202 DISEASE IN WILD MAMMALS AND BIRDS 
reaction as seen in the stomach. The carnivorous intes- 
tine shows frank catarrhal changes, the herbivorous 
presents congestions and superficial necroses. These two 
groups then follow the descriptions as already given for 
carnivores and ruminants. 
The colon presented in the first group, simple 
catarrhal or follicular change. In the second division 
the lesions resembled those in the stomach; they were 
only once of the three instances associated with 
streptothricosis. 
AVES. 
The class Aves has been treated in the chart precisely 
as have the mammals, but it is not possible to make the 
accurate diagnoses or to separate groups of lesions ac- 
cording to anatomy as was done for the latter class. Upon 
the average there is more gastroenteritis among birds 
than mammals, but when looking for an explanation of 
this, it was unfortunately necessary to enter in the ''unde- 
cided" column of Table 11 a very great number of cases. 
This column would be greater relatively were it not for the 
parasites in parrots and gallinaceous birds, the entries for 
which are high. Besides this fact and that the owl stands 
at the top, the pigeons at the bottom of the list numeri- 
cally, no further general statements are allowable. There 
are several orders with high values among those of which 
insufficient autopsies are at hand to cast percentages. 
The avian alimentary tract seems to have developed 
according to the character of food the different varieties 
of birds consume if one may judge by the construction of 
the bill, the gastric musculature and the intestinal wall. 
Zoological classification has only secondarily considered 
this point, it being made incidental to the habits and 
habitats of birds. For this reason the orders as outlined 
on pages 44-46, placed as they are in historical evolution- 
ary position, represent wdth few exceptions groups which 
have differing diets and, by the same token, differing gas- 
