Titles
- Letter from Alan Gregg to Walter B. Cannon2
- Letter from Barbara McClintock to Curt and Evelyn Stern2
- Letter from Catharine Macfarlane to Florence R. Sabin2
- Letter from Charles A. Doan to Florence R. Sabin2
- Letter from Charles R. Burnham to Barbara McClintock2
- Letter from Claude Forkner to Florence R. Sabin2
- Letter from Elvin A. Kabat to Michael Heidelberger2
- Letter from F. Elisabeth Crowell to Alan Gregg2
- Letter from Florence B. Seibert to Florence R. Sabin2
- Letter from Florence R. Sabin to Catharine Macfarlane2
- Letter from Florence R. Sabin to Charles A. Doan2
- Letter from Florence R. Sabin to Rudolph J. Anderson2
- Letter from Franklin Halpin to Lawrence Kolb2
- Letter from Fred L. Soper to Wilbur A. Sawyer2
- Letter from George W. Beadle to Edward L. Tatum2
- Letter from Karl A. Connell to Virginia Apgar2
- Letter from Lawrence Kolb to the Surgeon General2
- Letter from MacGregor Instrument Company to Michael E. DeBakey and William H. Gillentine2
- Letter from Michael Heidelberger to Hugh S. Taylor, Princeton University2
- Letter from Michael Heidelberger to Kai O. Pedersen2