Known primarily for his zoological work in India where he moved in 188I after leaving his post as Assistant Professor of Zoology at Aberdeen. His interest in entomology developed after his appointment as Superintendent of the India Museum, Calcutta, in 1893 in succession to J. Wood-Mason. His main entomological work was on mosquitoes, although beetles collected by him survive there. He left India in 1907 when he was appointed Lecturer in Entomology at the London School of Tropical Medicine. In 1919 he was appointed Professor of Medical Zoology in the University of London.
He gave 113 Coleoptera from Samoa to the Natural History Museum in 1923.
Gilbert (1977) lists three obituaries, and there is an account of Alcock by Annandale in Records of the Indian Museum (1908-9, 2: 1-9). Manuscripts and drawings survive in the Natural Hisory Museum, and the London School of Hygiene and Tropical Medicine has some autobiographical notes of 1906.He is not mentioned in Cotes, E.C. ‘A decade of entomology in the Indian Museum 1884-1894’ (Indian Museum Notes 1889-1903, 3: 1-7) (MD 7.01, 9/22)