—-z- Tk rs ha Lewes “eG pe ‘ ~~ . University of Wisconsin-Madison ( er ret UD ee 7 OKEF ELL. RUS ae “ ‘ VERS Thomas D. Brock 1550 Linden Drive Madison, Wisconsin 53706 USA 608-262-1261 (Office) 608-238-5050 (Residence) November 20, 1988 Dr. Joshua Lederberg The Rockefeller University New York, NY 10021 Dear Josh, I have your inquiry regarding Koch and Darwin. I cover this in a chapter of my book, but unfortunately, the manuscript is still too scribbled to send you a copy. However, I can state categorically that Koch and his school were aware of Darwin. Ferdinand Cohn actually visited Darwin in England in 1876, at a time that he and Koch were close. Further, Fliigge, one of Koch’s closest associates, wrote extensively of bacterial variation and Darwinian evolution in bacteria in his book published in 1886. You certainly have the English translation of this book in your library. The Darwin material is in the Appendix. Fligge, C. 1886. Fermente und Mikroparasiten. Vogel, Leipzig. A~ The English translation was published in 1890 by the New Sydenham Society in RA lL. London (translated by W.W. Cheyne). Qu Lee The strongest proponent of sexual cycles in bacteria at this time was W. Zopf, who Lk eegd, published a book and several papers on this subject. For instance, in 1881 he published lWewees a paper in the Monatsberichte der Akademie der Berlin (pp. 277-284) entitled EB "Genetic relationships of fission fungi" (my translation). He had also described life “ Ie cycles in the iron bacterium Crenothrix polyspora in 1879. However, Fligge thinks that Zopf was working with contaminated cultures. , One of the difficulties of studying variation in bacteria in those days was that everyone worked with complex media, so that only colonial variation could be observed. Fliigge describes various morphological forms of colonies, but does not come down very firmly on the side of variability. It must have been in the 1890’s that medical bacteriologists gradually began to think about variability, when they could characterize bacteria antigenically and began to see antigenic (as well as virulence) variations. Richard Pfeiffer did some fine work on Vibrio cholerae in this regard, and clearly distinguished pathogenic from nonpathogenic isolates. In 1900, prompted by de Vries, Beijerinck’s first paper on mutation appeared. The topic of mutation was frequently discussed in papers and textbooks after this time. However, it was frequently confused by ideas on bacterial life cycles. Do you known Loéhnis’ 1921 book published as a Memoir of the U.S. National Academy of Sciences, entitled Studies upon the life cycles of the bacteria, Part I. Review of the literature, 1838-1919? As far as I can determine, you did not cite this in any of your early papers. Sincerely, T, [puny Thomas D. Brock E.B. Fred Professor of Natural Sciences I hope the above is of some help. University of Wisconsin-Madison provides equal opportunities for admission and employment.