HOG CHOLERA. 
7 
teritis, a disease somewhat similar in lesions to our hog cholera. 
Too much stress, however, was apparently laid upon the lung le¬ 
sions and the germ was not described with sufficient detail to admit 
of identification. 
The bacterium of hog cholera, as studied in our labora¬ 
tory, is found chiefly in pairs, appearing as elongated ovals 
from lrotolro micromillimeters in width. Occasionally longer 
elements are observed reaching 1A micromillimeters in length, 
and even longer under certain conditions. In liquid media 
the bacterium is motile and its movements resemble very closely 
bacterium termo. That the bacterium which we have studied is 
not bacterium termo is shown by the fact that it does not liquify 
gelatine and that there is not the slightest putrefactive odor em¬ 
itted from the culture containing it, and also by its pathogenic 
effects. This germ may be stained with an aqueous solution of 
methyl violet and various other aniline stains. When colored 
with methyl violet, particularly when in eoverglass preparations 
made from the organs of affected animals, the central portion is 
much paler than the periphery. A dark border extends entirely 
around the germ and although it may be thicker at the ends than 
at the sides it does not give that distinct appearance of polar 
staining that is seen in the germs of rabbit septicsemia. Like 
most other germs, the staining varies somewhat with its age and 
conditions, and its size varies also according to the medium in 
in which it is grown, and also to a certain extent when obtained 
from different outbreaks of the disease. 
The most recent microbe described by Klein in connnection 
with pneumo-enteritis resembles considerably the germ which 
we have found in hog cholera. It is motile in liquid cultures and 
is described as from two to three micromillimeters long. It is 
also said to be spore-bearing and that pigeons are wholly insus¬ 
ceptible to it. The germ of our hog cholera does not produce 
spores, so far as our observation goes, and it is fatal to pigeons 
when inoculated in considerable doses. 
In virulent outbreaks the percentage of mortality produced by 
this germ is very high. In a recent outbreak in the District of 
Columbia out of 139 animals of a herd, about one hundred per- 
