478 
Journal of Agricultural Research 
Vol. I, No. 6 
Table I also shows that Cladosporium gramineum and Fusarium cul- 
morum did not form leaf spots, even though the number of inoculated 
leaves was fairly large. This was rather unexpected in the case of 
Cladosporium, as it was obtained in pure culture by plating direct from 
a fresh mass of spores from a badly infected oat leaf in the field. Con¬ 
tinuous culture on artificial media apparently either reduced its virulence, 
the temperature and moisture conditions in the greenhouse not being 
such as were conducive to infection by this fungus, or infection took 
place normally only after aphid injury or other wound. That Fusarium 
culmorum did not produce leaf spot was to be expected, as it usually 
does not occur in this manner and was not isolated from a leaf but from 
a wilted plant. 
INOCULATION OF SEED OF WHEAT, OATS, BARLEY, AND RYE WITH 
SPECIES OF IMPERFECT FUNGI 
Seed of wheat, oats, barley, and rye was inoculated with spores of the 
same strains of imperfect fungi used in the seedling-leaf inoculation tests. 
The fungi were grown in pure cultures in the same manner as those used 
for the leaf inoculation work. When sporulating profusely, sterile water 
was poured into the test tubes, the spore masses were loosened by the 
use of platinum needles, and the contents were well shaken. The water 
containing the spores was then poured off and diluted with sterile water 
until a drop placed under the microscope was found to contain from 5 
to 25 or more spores. Seed of wheat, barley, oats, and rye was sterilized 
by immersion for one hour in a formalin solution consisting of 2.5 parts 
of 40 per cent formaldehyde to 1,000 parts of water and was immediately 
dried and inoculated with spores by soaking it in the water containing 
them. The seed was then planted in 6-inch pots filled with a sandy loam 
soil rich in humus and placed in the greenhouse at temperatures ranging 
from 55 0 to 65° F. The soil used had been sterilized previously in a 
steam sterilizer at a pressure of 15 pounds for two hours, the tempera¬ 
ture being approximately 265° F. Control seed which had been steril¬ 
ized but not inoculated was planted for comparison in every case. The 
results from such inoculation and plantings in the greenhouse are shown 
in Table II. 
