Pathogenic Bacteria

MOUSE-SEPTICEMIA. 429

The guinea-pig, which is-generally the victim of labora-
tory experiments, is not susceptible to it Field- and
wood-mice, cattle, horses asses, dogs, cats, chickens, and
geese are immune.

When mice are inoculated with a pure culture they
soon become ill, lose their appetite, mope in a corner,
and are not readily disturbed. As the disease becomes
worse they assume a sitting posture with the back much
bent; the eyelids are glued together by adhesive pus; and
when death comes to their relief, in the course of forty
to sixty hours after inoculation, they remain sitting in
the same characteristic position.

When the ears of rabbits are inoculated with the
bacillus from cases of erysipelas suis, a violent inflam-
matory edema and distinct redness occurs, much re-
sembling erysipelas. This lesion gradually spreads, in-
volves the head, then the body of the animal, and ulti-
mately causes death.

When swine are affected, they are dull and weak, and
have a kind of paralytic weakness of the hind quarters.
The temperature is elevated ; red patches appear upon
the skin and swell and become tender. Death follows in
two or three days. Sixty per cent, of the diseased
animals die.

In all animals the anatomical changes are much alike.
The disease proves to be a septicemia, and the bacilli can
be found in all the organs, especially the lungs and spleen.
They are- few in number in the streaming blood.

As the organisms stain well by Grain's method, this
stain is of great value for their discovery in the tissues,
and can be highly recommended.

Most of the bacilli occupy the capillary blood-vessels ;
many of them are enclosed in leucocytes. The organs in
such cases do not appear distinctly abnormal, except the
spleen, which is considerably enlarged. The mesenteric
and other lymphatics are also enlarged, and the gastric
and intestinal mucous membranes are usually inflamed
and mottled. The bacilli also occupy the intestinal con-