68 AUTOBIOGRAPHY. 



perhaps be thrown on the whole subject. My first note-book 

 was opened in July 1837. I worked on true Baconian prin- 

 ciples, and without any theory collected facts on a wholesale 

 scale, more especially with respect to domesticated produc- 

 tions, by printed enquiries, by conversation with skilful 

 breeders and gardeners, and by extensive reading. When I 

 see the list of books of all kinds which I read and abstracted, 

 including whole series of Journals and Transactions, I am 

 surprised at my industry. I soon perceived that selection 

 was the keystone of man's success in making useful races of 

 animals and plants. But how selection could be applied to 

 organisms living in a state of nature remained for some time 

 a mystery to me. 



In October 1838, that is, fifteen months after I had begun 

 my systematic enquiry, I happened to read for amusement 

 ' Malthus on Population,' and being well prepared to appre- 

 ciate the struggle for existence which everywhere goes on 

 from long-continued observation of the habits of animals and 

 plants, it at once struck me that under these circumstances 

 favourable variations would tend to be preserved, and unfa- 

 vourable ones to be destroyed. The result of this would be 

 the formation of new species. Here then I had at last got a 

 theory by which to work ; but I was so anxious to avoid 

 prejudice, that I determined not for some time to write even 

 the briefest sketch of it. In June 1842 I first allowed myself 

 the satisfaction of writing a very brief abstract of my theory 

 in pencil in 35 pages ; and this was enlarged during the sum- 

 mer of 1844 into one of 230 pages, which I had fairly copied 

 out and still possess. 



But at that time I overlooked one problem of great impor- 

 tance ; and it is astonishing to me, except on the principle of 

 Columbus and his egg, how I could have .overlooked it and 

 its solution. This problem is the tendency in organic beings 

 descended from the same stock to diverge in character as 

 they become modified. That they have diverged greatly is 

 obvious from the manner in which species of all kinds can be 

 classed under genera, genera under families, families under 



