HOG CHOLERA 425 
by the action of the virus upon these cells or that the cement substance 
holding them together is dissolved or chemically broken down in 
which case the cells would be indirectly affected. In some cases the 
petechiae are restricted to one or more organs and in others they are 
wide-spread. The lungs are occasionally sprinkled with hemorrhages. 
In addition, there are usually distinct parenchymatous degenerations, 
especially in the kidney and liver. The extent of these changes 
depends upon the duration of the disease. 
The lungs, in a small percentage of cases, show subpleural ecchy- 
moses. On section small hemorrhagic foci are sometimes observed 
throughout the lung tissue. In a few cases severe hemorrhages 
involving one or more lobes have been observed. The subcutaneous 
tissue over the ventral surface of the body may be dotted with 
petechize and occasionally collections of blood (hematomata) are 
found in the superficial muscular tissue. Petechise have been observed 
on the cerebellum. The skin over the abdomen, inside of legs and 
back of ears is usually hyperemic. 
The digestive tract is usually the seat of extensive lesions. The 
fundus of the stomach may be deeply reddened; there may be more 
or less hemorrhage on the surface, giving rise to larger areas of blood 
clots. In some cases the small intestine has submucous ecchymoses 
throughout its entire length. In the large intestines these may be so 
numerous as to give the membrane a dark red appearance. The 
intestinal contents are now and then incased in a layer of blood 
clot. 
The chronic form is perhaps the most common, at least in those 
epizodtics which have been reported. The lesions of the large intes- 
tines are diphtheritic and ulcerative in character. The ulcers may be 
isolated and appear as circular, slightly projecting masses, stained 
yellowish or blackish or both in alternate rings, or they may be slightly 
depressed and somewhat ragged in outline. When the superficial 
slough is scraped away many ulcers show a grayish or white base. A 
vertical section reveals a rather firm neoplastic growth, extending 
usually to the inner muscular coat. When the ‘sections are stained 
with aniline dyes and examined under the microscope, the submucous 
tissue is very much thickened, infiltrated with round cells and contain- 
ing a large number of dilated vessels. Resting upon this thickened 
submucosa, is a line of very deeply stained amorphous matter and 
upon this is situated the necrotic mass which fails to retain the color- 
ing matter and which is permeated by a very large number of bacteria 
