5 An unantioipated finding was the relatively high incidence of pituitary tuners in irradiated mice. These were move comson in femles (Table 2), and their frequency was roughly proportional to the dese with the exception of doses above the LD... thay appeared late in life, the peak incidence 4 ecourring 2«25 months! pestirradiation. All ‘enon fur studied tave been steuaopiiable. Ioperinental studies indicate that moat of tnese searate ACTH) a feu, however, have given evidence of 2oli-ssaretion. Another unexpected and intoaresting necplag observed tn the irradiated mice is adenoma of the darcerian, or posterior lacrynel, gland. This growth occurred mare commonly at low ddse levels (Table 3), pretably because of its long Latent period (15-17 months). it 4s a locally invasive necplass, often obliterating the orbit, surrounding skull, and adjacent soft tiscue (Mig. 2). Thus far no such tumors have been observed in the controls. The frequency cof mamuary gland tumors was inereased by irradiation (Chart 6). ‘The neoplame oocurring earliest were predominmtly adenomes and adenocarctacass, those developing late in life sarcomas. om earlicr investigations a correlation between these neoplasms and tumors of the ovary "DomARCHIVES * - aye