Prof. Owen on the Gorilla. 389 



The thirteen pairs of ribs, therefore, in the Gorilla and Chimpan- 

 zee, are of no weight, as against the really important characters sig- 

 nificative of affinity with the human type. But, supposing the fact 

 of any real value, how do the advocates of the superior resemblance 

 of the Siamang's or Gibbon's skeleton to that of man dispose of the 

 thirteenth pair of ribs ? 



In applying the characters of the skull to the determination of the 

 important question at issue, those must first be ascertained by which 

 the genus Hono trenchantly differs from the genus Simia, of Lin- 

 naeus. To determine these osteal distinctions, the author stated 

 that he had compared the skulls of many individuals of different 

 varieties of the human race together with those of the male, female, 

 and young of species of Troglodytes^ Pithecus^ and Hylobates ; 

 Professor Owen referred to his * Catalogue of the Osteological Series 

 in the Museum of the Royal College of Surgeons,' 4to, 1853, for 

 the detailed results of these comparisons. On the present occasion 

 he would restrict himself to a few of these results. 



The first and most obvious differential character is the globular 

 form of the brain-case, and its superior relative size to the face, 

 especially the jaws, in man. But this, for the reasons he had already 

 assigned, is not an instructive or decisive character, when comparing 

 quadrumanous species, in reference to the question at issue. It is 

 exaggerated in the human child, owing to the acquisition of its full, 

 or nearly full size, by the brain, before the jaws have expanded to 

 lodge the second set of teeth. It is an anthropoid character in 

 which the Quadrumana resemble man, in proportion to the dimi- 

 nution of their general bulk. If a Gorilla, with milk-teeth, have a 

 somewhat larger brain and brain-case than a Chimpanzee at the same 

 immature age, the acquisition of greater bulk by the Gorilla, and of a 

 more formidable physical development of the skull, in reference to the 

 great canines in the male, will give to the Chimpanzee the appearance 

 of a more anthropoid character, which really does not belong to it, — 

 which could be as little depended upon in a question of precise affi- 

 nity as the like more anthropoid characters of the female, as com- 

 pared with the male. Gorilla or Chimpanzee. 



Much more important and significant were the following cha- 

 racters of the human skull : — the position and plane of the occipital 

 foramen ; the proportional size of the condyloid and petrous pro- 

 cesses ; the mastoid processes, which relate to balancing the head 

 upon the trunk in the erect attitude ; the small premaxillaries and 

 concomitant small size of the incisor teeth, as compared with the 

 molar teeth. The latter character relates to the superiority of the 

 psychical over the physical powers in man : it governs the feature in 

 which man recedes from the brute ; as does also the prominence of 

 the nasal bones in most, and in all the typical, races of man. The 

 somewhat angular form of the bony orbits, tending to a square, 

 with the corners rounded off, is a good human character of the 

 skull, which is difficult to comprehend as an adaptive one, and 

 therefore the better in the present inquiry. The same may be said 

 of the production of the floor of the tympanic or auditory tube into 

 the plate called " vaginal." 



