THE VERTEBRAL COLUMN. 5 
Differential Characters of the Thoracic Vertebre (Fig. 4). 
—Following the thoracic vertebrz 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. 
; 4, caudal articular pro- 
¢, transverse costal facets; d, intervertebral 
Fic. 4,—THORACIC VERTEBR&, SIDE VIEW. 
; 6, cranial articular processes; 
; f; accessory processes; g, mammillary processes 
Ss processes 
costal facets 
a, spinow 
foramina; ¢, 
cesses. 
The dorsoventral measurements remain nearly the same. 
The costal facets (Fig. 4, ¢) shift caudad so that on the 
eleventh, twelfth, and thirteenth thoracic vertebre each lies 
entirely on the cranial end of its centrum, while the caudal end 
