5. Graying of the hair cecurred in anirals in definite relntion to the intensity of the axpusure as one mivat expect from deta tn the literctore. 6. ; _ A mmemary of observetions is civen om “able 3. Timers cccurred in the meriory glend region in many expoved mice, as indicated in Table 1. This was unexpected us, according to Ur. Lorenz, memmostuners secu ‘ute 23 thea ul wise oO: Unis cirain exposed “oO GommeTOYS » an’ ewtanecustamors are very rare. Section: of theso turot: will be sent to Mrs. Shiels Varren aad a. Lorena. Tho mention ts whowicr these tumors could be caused by asutron miclacr reactiana tue to come olomont measent in the accessory glands of the skin or in the memary ducts, Uther tepes of tumor are not apmercnt thon fer > oO 7, The %Ray controls have boen recaived only recently from Te. J, Bond, ue Se Naval Rysearch Loboratery, san Yrancisco. aa these uisu vera set up later an’? reared Im the United states, they are not perfact controls but ill verve for tontative orientation as te the telative offleieney of newirons ond Xerzage in producing crantng, catareets, teukenin, on? tmor-. I is prrmatore to draw final conclusions, Lut the *nllowing zaner1 consLiovations arm subittied: - a) Atomic Leab explosions can be utiliserl for bavic seientific and anrlied studies which in neny respects are sunarior to the laborctory experinents performed tims far, fe Ses certain -ajor foetorn are ideally ‘dentiea® and unilorm, cuca us tneaxpocure scurte, the neriod of obterration, on] other verieble: reicted te time ond space. Heutron expocuce of mumcals on a “arge ceale in bareiy feasible vtharvtse. + nos anew ay &