Notes by Julian Huxley on visits to the Zoological Gardens at New York (Bronx Park), Philadelphia, Washington DC, Paris (Vincennes), Hamburg, Berlin, Munich (Hellabrunn) and Frankfort, also the Aquarium at Chicago

List of American zoos by A Lindsay; Report of a visit to New York and Chicago (1936); 'Notes on visits to some foreign zoos, 1934 and 1935' by Huxley (covering New York Bronx, Philadelphia, Washington, Paris Vincennes, Hamburg, Berlin, Munich Hellabrun, & Frankfurt); extract from report on the British Colonial Exhibit, World's Fair, New York, 1939; Report on visit to Austria and Germany by D Seth Smith (c1937); Report on a visit to the Zoological Gardens at Antwerp, Rotterdam and Amsterdam (1935); Report on a visit to France (1938); letter from Chalmers Mitchell to the Directors of Zoological Gardens in Germany, introducing Huxley, 1935; handwritten notes on zoos; notebook; 'La Reproduction des Animaux Sauvages en Captivite' by A Urbain; Report on visit to Brookfield Zoo (1940); guide to Internationalen Jagdaustellung, Berlin, 1937.

Draft notes by Julian Huxley on visits to the Zoological Gardens at New York (Bronx Park), Philadelphia, Washington DC, Paris (Vincennes), Hamburg, Berlin, Munich (Hellabrunn) and Frankfort, also the Aquarium at Chicago

Letters from Spencer Fullerton Baird of Washington to Philip Lutley Sclater regarding ornithology

Letter from Samuel Pierpont Langley of the Smithsonian Institution to Philip Lutley Sclater regarding the establishment of a Zoological Park in the City of Washington