34 GROWTH OF THE 'ORIGIN.' [1845? 



occur to you, I should be most grateful for the benefit of 

 them. 



With respect to my far distant work on species, I must 

 have expressed myself with singular inaccuracy if I led you 

 to suppose that I meant to say that my conclusions were 

 inevitable. They have become so, after years of weighing 

 puzzles, to myself alone but in my wildest day-dream, I 

 never expect more than to be able to show that there are 

 two sides to the question of the immutability of species,. 

 i.e. whether species are directly created or by intermediate 

 laws (as with the life and death of individuals). I did not 

 approach the subject on the side of the difficulty in deter- 

 mining what are species and what are varieties, but (though 

 why I should give you such a history of my doings it would 

 be hard to say) from such facts as the relationship between 

 the living and extinct mammifers in South America, and 

 between those living on the Continent and on adjoining 

 islands, such as the Galapagos. It occurred to me that 

 a collection of all such analogous facts would throw light 

 either for or against the view of related species being co- 

 descendants from a common stock. A long searching" 

 amongst agricultural and horticultural books and people 

 makes me believe (I well know how absurdly presumptuous- 

 this must appear) that I see the way in which new varieties 

 become exquisitely adapted to the external conditions of life 

 and to other surrounding beings. I am a bold man to lay 

 myself open to being thought a complete fool, and a most 

 deliberate one. From the nature of the grounds which make 

 me believe that species are mutable in form, these grounds, 

 cannot be restricted to the closest-allied species ; but how far 

 they extend I cannot tell, as my reasons fall away by degrees,, 

 when applied to species more and more remote from each 

 other. Pray do not think that I am so blind as not to see 

 that there are numerous immense difficulties in my notions, 

 but they appear to me less than on the common view. I have 



