f 575. 297 



;i30. 



I. 



The Influence of Mind in Evolution. 



THAT Charles Darwin, intent on his own discovery, the influence of 

 natural selection by the survival of the fittest, should have given 

 less than their due to other causes that may have contributed to the 

 evolution of the colours and forms of animals was natural enough. 

 Perhaps it was equally natural that his more ardent followers should 

 go further than himself, and see in natural selection the sufficient 

 explanation of everything. The tendency towards sheer materialism, 

 which is perhaps an inevitable first result of accepting Darwin's 

 theory, has disinclined them even to allow to an animal's habits and 

 actions any influence in modifying the form of the species. All animal 

 life is to them a gambling-table, in which every number in turn comes 

 up, but only those which chance to fall into the right hole, labelled 

 " environment," count towards the winning of the game. This view 

 reaches its climax in Weismann's doctrine that characters acquired 

 by an individual after birth are not transmitted to its posterity. 

 Weismann is a great name, but since Herbert Spencer has stood up 

 against him as the champion of the opposite doctrine, that acquired 

 characters are transmitted and that the use or disuse of any organ i& 

 one of the most potent among the influences that control its develop- 

 ment, meaner men who have never been able to beHeve that natural 

 selection does explain everything may take courage to admit their 

 conviction. I am one of these. Natural selection alone has always 

 seemed to me utterly inadequate to explain many of the phenomena 

 which come under the notice of every naturalist. In fact, natural 

 selection itself appears to require an antecedent cause. Look, for 

 example, at the phenomenon known as protective resemblance or 

 mimicry. If the Ukeness of an insect to a leaf, or a twig, or another 

 insect, often procures its escape from its enemies, then it is easy to 

 see how natural selection may operate in maintaining and perfecting 

 that likeness, for those in which it is least exact will be soonest dis- 

 covered and killed. But it is obvious that the resemblance must be 

 initiated and carried a certain length before natural selection can begin 

 to operate at all ; for until the likeness of an insect to some other 

 object is sufficient to cause it sometimes to be actually mistaken for 

 that object, no step in the direction of that likeness can be of 



Y 



