VOLUME LXXxI NUMBER 6 
THE e 
BOTANICA (AZ ETTE 
FUNE tro92r 
CHEMICAL CHANGES IN WHEAT DURING 
GERMINATION 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 281 
HELEN A. CHOATE 
(WITH PLATE XXVIII AND TWO FIGURES) 
Introduction 
The subject of germination has received much attention of late, 
and the literature is extensive. In general, however, investigations 
have been directed toward two phases of the subject: (1) the 
external factors necessary for and affecting germination, and (2) the 
chemical changes occurring within the various parts of the seed 
during the process. The earlier investigations of this second phase, 
to which fuller reference will be made later, dealt directly with the 
chemical changes occurring within endosperm or storage sub- 
stances of the embryo as germination advanced; but as a rule each 
of these studies has been limited to the consideration of some one 
substance, and hardly any two investigations have dealt with the 
same kind of plant. More recent work bearing upon chemical 
phenomena has been directed toward the problem of delayed 
germination. The results as summarized by CRocKER (8) show 
that in most cases this delay is due either to conditions existing 
within the seed coat, or to a morphological or physiological 
immaturity within the embryo, leading in the latter case to phe- 
nomena of after-ripening. This investigation is an attempt to 
determine somewhat more comprehensively the principal chemical 
409 
