This collection consists of materials relating to Shull's work commissioned by the Carnegie Institution of Washington to collaborate with their grantee, Luther Burbank, with the aim of analyzing Burbank's data on plant breeding and hybridization and preparing it for publication in suitable scientific journals. Shull visited Burbank's plant-breeding farm in California eight times between 1906 and 1910. There are files for each plant genus involved in Burbank's work. These files contain notes, calculations, clippings from newspapers or periodicals, and an unpublished manuscript of Shull's final report to the Carnegie Institution. There is also a report by Edwin C. MacDowell, which gives background information about the collection.

This collection contains correspondence, drafts of papers, the manuscript of an unpublished book, and photographs. Osterhout's interest in the electrophysiology of plants is documented, as well as his professional career at the University of California, Berkeley; Harvard University; and the Rockefeller Institute.

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and correlation; vitalism; Japanese language); commonplace book (1924); autobiography; and over one hundred folders of unpublished writings.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.