CHAPTEB'V 

 PLANT BREEDING 



432. Plants Have Improved Under Culture. From our 

 point of view, our cultivated varieties of plants are su- 

 perior 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 vigor- 

 ous, more tender and milder in flavor than wild lettuces; 

 and the cultivated cabbages and cauliflower are greatly 

 superior, in the food products they fumis'i, to their pro- 

 genitor. The superior qualities of long-cultivated plants, 

 as compared with their wild parents, is conspicuous when- 

 ever the wild form is known. 



433. Whence this Improvement? It probably results 

 from two causes, a In culture, the natural hindrances 

 to development are largely removed. Cultivated 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 beginnings of culture (19). 

 All of our cultivated plants must have existed originally 

 in the wild state. The most satisfactory plants of any 

 desirable species have been most carefully guarded, and 

 when the art of propagation became known, these plants 

 were most multiplied. In each successive generation, 



(259) 



