Published online by Cambridge University Press: 31 July 2008
The Twelfth Oliver Bird Lecture was delivered by Professor Richard Doll, Regius Professor of Medicine in the University of Oxford, at the London School of Hygiene and Tropical Medicine on 19th March 1970. This was the last lecture to be given under the auspices of the Oliver Bird Trust, an account of which starts on page 359. Professor Doll was formerly Director of the MRC Unit of Medical Statistics, in which capacity he had exceptional experience in assessing the significance of changes in the incidences of abnormal conditions. The subject of his lecture was therefore highly appropriate to his special knowledge, as well as to current controversy and to the series of Oliver Bird lectures. The Journal of Biosocial Science is glad to publish this authoritative exposition of a most important problem.