Qualified in medicine at the London Hospital and became a naval surgeon. He saw active service in the Boer War and in the 1914-18 War, taking part in the Battle of the Falkland Islands in H.M.S. Cornwall, and in the East African campaign. At the end of the War he was posted to the Admiralty, but not being particularly interested in administration he retired about 1920, with the rank of Surgeon Commander, to devote his life to entomology. He went to the Indian Forestry Research Institute at Dehra Dun, but after two years he was invalided to Switzerland with a suspected lung infection. After his health was restored he came back to London in 1925.
Cameron's interest in entomology appears to have started with Lepidoptera and his first recorded publication was on Lycaena icarus in Ent, 20, 1887, 40. By 1900, when he published on the 'Reoccurence of Actocharis readingi Sharp at Plymouth' in EMM, 36, 1910, 261, he had not only taken up the Coleoptera, but in particular the Staphylinidae, the family with which his name is most closely associated.
Camerons' travels afforded him considerable opportunities for collecting all over the world, and, as many of his more than 150 papers testify, he seized these chances with alacrity. The Staphylinidae of Java, Borneo, China, Japan, Turkey, New Zealand, Africa, Haiti, Mauritius and many other countries were all studied by him. His most important publication however, and undoubtedly the one for which he is best known, is the four volumes (in five) on Staphylinidae for the FBI series from 1930 to 1939, which amount to some 1,862 pages.
It is perhaps hardly surprising that many of Cameron's papers on the British fauna relate to specimens taken in close proximity to the ports of Devonport and Plymouth. It was at the former in 1898 that he first met J.H. Keys with whom he was to become friendly. He recorded in the obituary of Keys which he wrote in the EMM, 77, 1941, 60-61, that he looked back with great pleasure on the many excursions which they had made together over Dartmoor.
Cameron gave a collection of 12,000 beetles to the NHM in 1936 (1936-555) and bequeathed his collection of Staphylinidae, amounting to some 55,000 specimens, including 2,230 holotypes and 1,064 paratypes, as well as much unidentified material, to the NHM too. According to a ms notebook of Sir T. Hudson Beare in the RSM, Cameron gave other specimens to him. The following MS material in the NHM: Typescript List of Coleoptera observed in the Maltese Islands by Cameron and A.Caruana Gatte, 1907; five MS notebooks titled Cameron European Coleoptera, 1898-1907; one MS notebook titled Catalogue of Mr M. Cameron’s collection from the West Indies, 1908 (taken during his cruise in the Indefatigable); miscellaneous notes; and correspondence with 30 British and foreign entomologists. (Harvey et al. (1996), 38-39).
There are obituaries in EMM, 90, 1954, 290 (by E.B. Britton); Proc. RESL., (C), 19, 1955, 68 (by P.A.Buxton); and in Publicacoes Culturais de Companhia de Diamantes de Angola, 48, 1959, 111-112. (MD 1/O2, 10/03, 1/22)