OKIGIN OF SPECIES. 



INTEODUCTIOK 



When on board H.M.3. ' Beagle/ as naturalist, I was 

 much struck with certain facts in the distribution of 

 the organic beings inhabiting 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 return home, it 

 occurred to me, in 1837, that something might perhaps 

 be made out on this question by patiently accumulating 

 and reflecting on all sorts of facts which could possibly 

 have any bearing 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 entering on these personal details, as 

 I give them to show that I have not been hasty in 

 coming to a decision. 



