Modification of Germinal Constitutioit of Organisms 221 



identical materials, simply by the duration of time which 

 the process is allowed to act. This can readily be shown 

 in any of this material in the ontogenetic development of 

 the individual. The oxidative process may be stopped at 

 any stage, and the coloration of the organism then remains 

 at the stage in which the oxidation was stopped. On the 

 other hand, the process may be continued for an abnor- 

 mally long time, producing an unusual amount of pigment 

 substances, giving the organism a dark appearance. 



We are ignorant of any mechanism in the germ cell 

 which would bring about such inhibition of the oxidative 

 process, supposing that the amount of chromogen and 

 oxidizer remains the same. Of course one could, in explain- 

 ing this condition, adopt the idea developed by Dax'enport 

 of the existence of inhibitors, and while it is highly probable 

 that there are such inhibitors present in the germinal 

 mechanism, information concerning them is so fragmentary 

 that anv extended use thereof in explaining these phenomena 

 would better be postponed. 



The inteq^retation of the results produced is that the 

 germinal complex has been permanently modified in some 

 wav, such that either the chromogen is not present in 

 sufficient amount to produce the color of the parental genera- 

 tion, or the oxidation is deficient, but which of the tivo 

 possibilities is correct cannot at the present time be decided. 

 It is entirely probable that it might be one in some instances 

 and in another the other factor that was deficient, both 

 conditions bringing about identical results. It does not 

 follow from this that there exists in the germ a definite 

 representative of the chromogen and of the katalytic agent. 



In the germ cells, as in all other cells, oxidases and sub- 

 stances which may serve as a chromogen are present and 



