IN SUSCEPTIBLE ANIMALS. 515 
Cornevin and Kitt have shown that the contents of the intestine 
also contain the bacilli in large numbers, and the disease appears to 
be propagated among swine principally by the contamination of their 
food with the alvine discharges of diseased animals. 
Pigeons are very susceptible to the pathogenic action of this ba- 
cillus, and usually die within three or four days after inoculation 
with a pure culture. Rabbits are not so susceptible, although a 
certain proportion die from general infection after being inoculated 
in theear. The first effect of such an inoculation is to produce an 
erysipelatous inflammation. When the animal recovers it is subse- 
quently immune. 
White mice and house mice are extremely susceptible, but field 
mice are immune. This remarkable fact was first ascertained by 
Koch by experiments with his bacillus of mouse septicemia. House 
mice which have been inoculated with a minute quantity of a pure 
culture of the rothlauf, or mouse septiceemia, bacillus, die in from 
forty to sixty hours. The animal is usually found dead in a sitting 
position, with its back strongly curved, and for many hours before 
death it remains quietly sitting in the same position ; the eyes are 
glued together by a sticky secretion from the conjunctival mucous 
membrane. At the autopsy the spleen is found to be very much en- 
larged, and there may be a slight amount of cedema at the point of 
inoculation. 
The bacilli are found in the blood vessels generally, and are very 
numerous in the interior of the leucocytes, which are sometimes com- 
pletely filled with them. 
BACILLUS COPROGENES PARVUS. 
Synonym. —Mauseseptikaimiedhnlicher Bacillus (Hisenberg). 
Obtained by Bienstock from human faces. 
Morphology.—A very minute bacillus, which is but little longer than it 
is broad, and might easily be mistaken for a micrococcus. 
Biological Characters.—Grows very slowly on nutrient gelatin, forming 
a scarcely visible film along the line of inoculation, which at the end of 
several weeks is scarcely one millimetre wide. Is not motile. 
Pathogenesis.—In white mice an extensive cedema is developed at the 
point of inoculation at the end of ten or twelve hours, and the animal dies 
within thirty-six hours. The bacilli are found in great numbers in the 
effused serum at the point of inoculation and in comparatively small num- 
bers in the blood. A rabbit inoculated with a pure culture obtained from a 
mouse died at the end of eight days. The inoculation, which was made in 
the ear, gave rise to a local erysipelatous inflammation. 
