Tumors of the pancreas have been three in number, two being of academic interest only. One of these concerned an apparent adenoma of the ducts within the organ, discovered microscopically in the sections from a Corsac Fox (_Canis corsac_). This is the only specimen we have had, and I can find no description of the normal microanatomy of this species, so that with a knowledge that certain carnivores have convoluted ducts, the determination is made tentatively; it corresponds microscopically to a ductal adenoma. The pancreas of a raccoon (_Procyon lotor_) showed a true adenoma of glandular acini as two separate but closely applied firm nodules surrounded by a capsule, and with distorted acini as seen under magnification. The most important tumor was found in an Indian Paradoxure (_Paradoxurus niger_), an adenocarcinoma involving the head of the organ, enlarging it to twice its normal size; there were no metastases. The animal suffered also with an infective hepatic cirrhosis of recent origin, chronic nephritis of the arteriosclerotic type, chronic fibroid splenitis. No obstruction to the biliary channels existed. SECTION VII THE ALIMENTARY TRACT, PART 4. THE PERITONEUM This visceral envelope is principally important because of the fatal character of its acute inflammations. In man peritonitis of acute origin and type is commonly secondary to a focus of progressive inflammation in some abdominal organ and usually speaks for the virulence of the primary disease and for the low resistance of the serous membrane. Because of this vulnerability, greater foresight is attempted to prevent the extension of acute intra-abdominal inflammations and under operative conditions punctilious care is used to avoid contamination of the general peritoneal cavity. Involvement of the peritoneum in septicemic states is relatively uncommon in man, but seemingly more frequent in the lower mammal. This surface seems more resistant to infection at operation in the lower animals since post-operative peritonitis after castration and experimental procedure is certainly infrequent; our data will permit no percentage figures of vulnerability under such conditions. Judging, however, from the number of times at which the diagnosis of acute peritonitis has been made, the lower animal has a decidedly low percentage resistance although its pathological states are primary or secondary to conditions unusual in man. Among the 5365 autopsies acute peritonitis appears in the diagnoses 137 times or 2.4 per cent.; mammals, 57 or 3 per cent.; birds, 80 or 2.3 per cent.