Reactions to On the Origin of Species stage where he was able to turn his attention fully to "Species", and from this point he was working to publish his theory. On 18 June 1858 he received a parcel from Alfred Russel Wallace enclosing about twenty pages describing an evolutionary mechanism that was similar to Darwin's own theory. Darwin put matters in the hands of his friends Lyell and Hooker, who agreed on a joint presentation to the Linnean Society on 1 July 1858. Their papers were entitled, collectively, "On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means
Essay on the Origin of Languages Essay on the Origin of Languages Essay on the Origin of Languages () is an essay by Jean-Jacques Rousseau published posthumously in 1781. Rousseau had meant to publish the essay in a short volume which was also to include essays "On Theatrical Imitation" and "The Levite of Ephraim." In the preface to this would-be volume, Rousseau wrote that the "Essay" was originally meant to be included in the "Discourse on Inequality", but was omitted because it "was too long and out of place". The essay was mentioned in Rousseau's 1762 book, "Emile". In this text, Rousseau lays out a narrative