198 HUMAN FOSSILS 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 prognathous 

 skulls than in the orthognathons; 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 de- 

 cidedly 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 immense range of variation in the capacity and 

 relative proportion to the cranial axis, of the 

 different regions of the cavity which contains the 

 brain, in the different skulls. Nor is the differ- 

 ence in the extent to which the cerebral overlaps 

 the cerebellar cavity less singular. A round 

 skull (Fig. 30, Const.} may have a greater posterior 

 cerebral 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 single skull which is not 

 bisected longitudinally until the angles and 

 measurements here mentioned, together with a 



