Titles
- Letter from Alexander Makinsky to Alan Gregg1
- Letter from Allen O. Whipple to Virginia Apgar1
- Letter from Austin Brues to Clarence Dennis1
- Letter from Carl E. Buck to Louis Dublin1
- Letter from Charles D. Hurd, Northwestern University to Michael Heidelberger1
- Letter from Charles R. Drew [to the New Year]1
- Letter from Charles R. Drew to his mother, Nora1
- Letter from Charles Seymour to Alan Gregg1
- Letter from Courtenay Crocker to Wilbur A. Sawyer1
- Letter from Curt Stern to Barbara McClintock1
- Letter from E. B. Fred to Edward L. Tatum1
- Letter from Edward L. Tatum to Nils Fries1
- Letter from F. W. Clement to Virginia Apgar1
- Letter from Florence R. Sabin to Austin Joyner1
- Letter from Florence R. Sabin to George W. Corner1
- Letter from Florence R. Sabin to Robert S. Cunningham1
- Letter from Frank B. Hanson to Edward L. Tatum1
- Letter from Frank S. Burch to Clarence Dennis1
- Letter from Fred E. Wright, National Academy of Sciences to Oswald T. Avery1
- Letter from Good Housekeeping Magazine to Florence R. Sabin1