STRUCTURE OF THE VERTEBRATES 



151 



Vertebral Regions. The vertebrae of the land vertebrates 

 can be divided into five more or less distinct regions: (1) the 

 cervical, or neck; (2) the thoracic, bearing the pleural ribs; (3) 

 the lumbar, lying in the lower abdominal region; (4) the sacral, 

 to which the pelvic girdle attaches; and (5) the caudal, or tail, 

 vertebrae. 



Cervical vertebrae. In the lower forms these are only slightly 

 modified from the more posterior ones. The higher reptiles show 

 definite differentiation, connecting the primitive type and the 



O ft^ 



Sacrum 



Coccyx 



Fig. 87. Vertebral Regions. The spinal column of man with vertebrae 

 from the different body regions. 



