CHAPTER XX 



IMPROVING PLANTS AND SEEDS 



202. Domesticated Plants. The cultivated plants 

 were originally wild sorts. Some of them have been 

 cultivated so long and so improved by man's care that 

 the original or wild form is not certainly recognized, such 

 as wheat, potato, onion, cabbage, etc. Other sorts have 

 been brought into cultivation in comparatively recent 

 times, and the original wild form is well known, as the 

 tomato, carrot, chrysanthemum. Cultivated forms are 

 vastly superior to the wild forms. The strawberries of 

 our gardens are more palatable and productive than the 

 wild sorts. The cultivated tomato is much larger and 

 firmer than the original wild form. Wherever a plant 

 has been long under cultivation it has been greatly 

 modified. We may ask, "How are these improvements 

 secured?" 



203. Variation in Plants is the starting point for 

 improvement. Scientists have a theory that all the 

 plant and animal forms de- 

 scended from some common 



ancestor. This theory of the 

 origin of living forms, called the 

 "theory of evolution," finds its 

 support in the similarity of 

 many forms, suggesting rela- 

 tionship, and the further fact 

 that, through natural varia- 



Fig. 83. Old-time and new-time 

 tlOn, new forms are constantly forms of tomato. After Bailey. 



(139) 



