180 NATURAL SCIENCE [September 



successive generations these changes continue until ultimately the 

 new conditions become the natural ones. . . . They can show that 

 throughout all organic nature there is at work a modifying, influence 

 of the kind they assign as the causes of specific differences ; an 

 influence which, though slow in its action, does in time, if the 

 circumstances demand it, produce marked changes." x 



All, therefore, I ask of my readers is to weigh well the evidence 

 that has been again of late years brought forward in favour of 

 adaptation in lieu of natural selection as the means by which 

 varieties originate ; and not to be biassed by, it may be, many 

 years of conviction that Darwinism was all-sufficient. It is solely 

 a question of evidence, and as the doctrine of evolution ultimately 

 broke down men's faith in Creation by " Fiats " and the 

 Argument of Design, so it is hoped that before this century closes, 

 it will be seen that Darwin's deduction of " The Origin of Species 

 by Means of Natural Selection " was a most unfortunate one, as it 

 is quite incapable of verification ; while the conclusion of Mr 

 Herbert Spencer has been abundantly verified, both by inductive 

 evidence and experimental proof. Geokge Henslow. 



i i< 



Essay on The Development Hypothesis," 1852. 



