THE FACTORS OP ORGANIC EVOLUTION. 29 



has been made by one whose competence as an observer is 

 beyond question, and whose testimony is less liable than 

 that of all others to any bias towards the conclusion that 

 such inheritance takes place. I refer to the author of 

 the Origin of Species. 



Now-a-dayjj_.most naturalists are more Darwinian than 

 MrrParwrfl frrmpplf- I do not mean that their beliefs in 

 organic evolution are more decided ; though I shall be 

 supposed to mean this by the mass of readers, who identify 

 Mr. Darwin s great contribution to the theory of organic 

 evolution, with the theory of organic evolution itself, and 

 even with the theory of evolution at large. But I mean 

 that the particular factor which he first recognized as 

 having played so immense a part in organic evolution, has r 

 come to be regarded by his followers as the sole factor, | 

 though it was not so regarded by him. It is true that he 

 apparently rejected altogether the causal agencies alleged 

 by earlier inquirers. In the Historical Sketch prefixed to 

 the later editions of his Origin of Species (p. xiv, note), 

 he writes : &quot; It is curious how largely my grandfather, 

 Dr. Erasmus Darwin, anticipated the views and erroneous 

 grounds of opinion of Lamarck in his f Zoonomia (vol. i, 

 pp. 500-510), published in 1794.&quot; And since, among the 

 views thus referred to, was the view that changes of 

 structure in organisms arise by the inheritance of function 

 ally-produced changes, Mr. Darwin seems, by the above 

 sentence, to have implied his disbelief in such inheritance. 

 But he did not mean to imply this; for his belief in it as (, 

 a cause of evolution, if not an important cause, is proved 

 by many passages in his works. In the first chapter of 

 the Origin of Species (p. 11 of the first edition), he says 

 respecting the inherited effects of habit, that &quot;with 

 animals the increased use or disuse of parts has had a 

 marked influence ; &quot; and he gives as instances the changed 

 relative weights of the wing bones and leg bones of the 



