106 THE STKUCTUKE OF THE HOESE. 



the brain j and a facial part, for the support of the 

 organs of sight, taste, and smell, and of those con- 

 cerned in seizing and masticating the food. 



The skull of a man (Fig. 15) and the skull of a 

 horse (Fig. 16) are composed of exactly the same 

 number of bones, having the same general arrange- 

 ment and relation to each other. Not only the in- 

 dividual bones, but every ridge and surface for the 

 attachment of muscles, and every hole for the pas- 

 sage of artery or nerve, seen in the one can be traced 

 in the other. Yet they differ remarkably in general 

 aspect. The difference mainly lies in this : in man 

 the brain-case is very large and the face of relatively 

 minute proportions. In the horse, on the other hand, 

 the brain is extremely reduced, and the face, espe- 

 cially the mouth, of enormous size. In other words, 

 the characteristic form of man's head is chiefly due 

 to his great brain, that of the horse to the compara- 

 tively large development of the apparatus for mas- 

 ticating his food. 



Taking the different regions of the horse's skull 

 (Fig. 16) into closer consideration, and beginning at 

 the hinder, or " occipital " end, we may observe the 

 rounded, almost polished surface of the condyles (oc), 

 already mentioned, which, fitting accurately into the 

 corresponding depressions of the atlas, and in life 

 covered with a soft, perfectly smooth layer of carti- 



