Strophanthus seeds, but there was confusion about which species. During the course of this work Callow went to Nigeria at the invitation of Ibadan University, for six months with R.D. Meikle, a botanist from the Royal Botanic Gardens, Kew, to collect arrow poison material. S. sarmentosus was found to contain sarmentogenin but it was not easy to cultivate or to produce in sufficiently large quantities. Another possible source was hecogenin from Agave sisalana, a plant native to Mexico, grown commercially in Kenya. This was a less direct way of producing cortisone, but the successful extraction and purification of hecogenin from the sisal plant, and its availability made it a suitable commercial source. Glaxo Laboratories cooperated with Cornforth and Callow to devise a production process for cortisone from hecogenin. In this case the work done by NIMR staff was patented and sold to Glaxo Labs. Callow was elected as a Fellow of the Royal Society (FRS) in 1958. Honeybee pheromones Callow became interested in the structure and action of "queen substance," produced by the queen honeybee, after hearing a talk by Dr. Colin G. Butler on honeybee behaviour at NIMR. Queen substance controls queen-rearing by honeybees, as well as being the sex pheromone attracting drones to a queen on her nuptial flights. Callow isolated and identified this as 9-oxodec-trans-2-enoic acid in 1959. This work led to a general interest in the biochemistry of insects. After he retired from the NIMR in 1966, Callow joined the staff at Rothamsted Experimental Station in the insecticide department. Using a mass spectrometer, he carried out work in the field of insect pheromones until 1971. Editorial and other work Kenneth Callow was a member of the editorial board of the Biochemical Journal from 1946 until 1953. Later he was chairman of Biological and Medical Abstracts Ltd. He was a member of the Council of the Bee Research Association from 1962 to 1974, being chairman 1963–68, and later Vice-President. Personal life In his work on oestrone he was assisted by Nancy Newman (1913–1989), whom he married in 1937. He was the father of John Callow (1944–2000) a merchant navy officer and arboriculturalist, and "Mo" Callow (Mo Laidlaw), an ergonomist at Bell Northern Research in Ottawa from 1978 to 1987. He died 12 April 1983 in Maughold, Isle of Man where he had moved in 1980, in pursuit of his Manx ancestors. His grandfather Edward Callow wrote a