Francis Albert Eley Crew (1886-1973) was the dynamic first director of Edinburgh's Animal Breeding Research Station (later Institute of Animal Genetics) and occupied the University's first Chair of Animal Genetics. A former student of both Ewart and Darbishire, Crew was offered the directorship in 1919 following Darbishire's untimely death. Crew was the first to fully analyse complete sex reversal in birds. He observed that an apparently normal hen � a female - later exhibited male characteristics and was capable of fertilising the eggs of another hen. This research appeared at a time when the functions of hormones and chromosomes in sex determination was still uncertain.