DARWIN'S VARIATIONS. 185 



aided in an important manner by the inherited effects 

 of the use and disuse of parts ; and in an unimportant 

 manner, that is, in relation to adaptive structures, 

 whether past or present, by the direct action of 

 external conditions, and by variations which seem to 

 us in our ignorance to arise spontaneously. It appears 

 that I formerly underrated the frequency and value of 

 these latter forms of variation as leading to permanent 

 modifications of structure independently of natural 

 selection." 



Here, again, it is not use and disuse which Mr. 

 Darwin declares himself to have undervalued, but 

 spontaneous variations. The sentence just given is 

 one of the most confusing I ever read even in the 

 works of Mr. Darwin. It is the essence of his theory 

 that the " numerous successive, slight, favourable 

 variations," above referred to, should be fortuitous, 

 accidental, spontaneous ; it is evident, moreover, that 

 they are intended in this passage to be accidental or 

 spontaneous, although neither of these words is em- 

 ployed, inasmuch as use and disuse and the action of 

 the conditions of existence, whether direct or indirect, 

 are mentioned specially as separate causes which purvey 

 only the minor part of the variations from among 

 which nature selects. The words " that is, in relation 

 to adaptive forms " should be omitted, as surplusage 

 that draws the reader's attention from the point at 

 issue ; the sentence really amounts to this — that 

 modification has been efiiected chiefly through selection 

 in the ordinary course of nature from among spontane- 

 ous variations, aided in an unimportant manner ly 



