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THE AMERICAN NATURALIST [Vol. XLIII 



ite in agreement with the present-day distinction 

 fluctuating variations and mutations. Indeed, 

 there are many who think that the distinction between 

 the ampler fluctuations, on the one hand, and the lesser 

 mutations, on the other, is not entirely established. 



Darwin nowhere claims that natural selection is of the 

 nature of a creative force. 



I shall now cite a few passages in support of the above 

 findings. Eeferences are made to the sixth edition. All 

 italics are mine. 



I. The main thesis is the origin of species by descent 

 as opposed to the theory of the immutability of species 

 or the independent creation of species. 



While Darwin believed that varieties are incipient 

 species he also believed that this identity had not yet 

 been demonstrated. In speaking of the resemblance of 

 varieties to species he says: 



Independently of the question of fertility and sterility, in all other 

 respects there seems to he a general and close similarity in the. offspring 

 'of crossed species and of crossed varieties. If we look at species as 

 having been specially created, and at varieties as having been produced 

 by secondary laws this similarity would be an astonishing fact. But 

 it harmonizes perfectly with the view that there is no essential differ- 

 ence between species and varieties (pp. 261-2). 

 Again : 



It has been asserted over and over again by writers who believe 

 in the immutability of species that geology yields no linking forms 

 (p. 208). 



And on page 290 : 



ether the several facts and laws relating to the 

 of organic beings accord best with the common 



