138 Elementary Principles of Agriculture 



coming into existence. Plant -breeders try to cause 

 variations. 



204. Fixing Variations. Variations in cultivated 

 plants more often resemble earlier and less valuable 

 forms. Where improvement is desired, great numbers of 

 individuals should be observed and a few of the most 

 promising saved for seed. This is called selection. When 

 seeds are saved from individual plants with desirable 



* t 1 1 



Fig. 84. A chance for selection. The two kernels in the center are the best. 

 The two outside grains at each end of the upper row are too short. The 

 two outside ones in the lower row are too pointed at the tip, showing lack 

 of vitality. 



characters, they should be planted away from other 

 plants of the same kind. Usually, only a few specimens 

 of the progeny will retain the good qualities of the 

 parent. Selections should again be made. By repeated 

 selection, a large per cent may be made to "come true 

 to seed." This is called "fixing the type." Where the 

 crop is grown for seed, the field should be gone over and 

 all plants that are noticeably inferior or not true to type 

 should be removed. This is what the seed-grower calls 

 "rogueing." 



