384 LUTHER BURBANK 



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 intermediate forms find recognition 

 in the case of different 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 devel- 

 oper who thus brings together racial strains that 

 have been long separated, introduces a dis- 

 turbing element that in its practical effects may 

 produce such modifications as could only be 

 produced otherwise through the aggregate in- 

 fluences of environment for almost numberless 

 generations. 



But let it be repeated that even when the hy- 

 bridizer effects such a disturbance as this, he can 

 do no more than to enable subordinated heredi- 

 tary 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. 



