4osoes October 7, Dr. Charles L. Dunham, i355 Director Division of Biology and Medicine U.S. Atomic Energy Commission Washington, D.C. 20545 Dear Dr. Dunham: I very mucn regret. that I will not be able to attend the Biomedical Program Directors meeting, October 14 and 15, at Los Alamos Scientific Laboratory. Dr. Allyn H. Seymour, Associate Director of our Laboratory, will attend as our representative. Al has never been to LASL so this will provide him with a new and stimulating experience. This is an especiaily busy season for us at the Laboratory of Radiation Biology. All the programs are in full swing, with Long Shot as an extra. The salmon are returning in numbers, providing very exciting information on the earlier exposures to 0.5 r per day during the embryonic period. We are now ready to start another series, with the dose increased to 1.0 r per day for yCz days. These long-term chronic exposures are extremely time-consuming, but provide many very useful blocks of data. With best personal wishes, Sincerely yours, Lauren R. Director LRD:ep ce: Dr. John N. Wolfe Dr. Allyn H. Seymour Donaidson