No. 523] ABE FLUCTUATIONS INHERITED? 



413 



He further states : 



DeVries after much careful experimentation and study 

 of results of agricultural breeding (mainly the results 

 at Svalof and those of the German breeders) showed 

 that much of the improvement which has occurred was 

 not due to cumulative selection but must he explained in 

 some other manner. 



In recent years much careful scientific work has been 

 done along this line to test the action of selection within 

 a pure line and in a mixed population. 



The Svalof Experiment Slat ion lias done much in prac- 

 tical plant -breeding to show that, with reference to the 

 cereals especially, the effect of selection went no further 

 than to isolate the pure lines, and when this was accom- 

 plished no further gain was made by selection. 



Johannsen, 4 working with beans and Jennings 5 with 



