198 EVOLUTION 



stature, even to save their lives; yet they are 

 fertile in device, persistent in endeavour. 

 Even the worm will turn; even the plant will 

 answer back. Living creatures are agents; 

 they thrust as well as parry; they act on 

 their surroundings, modifying them; they 

 are ever seeking out new environments, and 

 conquering them. 



The foregoing analysis has sufficiently 

 shown that the range of relations between the 

 living creature and its surroundings is a very 

 complex one, of functional dependence, of 

 periodic punctuation, of transient adjust- 

 ment, of more lasting adjustment, of per- 

 manent modification, of variational stimulus, 

 of elimination or selection, up to active 

 initiative upon the organism's part. The 

 evolutionary import of these relations is no 

 doubt even more intricate than we can yet 

 see. The old theories of direct adaptation 

 in response to altered environmental con- 

 ditions, or as the result of use and disuse, 

 were much too simple. But there has also 

 been far too great simplicity in the view 

 too long prevalent in the generation after 

 Darwin, and to some extent even to-day, 

 that each species must, so to speak, wait 

 with folded hands, until fit variations emerge, 

 whether these be "spontaneous" (i. e. un- 

 explained), or arise in course of shufflings of 



