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
On the Origin of Species it made more widely available; the price was halved to 7s 6d by printing in a smaller font. It includes a glossary compiled by W.S. Dallas. Book sales increased from 60 to 250 per month. In the United States, botanist Asa Gray, an American colleague of Darwin, negotiated with a Boston publisher for publication of an authorised American version, but learnt that two New York publishing firms were already planning to exploit the absence of international copyright to print "Origin". Darwin was delighted by the popularity of the book, and asked Gray to keep any profits. Gray managed to negotiate