54 FISTULA AND POLL-EVIL 



sore. The local dry gangrene called sit fast at 

 the level of the collar seat is one of the com- 

 monest causes as well as the initial lesion of the 

 very gravest of fistulas of this kind. Here the 

 thick, folded, hair-clothed skin and also the 

 thick pad of connective tissue underlying the 

 mane first undergo gangrene from collar pres- 

 sure. Some of these sitfasts involve only the 

 skin (superficial sitfast), others invade into 

 the connective tissue and still others entirely 

 through it, exposing the ligamentum nuchse 

 beneath. From this exposure the process 

 marches on along the course of the ligament 

 and there sows the seed of a chronic state pre- 

 cisely the same as fistula from other causes, 

 and requiring the same remedial measures. In 

 fact, it is our experience that fistula of this 

 origin are the most stubborn of all. 



Once seated in the ligament and bones, 

 atypical fistula is identical with the one having 

 its origin in a pre-existing cyst (typical fistula) 

 and will henceforth undergo the same course of 

 successive abscess and tract formation. Ab- 

 scesses form, burrow to the surface, discharge 

 for a time, heal up, gather again and burst at 

 another point, and this chain of events may re- 

 cur indefinitely. During the formation of a 

 new abscess there is local pain, distressed move- 

 ments, fever and a general indisposition just 



