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 Papers of Curt Stern include extensive correspondence, lectures (1920s-1970s, 1.5 boxes), autobiographical material, articles, zoological course notes, photographs, etc. Stern's various areas of scientific interest are documented in the collection: the chromosome theory of heredity, role of gene mutation and chromosome rearrangements in evolution, action and interaction of genes during individual development, and particularly his contribution to the development of human genetics as a discipline (centered on his popular and influential book, Principles of Human Genetics, 1949, 1960, 1973). Both his career in Germany and the United States is documented in his correspondence. After studying with T. H. Morgan at Columbia University on a Rockefeller Foundation Fellowship (1924-1926), Stern returned to Richard Goldschmidt's lab at the Kaiser-Wilhelm Institute (1926-1932). There is material of note in the collection concerning this period when Stern helped to establish the cytological basis of crossing over. After a short stay at the California Institute of Technology in 1932, Stern's temporary residence in the U. S. became permanent, and his later career at the University of Rochester, 1933-1947 (Chairman, Department of Zoology) and at the University of California, Berkeley, 1947-1970 (there is abundant material on the Department of Zoology) is covered in the collection. There is other material on: American Association for the Advancement of Science Inter-Society Committee on Science Foundation Legislation, 1946-1947; American Society of Human Genetics (Pres., 1957); Atomic Energy Commission (Advisory Committee for Biology and Medicine, 1950-1955); Genetics (journal); Oak Ridge National Laboratory (Advisory Committee for Biology, 1955-1968); and the Rockefeller Foundation. Stern's correspondence with friends and colleagues in Germany, England, and the U. S., during the 1920s-1930s, is of particular note as it documents not only the developments in genetics and the institutional and administrative networks supporting research, but it also offers general comments and observations on science, Germany, and politics. The photographs (2 boxes) include pictures of many prominent geneticists and scientists.