176 GROWTH OF THE ORIGIN OF SPECIES. [Ch. X. 



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 determining 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 pre- 

 sumptuous 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 

 drawn up a sketch and had it copied (in 200 pages) of my 

 conclusions ; and if I thought at some future time that you 

 would think it worth reading, I should, of course, be most 

 thankful to have the criticism of so competent a critic. 

 Excuse this very long and egotistical and ill-written letter, 

 which by your remarks you have led me into. 



C. D. to J. D. Hooker. Down [1849-50 ?]. 



.... How painfully (to me) true is your remark, that no 

 one has hardly a right to examine the question of species who 

 has not minutely described many. I was, however, pleased to 

 hear from Owen (who is vehemently opposed to any mutability 

 in species), that he thought it was a very fair subject, and that 

 there was a mass of facts to be brought to bear on the question, 



