This collection includes correspondence, manuscripts (lectures and articles), research grant material, research data, and participation in organizations, such as, the American Society of Naturalists (President, 1968), Genetics Society of America (President, 1963), and the National Research Council. Of particular note, are the detailed data related to Drosophila eye pigment, and human chromosomes.

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and correlation; vitalism; Japanese language); commonplace book (1924); autobiography; and over one hundred folders of unpublished writings.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

L.C. Dunn was one of the most significant figures in the emerging field of developmental genetics in the 20th century. His T-locus work with the mouse established a number of important genetic principles, including ideas of gene interaction, the distribution of alleles in wild populations, and the factors that influence fertility. He wrote an important textbook of genetics, Principles of Genetics (1925), in collaboration with Sinnott (and later Dobzhansky); other significant books authored or co-authored by him include Heredity, Race and Society (1946), and A Short History of Genetics (1965). He worked in poultry genetics for eight years at the Agricultural Experiment Station in Storrs, CT, from 1920-1928. The remainder of his career was spent at Columbia University, where he worked with rats, mice, and fruit flies, and proved himself to be an inspiring teacher as well. His interest in international scientific collaboration led him to establish ties to Soviet scientists, and to help relocate refugee scientists during World War II. He remained active in his profession to the end of his life. This collection includes correspondence, reports, notebooks, lectures, and photographs. It is a rich collection, documenting the development of American genetics as well as Dunn's interests in humanitarian efforts and international affairs. There is significant material relating to American-U.S.S.R. contacts, particularly in the files on the American-Soviet Friendship Council and the American-Soviet Science Society. There is much, as well, on the impact of the Lysenko controversy in the U. S. Dunn's interest in European scientists can also be seen in the sizable amount of material on the Emergency Committee in Aid of Displaced German Scholars. Material relating to the Kilgore and Magnusson bills for the support of science (predecessors to the NSF) are also in the collection. Of note are data on the following: National Research Council Committee on Experimental Animals and Plants; research on the population study of the Jewish community in Rome; and Columbia University. There is much in the correspondence concerning Drosophila, poultry genetics, and other such topics; Walter Landauer is Dunn's major correspondent.

The geneticist Milislav Demerec emigrated from Yugloslavia in 1919, spending nearly his entire career in the Department of Genetics at Cold Spring Harbor Laboratory. Working initially on the genetics of maize and later on Drosophila virilis, his research interests included radiation and chemical mutagenesis, and during the Second World War, penicillin and the genetics of antibiotic resistance. Demerec served as head of the laboratory at Cold Spring Harbor from 1941 until 1960. The Demerec collection contains the extant professional papers of Milislav Demerec, dating primarily from the time of his arrival at Cold Spring Harbor until his retirement. In addition to his correspondence with colleagues, the collection includes interesting material on the administration of Cold Spring Harbor laboratory during the 1940s and 1950s, data and research notes, material relating to professional organizations (e.g. Genetics Society of America, American Society of Naturalists), a lengthy series of lectures given by Demerec, and a large number of photographs pertaining to Demerec's research, but also to his colleagues and Cold Spring Harbor itself. There is also a Register of visitors to the laboratory (1927-1945) and a Milislav Demerec reprint list.

The James V. Neel Papers document nearly every phase of the career of one of the founders of human population genetics in the United States. Neel was particularly thorough and organized, and retained virtually all of his significant scientific correspondence, committee reports, minutes of meetings, and drafts of manuscripts. The collection also includes data collected during Neel's work among the Xavante, Yanomanö and other indigenous populations. In a career that spanned the period from the late work of Thomas Hunt Morgan and Charles B. Davenport to the contemporary world of molecular genetics and nucleic acids, Neel knew, worked with, and corresponded with many of the most influential 20th century practitioners of genetics. The collection begins in earnest in 1943, after Neel had decided to focus on human genetics. Neel's work with Drosophila and none of his Drosophila manuscripts are found in the collection.