210 AA'XHKOPOID APES. 



CHAPTER IV. 



ON VARIETIES IN THE FORM OF ANTHROPOIDS. 



Up to recent times it was generally supposed that 

 there was only one species of gorilla, and the differ- 

 ences in the structure of the skeleton and of the 

 external body which were observed in the several 

 specimens under examination, were either regarded 

 as the expression of a purely individual variation 

 or as due to differences in age and sex. Not long 

 ago Alix and Bouvier obtained from Landana on the 

 Congo the skeleton and skin of an aged female 

 gorilla, which had been killed by Lucan and Petit 

 in the village of the negro chief Mayema, on the 

 Kuilu river in 4° 35' south latitude. This speci- 

 men was of less bulk than the common gorilla 

 {Gorilla Oina), and its head was comparatively small. 

 The occipito-temporal crest, or transverse crest of the 

 occiput, was much more strongly developed in this 

 animal and the temporal fossae were deeper. That part 

 of the pkuU which extends behind the supra-orbital 

 arches was narrower,and so also was the space between 

 the eyes. The keel-shaped prominence rising in the 



