University of Wisconsin-Madison Thomas D. Brock I550 Linden Drive Madison, Wisconsin 53706 USA 608-2624261 (Office) 608-238-5050 (Residence) January 4, 1989 Dr. Joshua Lederberg The Rockefeller University New York, NY 10021 Dear Josh, Thanks for the handout on estimation of mutation rates from your Genetics 107 course. Did I tell you that we found Ken Raper’s notes from your course for 1953, which also had a copy of this material? I was quite interested to see Ken’s notes, as they gave quite an insight into what bacterial genetics was like in those days. Unfortunately, he missed several key lectures when you covered mating. I continue to plug away at the first draft, which is nearing completion. But it will be several months before I have a version that I feel I can send out for review. I am just finishing the transformation chapter, which I kept to the end because I didn’t know quite what to do with it. Now that I have finished it I don’t know where to put it! Except for the evidence regarding DNA, pneumococcus transformation did not advance bacterial genetics very much. Indeed, according to my reading of the literature, it was your discovery of transduction which led to the proper interpretation of transformation (as a fragmentary genetic exchange). I appreciate all the things you have been sending me! Sincerely, - Thomas D. Brock E.B. Fred Professor of Natural Sciences k University of Wisconsin-Madison provides equal opportunities for admission and employment.