Typed letter from H.J. Muller to Elof Carlson regarding the birth of Elof's daughter and a manuscript of Elof's with handwritten note from Muller's secretary, Sue Hickham, 1961.
Typed letter with handwritten additions and postscript from H.J. Muller to Elof Carlson regarding Joravsky's writing on Serebrovsky, Lysenkoism, Isreal Agol, and Soloman Levit, 1962.
Typed letter with handwritten additions from H.J. Muller to Elof Carlson regarding a colleague's (William R. Lee) trip to California and about a Irwin Oster, 1963.
Typed letter with handwritten corrections from H.J. Muller to Elof Carlson regarding Elof's book "The Gene", Muller's additions to "Out of the Night", and Elof's request to write a biography of Muller, 1966.