ON THE QUICK GROWING WALNUT 



their hitherto harmonious coalitions, are reasserted 

 in the second generation, as united groups acting 

 along Mendelian lines, so that part of the progeny 

 of the second generation are giants, and part of 

 them are dwarfs, and that all manner of inter- 

 mediate forms find recognition in the case of dif- 

 ferent individuals. 



In no other way known to us could such a dis- 

 turbance of the coalitions of hereditary factors 

 have been brought about. So the plant developer 

 who thus brings together racial strains that have 

 been long separated introduces a disturbing ele- 

 ment that in its practical effects may produce such 

 modifications as could only be produced otherwise 

 through the aggregate influences of environment 

 for almost numberless generations. 



But let it be repeated that even when the 

 hybridizer effects such a disturbance as this, he 

 can do no more than to enable subordinated her- 

 editary factors to make themselves manifest. 



He is dealing with material that has been 

 brought together through age-long experiments, 

 and even though the new combinations that he 

 effects may be striking ones, he may rest assured 

 that even his most spectacular achievement is but 

 a feeble replica of plant developments with which 

 nature has experimented thousands of times over 

 in the course of the long evolutionary ages. 



[237] 



