FISTULA. 
529 
Kraske has made a special study of acute osteomyelitis, 
and reached a positive conclusion that infection may take 
place through abrasions of the skin, through the respiratory 
organs or intestinal mucous membrane, but most commonly 
through the abraded skin. In one case he traces an acute 
attack to infection from a furuncle of the lip. Garre, Braun¬ 
schweig, Schimmelbush, Roth and others have all demon¬ 
strated that healthy skin is not impenetrable to living micro¬ 
organisms. The experiments of Buchner show positively that 
the respiratory organs may furnish an entrance to a variety 
of microscopic germs. There can be no doubt that abrasions 
of either the respiratory or intestinal mucous membranes, or 
of the skin, greatly facilitate their entrance, but it is equally 
certain that their entrance is possible and common when no 
such conditions are offered. 
Locating Factors. —After discussing the bacterial origin, 
sources from which infection may be drawn and mode of en¬ 
trance, there remains the query, what determines the location 
of the pre-fistular abscess ? It has long been a matter of dispute 
whether pathogenic microbes exist in healthy animal tissues. 
I think the view is gaining general support that such condi¬ 
tions are possible, but that these same microbes do not ex¬ 
hibit their pathogenic properties so long as they remain in cir¬ 
culating blood and every body tissue remains healthy. Then 
to furnish the requisite conditions under which these pyogenic 
microbes may exhibit their pathogenic functions, some sus¬ 
ceptible tissue must become injured or diseased. The blood 
or lymphatic fluid must be checked in its flow at that point, 
thromboses be formed, and the microbes be permitted to 
locate and multiply. In other words, to locate pre-fistular 
abscess there must be furnished a loais minoris resist entice, 
which Senn defines as being an area of lessened resistance 
due to a tissue injury, which so changes the tissue that patho¬ 
genic microbes previously present in the circulation become 
arrested, and find favorable conditions for multiplication. 
Huber asserts that several infectious diseases, as tubercular 
ostitis and arthritis, osteomyelitis and pysemia may follow 
trauma in the absence of any possible local external infection. 
