Photograph of Carlos Offermann holding a cigarette and posing with his arm around another man. Part of a series of photographs in the same folder.

Typed letter with handwritten calculations in the margin from Lewis Mott-Smith to H.J. Muller, 1929.

Handwritten letter from Carl Hartman to H.J. Muller, 1927.

Photograph of a young boy (David Muller?) feeding goats while they crowd around him at a park or zoo. Part of a series of photographs in the same folder.

Photograph of young boy (David Muller?) walking towards the camera. Part of a series of photographs in the same folder.

Photograph of H.J. Muller standing on a snow covered path with mountains behind him. Taken during H.J. Muller's trip to Germany in 1932.

Photograph of Georg Griesmaier and Ada Muller Griesmaier posing together outside with handwritten note "Aunt Ada and Uncle Georg" on back. Taken during H.J. Muller's trip to Germany in 1932.

Photograph of Ada Muller Griesmaier posing outside with snow on the ground. Photograph taken during H.J. Muller's trip to Germany in 1932.

Photograph of a room of about 17 ship passengers (among them is H.J. Muller) with raised glasses and wearing caps during a beer drinking contest on board a ship sailing to Europe.

Photograph taken at Erwin Baur's farm near Berlin of 8 people with handwritten identification of front "Prof. Baur's son, Mrs. Baur, Prof. Nachtsheim, Prof. Goldschmidt, Prof. Baur, Dr. von Stein, Dr. H[...], Prof. Altenberg" and with handwritten…