answer of the Counittee = The anawer is substantially the same as to Question isthat 3, at least eight miseiens can be earried cut. Personnel cought to be carefully checked and evaluated after each nission. The possibility of substantial reduction in life expectanay by radiztion . doses totaling ever 20Grshould not be ignored. Biology Sranch (guuieGneeas Human Genetics ~ At the November ncating of the Biology end Kedicine Advisory Committee the question of supporting work in human genetics was discussed. In compliance with the general tenor of the discussion, a propesal for investigation of certain humen mutation rates wag invited from Dr. James ¥. Neel. ef the University of Michigan whe had discussed this problex @m several previous occasions with Dr. Zelle. br. Neal's greposal will be disacuased at the January aceting of the Advisery Comaittes andwill be the firet research contract in human genetios if if is approved. This wrk sill “pet ee takeOM woe not deal with the effect of irradiation but enly with paturally ocouring mutationg in man. hengextty Studios - Some of the aioe surviving operation Greeshouse are tc ba re tad States for observations aver the rest of théir life span. ‘This work will be done in the Siology Division at GRYL. The Stology Branch ws represented by Dr. Zelle at the December 1th Gonference at Oak Ridge to discuss specific plans for the cataract, tuner incidence, and longevity studies of these mice. The sverall sise ofthe study wes reduced, a better statistical denign developed especially for the control mice, ands convenient ayaten of recording data on tha ISM eard outlined at the ocufarmee. Personnel requirements, finsncing, end other problems perteining to the program were discussed, the studies on the longevity of the aice fron dreonhouse oomprise only one part of a program on the effects of radiation on longevity. Other studies . using external seurses of radiation will be initiated with dogea and other species, Aninals will be exposed to single »ray treatments at various dosage levels, ad also to intermittent exposures, Irradiation iffects on Plents ~ Hesearch at the U. 3. Department of agriculture at Saiteville on mm ACC project has dealt extensively with the effect of radicactive isotopes on plant growth. In messuring the immediate effect of irradiation on plants it has been possible to measure a decrease in root length, in top growth, and the sise of new leaves. These sethods are only qualitative and with thea little visible injury to plants is noticeable in such planta a# barley and alfalfa when the plants are grown in nutrient solutions containing less than 50 microcuries of p22 per Liiexs It bas recently besn observed that oall division ceascs in the meristematic region such as the root tip or atem tip when subjected te s« constant relatively OFFICE >