OY The X. 5[Rockefeller\ THE ROCKEFELLER UNIVERSITY m University /< 1230 YORK AVENUE NEW YORK, NY 10021 Oy Lo GS April 8, 1981 JOSHUA LEDERBERG PRESIDENT VY Ms. Susan E. Garfield Coordinator _ Bellagio Study & Conference Center The Rockefeller Foundation 1133 Avenue of the Americas New York, New York 10036 Dear Ms. Garfield: I was very glad to hear that you may have an oppor- tunity to accommodate Dr. Isac Halbrecht for a residency at your center in Bellagio. I have known Dr. Halbrecht for many years and am de- lighted to note that his advancing age has been no barrier to his continued productive activity well past normal re- tirement. He has played a very important role in building the foundations of human population genetics, especially in Israel, and as concerns the genetic history of Jewish people scattered in communities throughout the world. In previous years he was very important in bringing advances in genetics into pediatric research and training at a very high level of competence. . I am happy indeed to endorse his request and believe that you can do no wrong in complying with it. Yours sincerely, Joghua Lederberg