FUNCTION AND ENVIRONMENT 199 



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 con- 

 ditions. Those whose innate plasticity is 

 equal to the occasion are modified and sur- 

 vive. 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 congenital variations similar 

 in direction to these modifications will tend 

 to support them, and to favour the organism 

 in which they occur. Thus will arise a con- 

 genital predisposition to the modifications 

 in question." 



"The plasticity still continuing, the modi- 

 fications become yet further adaptive. Thus 

 plastic modification leads, and germinal 

 variation follows; the one paves the way 

 for the other." 



"The modification, as such, is not in- 

 herited, but is the condition under which 



