Titles
- Letter from Louis S. Baron to Joshua and Esther Lederberg4
- Letter from M. Demerec to Erwin Chargaff4
- Letter from M. R. Irwin to Joshua Lederberg4
- Letter from Maclyn McCarty to Joshua Lederberg4
- Letter from Maclyn McCarty to Wendell M. Stanley4
- Letter from Margaret MacDonald to William Osler [Transcript]4
- Letter from Marguerite Stein to Florence R. Sabin4
- Letter from Mario U. Dianzani to Joshua Lederberg4
- Letter from Marshall W. Nirenberg to Francis Crick4
- Letter from Martin R. Pollock to Sol Spiegelman4
- Letter from Marvin L. Minsky to Joshua Lederberg4
- Letter from Maurice B. Visscher to Joshua Lederberg4
- Letter from Maurice H. F. Wilkins to Francis Crick4
- Letter from Maurice R. Green to Joshua Lederberg4
- Letter from Maurice R. Green, St. Luke's Hospital Center to Joshua Lederberg4
- Letter from Maxine Singer to Debi P. Burma4
- Letter from Michael E. DeBakey to William G. Reidy4
- Letter from Michael E. DeBakey to his father, Shaker4
- Letter from Michael G. P. Stoker to Paul Berg4
- Letter from N. W. Pirie, Rothamsted Experimental Station to Joshua Lederberg4