Born on 6 February 1871 at Padisham, Lancashire, the only son of Mr Stephenson, gentleman, and Susannah Hudson, his wife. He was educated at Burnley Grammar School and Manchester University. He served as house physician at the Manchester Royal Infirmary, 1893-94, and as house physician at the Royal Hospital for Diseases of the Chest, London, in 1894. He passed into the Indian Medical Service, taking the first place in the examination and being gazetted lieutenant on 29 July 1895, captain on 29 July 1898, major 29 July 1907, lieutenant-colonel 20 January 1915. He served with the NW Frontier expedition 1897 (medal and two clasps), and was present at the operations in Bajaur and the Mamund country. He was also occupied on plague duty and held various civil appointments in the Punjab between 1900 and 1906. During the first world war he was recalled and served in Egypt. He was appointed professor of biology at the Government College, Lahore in 1906, and professor of zoology in 1912. In this position he inspired a number of Punjabi students with something of his own enthusiasm for the study of the fauna of India. In 1912 the government appointed him principal of the College at Lahore, a position which had not previously been held by a member of the Indian Medical Service, and in 1918 he became vice-chancellor of the Punjab University. He retired from the IMS on 6 September 1921 and, returning to England, was appointed lecturer in zoology at the University of Edinburgh. He held the post until 1929, when he settled in London to edit the *Fauna of British India* series at the Natural History Museum. He married Gertrude, daughter of T Bayne, of St Anne's-on-the-Sea, who survived him but without children. He died at 42 Orsett Terrace, W2, on 2 February 1933, and was buried at Kensal Green cemetery. Stephenson had many gifts. He was a first-rate zoologist, a good Oriental scholar, a fine teacher, and a good medical officer. All this was concealed in a body made delicate by chronic weakness of the heart, which rendered it necessary for him to live a very retired life. But he was a friend to all zoologists, and was valued for his knowledge, gentleness, and sympathy. He was more especially interested in the oligochaetes (earthworms) of India, and was recognized as the first living authority upon them. The subject fascinated him on account of the light which the study threw upon the present distribution of creatures with very little power of migration and with an intolerance of salt water. It opened up problems of distribution, evolution, zoological geography, and the past history of oceans and continents. Publications: *Indian toxicology*. 1906. *The Hadigatu-l-Haqiqat of the Hakim Sanai*, text, translation, and commentary, 1910. *Oligochaeta*, in *Fauna of British India series*. London, 1923. *Intelligence exercises in English*. Oxford, 1927. The Nuzhatu-l-Qulub, edition and translation of the zoological portion. *Isis*, 1928, 11, No 36. *The oligochaeta*. Oxford, 1930. Robert Brown's discovery of the nucleus in relation to the history of the cell theory. *Proc Linn Soc* 1931-32, 144, 45.