CHAPTER V. 

 PLANT BREEDING. 



432. Plants Have Improved Under Culture. From 

 our point of view, our cultivated varieties of plants are 

 superior to their wild prototypes.*- The strawberries of 

 our gardens are larger, more productive and firmer 

 than those of the fields; the cultivated lettuces are 

 more vigorous, more tender arid milder in flavor than 

 wild lettuces; and the cultivated cabbages and cauli- 

 flower are greatly superior, in the food products they 

 furnish, to their progenitor. The superior qualities of 

 long-cultivated plants, as compared with their wild 

 parents, is conspicuous whenever the wild form is 

 known. 



433. Whence this Improvement? It probably re- 

 sults from two causes, a In culture, the natural hin- 

 drances to development are largely removed. Culti- 

 vated plants are less crowded by too-near neighbors 

 than wild plants, and they commonly receive more 

 abundant food and moisture. They are, therefore, able 

 to reach higher stages of development than is possible 

 in nature, where plants are constantly restricted by 

 environment. 



b The principle of selection has doubtless been more 

 or less operative since the beginning of culture (19). 

 All of our cultivated plants must have existed origi- 

 nally in the wild state. The most satisfactory plants 

 of any desirable species have been most carefully 



