ARTIFICIAL SELECTION 



91 



superior to the others. From the subdivision of the tubers of 

 this seedling arose the Burbank potato, the most valuable 

 variety in its economic relations now cultivated in America. 

 But with the choice of this form for preservation, selection 

 ceased, as all plants of the Burbank potato in cultivation are 



FIG. 56. Heads of timothy, showing improvement by selection. 



(After Hays.) 



subdivisions of a single original plant. New forms would come 

 from further selection of the Burbank potato seed. 



As illustrations of the more complex art of hybridization and 

 selection, we give in the following paragraphs a brief account of 

 the work of Luther Burbank, the most ingenious and successful 

 of all recent experimenters in plant breeding. 



