THE ORIGIN OF SPECIES 



INTRODUCTION 



When on board H. M. S. Beagle, as naturalist. I was much struck 

 with certain facts in the distribution of the organic beings in- 

 habiting South America, and in the geological relations of the 

 present to the past inhabitants of that continent. These facts, as 

 will be seen in the latter chapters of this volume, seemed to throw 

 some light on the origin of species — that mystery of mysteries, as 

 it has been called by one of our greatest philosophers. On my re- 

 turn home it occurred to me, in 1837, that something might per- 

 haps be made out on this question by patiently accumulating and 

 reflecting on all sorts of facts which could possibly have any bear- 

 ing on it. After five years work I allowed myself to speculate on 

 the subject, and drew up some short notes; these I enlarged in 

 , 1844 into a sketch of the conclusions which then seemed to me 

 probable: from that period to the present day I have steadily 

 pursued the same object. I hope that I may be excused for enter- 

 ing on these personal details, as I give them to show that I have 

 not been hasty in coming to a decision. 



My _ work is now (1859) nearly finished; but as it will take me 

 many more years to complete it, and as my health is far from 

 strong, I have been urged to publish this abstract. I have more 

 especially been induced to do this, as Mr. Wallace, who is now 

 studying the natural history of the Malay Archipelago, has ar- 

 rived at almost exactly the same general conclusions that I have 

 on the origin of species. In 1858 he sent me a memoir on this 

 subject, with a request that I would forward it to Sir Charles 

 Lyell, who sent it to the Linnean Society, and it is published 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 read 

 my sketch of 1844 — honored me by thinking it advisable to pub- 

 lish, with Mr. Wallace's excellent memoir, some brief extracts from 

 my manuscripts. 



