MORPHOLOGY OF THE BARLEY GRAIN. 21 
secreting surface to the starch endosperm. The growth of the grain 
in such cases is not normal. The stimulation of the vegetative 
growth has been greater than the later starch infiltration could 
balance. The embryo and general structure of the grain have 
attained large proportions, but the starch infiltration has been incom- 
plete. A normally grown and matured grain of 2-rowed barley pos- 
sesses a highly developed starch endosperm. Although this endo- 
sperm is the first part of the grain to commence active growth, it is 
the last to be completed in the process of ripening. If any feature of 
climate or culture interferes with the process of starch deposition, the 
grain remains high in nitrogen content. This excess is due more to 
the absence of starch than to the presence of nitrogen. There is, 
then, a large scutellum without the corresponding bulk of starch. 
The enzymatic secretions intended for the conversion of a large endo- 
sperm are more than sufficient for the reduced starch content, and 
both diastatic power and nitrogen content are higher than usual. 
In substantiation of this view, measurements were made upon two 
samples of Princess barley. These were grown at Huntley, Mont., 
in 1911. One sample was produced upon dry land, while the second 
came from a neighboring plat which had been irrigated. The thou- 
sand-berry weight of the irrigated barley was 45.5 grams, while that 
from the dry-land plat was only 30.1 grams. The scutellums in 
either case were quite uniform. Those from the irrigated sample 
averaged a little less than 2.6 millimeters in diameter, while those 
from the dry-land sample fell to 2.4 millimeters. The scutellar areas 
were, then, 5 square millimeters for the one and 4.3 square millimeters 
for the other. That is to say, under such conditions that the grain 
did not develop to its fullest extent the scutellar area was reduced 
approximately 14 per cent. However, at the same time, the total 
reduction of the grain was 33 per cent. As the hulls are more or less 
a constant factor, the actual reduction of. endosperm was probably 
far in excess of 33 per cent. This case is but a slight exaggeration of 
the conditions of incomplete development that usually obtain over a 
considerable part of the upper Mississippi Valley. The scutellum of 
2-rowed barleys in this section is, for the most part, likely to be rela- 
tively a greater part of the grain than is normally the case in this 
group. Such barleys grown in this section are likely to show a much 
greater converting power than has been suspected. 
EFFICIENCY OF CONVERSION. 
If the conclusions of the writers be correct, the application of these 
facts to barley production and utilization is of much importance. 
If the secretion of enzyms takes place in the epithelial layer, the 
eross morphology of the grain must govern its behavior in germi- 
nation, including that modified form of germination known as 
