THE PANCREAS 251 
rhage may be added by digesting of blood vessels. 
Exudative cases seem due to extension of ulcerative 
inflammation, from a perforated gastric ulcer for 
example, to which digestive pancreatitis may be added. 
The interacinus chronic inflammations are usually con- 
sidered as due to obstruction or infection through the 
biliary or pancreatic ducts whereas vascular disease pro- 
duces intra-acinus connective tissue overgrowth. Analysis 
of the records of this laboratory would seem to indicate 
that necrotizing and hemon-hagic processes belong 
together, exudative in a class by themselves, and that 
chronic disease may be either interlobular or intra-acinar 
without regard to associated pathology. I have therefore 
studied our cases from this standpoint. 
Pancreatitis has occurred in thirty-eight mammals 
and birds among the 5365 autopsies, an incidence of 
0.7 per cent. ; class incidence in mammals twenty-seven or 
1.5 per cent.; birds eleven or .3 per cent. (Table 14.) 
Among the higher class all the important orders are rep- 
resented, but by no means in equal degree, whereas in the 
birds, less than half of the orders are listed, with the 
important Psittaci missing, despite a high death rate. 
It is perhaps well to be guarded in stating the relative 
vulnerability of the pancreas in various orders, but one 
cannot avoid the observation that Carnivora stand well 
in advance of the others (3. per cent, of autopsies), to be 
followed by Ungulata (1.9 per cent.) and Rodentia 
(1.7 per cent.). Nor can one fail to see that mammals 
have inflammations of this organ five times as often as 
do birds. 
Further analysis of the data leads into a consideration 
of the anatomy of the viscus in terms of the acceptable 
theories of the origin of the lesion. It is commonly 
believed that infection of the gland occurs by passage of 
organisms through the duct opening in the intestines, 
especially when there is swelling of the mucosa of both. 
For the human being the idea is current that infection or 
