THE ALIMENTARY TRACT 193 
In regard to incidence of gastrointestinal disease, 
rodents occupy a middle position in the table. The 
stomach seems a vulnerable section of the tract. Dilata- 
tion of the left hand section is common, due, to all appear- 
ances, to fermentative processes which have as a result 
the softening of the mucosa so that even immediately 
after death it will separate almost entirely. In these 
cases the pyloric part need not participate but may 
remain flat, smooth, soft and pink. This condition is 
slightly more common in the compound than in the simple 
stomachs. In some of this order, especially rats and 
cavies, there is a fermentative gastroenteritis expressed 
by injection and edema of the pylorus and duodenum, and 
much frothy mucus. It was at first thought that some 
relation might exist between this condition and the 
absence of the gall-bladder, but it occurs in varieties 
possessing this structure. The reaction of the intestine 
to irritation in this order is peculiar in two ways, the 
occurrence of mucus and the activity of the lymphatics. 
In all the inflammations from and including the stomach 
to the cecum, mucus is conspicuous. At times it is thin 
or loose and mixed with contents, while at others it forms 
a relatively close covering for the mucosa almost like a 
false membrane. Rodentia are peculiar in the prompt- 
ness and clearness with which the follicles of the intestinal 
wall and mesentery enlarge in inflammation. They 
appear as pale, well outlined or diffuse opacities in the 
wall or as distinct plaques prominent on the surface. 
The Pkoboscidea are represented by one Elephant 
{Elephas indicus), in which a mild catarrhal change 
was seen in the middle stretches of the small intestine. 
This was of little importance as a cause of death, there 
being several other diagnoses, and was probably a termi- 
nal affair. 
Hyeaces, of which we have a total of seven ex- 
amples, present two mild involvements of the intestine but 
none of the stomach. It would appear from the records 
