Jan. 13,1923 
Forcing the Germination of Freshly Harvested Wheat 91 
A number of the poorer germinating samples of wheat were kept in 
the germinators for two weeks. With these, as with oats and barley, 
nearly all the grains previously ungerminated began to develop at the 
lower temperatures, but the germination of several samples remained 
far from complete at 19 0 C. and especially at 22 °. 
When barley and oats were kept in the cool germinators for the longer 
period, the endosperms usually became fluid and milky, while the later 
appearing germinations were often abnormal and weak. It is question¬ 
able, therefore, whether these should be counted as germinated. Atter- 
berg’s (6) combination of artificial drying with subsequent germination at 
cool temperature should be used with such samples. No such doubt is 
attached to the result with wheat, or to the early appearing germinations 
of barley and oats. 
A temperature somewhat lower than 20° C. is of advantage also in 
making germination tests of older samples of cereals. Probably about 
16° is the optimum. The percentage of germination of old samples fre¬ 
quently is slightly greater, and never is significantly less than at 20°, 
the development of the seedlings is sufficiently rapid, and the tendency 
to mold or decay is markedly less than at 20°. The results of this inves¬ 
tigation show this to be true with oats and wheat, and incidental refer¬ 
ences in the literature on germination indicate that it is probably true 
also of barley and rye. 
Several samples of spring wheat were very poorly developed on ac¬ 
count of the rust epidemic, the selected grains for some samples being 
hardly more than half normal weight. Nevertheless, these samples, re¬ 
sponded as well to the mechanical treatments described in the previous 
section and to low temperatures as did the well-matured samples. 
The use of relatively low germinating temperatures for winter cereals 
has the added advantage of simulating much more nearly the conditions 
under which the grain would germinate in the field. Planted in the fall, 
it has cool nights at least, and soon the average soil temperature, even 
in the day, is well below 20° C. Furthermore, Aderhold (/), Appel and 
Gassner (4), Gutzeit ( 18 ), Gassner (17), and Walster (43) have shown that 
the exposure of different kinds of seed or very young seedlings to low 
temperatures—always well below 20° C and frequently around o°—has a 
very marked effect upon the subsequent development of the plant. In 
the case of cereals (especially winter cereals) this effect is decidedly 
beneficial, since it promotes an early, uniform, and abundant fruitage. 
The formative effect of temperature upon the plastic organs of plants 
has recently been further illuminated by Child and Bellamy (jj). All of 
these investigations taken together open up a very interesting field for 
further study in connection with the after-ripening and germination of 
cereals. 
EFFECT OF INCREASED OXYGEN PRESSURE UPON GERMINATION 
As indicated in earlier pages Atwood (7) has found increased oxygen 
pressures efficient in forcing the germination of dormant wild oats, 
Kiessling {28) obtained similar results with tame oats and also found 
oxygen treatments helpful in increasing the germination of barley in 
the early stages of after-ripening but harmful in the later stages of after¬ 
ripening. Kondo (30) concluded that after-ripening in rice consisted of 
a process of oxygen storage and enzym formation and that the bene¬ 
ficial effect of drying was related to increase oxygen entrance. . Hoffman 
