THE COLLEGE Zoological Laboratory 38th Street and Woodland Avenue Juno ol, 1951 Dr. Joshua Lederb@re Department of Genetics University of Wisconsin College of Agriculture Madison 6, Wisconsin Dear Dr. Lederb&rz; Your letter of June 20 arrived this morn inge Naturally I am very much disappointed that you do not find it possible to partici- pate in our symposium on "Sex in Microorzan- isms" scheduled for next December. I an following one of your suggestions and writing to Professor Luria to see if he will join with us in this project. Very sincerely yours, "Of * D. He WVenrich DEWemre