176 FOSSIL KEMAESrS OF MAN. 



the skulls only) show the differences of the skulls from 

 one another when these axes are regarded as relatively 

 fixed lines. 



The dark contours are those of an Australian and of a 

 Negro skull : the light contours are those of a Tartar 

 skull, in the Museum of the Eoyal College of Surgeons ; 

 and of a well developed round skull from a cemetery in 

 Constantinople, of uncertain race, in my own possession. 



It appears, at once, from these views, that the progna- 

 thous skulls, so far as their jaws are concerned, do really 

 differ from the orthognathous in much the same way as, 

 though to a far less degree than, the skulls of the lower 

 mammals differ from those of Man. Furthermore, the 

 plane of the occipital foramen (b c) forms a somewhat 

 smaller angle with the axis in these particular progna- 

 thous skulls than in the orthognathous ; and the like may 

 be slightly true of the perforated plate of the ethmoid — 

 though this point is not so clear. But it is singular to 

 remark that, in another respect, the prognathous skulls 

 are less ape-like than the orthognathous, the cerebral 

 cavity projecting decidedly more beyond the anterior end 

 of the axis in the prognathous, than in the orthognathous, 

 skulls. 



It will be observed that these diagrams reveal an im- 

 mense range of variation in the capacity and relative pro- 

 portion to the cranial axis, of the different regions of the 

 cavity which contains the brain, in the different skulls. 

 !Nor is the difference in the extent to which the cerebral 

 overlaps the cerebellar cavity less singular. A round 

 skull (Fig. 30, Const.) may have a greater posterior cere- 

 bral projection than a long one (Fig. 30, Negro). 



Until human crania have been largely worked out in 

 a manner similar to that here suggested — until it shall be 

 an opprobrium to an ethnological collection to possess a 



