THE VERTEBRAL COLUMN. 5 



Differential Characters of the Thoracic Vertebra (Fig. 4). 

 —Following the thoracic vertebrae caudad there is to be seen 

 a gradual increase in the size of the centra brought about by 

 an increase in their craniocaudal and transverse measurements. 



The dorsoventral measurements remain nearly the same. 

 The costal facets (Fig. 4, c) shift caudad so 'that on the 

 eleventh, twelfth, and thirteenth thoracic vertebra; each lies 

 entirely on the cranial end of its centrum, while the caudal end 



