GALTON AND WEISMANN 275 



His teachings have led to the general, but not 

 the universal, abandonment of the Lamarckian 

 element in evolution as Darwin conceived of 

 it. They receive support from the numerous 

 Mendelian and Mutationist researches which 

 lead to the conviction that variation is essentially 

 of germinal origin. 



Weismann's conceptions of evolution are as 

 much affected by the facts of adaptation as were 

 those of Darwin himself, and he is equally con- 

 vinced that the onward progress of evolution has 

 been by small steps and not by large ones. 



In speaking of 'acquired characters' it may 

 not be out of place to point out that every 

 character contains acquired elements, because en- 

 vironmental influence of some kind is necessary 

 for the existence of all characters. When the 

 differences between corresponding characters in 

 different individuals can be traced to environmental 

 influences the characters are called acquired, when 

 they can be traced to germinal influence they are 

 called inherent. ' Environmental influence ' is 

 here used in the broadest sense and includes the 

 other parts of the same organism. Thus the use 

 or disuse of a part, when determined by the 

 brain, is no less an acquired character than when 

 it is imposed by the conditions of the external 

 world. 



of the properties of natural substances and of changes introduced 

 by art' (p. 144). 



(3) ' Whenever change in the environment regularly produces 

 appreciable change in an organism, such difference may be called 

 an acquired character ' (p. 143). 



T2 



