VOLUME LXII NUMBER 6 
PLES 6 ox 
HOTANICAL: AGAZETTE 
DECEMBER 1916 
SOME RECENT INVESTIGATIONS IN SUGAR-BEET 
FREDERICK J. PRITCHARD 
(WITH FIFTY-ONE FIGURES) 
Introduction 
This investigation was made for the purpose of ascertaining 
certain facts and principles which have an important bearing upon 
methods of breeding. The introduction of more economical 
methods, based upon correlated characters or upon a better knowl- 
edge of scientific principles, would aid materially in the improve- 
ment of beets. 
The efficiency of breeding methods depends largely upon the 
soundness of the scientific principles on which they are based. 
Unfortunately, many principles of breeding are still obscure, and 
even doubtful principles are employed as the basis of improving or 
originating a variety. Biologists who believe that improvement 
results from a gradual accumulation of small variations practice 
continuous selection, while those who adhere to a belief in improve- 
ment by the use of a few exceptional, prepotent individuals work 
with larger numbers and depend upon the isolation of mutations. 
In studying the effects of our own methods we have endeavored to 
determine whether improvement is accomplished through continu- 
Ous selection, and also whether prepotent plants of exceptional 
quality occur within the limited range of our cultures. 
A sugar-beet variety as ordinarily developed and maintained 
differs from a variety of other crops in that it consists of a number of 
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