110 TRANSACTIONS OF THE 
Plat 3. Plants produced from sterilized seed planted 
in a soil which has been inoculated with spores, 250 stalks, 
none smutted. 
Plat 4. Control. 1000 stalks—one smutted specimen. 
Experiments, the results of which were similar to this 
already quoted, were carried out by Brefeld from 1900 to 
1905. These experiments included thousands of plants, — 
the results in general were always the same. In the words 
of Brefeld, we may say: Here it is proved positively that 
young ovaries are directly attacked through their stigmas 
by the germs of infection scattered by the wind; that the 
smut, however, is not developed in the same year but that 
rather the germs of infection which penetrated into the 
young embryonic fruit remain latent in the ripening grain 
and after the dormant period of the seed grow out of 
these equally with the germination of the embryo in order 
to pass over in the inflorescence to the production of the 
spore masses. 
Now, how is the condition of the experiment simu- 
lated on a natural scale? It happens as follows. The plants 
affected with the loose smut mature earlier than the nor- 
mal healthy ones. In fact, they mature so that the smut 
is being distributed by the wind at the time of flowering 
of healthy plants. The distribution of the smut continues 
for days, a condition which is closely associated with the 
variation of the time of opening of flowers, which continues 
also for several days. This condition has been shown to 
hold true for the loose smuts of wheat, barley, and oats. 
Definite experiments have been carried out with barley, 
giving the same general results, as with wheat and the 
infection of the blossom has become a scientific fact as far 
as these two crops are concerned. The infection of the 
blossom of the oats with loose smut has not been attained 
with as definite results as with barley and wheat. There 
is no question but that the smut is distributed at blossom- 
ing time but in general it appears as if the smut spores do 
not germinate until the following year. They lie securely 
protected within the hull next the kernel. In the spring 
at the time of planting and upon germination of the seed, 
