THE ANIMAL BODY 



143 



ns 



whole arise PROCESSES for movable articulation with its 

 neighbors, the attachment of muscles, etc. Between the 

 vertebrae of the Mammals are 

 cushions of cartilage which ab- 

 sorb shock. (Fig. 79.) 



In some forms, RIBS are at- 

 tached to the transverse pro- 

 cesses of certain vertebrae. 

 These extend outward and down- 

 ward within the body wall, and 

 become attached in the mid- 

 ventral line to the breast bone 

 (STERNUM). Thus, in the adult 



of thp hip-hpr Vprtphrafps thp FlG- 79 -~ A tv P ical human ver- 



eS ' ' tebra (tenth thoracic) viewed from 



Series Of Centra Of the Vertebrae the dorsal surface. C, centrum; lam, 



. . . ped, neural arch; 7i.s, neural spine; 



COme tO OCCUpy the position prez> ant erior articulating process; 



formerly held by the notochord; tr ' transverse P rocess ; * neural 



canal through which the spinal cord 

 While above, the neural arches passes. (From Walter, after Spalte- 



encircle the NEURAL CANAL con- 

 taining the spinal cord; and below, the transverse pro- 

 cesses, ribs, and sternum surround the anterior portion of 

 the coelom. (Fig. 75.) 



The Vertebrate head, containing the anterior end of the 

 alimentary and neural canals, the brain, and the chief sense 

 organs, is protected in the lower Fishes by a case of cartilage. 

 In higher forms the cartilage is replaced by a bony SKULL 

 which articulates with the first vertebra of the backbone. 

 JAWS, or supporting structures of the rnouth, are attached 

 to the skull. 



The skull, vertebral column, ribs, and sternum together 

 comprise the AXIAL skeleton, from which is suspended the 

 APPENDICULAR skeleton, or bony frame-work of the paired 

 appendages. This is relatively simple in the anterior (pec- 



