PUBLIC HEALTH LABORATORY SERVICE (Directed by the Medical Research Council for the Ministry of Health) CENTRAL PUBLIC HEALTH LABORATORY, COLINDALE AVENUE, Lonpbon, N.W.9. Telephone : COLINDALE 6041 & 4081. Telegrams : DEFENDER, HyDE, LONDON. 10th, June 1952 Dear Yrofessor Lederberg, Thanks for your two letters. I have just had the final confirmation from Geneva about the fellowship and can now start booking my passage. There must be some discrepancy between the time I applied for and the time I thought I applied for which was 3-6 months depending on how the work progressed. I shall try and sort this out with the WHO authorities, who, I think, are fairly co-operative, In one of your letters you suggested that the salary is somewhat penurious. There have been complaints about this before but one of my friends who was over last year tells me that it is reasonably adequate for single men of simple tastes, except in New York. My employers continue to pay me over here so that my family are provided for, though I cannot take any money over to the U.S.A. because of the dollar shortage. However, there is no objection to my earning a little on the side provided I have the right visa, I am sending two reprints under separate cover. They are all I have available at the moment. I have a joint paper in the press for the J.Genetics (it has been there for two years\) which is a straight forward piece of mouse genetics, Both the papers I am sending are a bit misleading as they are rather mathematical. I was mainly interested in statistics and mathe- matios because of the work I did during the war and it has taken me some time to get around to the idea that results are obtained by experiments not mathematics, I feel that I should emphasise this, ag a good many biologists are allergic to mathematics and perhaps you are among them. , I will let you know in due course when I expect to arrive in the States, which will depend on the date when I can get a passage. The end of September is a difficult time as many people are returning from Europe then. Yours sincerely, Professor J.Lederberg, Dept. of Genetics, University of Wisconsin, Madison 6, Wisconsin, U.S .Ae