FUNCTION AND ENVIRONMENT 199 



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. unex- 

 plained), or arise in course of shufflings of 

 qualities and properties that undoubtedly 

 must occur in the history of the germ- 

 cells. 



INDIRECT IMPORTANCE OF MODIFICATIONS. 

 The interesting suggestion has been made, 

 independently by Mark Baldwin, Lloyd 

 Morgan, and Osborn, that useful " modifica- 

 tions " may serve as the fostering nurses of 

 " variations " in the same direction. We 

 quote from Lloyd Morgan a brief statement 

 of this idea : " Suppose that a group of plastic 

 organisms is placed under new conditions. 

 Those whose innate plasticity is equal to the 

 occasion are modified and survive. Those 

 whose plasticity is not equal to the occasion 

 are eliminated. . . . Such modification 

 takes place generation after generation, but, 

 as such, is not inherited. . . . But any con- 

 genital variations similar hi direction to these 

 modifications will tend to support them, and 

 to favour the organism hi which they occur. 



