SECTION VIII. IMPROVEMENT OF PLANTS 



OUR valuable cultivated plants have been changed from 

 poor or useless wild plants. The tomato, for example, 

 bore very small and worthless fruits, and the cultivated 

 rose was once a wild rose with few petals. Greatly as 

 man has improved plants in the past, recent discoveries 

 of some of the laws of improvement should make future 

 progress still more rapid. 



Selection. By selection, or choosing seeds from the 

 most desirable individuals, plants may be slowly changed. 

 Selection is the easiest, surest, and usual method of im- 

 provement. In plants and animals the general rule is 

 that the offspring resembles the parents and grandparents. 

 But among the five hundred or more stalks grown by 

 planting the kernels of a single ear of corn, there may 

 usually be found several that have larger ears than others 

 from the same ear. All crops can be made more produc- 

 tive by using seeds from a small seed-plot that is planted 

 every year with the seeds from the best plants of the year 

 before. 



In selecting, we may, for example, take a variety of 

 corn that has usually produced only one ear and select the 

 few plants that have several ears. If we plant these seed 

 by themselves and in that crop again select the stalks with 

 most ears, and so on every season, in a few years we shall 



46 



