How Domestic Varieties Originate 263 



sent along every row of a whole field on their hands 

 and knees, critically examining every plant. The effect 

 of "this continual selection is always to push the variety 

 to greater excellence. The various " improved" strains 

 of plants are obtained in essen- 

 tially this way. If the grower 

 has been painstaking with his 

 roguing, he soon finds that 

 his seed gives better and 

 more uniform crops than the 

 common stock of the variety. 

 If the improvement is marked, 

 he may dignify his strain 

 with a distinct name, and 

 it thereby becomes a new 

 variety The improvement 

 may be a very important one 

 to a careful bean-grower and 

 at the same time be so slight 

 as to escape the attention of 

 the general farmer, or even 

 of experimenters who are not 

 particularly skilled in judging 

 the merits of beans. 



All these examples drawn from the bean are excellent 

 illustrations of the best and most scientific plant-breeding, 

 and the same methods varied to suit the different needs 

 apply to the amelioration of all other plants. The 

 recent dwarf lima beans may be cited as examples of 

 accidental or fortuitous varieties, in which the precon- 

 ceived ideal of the plant-breeder had no place. Four 



FIG. 75. New type with short 

 stem, which is becoming very 

 popular with commercial 

 growers. 



