36 SWINE PLAGUE 
The inflammation of the pleura frequently extends to the peri- 
cardium. This membrane is opaque, thickened and its vessels dis- 
tended. It may be g‘ued to the contiguous lobes of the lungs and 
covered by a false membrane, smooth or roughened, which extends 
upon the large vessels emerging at its base. 
Disease of the digestive tract in a considerable proportion of 
animals inoculated with swine-plague cultures consisted in a severe 
catarrhal inflammation of the lining membrane of the stomach. 
The hyperemia was very intense, bordering on hemorrhage. Occa- 
sionally the extension of the peritonitis, produced by intra-abdominal 
inoculation along the mesentery, causes a severe inflammation, with 
exudation on the mucosa of the small intestine. A case is reported 
where all the Peyer’s patches of the small intestine were in a hypere- 
mic and partly hemorrhagic condition. 
In the: naturally contracted disease extensive hyperemia of the 
mucosa of the large intestine, bordering on a hemorrhagic condition, 
has been observed. In other cases a peculiar croupous exudation 
appeared, which seemingly resulted from the effect of swine-plague 
bacteria in the large intestine. 
The production of intestinal lesions by Bact. suisepticum may be 
supposed to go on as follows: The bacteria first attack the lung 
tissues and there produce more or less hepatization. The blood 
through the lungs finds its path partly obstructed. This reacts on 
the blood in the right side of the heart and the venous blood entering 
it. Hence there may be more or less stasis of blood in the portal 
circulation which in turn impairs the digestive functions of the 
stomach. The swine-plague bacteria in the lungs in the later stages 
of the pneumonia may be coughed up in the contents of the bronchial 
tubes, swallowed and passed through the impaired stomach unharmed 
into the intestines. The stagnation of the feces in the large intestine 
furnishes the bacteria an opportunity to cause inflammation with 
exudation on the mucous membrane. The tendency of swine-plague 
bacteria to cause fibrinous inflammatory deposits on serous mem- 
branes may serve to explain such action on mucous membranes. 
There is general congestion with resulting degeneration of the 
parenchyma of the spleen, kidneys and liver in the acute septicemic 
forms of the disease. In these cases the specific bacterium is easily 
obtained from the abdominal organs. In brief, the lesions of Swine 
plague as they appear in various outbreaks may be summarized in 
four classes, namely: 
