enabled me to present a summary of characters showing 

 the difference between those two tailless Apes to be equivalent to that which Cuvier 

 {loc. cit. p. 90) sanctions as supporting the generic distinction between the Gibbons and 

 the Orangs. So long, therefore, as groups of this value shall continue to retain proper 

 generic or subgeneric names, Troglodytes and Pithecus will remain the signs of such 

 distinctions of the Chimpanzees and Orangs respectively, just as Hylobates is universally 

 used as the sign of the corresponding distinction of the long-armed tailless Apes*. 



Whilst, therefore, the amount and kind of difference between the Chimpanzee and 

 Orang were thus estabhshed, the actual extent to which both deviated from the human 

 structure was made known and illustrated by reference not only to the normally developed 

 skull in different races, but by those rare abnormal examples in idiots in which the 

 development of the cranial part of the human skull is arrested at the point to which it 

 arrives in the Anthropoid Apes (lb. p. 372, Pi. 57 and 58). 



In a subsequent memoir f the order of development and succession of the permanent 

 teeth in the Orang {Pithecus) were described : the differences in the form of the cranium 

 of the adult males of the two kinds of Orang with great canine teeth, inhabiting respec- 

 tively the islands of Sumatra {Pithecus Abelii) and Borneo {Pithecus Wurmbii), were 

 illustrated : some of the dental distinctions between the male and female Pithecus 

 Wurmbii, especially in the relative size of the canines, were pointed out ; and a smaller 

 and more anthropoid species of Orang from Borneo, with canine teeth relativelv shorter 

 than in the female Pithecus Wurmbii, with absolutely smaller molar teeth, but with the 

 superior incisors nearly as large, and the inferior incisors quite as large, as those of the 

 Pithecus Wurmbii, was established on the characters of the skull and dentition. The 

 differences observed in the two skulls belonging, the one to the great Orang of Borneo, 

 and the other to the great Orang of Sumatra, were not deemed to establish satisfactorily 

 their specific distinction ; but with respect to those diff'erences in the proportions of the 

 molar and incisor teeth of a not merely adult but aged skull of the smaller Bornean 

 Orang, as they were superadded to diff'erences of size and figure of the skull itself, 

 greater in degree than the differences between the skulls of the so-called Pithecus 

 Wurmbii and Pithecus Abelii, they were regarded, according to the analogy of correspond- 

 ing characters allowed to establish specific distinctions in other genera of Quadrumana, 



* Professor Andreas Wagner has expressed his opinion, in his admirable Monograph on the Quadrumana, 

 that the osteological differences which divide the Gibbons from the Orangs are greater than those which distin- 

 guish the true Orangs from the Chimpanzees. They are greater in degree, but not in kind. 



t Zool. Trans, vol. ii. p. 165, 1836. 



3q2 



