126 



PLANT-BREEDING 



the time of husking. Part of their pollen will be carried to 

 the true representatives of the chosen race, and repeat the 



mixture of the charac- 

 ters of the paternal and 

 maternal strains. 



It is easily seen that 

 in the ordinary process 

 of selection, the result of 

 this open fertilizing con- 

 dition must be that the 

 choice is partly initial 

 and partly repeated or 

 continuous. The initial 

 choice is the main one on 

 which almost all further 

 success depends, but the 

 repeated choice gradual- 

 ly eliminates the bad 

 effects of the unavoidable 

 cross-fertilization of the 

 first chosen ear. The 

 initial choice corresponds 

 to the Svalof method but 

 the subsequent repeated 

 choice can be compared 



Fig. 38. The hand pollination of corn with the German meth- 

 in one of the breeding blocks on the farms , , ., , . 



of Funk Bros. Seed Co., Bloomington, 111. ^ as described in my 



previous chapter. 



Or to put it in other words, the pedigree on the female 

 side is pure and fully known, but on the male side it is impure 

 and only vaguely known and must be purified by repeated 

 selections. Fortunately in practice this difficulty is not so 

 great as it might seem to be, for experience shows that as a 

 rule there is a great uniformity in the progeny of a single ear, 



