MAN AS THE TYPE OF A DISTINCT ORDER. 



205 



and the Orang, is very remarkable. Again, the distance from this fora- 

 men to the incisor teeth (which is so considerable in the anthropomorphous 

 Simise), compared with its distance from the occiput, is nearly the same in 

 the Negro as in the European : and, as Dr. Prichard remarks, the antero- 

 posterior admeasurement of the basis of the skull is, relatively, very much 

 larger, in the Orang and Chimpanzee, than in Man ; as is strikingly dis- 

 played by the different situation which the zygomatic arch occupies in the 

 plane of the basis of the skull. In Man, the zygoma is included in the 

 anterior half of the basis of the cranium : in the head of the adult Chim- 

 panzee, as well as in that of the Orang, the zygoma is situated in the 

 middle region of the skull, and, in the basis, occupies just one third part 

 of the entire length of its diameter. The extent, besides, of the bony 

 palate, and the greater breadth between the canines than between the 

 last molars, both in the Chimpanzee and Orang, so as to allow of the 

 spreading and want of continuity of the incisors, with respect to each 

 other and to the canines, widely distinguish between the skulls of these 

 animals and those of any of the human race. Both in the Negro and 

 European, the base of the skull, around the foramen magnum, is boldly 

 convex, according to the development of the cerebrum ; whilst, in the 

 " Simiae, the base of the skull is flat, which form is indicative of a curtail- 

 ment of the volume of the brain beneath, in accordance with that of the 

 cerebral hemispheres at their upper and anterior aspect. 



The cancellous mastoid processes, which are so large in the human 

 skull, are scarcely to be discovered in the skulls of the Simiae : these 



178 



179 



Base of human skull. 



Base of skull ofOrang. 



processes are represented, in the Chimpanzee, by a ridge behind each 

 auditory foramen, the internal cellular structure of which, as Professor Owen 



