On August 20, 1858 Charles Darwin and Alfred Russel Wallace published "On the tendency of species to form varieties; and on the perpetuation of varieties and species by natural selection" in the Journal of the Proceedings of the Linnean Society. This was the first printed formal exposition of the theory of evolution by natural selection. Darwin had developed the essential elements of his theory by 1838 and set them on paper in 1844; however, he chose to keep his work on evolution unpublished for the time, instead concentrating his energies first on the preparation for publication of his geological work on the Beagle voyage , and then on an exhaustive eight-year study of the barnacle genus Cirripedia.
In 1856, at the urging of Charles Lyell, Darwin began writing a vast encyclopedic work on natural selection; however, it is possible that the extremely cautious Darwin might never have published his evolutionary theories during his lifetime had not the naturalist Alfred Russel Wallace independently discovered the theory of natural selection. Wallace conceived the theory of natural selection during an attack of malarial fever in Ternate in the Mollucas, Indonesia (Febuary, 1858) and sent a manuscript summary to Darwin, who feared that his discovery would be pre-empted.
In the interest of justice Joseph Dalton Hooker and Charles Lyell suggested joint publication of Wallace's paper prefaced by a section of a manuscript of a work on species written by Darwin in 1844, when it was read by Hooker, plus an abstract of a letter by Darwin to Asa Gray, dated 1857, to show that Darwin's views on the subject had not changed between 1844 and 1857. The papers by Darwin and Wallace were read by Lyell before the Linnean Society on July 1, 1858 and published on August 20.
"There are five different forms in which the original edition can be found, but they are all from the same setting of type. Four of these are the results of the publishing customs of the Linnean Society of London and the fifth is the authors' offprints. The Journal came out in parts and was available to Fellows of the Society with Zoology and Botany together in each part, Zoology alone, or Botany alone. Later it appeared in volume form made up from reserved stock of the parts with new title pages, dated in the year of completion of the volume, and indexes. This again was available complete or as Zoology or Botany alone. The Zoology was signed with numbers and the Botany with letters. The Darwin-Wallace paper occurs in the complete part in blue wrappers, or in the Zoology part in pink wrappers; the Botany parts were in green. The Linnean Society has all the forms in its reference files, although it does not hold the offprint.
"The authors' offprints were issued in buff printed wrappers with the original pagination retained. They have 'From the Journal of the Proceedings of the Linnean Society for August 1858.' on page . They were printed from the standing type but, presumably, after the copies of the number had been run off. The only copies which I have seen have been inscribed personally by Darwin, but Life and letters, Vol. II, p. 138, notes that Darwin had sent eight copies to Wallace, still in the far-east, and had kept others for him" (http://darwin-online.org.uk/EditorialIntroductions/Freeman_TendencyofVarieties.html, accessed 11-25-2014).
On November 24, 2014, as a result of an international collaboration with the Darwin Manuscript Project based at the American Museum of Natural History, New York, Cambridge University's Cambridge Digital Library published online more than 12,000 hi-resolution images of manuscripts by Darwin, with transcriptions and detailed notes. These papers chart the evolution of Darwin’s intellectual journey, from early theoretical reflections while on board HMS Beagle, to the publication of On the Origin of Species 155 years earlier, on November 24, 1859. The papers document the origins of Darwin’s theory of evolution – including the pages where he first coined and committed to paper the term "natural selection."