Elected F.R.S. 1973
L.E.A. Rowson was always known as Tim to his family, friends and colleagues alike. He was a veterinary surgeon who made important contributions to research in reproductive physiology in farm animals and its application to animal breeding. In particular, he was a pioneer of artificial insemination (AI) and embryo transfer, which have become two of the most important technologies for livestock improvement in modern times.He was appointed Director of the first AI centre for cattle breeding in Britain, established at Cambridge in 1942, and played a leading role in the application and rapid growth of this technology. In 1952 he contributed to the development of successful methods for the freezing and long-term storage of bull semen at very low temperatures. This had far-reaching consequences for the future of AI and cattle breeding worldwide.For thirty years he also worked at the Animal Research Station in Cambridge on methods for embryo transfer in sheep and cattle and their use in research and breeding. This culminated in the 1970s with the development of effective methods for collection and transfer of cattle embryos by non-surgical means. The birth of the first calf after transfer of a deepfrozen embryo in 1973 was another landmark, and these advances led quite quickly to the commercial application of embryo transfer in cattle breeding.Tim Rowson is generally regarded as the founder of embryo transfer in farm animals, but important contributions were made by many collaborators. He always considered that he was privileged during his early years to have worked with Dr John (later Sir John) Hammond, F.R.S., who maintained that the function of applied science was to synthesize the detailed knowledge gained from fundamental research into a constructive whole so that it could be used for a specific purpose. Tim was a true disciple of this philosophy and always tried to relate a fundamental approach to a practical outcome.