366 THE GROWTH OF THE 'ORIGIN OF SPECIES. 5 



he is merely " tempted to believe in such simple relations as 

 variation of climate and food, or introduction of enemies, or 

 the increased number of other species, as the cause of the 

 succession of races." But finally (ist edit.) he ends the 

 chapter by comparing the extinction of a species to the ex- 

 haustion and disappearance of varieties of fruit-trees : as if 

 he thought that a mysterious term of life was impressed on 

 each species at its creation. 



The difference of treatment of the Galapagos problem is 

 of some interest. In the earlier book, the American type of 

 the productions of the islands is noticed, as is the fact that 

 the different islands possess forms specially their own, but the 

 importance of the whole problem is not so strongly put for- 

 ward. Thus, in the first edition, he merely says : 



" This similarity of type between distant islands and con- 

 tinents, while the species are distinct, has scarcely been suffi- 

 ciently noticed. The circumstance would be explained, ac- 

 cording to the views of some authors, by saying that the crea- 

 tive power had acted according to the same law over a wide 

 area." (ist edit. p. 474.) 



This passage is not given in the second edition, and the 

 generalisations on geographical distribution are much wider 

 and fuller. Thus he asks : 



"Why were their aboriginal inhabitants, associated . . . 

 in different proportions both in kind and number from those 

 on the Continent, and therefore acting on each other in a dif- 

 ferent manner why were they created on American types of 

 organisation ? " (2nd edit. p. 393.) 



The same difference of treatment is shown elsewhere in 

 this chapter. Thus the gradation in the form of beak pre- 

 sented by the thirteen allied species of finch is described in 

 the first edition (p. 461) without comment. Whereas in the 

 second edition (p. 380) he concludes : 



" One might really fancy that from an original paucity of 

 birds in this Archipelago, one species has been taken and 

 modified for different ends." 



On the whole it seems to me remarkable that the difference 



