62 EVOLUTION, OLD AND NEW. 



follow the development of a great conception as it haa 

 grown up in the minds of successive men of genius, and 

 by thus growing with it, as it were, through its em- 

 bryonic stages, he will make himself more thoroughly 

 master of it in all its bearings. 



I will then contrast the older with the newer Dar- 

 winism, and will show why the 'Origin of Species,' 

 though an episode of incalculable value, cannot, any 

 more than the ' Vestiges of Creation,' take permanent 

 rank in the literature of evolution. 



It will appear that the evolution of evolution has 

 gone through the following principal stages : — 



I. A general conception of the fact that specific types 

 were not always immutable. 



This was common to many writers, both ancient and 

 modern ; it has been occasionally asserted from the 

 times of Anaximander and Lucretius to those of Bacon 

 and Sir Walter Raleigh. 



II. A definite conception that animal and vegetable 

 forms were so extensively mutable that few (and, if 

 so, perhaps but one) could claim to be of an original 

 stock ; the direct effect of changed conditions being 

 assigned as the cause of modification, and the important 

 consequences of the struggle for existence being in many 

 respects fully recognized. The fact of design or pur- 

 pose in coimection with organism, as causing habits and 

 thus as underlying all variation, was also indicated with 

 some clearness, but was not thoroughly understood. 



This phase must be identified with the name of 

 BufFon, who, as I will show reason for believing, would 

 have carried his theory much further if he had not 



