102 VETERINARY SURGICAL THERAPEUTICS. 
through tissues (projectiles, needles, nails and other sharp metallic 
bodies swallowed by cattle, etc). The pathogeny of some varieties ot 
abscesses (critical or sudden) is yet imperfectly known. 
Suppuration does not establish itself with the same facility in the 
various domestic species; under the head of “pyogenic aptitude,” or 
the frequency of abscesses, these species are arranged in the following 
order: horses, sheep, swine, dogs, cats and cattle. 
Among horses, warm and cold abscesses of every size are very com-. 
mon. Among cattle, they are undoubtedly less frequent, less rapid in 
their development, and ordinarily are surrounded by a thick, hardened. 
layer ; although among young animals principally acute diffuse abscesses. 
are also observed. Among dogs, diffused abscesses, “in sheets” (ex 
nappe), with bloody pus and with copious cedema, are frequent. 
The bacteriological researches of the last twenty-years, especially those- 
of Rosenbach, Ogston, Strauss, Roser, Socin and Garré, have shown be- 
yond a doubt the microbic origin of surgical suppurations. All phleg-- 
masiz which bring on suppuration are the work of pyogenic microbes.. 
The staphylococcus albus and aurens, the streptococcus pyogenis, and_ 
that of Schutz (microbe of distemper), are the most frequent. The 
yellow staphylococcus of Babes, the citrinus, the foetid dacillus pyogenis 
of Passet, the pyogenic microbe of Pasteur, daczlus coli, and several 
others, whose presence has been detected in the pus of some abscesses, 
have a less important part to play. According to Lucet, among cattle, 
ordinary abscesses are due to special micro-organisms. 
The pyogenic agents penetrate the tissues through the presence of a 
wound or the interruption of the continuity of the epithelium or- 
epidermis; often, also, they are carried into them by sharp substances. 
Suppuration does not unavoidably follow in all cases where the animal 
tissues are thus invaded by these microbes. Unless there is additional 
help (local anzemia and alterations of anatomical elements), “ positive- 
inoculations ” ordinarily require a large number of microbes. Fehleisen 
tells us that sometimes one cubic centimeter of a culture of staphy-- 
lococci or of streptococci is necessary to bring on suppuration. Wat-. 
son Cheyne estimates that for an abscess in the rabbit—an animal. 
whose “ pyogenic aptitude” is wel] marked—z250 millions of cocci are 
required to make the tissues react, and Bujwid, in order to reach the 
same results, had to inject several millions of staphylococci. 
Several authors (Ponfick, Gravitz, de Bary, de Christmas) have suc-- 
ceeded in bringing on suppuration in subjects from among certain 
species of animals by injecting aseptically, under the skin or in the eye, 
amicrobic. irritating substances (nitrate of silver, mercury, or oil of 
turpentine), or sterilized cultures of pyogenic microbes. It has beem 
