52 



CORN 



though most of the effect is seen the next year in the plants grown 

 from the hybrid seed. 



If a sweet corn ear be fertilized by pollen from a dent corn plant, 

 a large proportion of the sweet corn kernels crossed will be smooth, 

 like a dent corn, though not all the crossed kernels are so affected. 



The second year, however, if the kernels are planted, the ears 

 produced will be mixed sweet and dent. Plant all the kernels pro- 



FIG. 21. Corn plant prepared for artificial crossing. The tassels are covered with sacs 

 to catch pollen, while the ears are protected. 



duced by this first generation, and in the second generation it will be 

 found that one-fourth of the ears produced are pure sweet corn and 

 will come true afterward with no sign of the dent. One-fourth of 

 the ears will be true dent that will come true afterward, but one-half 

 the ears will again be hybrids. This rule applies to a great many 

 plants and is called Mendel's law, after the man who discovered it. 

 The effect of crossing on the vigor and yield is very marked also 

 (Fig. 22). When the seed* has been fertilized by pollen from the 



