198 DISEASE IN WILD MAMMALS AND BIRDS 
of the left hand sections. So far as I know, the relative 
incidence of gastric disorders in the above outlined 
groups has not been pointed out before. 
The pathological types of gastroenteritis do not pre- 
sent many unusual features. Simple injection of vessels 
during digestion seems more evident in this than any 
other order, while mucus production seems less marked. 
The mucosa of the reservoir portions may, in simple over- 
filling and feraientative distention (gastric tympanites), 
be quite normal or dull red ; when active fermentation has 
occurred it may be digested and peel off. More or less 
true inflammation as seen in the digestive stomachs is 
definitely better expressed in the compound ruminant 
organ than in the simple equine variety where congestion 
and edematous swelling with hemorrhage form the usual 
picture. True catarrhal changes both gross and minute, 
are often well seen and ulcerative lesions are not 
uncommon; ulcers are unusual in the simple stomach. 
These statements hold good also for the small intestine. 
Enteritis affects the duodenum and jejunum more in the 
Perissodactyla and s^vine than in the ruminants. 
Ungulata do not react with hyperplasia of the mural 
hinphatics as do many other orders, but the swelling of 
the mesenteric nodes is often noteworthy. As might be 
expected this is more definite with catarrhal changes and 
therefore best seen in the ruminants. In the colon, how- 
ever, the solitary follicles are often quite prominent in 
simple inflammation. Histologically the greatest changes 
seen in this order are superficial degenerations with 
mononuclear increase in the deep submucosa, mostly 
arranged in perivascular fashion. The villi do not con- 
tain the large number of cells seen in the Carnivora. 
Marsupialia. 
Consultation of the figures for this order in 
Table 11 arrests attention at once because of the 
peculiar percentages found under the detailed factors. 
