104 PROFESSOR OWEN ON THE OSTEOLOGY OF 



diapophysis is suddenly elongated, as compared with that of the corresponding Hunian 

 vertebra ; the chief difference is seen in the smaller size of the neural canal, and in the 

 greater length, terminal expanse and downward slope of the neural spine. The same 

 difference obtains in the second lumbar vertebra ; the diapophyses are broader and more 

 depressed in the Gorilla ; the upper zygapophyses are more convex in part, not wholly 

 concave as in Man ; a fossa divides them from the metapophyses ; the centrum is as 

 broad as in Man, but is deeper and longer; the neural spine extends more obliquely 

 downwards, and its expanded apex is bifid {fig. 4, ns). In the last lumbar vertebra 

 (fig. 1, 4) the difference is very striking in the minor expanse of the centrum in the Gorilla, 

 especially below, in the much smaller and more depressed form of the neural canal, in 

 the shorter and broader diapophysis, the more distinct metapophysis, in the convex 

 anterior and more approximated posterior zygapophysis, and in the greater length of 

 the centrum. 



[The tendency to a sacral modification of the transverse processes of the last lumbar 

 vertebra is more constant and more marked in the Gorilla than in Man: this, at least, 

 is the result of an examination of four adult skeletons, two male and two female, which 

 have now reached Europe. In the adult, but not aged male skeleton, in the Museum 

 of the Royal College of Surgeons, the right transverse process is the broadest and 

 thickest, but both touch and were syndesmotically attached to the iliac bones. Yet it 

 is plain, that the proper sacrum commences by the succeeding vertebrae ; the homology 

 of the fourth lumbar of the Gorilla with the fifth lumbar of Man is unmistakeable. Tn 

 the skeleton of the older male Gorilla in the Paris Museum the sacral modification 

 of the last lumbar vertebra is complete ; the transverse processes are not only articu- 

 lated to the ilia, but are so expanded as to join and coalesce with the similarly modified 

 parts of the first sacral vertebra. The less expanded transverse processes of the penul- 

 timate lumbar are joined by ligament to the ilia. The spine of this vertebra is distinct : 

 that of the last lumbar has coalesced with the beginning of the strong i-idge formed by 

 the confluent spines of the proper sacral vertebra : and, as the first two of the coccygeal 

 vertebrae have coalesced with each other and with the last sacral vertebra, the sacrum of 

 this old male Gorilla, as characterized by coalescence, includes not less than eight ver- 

 tebrae. In the skeleton of the adult female Gorilla in the Paris Museum the trans- 

 verse processes of the last lumbar vertebra are short, broad and deep, and are joined by 

 ligament to the iliac bones ; but have not coalesced with the sacrum, which consists, as 

 normally, of five vertebrae.] 



The chief differences between the normal lumbar vertebrae of the Gorilla and Man 

 are exemplified in the views of the second lumbar vertebra of the great Ape (PI. XXXV. 

 figs. 3 & 4), and of its homologue the third lumbar vertebra of an adult male Negro 

 {ib. fig. 5). They are, in the Gorilla, the greater length of the centrum ; the greater 

 inclination downwards and less inclination backwards of the diapophysis {d) ; the more 

 upward production of the upper zygapophysis {z), giving greater distinctness to the 



