75 



long-armed gibbons, more nearly related to the genus Homo ? O 

 the broad-breast-boned quadramana, are the knuckle-walkers or 

 the brachiators, i.e. the long-armed gibbons, most nearly and essen- 

 tially related to the human subject 1 ? 



At the first aspect, whether of the entire animal or of the 

 skeleton, the gorilla strikes the observer as being a much more 

 bestial and brutish animal than the chimpanzee. All the features 

 that relate to the wielding of the strong jaws and large canines are 

 exaggerated; the evidence of brain is less; its proper cavity is 

 more masked by the outgrowth of the strong occipital and other 

 cranial ridges. But then the impression so made that the gorilla 

 is less like man, is the same which is derived from comparing a 

 young with an adult chimpanzee, or some small tailless monkey 

 with a full-grown male orang or chimpanzee. Taking the cha- 

 racters that cause that impression at a first inspection of the gorilla, 

 most of the small South American monkeys are more anthropoid ; 

 they have a proportionally larger and more human-shaped cranium, 

 much less prominent jaws, with more equable teeth. 



On comparing the skeletons of the adult males of the gorilla, 

 chimpanzee, orang, and gibbon, the globular cranium of the last, 

 and its superior size compared with the jaws and teeth, seemed to 

 shew the gibbons to be more nearly akin to man than any of the 

 larger tailless apes. And this conclusion had been formed by 

 a distinguished French palaeontologist, M. Lartet, and accepted 

 by a high geological authority at home l . The experienced Professor 

 of Human Anatomy at Amsterdam had been also cited as supporting 

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

 upon which it was sustained. In the art. Quadrumana of Todd's 

 Cyclopaedia, cited by Lartet 2 , Professor Yrolik briefly treats of the 

 osteology of the Quadrumana according to their natural families. 

 In 'a first genus, Simla proper, or ape,' he includes 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 gibbon (Hylobates), 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, Yrolik says, 

 * its skeleton approaches most to that of man,' which may be true 



1 Sir C. Lyell, Supplement to tlie 5th Edition of a Manual of Elementary 

 Geology, 1859, p. 15. 



2 Comptes Rendus de V Academic des Sciences, Juillet 28, 1856. 



