26o Heredity and Eugenics 



acters which, when a definite array of conditions are brought 

 together, i:)roduce a definite color, and when another array 

 is brought together a different color results, or perhaps 

 no color. 



At the present time there is no evidence that in the cells 

 there is incapacity for the production of pigment, or inca- 

 pacity for the production of either chromogen or enzyme. 

 The only e\'idence is that the pigment does or does not 

 appear when germ cells derived from parents of a certain 

 character are combined. In the minds of some it follows 

 from this that something is lacking in the way of a specific 

 activity; in the minds of others it is due to the fact that a 

 sufficient cjuantity of one or the other of two necessary 

 substances is not present. Still another explanation is 

 that there is lacking strength or energy to produce the one 

 or the other. 



Further, the situation can be explained by adopting the 

 idea of inhibitors, activators, etc., which would inhibit the 

 appearance of pigment in one case, and then, by the inhibi- 

 tion of the inhibitor permit the appearance of pigment in 

 another case. Much fine evidence exists from the work 

 of the neo-Mendelian hybridologists that factors, deter- 

 miners, accelerators, and inhibitors exist and can be sub- 

 jected to experimental tests; however, to attempt to 

 explain observed conditions by asserting that the organism 

 is incapable of producing the requisite amount of chromogen 

 or activator is really no explanation, because it is well known 

 that a minimum amount of actix'ator may convert an almost 

 unlimited amount of chromogen into a color-forming sub- 

 stance, provided the substance produced as a result of the 

 katal}-zing process is removed with sufficient rapidity so as 

 not to impede the process. This is a well-known principle 



