710 AFRICAN GAME ANIMALS 



less solid hoof which shows evidence of three or four of the 

 toes in the nail-like division on its margin. Placed almost 

 immediately above the hoof we find the ankle, which occu- 

 pies a position somewhat similar to that in man and the apes. 

 This arrangement gives the foot great flexibility and enables 

 the elephant to perform many movements of which the 

 hoofed mammals are quite incapable. The head is im- 

 mensely enlarged so as to support the tusks or canine teeth, 

 the enormous size of which is a further peculiarity of ele- 

 phants. In order to increase the size of the skull so as to 

 give greater surface for muscular attachment, the occipital 

 and parietal bones have been increased greatly in extent 

 and thickness by the development of sinuses having a 

 light honeycomb structure. The brain case has in this 

 way attained a thickness of some fifteen or twenty inches, 

 and it is this great mass of bony tissue surrounding the 

 brain which makes the elephant so difficult an animal to 

 kill, owing to the diflFiculty of locating the brain. The bony 

 expansion of the skull is chiefly upward, over the occipital 

 portion, in the form of a great dome, which is cut off abruptly 

 at the back so as to build a great wall for the attachment 

 of the muscles which move the head. A further striking 

 peculiarity of the skull is the expansion of the premaxillary 

 bones into great sheaths for the support of the immense 

 tusks. The elephants also show marked specialization in 

 the structure of their molar or cheek-teeth. These in the 

 true elephants are made up of a series of folds of enamel and 

 dentine, which are bound together by a cement layer form- 

 ing a tooth with a very long crown, a foot or more in length 

 and of great height, so that it can withstand an immense 

 amount of wear. Only one or part of two teeth are in use 



