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 miles wide. His explanation was a combination of migration and descent with modification. He went on to say: "On this principle of inheritance with modification, we can understand how it is that sections of genera, whole genera, and even families are confined to the same areas, as is so commonly and notoriously the case." Darwin explained how a volcanic island formed a few hundred miles from a continent might be colonised by a few species from that continent. These species would become modified over time, but would still be related to species found on the continent, and Darwin observed that