PATHOGENESIS 119 
explain at the present time. We believe, how- 
ever, that infectious diseases such as influenza 
or strangles play an important role in the 
course if not also in the original cause. Where 
influenza is rampant so will poll-evil and fis- 
tula of the withers be found rampant. Weare, 
however, not today justified as laying this 
down as an absolute law, as subsequent inves- 
tigations no doubt may show that its cause 
is more specific. 
