'On keeping wild animals in zoos' Folder also contains other articles from Endeavour and Triangle. The origin of lizards by E. Kuhn-Schnyder, Alchemy in medieval Islam by E.J. Holmyard, The changing epidemiology of poliomyelitis by G. Fanconi, The mycorrhiza of forest trees by J.L. Harley, Vitamin B12 by A.W. Johnson and Sir Alexander Todd, The organisation within nerve cells by J.Z. Young, Sea urchin spermatozoa by Lord Rothschild. 1955