UNIVERSITY COLLEGE LONDON GOWER STREET W.C.1 Euston 4400 Dec. ith 19,6 Please quote : DEPARTMENT OF BIOMETRY (Entrance by Malet Place, or Gower Street) Professor J. B. S. Haldane Dr. Lederberg, Osborn Botanical Laboratory, Yale University, New Haven, Connecticut. Dear Dr. Lederberg, professor Haldane thanks you for your letter of October 12. He is sorry that it has been so long unanswered, but he has been trying to arrange to be in America in the New Year. It is now reasonably certain that he wiil be at the A.A.A.S. meetings at Boston from Dec 26th, and at the Conference at Princeton from Jan 4rd. He hopes to see you then, otherwise will try to answer you letter in detail later. Yours sincerely, A.C. Ch abste Gate