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-