Mostly concerned with Blakeslee's studies on beans, blood groups, colchicine, Datura, embryo cultures, and horticulture. Many letters relate to the support and direction of the Smith College Genetics Experiment Station, which he headed. Other letters are about the Carnegie Institution of Washington, "Biological Abstracts," American Association for the Advancement of Science, American Philosophical Society, Institut de France, University of Connecticut. Also contains travel letters from Germany and miscellaneous lectures.

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.

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.

Sewall Wright ranks among the most influential figures in the field of population genetics during the 20th century, and made important contributions to biostatistics, biometrics, and evolutionary theory. These papers contain much of Wright's professional correspondence, scattered research notes, and drafts of a small number of papers.

Founded by the Brooklyn Institute of Arts and Sciences in 1890, the Biological Laboratory at Cold Spring Harbor, N.Y., was little more than a languishing outpost until the arrival of Charles B. Davenport in 1898. Over the course of two decades, the ambitious young biologist used his extraordinary administrative skills to transform the institution into the premier center of eugenical study and, as its director, to position himself as the leading spokesman for eugenical research in North America. The Davenport Papers (ca. 63 lin. feet) is a large and nearly comprehensive body of correspondence, lectures, diaries (1878-1942, mostly brief entries of an uneven character), student notebooks and family correspondence pertaining to Charles Davenport and the Cold Spring Harbor Laboratory. The collection is divided into two series, the Charles Davenport Papers, which provides valuable documentation of the development of American biology, animal and plant genetics, and eugenics during the period 1898-1942, with some perspective on the international eugenics movement. Series II, the Cold Spring Harbor Records (ca.20 lin. feet), consists largely of administrative correspondence relating to the laboratory, including Davenport's correspondence with Carnegie administrators (esp. Robert Woodward and John Merriam), accounts and reports concerning financial matters, publications, salaries, material relative to the early history of Cold Spring Harbor labs, and records relative to the numerous professional assistants who worked under Davenport. Among the major correspondents are the American Breeders Association, Committee on Eugenics; American Eugenics Society; American Society of Naturalists; Committee on a Study of the American Negro; Galton Society (see also the extensive correspondence with William K. Gregory); Eugenics Education Society (see Mrs. S. Gotto correspondence); International Congresses of Eugenics; International Federation of Eugenic Organizations, Committee on Race Crossing; National Committee on Mental Hygiene; National Committee on Prisons and Prison Labor; and the Pan-American Conference on Eugenics and Homiculture. There are correspondence and papers relating to the Station for Experimental Evolution, the Eugenics Record Office, and the Carnegie Institution of Washington, and a substantial series relating to a long-range study of children carried out at Letchworth Village, Thiles, New York. This note is currently under review for revision.