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.

One of the four horsemen of the evolutionary synthesis of the 1940s, Theodosius Dobzhansky played a crucial role in bridging the gap between theoretical and empirical approaches in genetics and in promoting the Neo-Darwinian synthesis. His contributions to the biological species concept and to an understanding the evolutionary dynamics of wild populations of Drosophila were fundamental to the development of modern population genetics and evolutionary thought. The Dobzhansky Papers are a remnant of the correspondence and writings of the geneticist and evolutionary biologist, Theodosius Dobzhansky. The correspondence (7.5 linear feet) provides insight into Dobzhansky's scientific, philosophical, and social views, particularly during the last decade of his life. Equally valuable are the 54 notebooks (ca.1917-1975) which comprise an almost uninterrupted self-commentary on Dobzhansky's career, replete with typescripts of personal letters and short essays sent to colleagues and friends. The collection also contains two unbound volumes of annotated "reminiscences" from the Columbia Oral History Project, 1962; two bound volumes of papers dedicated to him on his 70th birthday; and 1.5 linear feet of photographs.