46 GENETICS AND EUGENICS 



If the germ-cells are thus capable of modification, evolu- 

 tion guided by the environment must be in some measure at 

 least a reality. The truth then lies neither in the extreme 

 Lamarckian view that all acquired characters are inherited 

 nor in the extreme Weismannian view, that no extraneous 

 influences modify the germ-plasm, but somewhere in 

 between. 



