104 EVOLUTION, OLD AND NEW. 



began his work with a belief in the fixity of species, 

 will find, that from the very first chapter onward, he 

 leant strongly to mutability, even if he did not openly 

 avow his belief in it. 



In support of this assertion, one quotation must 

 suffice : 



" Nature advances by gradations which pass unnoticed. 

 She passes from one species, and often from one genus 

 to another by imperceptible degrees, so that we meet 

 with a great number of mean species and objects of 

 such doubtful characters that we know not where to 

 place them." * 



The reader who turns to Buffon himself will find the 

 idea that Buffon took a less advanced position in his old 

 age than he had taken in middle life is also without 

 foundation. 



Mr. Darwin has said that Buffon " does not enter into 

 the causes or means of the transformation of species." 

 It is not easy to admit the justice of this. Inde- 

 pendently of his frequently insisting on the effect of all 

 kinds of changed surroundings, he has devoted a long 

 chapter of over sixty quarto pages to this very subject; 

 it is to be found in his fourteenth volume, and is headed 

 "De la Degeneration des Animaux," of which words 

 *' On descent with modification " will be hardly more 

 than a literal translation. 1 shall give a fuller but still 

 too brief outline of the chapter later on, and will con- 

 fine myself here to saying that the three principal causes 

 of modification which Buffon brings forward are changes 

 of climate, of food, and the effects of domestication. 



* Tom. i. p. 13, 1749. 



