Fonds contains forty-three letters to Casey A. Wood from Howland Wood describing the Gampala Larin hoard and the finding coins in Ceylon, 1929-1934.

The collection consists primarily of manuscripts and typescripts of papers written on natural history topics, such as insects, birds, marine life, plants, and reptiles. Most of the documents concern the collection and cataloguing of specimens, and the identification of new species. Also included are research notes, notebooks, field notes, lecture notes, correspondence, off-prints, proofs, and galley proofs, as well as drawings and mock-ups of illustrations for printing.

The Philippines are the most heavily-represented country in the subject material of the collection, followed by other areas of South-East Asia and the South Pacific, including Malaysia, Indonesia, India, Singapore, Taiwan, the Soloman Islands, and Hawaii. There is also material representing North and Central America, including Mexico, the United States of America (especially California and Alaska), El Salvador, the Galapagos, and Canada (especially Quebec and Newfoundland). Some works also relate to China, the British Isles, Russia, Japan, New Zealand, and Socotra (Yemen).

Significant figures represented in the collection include: Richard Crittenden McGregor, A.E. Wileman, Edward Charles Stuart Baker, Frank Spaeth, Casey Albert Wood, Averil Lysaght, Harry S. Swarth, Henry Seebohm, Henry George Vennor, Roy E. Dickerson, J. Muir, and Charles Fuller Baker.

Highlights from the collection include: a manuscript copy of Joseph Banks’ journal from his 1768-1771 voyage on the Endeavour, likely made by Maria Dawson Turner; a manuscript, and several annotated typescript versions of Volume 5 of E.C. Stuart Baker’s “Fauna of British India birds”; an assortment of Casey A. Wood’s research notes; annotated proofs, galley proofs, and a mock-up of Richard C. McGregor and Elizabeth J. Marshall’s “Philippine birds for boys and girls;” and a binder of ornithological notes recorded by G.G. Ommanney and others in the Whitlock Bird Sanctuary and surrounding district near Hudson, Quebec.

Many of the manuscripts in the collection were published by the Philippine Journal of Science; also included is correspondence related to publication in the journal, especially related to editing and corrections.

The collection consists primarily of correspondence on natural history topics between scientists and natural historians. Letters are sometimes accompanied by journal articles.

Figures with significant correspondence within the collection include: Casey Albert Wood, Henry Mousley, Robert Ridgway, and Bowdler Sharpe.

The fonds contains correspondence related to the Osler Library and its holdings with people such as Maude Abbott, Edward Archibald, William B. Bean, Edward Horton Bensley, Archibald Malloch, Casey Wood, as well as John Farquhar Fulton, Keeper of the Medical History Collections at Yale University's library; the fonds also contains a typescript of talks by W.W. Francis (titled "Showman's Patter") about books and other items held in the Osler Library.