of those he touched and in the scientific achievements of the next generation which meant so much to him.
This memoir draws on and expands upon the obituary notice I composed for the Infectious Diseases Society of America (Journal of Infectious Diseases 130( 1974) :311-12) and similar notices prepared by Sol Sherry (Transactions of the Association of American Physicians 88(1975):32-34) and A. McGehee Harvey ( The Interurban Clinical Club (1905-1976)— A Record of Achievement in Clinical Science (New York: Saunders, 1978), pp. 201. Additionally, the materials supplied by the Archives of New York University Medical Center, by Dr. Richard Ross, Dean of Johns Hopkins Medical School, and the office of the Home Secretary of the National Academy of Sciences were most helpful sources of additional biographical information. I am also indebted to the following of Dr. Tillett's colleagues and friends for careful reading of this memoir for accuracy and significant detail: Drs. Maclyn McCarty, Sol Sherry, Saul Farber, Michael Heidelberger, and Herbert Chasis.