VERTEBEAL COLUMN 



99 



end of the body of the first vertebra with the cephalic end of the body 

 of the second, and of the caudal end of the body of the second with 

 the cephalic end of the body of the third. The cephalic end of the 

 body of the first sacral vertebra articulates with the caudal end of the 

 last lumbar, and the caudal end of the body of the third sacral 

 articulates with the cephalic end of the first tail vertebra. 



(2) The cephalic and caudal articular processes become firmly 

 united, forming on the dorsal surface of the sacrum four tubercles, 



FIG. 70. 



VERTEBRAL COLUMN. 



Lumbar 



Sacral. 



THE AXIAL SKELETON. (Greatly reduced.) 



two on each side. Each of the cephalic pair represents the caudal 

 process of the first vertebra and the cephalic process of the second, 

 and each of the caudal pair represents the caudal process of the 

 second and the cephalic process of the third. The cephalic articular 

 processes of the first and the caudal articular processes of the third 

 are free, and become the cephalic and caudal processes of the sacrum, 

 articulating with the caudal and cephalic articular processes of the last 

 lumbar and first tail vertebrae, respectively. 



(3) The third union which takes place in the sacral vertebrae is 

 between contiguous edges of the laminae. 



(4) The fourth and most characteristic change affects the trans- 

 verse processes of all three vertebra?, which on each side are all joined 

 together into a common continuous mass. Those of the first vertebrae 

 are developed into large lateral masses, whereof the cephalo-caudal 

 and dorso-ventral diameters are much greater than those diameters of 

 the body of the vertebra. The transverse processes of the second ver- 

 tebra are low, but are prolonged in a cephalic direction to join the 

 lateral masses, and in a caudal direction to join the ends of the trans- 



