330 



THE MAINTENANCE OF THE INDIVIDUAL 



mammals are fused into a single occipital hone. Further study of a 

 series of forms from fish to man would furnish remarkable evidences 

 of homology besides emphasizing the interpretative importance of 

 the study of comparative anatomy. 



parietal 



temporal... 

 YTCCSal 



--frontal 



V L 1 u:m'vm r — ^^<2-noicC 



■^ 1 "^^^is^y/ \ loccriTTial 



Wi\ *^ -^^ incclccr' 



■<-/^ ■mccicjllcc 



mancCible 



parietal 



temponxl.. 

 occipital.. 



Tnasto\di process../ / 

 styloid process.../ 



frontal 

 " ' ..-.ethynoid 



nccsocl 



— lacrimal 

 mcclcc-T' 



<- . fe> nxxjcilloL 



ynarzdible- 



Bones of a human skull. (After Walter.) 



The skull bones of man are frequently divided into cranial bones, 

 which surround the brain itself, and those which are designated as 

 facial hones. 



The remainder of the axial skeleton is composed of the vertebral 

 column and its associated bones. In aquatic forms hke the fishes, 

 this part of the axial skeleton is comparatively unspecialized, being 

 divisible into the rib-bearing vertebrae of the trunk, and those without 

 ribs, called caudal vertebrae, which go to make up the tail. With 

 the evolution of land animals, protection of the under side of the 

 body became essential and therefore a ''thoracic basket" was de- 



I 



