18 FISTULA AND POLL-EVIL 



is bisected vertically with a central aponeurosis 

 that is attached ventrally to the tuber spinse of 

 the scapula. The anterior part is the trapezius 

 cervicalis and the posterior the trapezius thora- 

 calis. 



The Roof of the Withers 



Together with the skin, the fascia arid the 

 panniculus carnosis, the trapezius muscles may 

 he regarded as the 'Woof of the withers'' 



It is under this roof that typical fistula of 

 the withers develop and beneath which the 

 atypical (traumatic) fistulge burrow in direc- 

 tions of resistance less than that afforded by 

 its dense, aponeurotic character. 



Rhomboideus Thoracalis 



The rhomboideus thoracalis extends from 

 the spinous processes of the second, third, 

 fourth, fifth, sixth and seventh dorsal verte- 

 brae in a downward and outward direction to 

 the mesial face of the scapular cartilage. It 

 constitutes a thick, heavy curtain forming a 

 "second or inner roof of the withers." Com- 

 pared with the structures of a building, it 

 might be said to be a curtain, sagging slightly 

 in the middle, that extends from the comb of 

 the roof to a point on the wall just beneath the 

 plate beam. It is very loosely attached to the 



