PLANT BREEDING AND EVOLUTION 



203 



in nature, which bids fair to be of inestimable value in the 



improvement of wild and cultivated ornamental and food plants. 



Selection of mutations. According to the above theory a field 



of oats, corn, timothy, or beans is likely to be made up of plants 





FIG. 112. Inflorescences and rosettes of CE. lamarckiana and (E. gigas 



Left, (E. lamarckiana ; right, (E. gigas. Above, inflorescences ; below, young plants 

 (seedlings). From Babcock and Clausen's " Genetics in Relation to Agriculture " 



which differ from each other in almost every conceivable manner* 

 Some of these differences would certainly be due to fluctuating 

 variations, and some to previous hybridizations. In other in- 

 stances, if the experience of the Swedish and American experi- 

 ment stations is a criterion for judgment, the differences are 

 due to mutations, possibly induced by changes in soil, climate, 

 or culture methods. 



