Pathogenic Bacteria

YELLOW FEVER. 403

there are, in addition, nephritis, enteritis, albuminuria,
hemoglobinuria, and hemorrhages into the body-cavities.
The dog is the most susceptible animal. When it is
injected intravenously the disease-process that results is
almost immediately manifested with such violent symp-
toms and such complex lesions as to recall the clinical
and anatomical picture of yellow fever in the human
being. The most prominent symptom in experimental
yellow fever in the dog is vomiting, which begins directly
after the penetration of the virus into the blood and con-
tinues for a long time. Hemorrhages appear after the
vomiting, the urine is scanty and albuminous, or there is
suppression, which shortly precedes death. Once grave
jaundice was observed.

At the necropsy the lesions met are highly interesting,
and are almost identical with those observed in man.
Most conspicuous is the profound steatosis of the liver.
The liver-cells, even when examined fresh, appear com-
pletely degenerated into fat, this appearance correspond-
ing to that found in fatal cases of yellow fever. The
same result may be obtained by injecting the liver di-
rectly or through the abdominal wall. The kidneys are
the seat of acute parenchymatous nephritis, sometimes
with marked fatty degeneration. The whole digestive
tract is the seat of hemorrhagic gastro-enteritis comparable
in intensity only to poisoning by cyanid of potassium.

Experiments upon monkeys were also of interest, in-
asmuch as they demonstrated the possibility of obtaining
fatty degeneration more extensive than is observed in
man. In one case the liver was transformed into a mass
of fatty substance similar to wax.

Goats and sheep are also very sensitive to the icteroid
virus, and the lesions described also occur in them.

The death of a yellow fever victim is the result of one
of three causes:

i. It may be due to the specific infection principally,
when the Bacillus icteroides is found in the cadaver in
a certain quantity and in a state of relative purity.