148 



LECTURE VI. 



degrees. We sometimes find in young Negro skulls, as well 

 as in skulls of idiots (see figure 48, p. 145), traces of the max- 

 illary suture ; and, moreover, the sutures in apes are obliterated 

 at various ages. Thus the sutures remain open in the gorilla 

 to an advanced age, and are only closed in the oldest skulls, 

 Vfhilst in the chimpanzee the union takes place immediately 

 after the change of teeth. I have now before me skulls of the 

 same age, of the genus cehus, in which the teeth had just been 

 shed. In one genus {cehus apella) the intermaxillary is plainly 

 separated; in the other {cehus alhifrons) the union with the 

 maxillary is so perfect that there is no trace of any suture. 



Fig. 49. Base of the Skull of Cehus Apella, with the Maxillary Suture. 



