4 



ZOOLOGY. 



-m— Sckh. 



jxr.h 



supports the skull, -which encloses a cranial cavuy 

 (ScLh.) continuous with a vertebral canal bounded by 

 the vertebrae. Cranial cavity and vertebral canal 

 form together a second body-space, in which are con- 

 tained the brain and spinal cord. 



We wUl now consider the individual parts of the 

 body, beginning with the skeleton. The axis of the 



skeleton is formed by 

 the vertebral column 

 (spine), which is com- 

 posed of flat bones, 

 the vertebrce. A ver- 

 tebra usually consists 

 of (1) the body, which 

 occupies the front ; (2) 

 the arch, which pos- 

 sesses several projec- 

 tions or processes 

 (neural spine, trans- 

 verse processes, ar- 

 ticular processes) and 

 encloses the vertebral 

 canal (W.h.). All 

 mammals have seven 

 neck or cervical ver- 

 tebrce (Fig. 2, 1) ; 

 while the number of 

 the remaining verte- 

 brfe varies according 

 tothe species. Thecer- 

 vical vertebrae, which 

 support the head, are 

 followed by the dorsal 

 or thoracic vertebrce 

 (12 in man, Fig. 2, 2), 

 and these by the 

 strong loin or lumbar vertebrce (5 in man. Fig. 2, 3). 

 Cervical, thoracic, and lumbar vertebrfe are movable 



. 1. — Schematic Longitudinal Section of 

 the Hnman Body, 



