This diverse collection includes correspondence, field notes, lecture and meeting notes, publication material, drawings, and lantern slides. It documents Weber's professional career as an internationally known myrmecologist, or ant scientist, and his wider ranging interests in entomology and ecology. There are class and lab notes for his educational period at Harvard University (A.M. 1933; Ph.D. 1935), and substantial documentation on his primary academic career at Swarthmore College (1947-1974; includes teaching records, data on the Biology Dept. and the College). His field notes, 1930s-1970s (ca. 3 lin. ft.), contain detailed observations of the many scientific expeditions he was a member of, including trips to: West Indies, 1933-1936; Colombia, 1938; Sudan, Uganda, and Kenya, 1939. He also participated in numerous American Museum of Natural History expeditions: Central Africa, 1948; Middle East, 1950, 1952; and Tropical America, 1954. There are data for his time as visiting professor at the University of Baghdad, Iraq, 1950-1952, and his period as Scientific Attaché, Buenos Aires, for the U. S. Dept. of State, 1960-1962. Weber's contributions to polar scientific studies can be studied through his files of the National Academy of Sciences Committee on Polar Research, 1958-1960 (he was on the panel on biological and medical science), as well as many numerous miscellaneous files on polar research. There is substantial material on the Entomological Society of America, and on such local ecological groups as the Chester-Ridley-Crum Watersheds Assoc., Delaware County, Pennsylvania.

The maize geneticist Barbara McClintock (1902-1992) is credited with the discovery of "jumping genes," that is chromosomal "crossing over" and translocation. She received the Nobel Prize in Physiology or Medicine in 1983. The collection is organized into six series: I. Correspondence, 1931-1991; II. Subject files, 1938-1989; III. Works by McClintock, 1944-1989; IV. Works by others, 1927-1991; V. Research notes, notebooks, and card files, 1930s-1990s ; VI. Photographs, 1928-1991.