No. 519] THE EFFECTIVENESS OF SELECTION 143 



obscure in their significance simply because the workers 

 have not grasped this concept, have not shown the rela- 

 tion of their results to it. Further, in presenting one's 

 own work, or in interpreting the accounts of other.-, the 

 genotype concept is the instrument of precision to take 

 in hand. The results of the analysis made by its aid 

 indicate that most or all of the experiments in methodical 

 selection have consisted in shifting about, isolating and 

 recombining preexisting, permanent hereditary differ- 

 entiations, giving results that were interpreted as re- 

 vealing the law of actually progressive evolution, though 

 in reality they had no relation to such a law. 



To our conclusion as to the analytical value of the pure 

 line idea we may expect strenuous opposition on the part 

 of that last small remnant (if there he such a remnant) 

 of the biometrical school that still Bubmits to the dictation 

 of Pearson 3 — for by one of those sardonic paradoxes 

 through which nature revenges herself, the men who 

 from outside have lectured biology on the necessity of 

 becoming exact are the strongest opponents of exact ex- 

 perimental and biological analysis seeming to feel that 

 mathematical treatment renders other kinds of exactness 

 undesirable. 4 Those who find the genotype idea useful 

 may then prepare themselves for one of those justly 

 famous bludgeonings from the dictator of the whilom 

 orthodox biometrical school: this is the last honorable 

 mark of distinction which stamps the investigator as a 

 thorough and exact analyst of things biological. 5 



