Feeding effect of irradiated diets was studied on the pups born to mother fed either on irradiated normal diet or irradiated low protein diet. The study indicated that pups born to mother fed on the irradiated low protein diet had fewer spermatogonial cells in the testes than those given irradiated normal diet and unirradiated low protein diet. Similarly, pups maintained on the irradiated low protein diet showed marked decrease in alkaline phosphatase and cholesterol contents in the testes rather than in the pups fed irradiated normal as well as unirradiated low protein diets. The irradiated low protein diet fed pups showed increased depletion and vacuolization of adrenocortical and medullary cells. 13 refs., 15 figures.