366 LUTHER BURBAISTK 



ally a distinction without a difference when we 

 reflect that, at all events in the case of plants, 

 germ plasm and body plasm are everywhere 

 associated, so that we must suppose that if there 

 is really a distinction between the two, it is a 

 distinction within the substance of the individual 

 cell, as the plant body contains both body plasm 

 and germ plasm. Our earlier studies have 

 shown that we are forced to this conclusion ; and 

 obviously, if this interpretation of germ plasm 

 be accepted, it is a mere quibble as to whether 

 the change or modification of an individual plant 

 involves primarily the germ plasm or whether it 

 involves the body plasm of the same cell as well. 



Of course such mere incidental modifications 

 of an individual as have to do with injury of 

 its parts, the laceration of tissues, or the like, 

 cannot be supposed to have any influence in 

 heredity. 



If such accidental modifications are heritable, 

 the entire scheme of inheritance would become 

 chaotic. 



The modification that is heritable must be 

 one that involves the constitution, so to speak, of 

 the plant ; such modification as would be brought 

 about by changed conditions of nutrition, or by 

 an altered temperature. A certain amount of 

 experimental proof is already in hand that such 



