ch. ix.] 18311844. 179 



was growing in my father's mind. The same thing is how- 

 ever true of earlier days. 



So much for the general problem : the further question 

 as to the growth of Darwin's theory of natural selection is a 

 less complex one, and I need add but little to the history 

 given in the Autobiography of how he came by that great 

 conception by the help of which he was able to revivify " the 

 oldest of all philosophies that of evolution." 



The first point in the slow journey towards the Origin 

 of Species was the opening of that note-book of 1837 of 

 which mention has been already made. The reader who is 

 curious on the subject will find a series of citations from 

 this most interesting note-book, in the Life and Letters, 

 vol. ii. p. 5, et seq. 



The two following extracts show that he applied the 

 theory of evolution to the " whole organic kingdom " from 

 plants to man. 



" If we choose to let conjecture run wild, then animals, 

 our fellow brethren in pain, disease, death, suffering and 

 famine our slaves in the most laborious works, our com- 

 panions in our amusements they may partake [of] our 

 origin in one common ancestor we may be all melted 

 together." 



" The different intellects of man and animals not so great 

 as between living things without thought (plants), and liv- 

 ing things with thought (animals). 



Speaking of intermediate forms, he remarks : 



" Opponents will say shoiv them me. I will answer yes, 

 if you will show me every step between bulldog and grey- 

 hound." 



Here we see that the argument from domestic animals 

 was already present in his mind as bearing on the produc- 

 tion of natural species, an argument which he afterwards 

 used with such signal force in the Origin. 



A comparison of the two editions of the Naturalists' 

 Voyage is instructive, as giving some idea of the develop- 

 ment of his views on evolution. It does not give us a true 

 index of the mass of conjecture which was taking shape in 

 his mind, but it shows us that he felt sure enough of the 

 truth of his belief to allow a stronger tinge of evolution to 

 appear in the second edition. He has mentioned in the 

 Autobiography (p. 40), that it was not until he read Malthus 

 that he got a clear view of the potency of natural selection. 

 This was in 1838 a year after he finished the first edition 



