THE BONES. 21 



FlG. 5. The Skull. 1, 2, 3, 4, 5, bones of the skull proper ; 6, upper jaw; 

 7, cheek bone ; 8, lachrymal bone ; 9, nasal bone ; 10, lower jaw. 



10. The Skull. The bones of the skull are so constructed 

 as to make an admirable case for enclosing the brain. It also 

 lodges and protects the organs of special sense, namely, sight, 

 smell, taste and hearing. When the head receives a severe 

 blow, unless it is very direct, the rounded shape causes the 

 weapon to glance off without injury to the brain itself. Even 

 a bullet may be turned from its course, and pass around the 

 skull without penetrating the bone. Besides being round, 

 the skull affords a further protection to the brain by being 

 made up of an outer and inner table of hard, firm bone, 

 closely united by a spongy layer. In the more exposed parts 

 these plates are thickened and the outer layer is considerably 

 separated from the inner, so that blows severe enough to 

 break the outer may not injure the inner or disturb the brain, 

 spongy packing also helps to deaden the blow. 



