IN THE vast field of experimental diabetes, there are indications that several factors may play a role in modifying the diabetes of various animals. The mechanism responsible for these species-differences has not yet been clearly elucidated. Various explanations, such as variability of endocrine balance, disturbance of pancreatic secretions other than insulin, and previous dietary habits, have been offered to account for these differences. Minkowski1 made the general observation that carnivorous animals suffer from a more intense diabetes than do the Herbivora. Several of the variable factors observable in experimental diabetes appear to occur in human diabetes. The clinical pattern of the disease as it occurs in a tropical country like Ceylon exhibits several important variations, namely, the mildness of the disease, the rarity of ketosis and coma, except as a complication following infection and surgical procedures, and the extremely low incidence of arteriosclerotic occlusive disease and of obesity. The