Passerine birds have two pancreatic ducts usually on the ascending loop of the duodenum, or there may be one ahead of the pyloric biliary duct. The picarian varieties possess three ducts as a rule, one near the beginning of the pylorus, one near its end and a third of inconstant location. Owls have a system like Passeres, but the relation between the organ and the intestinal loop is looser and the ducts are wider. Columbæ have two pancreatic ducts in the ascending limb of the duodenum. Gallinaceous varieties have a double biliopancreatic system, a duct of each kind entering the descending and the ascending duodenal reaches, with the biliary placed after the pancreatic in each instance. Accipitres have always two and oftentimes three ducts as do Anseres, both orders frequently having the third duct opening at the bottom of the duodenal loop where stagnation can and does occur. Fulicariæ have usually three ducts. The foregoing are the orders presenting pancreatitis and therefore those whose anatomy concerns this study directly. The irregularity in number and arrangement of ducts continues through all the avian orders which show a greater aberration from standards than do the mammals. Theoretically the birds should cast some light upon the unsettled question of the causes of pancreatitis, and as a matter of fact such a result seems to have been realized. In 1915 I published an article upon a study of this subject which indicated that acute inflammations of this organ may arise _via_ the lumen of the duodenum and pancreatic ducts, while chronic processes were the result of periductal passage of pathogenic agents. Further study would seem to indicate that disease of the biliary tract is of importance in lesions of the pancreas since a decidedly large number of cases is found in mammals, where the relation of ducts is definitely more intimate than in birds. The work of Archibald,[28] Deaver and Sweet,[29] and Judd[30] seem to agree with the findings upon our material. This need not be, however, in discord with the idea that acute inflammation is superficial in origin, chronic lesions deep or lymphogenic. The discussion will be resumed in a subsequent paragraph. The amount of pancreas to be found in birds is greater than that in mammals. According to our figures the organ represents ¹⁄₄₀₀th of the body weight in the former and ¹⁄₆₀₀th in the latter. These figures are averages of a small number of instances and are not final. It is, however, obvious to casual daily observation that birds as a class have a large pancreas.