OLD TYPES AND NEW 153 



are selected in the hope that the gains made by them 



will be maintained in their offspring. 



We, h aye seen that it. is very questionable whether 



\acquired characters which are due to environmental 



(conditions play any role whatever in heredity. The 



phenotypic character does not always indicate what 



the germplasm will subsequently do, and when the 



true genotypic constitution of the germplasm is still 



further masked by the temporary fluctuations caused 



by a modified environment, it is increasingly difficult 



to select wisely from the display of variants those 



which will produce the best ancestors for the future 



stock. 



That this common procedure of selecting the best- 

 \ appearing animal in the flock and the biggest ear of 

 ( corn in the bin, has met with a large degree of success 

 Vin the past is due entirely to the fact that in many 

 I instances the phenotypic character is an actual ex- 

 / pression of the genotypic constitution. This is not 

 1 always the case, however, and we cannot now fail 

 to see that the method is blind and full of error. Its 

 successes are due to thev indirect results of chance 

 rather than to a direct control of the factors of hered- 

 ity. The great proportion of failures resulting from 

 this procedure now find a reasonable explanation from 

 the standpoint of Mendelism. 



b. The Method of Rimpau 



Contrasted with the Hallet method of augmenting 

 acquired characters and then selecting the best display 

 of them, is the method of Rimpau, who experimented 



