MancJiester Memoirs, Vol. I. (1906), No. 11. 13 



modified, or discarded, according as it fits well, badly, or 

 not at all with the growing mass of experimental data. 

 It is quite clear that it is impossible while this process is 

 going on to term anything whatever Mendelian as far as 

 theory is concerned."* 



But should we be right in refusing to commend the 

 efforts of a well-digger, if, in sinking his well, he alternately 

 used a spade, a pickaxe, and dynamite, according as he 

 had to deal with gravel, sandstone, or granite, provided 

 that he found, or even that he thought he would find, 

 water at last ? 



The aims of the Mendelian and the well-sinker are 

 the same — to discover something ; and they each employ 

 a definite method, but the tools they use are continually 

 being changed. That is why I think that the method is 

 at least as essential a part of Mendelism as the theory. 

 And that is why I think that there is no more connection 

 between Pearson's generalized theory of alternative 

 inheritance (with special reference to Mendel's Laws), and 

 Mendelism, than there is between the second law of 

 thermo-dynamics and the Maxwellian demon's knowledge 

 of atoms plus the method by which he has acquired it. 



There is a definite relation between a generalized 

 theory of alternative inheritance and that particular 

 doctrine on which it is based : it is the same as the 

 relation between the second law of thermo-dynamics and 

 the theory held — ex hypothesi — by the demon as to the 

 nature of the atom. 



But there can be no relation between any generalized 

 theory of inheritance and Mendelismf unless that term 



* Pearson, :03^, p. 53. 



t I do not, of course, intend to imply that Pearson tries to establish 

 any relation between a generalized theory of inheritance and Mendelism : 

 I know his was a generalized theory of alternative inheritance based on the 

 theory of the pure gamete. All I wish to insist on is that the theory which 



