Born at Cheltenham, the second- son of J.S.Forbes, a well known railway director. Educated at Winchester and, from 1876, at St. John's College, Cambridge where he took high honours in natural science. He was particularly interested in anatomical studies, especially of birds, and succeeded to the prosectorship of the Zoological Society after the premature death of his friend Professor Garrod. His vacations were devoted to zoological expeditions and included visits to Brazil in 1880, the United States in 1881, and an extended visit to the River Niger in 1882.