20 Professor Owen, [Feb. 4, 



by position, diverging from the other toes, in the gorilla, at an^ngle of 

 60 degrees from the axis of the foot. 



Man has 12 pairs of ribs, the gorilla and chimpanzee have 13 

 pairs, the orangs have 12 pairs, the gibbons have 13 pairs. Were the 

 naturalist to trust to this single cliaracter, as some have trusted to the 

 cranio-facial one, and in equal ignorance of the real condition and value 

 of both, he might think that the orangs (Pithecus) were nearer akin 

 to man than the chimpanzee ( Troglodytes^ are. But man has some- 

 times a thirteenth pair of ribs ; and what we term " ribs " are but 

 vertebral elements or appendages common to nearly all the true ver- 

 tebrae in man, and only so called, when they become long and free. 

 The genera Homo, Troglodytes, and Pithecus, have precisely the same 

 number of vertebrae : if Troglodytes, by the development and mobility of 

 the pleurapophyses of the 20th vertebra from the occiput seem to have 

 an additional thoracic vertebra, it has one vertebra less in the lumbar 

 region. So, if there be, as has been observed in the same genus, a differ- 

 ence in the number of sacral vertebrae, it is merely due to a last lumbar 

 having coalesced with what we reckon the first sacral vertebra in man. 



The thirteen pairs of ribs, therefore, in the gorilla and chimpanzee 

 are of no weight, as against the really important characters significative 

 of affinity with the human type. But, supposing the fact of any real 

 value, how do the advocates of the superior resemblance of the 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 firsltbe ascertained by which the 

 genus Homo trenchantly differs Irom the genus Simla, of Linnaeus. 

 To determine these osteal distinctions, the lecturer 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 Hylohates ; 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 com- 

 parisons. 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 diminution 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 chim- 

 panzee the appearance of a more anthropoid character, which really 

 does not belong to it ; which could be as little depended upon in a 



