for different radiations. He has denonstrated excellent families of curves which chow, for examrle, a decrease in thymic weight of 35 end 10 ser cent respectively for the same doses of 250 and 1000 k.v. x-rays. weighed The spleens are innedictely after sutocvsy of the animals, but the thymus is vleced in fornelin over nisht to permit easier separation of the fat. 1.300 Senerate weignings will be done in paired weighing bottles for each test. He has five seven other helpers to his grouc afte oR belances, @ resulsr steff of seven and will edd each test. me yr A trial run using ?50 k.v. x-rays wi be conducted on daptan on the seneretion of mice creceding tnose actually used in the first test. Mouse Experiments (other than dosimetry) The * hybrids of the LAF strain are being used because they zive the most consistent data on mortality studies eccording to Cronkite and Lorenz. Mortality vs. distence: for ganva rays. This will only be determined “There will be thirty animels of eech sex in the tventy-nine cylindrical stations, which ere so placed thet they will receive increasing ses of ganja reyS in increments of 25 roentsens. robable dose range which will be covered is 40-1200, but it may be 50-1400, or 80-1600 r., depending uron the bonb ef7iciency. I don't think these aninals will be sutorsied. Should be recovered in 4-5 hours. They Lethal dose studies under sinulatel field conditions heve o i ~ US DOR AQcH mn been convleted at Zunter's Foint. 3 1.