PLANT BREEDING 43 



which have been only partially appreciated, and 

 it has yet to approach the precision which we 

 expect in the handling of steam or electricity, 

 and, notwithstanding the occasional sneers of the 

 ignorant, these silent forces embodied in plant 

 life have yet a part to play in the regeneration 

 of the race which by comparison will dwarf into 

 insignificance the services which steam and elec- 

 tricity have so far given. Even unconscious or 

 half-conscious plant breeding has been one of 

 the principal forces in the elevation of the race. 

 The chemist and the mechanic have, so to speak, 

 domesticated some of the forces of nature, but 

 the plant breeder is now learning to guide even 

 the creative forces into new and useful channels. 

 This knowledge is a most priceless legacy, mak- 

 ing clear the way for some of the greatest bene- 

 fits which man has ever received from any source 

 by the study of nature. 



A general knowledge of the relations and 

 affinities of plants will not be a sufficient equip- 

 ment for the successful plant breeder. He must 

 be a skillful botanist and biologist, and, having a 

 definite plan, must be able to correctly estimate 

 the action of the two fundamental forces, inher- 

 ent and external, which he would guide. 



The main object of crossing genera, species, 

 or varieties is to combine various individual ten- 



