The papers provide full documentation for all aspects of Darlington's career. There is much autobiographical and personal material in the form of narratives, diaries and jotters, and family correspondence including letters and cards exchanged with his parents, 1920-1949. There are records of Darlington's own career at the John Innes Horticultural Institution and of general administration and organisation, 1923-1953, and later correspondence and papers, 1954-1980, including the Institution's move to Norwich, 1965-1967. There are records of his Oxford career including his interest in the Botanic and Genetic Gardens and the Nuneham Courtenay Arboretum and his involvement in 'Oxford reform' controversies, 1958-1970. The research material in the papers corresponds to Darlington's own designations and includes his own early notebooks and observations and a large component relating to the history of science, notably William Bateson and N.I. Vavilov, Russian genetics and the Lysenko controversy.
The most substantial body of material relates to Darlington's publications. The material includes scientific papers of all periods and technical range, as also the drafts and publishing history of the major books on evolution published in his later years, The evolution of man and society, 1969, and The little universe of man, 1978. There are also records of lectures and broadcasts, and societies and organisations including a full account of the journal Heredity founded by Darlington and R.A. Fisher and subsequently transferred to the Genetical Society. Visits and conferences documented include the formative early visits to Persia, USA and Japan, the Klampenborg meeting in 1938, and various International Genetics Conferences in which Russian colleagues were involved, or forbidden to be involved. There are also records of the International Chromosome Conferences which Darlington considered to be one of his most important tasks at Oxford. Darlington's scientific correspondence contains some extended exchanges with colleagues such as J.B.S. Haldane, J.S. Huxley, E.K. Janaki-Ammal, P.C. Koller and H.J. Muller.