Where is information on Wallace and evolution?

Wallace had once briefly met Darwin, and was one of Darwin's numerous correspondents from around the world, whose observations Darwin used to support his theories. Wallace knew that Darwin was interested in the question of how species originate, and trusted his opinion on the matter. Thus, he sent him his essay, On the Tendency of Varieties to Depart Indefinitely From the Original Type, and asked him to review it. On 18 June 1858 Darwin received the manuscript from Wallace. While Wallace's essay did not employ Darwin's term natural selection, it did outline the mechanics of an evolutionary divergence of species from similar ones due to environmental pressures. In this sense, it was essentially the same as the theory that Darwin had worked on for twenty years, but had yet to publish. Darwin wrote in a letter to Charles Lyell: "he could not have made a better short abstract! Even his terms now stand as heads of my chapters!" Although Wallace had not requested that his essay be published, Charles Lyell and Joseph Hooker decided to present the essay, together with excerpts from a paper that Darwin had written in 1844, and kept confidential, to the Linnean Society of London on 1 July 1858, highlighting Darwin's priority.