354 EVOLUTION, OLD AND NEW. 



fication, he must mean, consciously or unconsciously, 

 that " the conditions of existence " are the main but 

 not exclusive means of modification. But this is only 

 falling in with " the views and erroneous grounds of 

 opinion," as Mr. Darwin briefly calls them, of Lamarck 

 himself; a fact which Mr. Darwin's readers would have 

 seen more readily if he had kept to the use of the words 

 " survival of the fittest " instead of " natural selection." 

 Of that expression Mr. Darwin says* that it is "more 

 accurate" than natural selection, but naively adds, 

 " and sometimes equally convenient." 



I have said that there is a practical identity of 

 meaning between "natural selection" and "the con- 

 ditions of existence," when both expressions are fully 

 extended. I say this, however, without prejudice to 

 my right of maintaining that, of the two expressions, 

 the one is accurate, lucid, and calculated to keep the 

 thread of the argument well in sight of the reader, 

 while the other is inaccurate, and always, if I may 

 say so, less "convenient," as being always liable to 

 lead the reader astray. Nor should it be lost sight of 

 that Lamarck and Dr. Erasmus Darwin maintain that 

 species and genera have arisen because animals can 

 fashion themselves into accord with their conditions, so 

 that, as Lamarck is so continually insisting, the action 

 of the conditions is indirect only changed use and 

 disuse being the direct causes ; while, according to Mr. 

 Darwin, it is natural selection itself (which, as we have 

 seen, is but another way of saying conditions of existence) 

 that is the most important means of modification. 

 * Origin of Species,' p. 49. 



