On the Origin of Species by Means of Natural Selection

When on board H.M.S. 'Beagle,' as naturalist, I was much struck withcertain facts in the distribution of the inhabitants of South America,and in the geological relations of the present to the past inhabitantsof that continent. These facts seemed to me to throw some light on theorigin of species--that mystery of mysteries, as it has been called byone of our greatest philosophers. On my return home, it occurred to me,in 1837, that something might perhaps be made out on this question bypatiently accumulating and reflecting on all sorts of facts which couldpossibly have any bearing on it. After five years' work I allowed myselfto speculate on the subject, and drew up some short notes; these Ienlarged in 1844 into a sketch of the conclusions, which then seemed tome probable: from that period to the present day I have steadily pursuedthe same object. I hope that I may be excused for entering on thesepersonal details, as I give them to show that I have not been hasty incoming to a decision.My work is now nearly finished; but as it will take me two or three moreyears to complete it, and as my health is far from strong, I have beenurged to publish this Abstract. I have more especially been induced todo this, as Mr. Wallace, who is now studying the natural history ofthe Malay archipelago, has arrived at almost exactly the same generalconclusions that I have on the origin of species. Last year he sent tome a memoir on this subject, with a request that I would forward itto Sir Charles Lyell, who sent it to the Linnean Society, and it ispublished in the third volume of the Journal of that Society. Sir C.Lyell and Dr. Hooker, who both knew of my work--the latter having readmy sketch of 1844--honoured me by thinking it advisable to publish, withMr. Wallace's excellent memoir, some brief extracts from my manuscripts.