THE retirement on -Mar. 9, under the age clause, of Sir Sidney Harmer from the directorship of the Natural History Museum, South Kensington, will remove from active professional life one who has been for forty years conspicuous for his researches in zoology and influence upon this branch of science. Fellow of University College, London (1884), and later fellow, lecturer, and tutor of King's College, Cambridge, he made the latter his home -until in 1908 he came to London as keeper in zoology at the Natural History Museum, afterwards becoming director in 1919. Trained under F. M. Balfour, his first researches were directed to the elucidation of the anatomy, embryology, and position of the Polyzoa; later, his interest shifted to the natural history, evolution, and classification of the group. With Sir Arthur Shipley he edited the "Cambridge Natural History,“1896–1909, which owing to his painstaking care is recognised as giving a complete epitome of the facts of zoology at the dates of publication. He was president of Section D of the British Association in 1908, choosing the Polyzoa as his subject-suggesting that there may be segregation in the formation of a bud analogous to the segregation of characters in the formation of gametes. In recent years his interest turned to the whales, and this was the underlying force in sending out the Discovery expedition to South Georgia to investigate these forms. It says much for his enthusiasm and determination that he induced the British Government, in a time of great financial stress, to send out this the greatest British expedition since the Challenger, the results of which will be the monument to him as director of the Natural History Museum.