PATHOGENESIS AT 
tures and thus creates a less favorable con- 
dition. ; 
The duration of this stage like the former 
one is variable. If the infection is acute and the 
cyst wall thin, the abscess may ripen and burst 
in a few days, while on the other hand if less 
virulent and incarcerated in a thick wall, point- 
ing may be delayed for weeks and even months. 
When the abscess has once found a surface 
exit and has discharged its contents, the disease 
has passed into an entirely different stage, and 
for a time the systemic condition improves. 
3. Fistulous Stage. This is fistula of the 
withers. Heretofore the condition was fistula 
only in name, now it is a reality. Heretofore 
the course of the disease was guided solely by 
internal influences, now it is exposed also to 
secondary infections from without. It does not 
matter whether the pointing was spontaneous 
or whether an aperture was made artificially, 
we now have to deal with a deep-seated cavity 
that communicates freely with the outside 
where reinfection will continue to occur, and to 
make matters still worse the drainage is seldom 
good enough to evacuate the contents entirely. 
By remaining full of pus the cavity becomes a 
fertile field for microbian growth and cicatrizes 
very slowly. The pus-soaked walls of the cav- 
ity becoming carpeted with undulating indol- 
