Included in volume 16 (pages 6293- 6308) “Three papers on the tendency of species to form varieties; and on the perpetuation of varieties and species by natural means of selection”. Extracts from an unpublished work on Species by C Darwin Esq consisting of a portion of a chapter intituled “On the Variation of Organic Beings in a state of nature; on the Natural Means of Selection; on the comparison of Domestic Races and true Species”. Part III “On The Tendency of Varieties to depart indefinitely from the original type”. By Alfred Russell Wallace. Second appearance in print of the papers in which Darwin and Wallace jointly presented their theories of evolution by natural selection, at which they had arrived independently. These papers appeared earlier that year in the Journal of the Proceedings of the Linnean Society for 1858; both publications precede the appearance of Darwin's landmark On the Origin of Species, in which Darwin amplified the theory.