Previous investigations that the pancreas is a radioresistant organ. Ivy in 1924 noted the presence of a fibrotic atrophic pancreas in a dog which had received one erythema dose to the epigastrium. Fisher in 1923 reported that four to five erythema doses delivered in a single application caused complete disappearance of the irradiated pancreatic remnant in about two months. These dogs died because of uncontrolled diabetes. One dog that received four erythema doses (possibly 200 r) was sacrificed after five months. At autopsy the irradiated pancreas had disappeared, but 275 mgm of regenerated pancreas were found at the base of the main duct and 100 mgm at the base of the accessory duct. Leven in 1933 implanted radon seeds into the pancreas. Dosages varied from 528 to 1584 millicurie hours. At postmorten the pancreas surrounding the seeds demonstrated fibrous atropy and foci of necrosis. The islets appeared normal but were relatively larger in size. Rauch in 1952 reported that dogs given 200 r in air over the pancreas on alternate days until a total of 1600 r was received failed to show any histological changes after two months. Lushbaugh and Spalding and Lushbaugh reported that over 1500 r of whole-body …

Separate abstracts were prepared on 11 sections of this report. Abstracts of 5 sections have previously appeared in NSA. (C.H.)