i A CONTRIBUTION ONLY 19 



organic evolution." It is in his view a 

 "contribution," and nothing more a step 

 in the investigation of a subject of enor- 

 mous complexity and extent, but by no 

 means a complete or satisfactory solution 

 of even the most obvious difficulties pre- 

 sented by what we know of the structure 

 and the history of organic forms. 



It is no part of my object here 

 to criticise in detail the value of that 

 special conception with which Mr. 

 Herbert Spencer now supplements the 

 deficiencies of the Darwinian theory. 

 He calls it "inheritance of functionally 

 produced modifications," and he makes 

 a tremendous claim on its behalf. He 

 evidently thinks that it supplies not only 

 a new and wholly separate factor, but 

 that it goes a long way towards solving 

 many of the difficulties of organic evolu- 

 tion. Nothing could indicate more 

 strongly the immense proportions which 



