THE ALIMENTARY TRACT 201 
without jaw disease is somewhat different from that with 
it. Pathologically the process is a congestive and super- 
ficially necrotizing affair, forming upon the tips of the 
folds, small gray erosions or flat shallow irregular 
ulcers, which upon histological study consist of loss of 
tissue of the mucosa and some deep congestion with round 
cell groups but no reaction deep in mucosa or submucosa. 
True catarrhal inflanunation has occurred, but not like in 
the opossums. 
Chronic gastritis in the simple stomachs is almost 
exclusively in opossums harboring Physaloptera turgida, 
a worm which fastens itself more or less firmly in the 
mucosa and probably, with the assistance of bacteria, 
causes sufficient irritation to produce a hypertrophic 
change in the deeper layers and a destruction of 
the glands where it holds and a distortion of those nearby. 
One is reminded that Fibiger found spiroptera to be 
responsible for adenocarcinoma in rats ; no tumor forma- 
tion has been found in these animals, although one 
opossum with such a stomach had an adenocarcinoma 
mammae. Small hemorrhagic spots may occur in the 
deeper layers, possibly where the worms have bitten. 
The rugae are irregular or interi'upted by knobs 
and papillae. 
Group B, stomachs showing chronic change, were all 
kangaroos. The three cases resembled the infiltrating 
necrotizing lesions as discussed under ulcers (page 175). 
The process showed an infiltration of the subsurface tis- 
sues with a gray slough over the densest part. The 
mucosa as a whole was irregularly rugous and spotted 
with red gray areas. 
Altogether one gets the impression that in the simpler 
stomach, reactive inflammation is most prominent, while 
in the colonoid stomach degeneration is greater 
than reaction. 
Intestinal lesions in marsupials are not common and 
not peculiar except in that they carry out the pathological 
14 
