The Scottish naturalist W.S. Dallas lacked a university degree, but taught himself natural history. In 1847 he began writing articles for the Entomological Society of London and by 1849 he was elected a member of the Linnaean Society. In 1858, at the age of 31, he was appointed "keeper" or curator of the Yorkshire Philosophical Society's museum. By that time he had already made a name for himself, having contributed 28 chapters on natural history in 1854-55 to Orr's Circle of the Sciences, a scientific encyclopedia published as a weekly series. His chapters were reprinted separately in 1856 in a book entitled A Natural History of the Animal Kingdom. In 1857 he published Elements of Entomology. He was honorary secretary of the Yorkshire Naturalists Club from 1859 to 1869. He also was hired to arrange the Natural History collections in the Crystal Palace.
He resigned from the curator's post in 1868 when he was elected to the post of Assistant Secretary of the Geological Society of London. He continued to also work as editor and translator for a journal named Annals and Magazine of Natural History (1868-1890). He was also editor and translator for the Popular Science Review (1872-1890). He had learned French and German (and later taught himself Danish and Swedish) and translated several German scientific texts into English.
Dallas counted among his friends many renowned scientists including Charles Darwin, Sir Charles Lyell, and Thomas Huxley. He created an index for Darwin's "Variation of Animals and Plants under Domestication.”