2 On the Early History of 5-mC In the fall of 1966, Norton D. Zinder of Rockefeller University in New York City presented the Harvey Lecture on "Phage RNA as Genetic Material" (Zinder 1966). Frankly, I do not remember manydetailsofhis talk. However, one ofhis concluding remarks, in which he thanked his teacher Rollin Hotchkiss, stuck in my mind andbecame an important leitmotiffor much of my own scienti?c career. Norton's relevant passages went somethinglikethis (approximate quotation): When we hope to have made a scienti?c discovery, we better spend much of our time immediately after this...