42 IISTULA AND POLL-EVIL 



as is seen in some cases of fistula long before 

 infection has entered into the situation. 



Sunimarizing the condition during the sac- 

 cular stage we find a sac containing a sero- 

 fibrinous, sterile exudate, that may be large 

 and surrounded by a thin capsule or small and 

 enclosed in a very thick mass of connective tis- 

 sue. Between these two extremes we find the 

 intermediate varieties — for example, one the 

 size of a child's head containing a quart of 

 fluid and encapsulated with a fibrous envelope 

 one incli in thickness ; another the size of a foot- 

 ball with only a very thin wall; and finally, a 

 rare case with a very insignificant cavity sur- 

 rounded with a great volume of connective 

 tissue. Pathologically all of these are similar, 

 they differ only in the relative quantities of 

 the different elements entering into their con- 

 stituent parts. 



During this stage fistula is a benign disease. 

 It is not as yet infectious. There is no syste- 

 matic disorder. The patient suffers no appar- 

 ent inconvenience. Its general health is 

 undisturbed. 



Until now the process belongs to an order of 

 pathological conditions no more understood 

 than the growth of tumors. In fact, it re- 

 sem])les tumor and cyst formation in all 

 respects. It is but cellular activity around a 



