IMPROVEMENT OF VARIETIES 89 



64. Results with mass and pedigree selection. — With 

 all obvious characters, such as height or angle of ear, the 

 same results to a certain degree will be obtained by either 

 method ; but these results should be secured in less time 

 by the pedigree method. 



This is rendered more comprehensive by conceiving a 

 cornfield to be a mixture of types, and selection as a 



Fig. 28. — Selection for high and low ears at the III. Exp. Sta. The tape 

 shows height of ear. The original selection was from the same field 

 and had been continued for five years when this picture was taken. 



method of isolating these types.^ It is clear that pedigree 

 breeding is a more rapid method of isolation than contin- 

 uous selection. 



With selection for yield it is possible that no result would 

 be secured with mass selection, unless there were some 

 obvious character of the plant closely associated with 

 yield ; while on the other hand, rapid progress might be 

 expected from pedigree cultures, as a record would be 

 kept on the performance of each individual. 



1 The theory of isolating pure types by mass and pedigree selection 

 is expounded at length by De Vries, in Plant Breeding. Open Court, 

 Chicago. 



