272 PATHOGENIC BACTERIA. organism is injected subcutaneously into a guinea-pig, a voluminous abscess results. Not long afterward the lym- phatic vessels and glands of the region are the seat of swell- ing and induration, and extensive phlegmons form, which rupture externally and discharge considerable pus. The animal, of course, becomes extremely ill and seems about to die; instead, it slowly recovers its normal condition. In other animals, as the cow and the sheep, the subcu- taneous inoculation results in an abscess relatively less extensive. This ulcerates, then indurates, and seems to disappear, but after the lapse of several weeks or months opens again in the form of a new abscess. In animals which are immune or nearly immune, like the horse, the ass, the dog, and the rabbit, the subcuta- neous inoculation is followed by the formation of a small abscess which speedily cicatrizes. Intraperitoneal inoculation in the guinea-pig gives rise to an appearance resembling tuberculosis. The omentum may be extensively involved and full of softened nodes. The liver, spleen, and kidneys appear full of tubercles, but careful examination will satisfy the observer that the tubercles are only upon the peritoneal surfaces, not in the organs. Intravenous introduction of the cultures produces a condition much resembling general miliary tuberculosis. All the organs contain the pseudo-tubercles in consider- able numbers.