POLL-EVIL 107 
none of the characteristics of vertebrae in gen- 
eral. It articulates by means of diarthrodial 
articulations with the occipital condyles an- 
teriorly and with the odontoid process of the 
axis posteriorly. Its wide expansive dorsal 
surface gives attachment to the muscles to 
which it is related. 
Its wings which extend downward and out- 
ward become gradually thinner and thicken 
again into a roughed heavy border. Each one 
is perforated with a large foramen which gives 
passage to the occipital artery, in its course 
from the carotid to the region of the poll. 
The whole dorsal face is a smooth expanse 
interrupted only by a slight median elevation 
representing the superior spinous process. 
The dersal surface of the atlas is important 
in poll-evil because it sooner or later becomes 
affected with periosteitis and osteitis on ac- 
count of its close relations to the disease process 
in and about the ligamentum nuche. It 
serves as a floor for the abscess cavity from 
which it is often separated only by a carpet of 
granulation tissue attached to the periosteum. 
The awis or second cervical vertebra may be 
said to be the posterior boundary of the poll- 
evil process. It is seldom itself involved in 
disease. Its crest or superior spinous process 
stands above the level of the axis where it serves 
