THE PANCREAS 245 
part of this statement may possibly be found in the cats 
and dogs, in which there are firmer attachments of the 
duodenum and pancreas to the vertebral column and the 
liver; this is brought about by the short gastrohepatic 
omentum and the abrupt curvature of the duodenum 
toward the back, under the mesenteric stalk. In the 
Ungulata and Marsupialia and in some Eodentia, the 
pyloric, duodenal, and pancreatic attachments are rela- 
tively loose, and torsion of the pylorus seems to be 
allowed for, since in these animals great distention of the 
stomach is the rule. Among the Aves the anatomy is 
wholly different. The birds have no attaclunent of the 
duodenum and pancreas to the posterior abdominal wall, 
except indirectly through a narrow strip comparable to 
the gastrohepatic omentum, one division of which passes 
to the beginning of the duodenum, the other to its end, and 
by a thin tail of pancreas wliich goes toward the spleen. 
The bulk of the pancreas lies in the U made by the long 
free duodenal loop, the two organs being covered by the 
serous membranes forming the middle abdominal sac. It 
will be seen from the foregoing that the movability of the 
pancreas is considerable — a highly necessary provision, 
because the stomach and duodenum are also movable and 
subject to distention by food and alteration of position 
during flight. 
In the class Mammalia there are usually two ducts, 
one entering the duodenum in combination with the bile 
duct, the other variously above or below this common 
opening. As will be seen in Table 14, however, there are 
several exceptions to this statement, there being but one 
duct opening independently of the bile duct. The general 
anatomy is closely similar throughout this class, so I shall 
confine my notes to the exceptions from the general rule, 
especially where they seem to be of importance in the 
etiology of pancreatic lesions. 
In the class Aves the pancreas consists usually of two 
or three distinct lobes lying one in front and two behind 
