This is a diverse collection, including correspondence, drafts of letters, notes and notebooks (on biometric methods; tables and formulae; science, nature and method; coefficient and correlation; vitalism; Japanese language); commonplace book (1924); autobiography; and over one hundred folders of unpublished writings. The correspondence and other material covers a variety of topics, including biology, eugenics, evolution and natural selection, human heredity, paramecia, protozoa genetics, U.S. immigration policy. There is much on the Seventh International Congress of Zoology (1907); letters to his father and wives, and from students and colleagues on his seventy-fifth birthday, 1943 (1 v.); diplomas and certificates of membership; and photographs.

Leonard Carmichael was a psychologist whose most significant contributions were made in the fields of child psychology and biopsychology. Educated at Tufts and Harvard, he taught at Princeton, Brown, and Rochester, later returning to Tufts to serve as its President from 1938-1952. An outstanding administrator, Carmichael served as executive officer for the Smithsonian Institute from 1952-1964, and was subsequently vice president for research and exploration at the National Geographic Society. In his later years, he served as President of the American Philosophical Society from 1970-1973. This large and varied collection reflects the entire range of Carmichael's prolific career. It includes a variety of types of records, including correspondence, committee reports and records, long series of articles and speeches, drafts of papers and books, and pocket notebooks. All phases of his professional life are covered, from his years in academia, to his time at the Smithsonian Institute and the National Geographic Society, as well as his involvement in a large number of professional organizations.