I>ARWIN AND DESCENT. 215 



they are supposed to imply that variations which are 

 mainly matters of pure chance and unconnected in 

 any way with function will accumulate and result in 

 specific difference, no matter how much each one of 

 them may be preserved in the generation in which it 

 appears. In the one case, therefore, the expression 

 natural selection may he loosely used as a synonym 

 for descent with modification, and in the other it may 

 not. Unfortunately with Mr. Charles Darwin the varia- 

 tions are mainly accidental. The words " through 

 natural selection," therefore, in the passage last quoted 

 carry no weight, for it is the wrong natural selection 

 that is, or oijght to be, intended ; practically, however, 

 they derived a weight from Mr. Darwin's name to 

 which they had no title of their own, and we under- 

 stood that " the theory of descent with slow modifica- 

 tion " through the kind of natural selection ostensibly 

 intended by Mr. Darwin was a quasi-synonymous ex- 

 pression for the transmutation of species. We under- 

 stood — so far as we understood anything beyond that 

 we were to believe in descent with modification — that 

 natural selection was Mr. Darwin's theory ; we therefore 

 concluded, since Mr. Darwin seemed to say so, that 

 the theory of the transmutation of species generally 

 was so also. At any rate we felt as regards the 

 passage last quoted that the theory of descent with 

 modification was the point of attack and defence, and 

 we supposed it to be the theory so often referred to by 

 Mr. Darwin as " my." 



Again : — 



" Some of the most ancient Silurian animals, as the 



