The papers of Professor Sir Gavin Rylands De Beer comprise notebooks, typescript lecture texts and photographs, [1917-1947]; notably including four manuscript notebooks containing summaries of lectures attended by De Beer when he was an undergraduate and fellow at Oxford, consisting of notes on rudimentary embryology and zoology with sketches and bibliographies, [1917-1938]; proofs and fair copies of the text of De Beer's anniversary lecture as President of the Linnean Society on animal posture and morphology with photographs and drawings, [1947]; transparencies used in a talk on evolution, [1947]; microscopy photographs of the embryonic development of monotremes and marsupials and, at the cellular level, of the salamander, [1945-1972]; photographs and plaster casts of the brain case and other parts of a fossilised specimen of the bird-like Archaeopteryx, [1950-1960]; photographs of cross sections through a mature tree showing growth rings, [1950-1960].

Correspondence, 1887-1925, mainly between Dendy and fellow academics relating to the morphology and classification of sponges, notably with George Parker Bidder, President of the Marine Biological Association of the UK; Professor William John Dakin, Professor of Zoology, University of Liverpool; Francisco Ferrer Hernandez, Musea de Gencias Naturales, Madrid, Spain; Professor William A Haswell, Emeritus Professor of Biology, University of Sydney, Australia; Ernst Hentschel, Zoologisches Museum, Hamburg, Germany; William Abbott Herdman, University of Liverpool; Professor Sydney John Hickson, Emeritus Professor of Zoology, University of Liverpool; Randolph Kirkpartick, Natural History Museum, London; Professor James Herbert Orton, Emeritus Professor of Zoology, University of Liverpool; Joseph Pearson, Director of the Columbo Museum, Ceylon; and Edgar Thurston, Superintendent of the Government Museum, Madras, India. The correspondence also includes letters, 1919-1921, relating to the establishment of a research grant in memory of Harold Row, Dendy's assistant. Papers, 1886-1899, relating to sponge collections, particularly specimens in Australia and New Zealand, and including the dredging records for Port Phillip, Victoria, Australia, 1887-1890. Lecture notes written by Dendy, [1903-1925], including handwritten texts of lectures on 'Echinodermata', 'The development of starfish', 'Holothurioidea', 'Class Gastropoda', 'Mytilus', 'Anodarta cygnea', 'Helix', 'Mollusca', and 'Merozoa', and typescript texts of public lectures including 'The stream of life', given at a Citizens' Lecture in Edinburgh, 1921, and 'The evolution theory today', given at the Liverpool Meeting of the British Association for the Advancement of Science, 1923. Working notebooks, [1886]-1912, mainly containing scientific experiments and observations relating to sponges, notably the Challenger Amphipoda and the Grantia Compressa, and notes on the topographical distribution of, and biographical references to, sponge specimens. Two notebooks, 1917-1919, recording experiments and observations during Dendy's membership of the Royal Society's Committee for the Investigation of Grain Pests. Papers, 1892, relating to The Victorian land planarians [1894] by Dendy, comprising a volume of annotated and revised extracts from that work, and a letter to Dendy from Thomas Steel concerning flatworm species. Printed obituaries of Dendy, 1925-1926. Papers relating to the study of lizard-like reptiles commonly known as Tuatara (the scientific name being Sphenodon), [1897]-1910, including correspondence, 1908-1910, between Dendy and Edward Bles, Elliot Smith, Annie Howes and [William Thompson] Sedgwick, and catalogues, notes and photographs of Tuatara embryos.

One file of miscellaneous papers relating mainly to obstetrics, and comprising rough notes on embryology, the staining of blood, the condition of bones, and sketching the topography of the brain, 1899; a list of examination questions from the Royal College of Physicians of London and Royal College of Surgeons of England midwifery exam, 10 July 1902; King's College London Faculty of Medicine Tanner Prize examination question paper on obstetrics, 16 July, 1902; list of questions from the King's College London Faculty of Medicine Obstetric Medicine Prize Class Examination, 17 July, 1902; two examination appointment cards for Cheatle issued by the Royal College of Physicians of London and the Royal College of Surgeons for examinations leading to membership of the Colleges, taking place at the Exam Hall, Victoria Embankment, London, 14, 21 October 1903; programme sheet for a complimentary dinner in honour of Sir William Watson Cheyne at the Waldorf Hotel, London, 17 July 1908; circular from the Ministry of Health on orthopaedic services and on tetanus antitoxin,10 August 1946; an errata page from a printed formulary; typescript summaries of the symptoms and treatment of nasal catarrh and the means of avoiding accidental haemorrhage of the placenta [1945-1951]; photograph, probably late nineteenth century showing reclining clergyman in a walled garden, probably a cathedral or university cloister.