The Hermann Muller Collection spans his entire life plus a number of years following his death in which many scientists and historians wrote about his life and work. Series include correspondence, biographical material and memorabilia, research and publications, and photographs. His correspondence is mainly professional and the bulk of it is with his friend and colleague, Edgar Altenburg, and with Elof Carlson. The biographical material primarily consists of autobiographies, items taken from Muller's office at Indiana University upon his death, and obituary articles. The research and publications consist of lectures, photocopies of articles, scientific notes, reprints, audio tape of lectures, and manuscripts of articles (some eventually published, some unpublished). Of particular interest is a letter H.J. Muller wrote to Stalin in 1936 which precipitated his exit from the USSR. Also of note is a large manuscript Muller had been working on for Erwin Baur about the history of Drosophila studies. The manuscript was left incomplete upon the death of Erwin Baur. The photographs in this collection are primarily those used by Elof Carlson for his biography of Muller but also include unlabelled family photographs of unknown origin.