14 Darbishire, Lazvs of Heredity, 



signifies the Mendelian theory only ; and, even so, this 

 relation cannot be permanent unless the MendeHan is 

 pledged not to change his theory in the smallest degree. 

 I hold that, in the first place, Mendelism has, as 1 have 

 shewn, a wider signification, namely, that it embraces the 

 method as well ; and secondly, that no Mendelian can be 

 expected to take the pledge demanded, if, by doing, so he 

 believed, as he probably would, that he would' be pre- 

 vented from attaining his end. It is idle to accuse 

 him of inconsistency. What should we think of the 

 consistency of a well-digger who died of thirst because 

 he would stick to his spade although only a few feet of 

 granite separated him from water? 



And what right have we to expect that the demon 

 should pledge himself not to alter his theory of the nature 

 of atoms if he hopes that by being free to alter it he will 

 attain a knowledge of them that will enable him to live 

 in a warm compartment without having to do any work 

 for it? What right has a physicist to expect a demon 

 not to alter his theory, on the ground that such an altera- 

 tion makes it exceedingly difficult for him (the physicist) 

 to use the theory as a basis for statistical calculation ? 



3 {c). The difference betweeri Mendel's Law and the Law 

 of Contribution. 



Now that we come to discuss the difference between 

 Mendel's Law and the Law of Diminishing Individual 

 Contribution we must clearly understand that by Mendel's 

 Law we mean the theory associated with that name, and 

 not the method. 



Mendelians happen to be testing at the moment is, to my mind, not the 

 essential thing in Mendelism. If the commonly accepted explanation of the 

 proportion iDD : 2DR : iRR were shewn to be false, would experiments, 

 called Mendelian, now in progress be prosecuted with less zeal? By no 

 means. Such a discovery would even be an incentive to more strenuous 

 search. 



