24 DARWINIANA. 



facts to such assumption, and also to adduce instances 

 explicable by it and inexplicable by the received view, 

 so perhaps winning our assent to the doctrine, through 

 its competency to harmonize all the facts, even though 

 the cause of the assumed variation remain as occult as 

 that of the transformation of tadpoles into frogs, or 

 that of Coryne into Sarzia. 



The first line of proof, successfully carried out, 

 would establish derivation as a true physical theory ; 

 the second, as a sufficient hypothesis. 



Lamarck mainly undertook the first line, in a 

 theory which has been so assailed by ridicule that it 

 rarely receives the credit for ability to which in its day 

 it was entitled. But he assigned partly unreal, partly 

 insufficient causes ; and the attempt to account for a 

 progressive change in species through the direct in- 

 fluence of physical agencies, and through the appe- 

 tencies and habits of animals reacting upon their 

 structure, thus causing the production and the succes- 

 sive modification of organs, is a conceded and total 

 failure. The shadowy author of the " Yestiges of the 

 Natural History of Creation " can hardly be said to 

 have undertaken either line, in a scientific way. He 

 would explain the whole progressive evolution of Na- 

 ture by virtue of an inherent tendency to develop- 

 ment, thus giving us an idea or a word in place of a 

 natural cause, a restatement of the proposition instead 

 of an explanation. Mr. Darwin attempts both lines 

 of proof, and in a strictly scientific spirit ; but the 

 stress falls mainly upon the first, for, as he does assign 

 real causes, he is bound to prove their adequacy. 



It should be kept in mind that, while all direct 



