:'7 



774 Fluctuations 



In other words, there is a progression and a re- 

 gression. A progression in relation to the whole 

 race, and a regression in comparison with the 

 parent. The significance of this becomes clear 

 at once, if we recall the constancy of the variety 

 which could be obtained from the selected ex- 

 treme in the case of vegetative multiplication. 

 The progression is what the breeder wants, the 

 regression what he detests. Regression is the 

 permanency of part of the mediocrity which 

 the selection was invoked to overcome. Mani- 

 festly it is of the highest interest that the pro- 

 gression should be as large, and the regression 

 as small as possible. In order to attain this 

 goal the first question is to know the exact meas- 

 ure of progression and regression as they are 

 exhibiting themselves in the given cases, and 

 the second is to inquire into the influences, on 

 which this proportion may be incumbent. 



At present our notions concerning the first 

 point are still very limited and those concern- 

 ing the second extremely vague. Statistical in- 

 quiries have led to some definite ideas about the 

 importance of regression, and these furnish a 

 basis for experimental researches concerning 

 the causes of the phenomenon. Very ad- 

 vantageous material for the study of pro- 

 gression and regression in the realm of 

 fluctuating variability is afforded by the 



