SHORTER ARTICLES AND DISCUSSION 



AN ATTEMPT TO MODIFY THE GERM PLASM OF 

 CENOTHERA THROUGH THE GERMINATING SEED 



When a new character appears in a homozygous race or 

 species it may be either a mutation or an acquired character. 

 If a mutation it has been produced because the germ plasm has 

 in some way been affected and the succeeding generations may 

 be expected to show the same variation. If an acquired char- 

 acter it will be present for a single generation and is then lost 

 unless the cause that produced the somatic change also modified 

 the germ plasm in such a manner that it may develop the same 

 character, in succeeding generations. By "acquired characters" 

 is meant any and all changes that are wrought in the soma of 

 the organism by the environment considered in its broadest 

 sense. It is the creed of modern biology that acquired characters 

 are not inherited unless the environmental influences also play 

 on the germ cells even while focused on the body tissues, pro- 

 ducing at the same time potential alterations in the former and 

 visible changes in the latter. 



however, that in the reported iiistaiu-t's of nuitation the varia- 

 tions arose as the result of changes in the germ plasm. A muta- 

 tion, therefore, has its origin from within and this origin has 

 no very evident connection in any way with external condi- 

 tions. If a case of an acquired character is shown to be in- 

 herited it is clear that the germ plasm of the organism must 

 have been affected. Tli,' stimulus to ."hange, therefore, in con- 

 trast with the cause of imitation, would have come from without. 

 While the end result— the alteration of the germinal constitu- 

 tion—is the same in both cases, the method or cause by which 

 it is brought about is different. From this point of view, the 

 relative value in evolution of mutation and of hereditary 

 acquired characters is open to various interpretations. I tliink 

 that in the case of mutations it may soon be possible to demon- 

 strate that some of the so-called examples of "mutations" are 

 due to or are associated with irregularities of karyokinesis. It is 

 not at all inconceivable that outside conditions producing ac- 

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