Abstract
Data on the occurrence of lymphoreticular neoplasms in untreated mice of the NZO/B1 strain with hyperglycaemic obesity, are presented. 51% of the lymphomas were primary in Peyer's plaques, an uncommon lesion in most strains of mice. The incidence of lymphomas in males, virgin and breeder females, together with the age distributions and age-dependent cumulative probability curves, are given as background data for other laboratories working with NZO/B1 mice.