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. Extract from an unpublished work on Species by C. Darwin Esq consisting of a portion of a chapter intituled “On the Variation of Organic Beings in a state of nature; on the Natural Means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”. Reprinted from the “Proceedings of the Linnean Society” 1/ Tendency Of Species To Form Varieties Charles Darwin 2/ Abstract of a letter from Charles Darwin Esq to Prof Asa Gray Boston U.S.A September 1857 3/ On The Tendency of Varieties to depart indefinitely from the Original Type Alfred Russell Wallace The first appearance in 1858 in “Proceedings of the Linnean Society” Then “The Zoologist” This volume also includes two other papers on insects by Wallace, "Note on the Theory of Permanent and Geographical Varieties" and "On the Entomology of the Aru Islands," on pp. 5887-5894. Freeman 349/ 1700