"Independent" lecture agencies are a neglected element in the history of education. Between 1918 and 1939, the Selborne Lecture Bureau was a significant national provider of adult education in Britain, both in its own right and as a supplier of lecture(r)s to Women's Institutes and other bodies, and it pioneered the use of films in schools. For a brief period, it was an "educational" vehicle for the Empire Marketing Board with a programme of over 2400 lectures in 1929. The Bureau originated in the early twentieth century split between the conservative (and male) traditions of natural history and the radical (and female) campaigning (anti-) plumage movement that produced the RSPB. The interwar history of the Selborne Lecture Bureau provides a counterpoint to conventional accounts of adult education between the two world wars, part of an influential "third stream" alongside the "liberal tradition" and growing state and local authority provision. (Contains 4 figures and 55 footnotes.)