THE PANCREAS 255 
obstruction of the common bile duct may spread to the 
pancreatic duct, and that mechanical or inflammatory 
obstruction of the papilla of Vater may permit the bile to 
pass up the pancreatic duct. This theory is based upon 
certain observations, notably those of Opie, in cases, where 
a gall stone obstructed the ampulla, bile entered the 
pancreas and acute pancreatitis arose, partly by the acti- 
vating action of the bile upon the pancreatic juice and 
partly by bacteria introduced at the same time. This 
method of origin is perhaps accepted in most quarters, 
but there are some who believe that infection of the gland 
may occur by the infiltration of lymphatics around the 
pancreas by disease of adjacent parts — gall-bladder, 
stomach or lymph nodes. Quotation has already been 
given to reference literature, and I shall not go further 
into theory except in pointing out how our material may 
help to answer the question. 
In the first place it seems perfectly obvious that infec- 
tion might in any animal travel from the intestine to the 
pancreas via its ducts, the main question to be settled 
being the relative importance of the infection via the bile 
duct. Let us now see if the variations in anatomy will 
cast any light upon the matter. 
Among the 1860 mammals, there are as far as I can 
determine 1275 which have one pancreatic duct opening 
in conjunction with the bile duct, 585 in which the former 
has an intestinal opening independent of the latter. 
Among this 1275 there are nineteen cases of pancreatitis, 
while among the 585 there are eight cases, or as 14.9 to 
13.6. All Aves have separate biliaiy and pancreatic ducts 
and relatively little pancreatitis, although frequently 
suffering with its most cormnon accompaniment, namely 
duodenitis. There is therefore some evidence that more 
pancreatitis occurs when there is a physical proximity 
or combination of bile and pancreatic ducts. 
Active infections of the biliary system in relation to 
pancreatitis are, however, not as conspicuous as might be 
