MAKING NEW KIND'S OF PLANTS 435 



Corn. You would have before you the possibility 

 of improving along any one of the following lines: 



1. Increased yield. In the ordinary corn-field one 

 well -developed ear to a hill means a yield of about 

 fifty-five bushels to the acre; two ears means over 

 one hundred bushels, three ears over one hundred 

 and fifty bushels. Now in Illinois, where a great 

 corn -breeding movement is in progress, it was found 

 that there are, on the average, more than two stalks 

 to the hill, each capable of bearing a well -developed 

 ear; yet the average yield is less than thirty bushels 

 to the acre. The trouble is partly due to barren stalks, 

 partly to poorly developed ears. Consequently an 

 effort was made to improve the Corn in these respects. 

 Now, it was found that a barren stalk produces more 

 pollen than a productive one, since none of its 

 strength goes to producing an ear: consequently it 

 fertilizes a larger number of plants than the pollen 

 from a productive stalk: the result is that the tendency 

 to barrenness is consequently on the increase. Obvi- 

 ously one thing to do was to go through the fields 

 looking for barren stalks, and cutting off their tassels 

 before the pollen was shed. In this way the per- 

 centage of barren stalks was noticeably decreased. 



Another thing to be done was to select seed from 

 the best ears. To do this properly requires skill and 

 experience. Not only the size and shape of the ear 

 but the manner in which it is filled out, especially at 



