154 GENETICS 



for two decades with various grains and, finally, 

 among other results, produced the famous Schland- 

 stedt barley. 



Rimpau's method is to sow grain under ordinary 

 conditions with a minimum rather than a maximum 

 amount of fertilizer and then to select individuals, 

 neither from the rich spots nor from the edges of 

 the field where there is little crowding, but from situa- 

 tions where the environmental conditions are ordi- 

 nary or even unfavorable. Individuals making a 

 good showing under such usual, or even adverse, 

 conditions are worthy by nature rather than by nur- 

 ture and are consequently most desirable as progeni- 

 tors of future stock. By this method the attempt is 

 not to keep the progeny of single individuals sepa- 

 rate, but to mass together the best as they appear 

 under ordinary normal environment. 



This again is an indirect method of procedure, 

 although the character of the germplasm is more 

 nearly hit upon in this way than by Hallet's method, 

 since the mask of temporary accessory modifications 

 is stripped so far as possible from the somatoplasm, 

 and the phenotype made to approximate the geno- 

 typical constitution. 



c. The Method of de Vries 



The method of de Vries has already been in part 

 described in Chapter IV. It depends upon the pres- 

 ervation and exploitation of the mutations occurring 

 in nature. It recognizes clearly the fact that change 

 of type is dependent upon a germplasmal variation 



