IOWA ACADEMY OP SCIENCE 
95 
seed* Twenty-five seeds of each variety were taken, and the spores were placed, 
by means of a sterile platinum needle in direct contact with the grain. In 
the second set, twenty-five seeds of each variety were washed with the spores. 
In each case one row was used as a check. All the seeds were planted in the 
usual way. The stand from the directly inoculated seeds was very poor. Ex- 
amination at twenty-four hour intervals indicated that the seedlings lacked 
vigor. At the end of two weeks’ time there were not over seven seedlings to 
the row. The roots were not in any sense indicative of a healthy state of 
growth. The conditions above outlined were a contrast to the more vigorous 
appearances of the check row. The seedlings arising from the seeds that were 
merely washed with the spores, numbered more than in the first case, but in 
no case were there more than twenty plants. When these seedlings had at- 
tained a height of eight inches some of them began to show yellow demarka- 
tions, that were similar to the plants artificially infected and . placed under 
bell jars. 
Two rows of oats, with twenty-five seeds to the row were inoculated in the 
same manner as the first set of barley grains. Two rows were used as check. 
No effect was observed. 
Seeds of Festuca pratensis (Fescue Grass) were treated by being washed with 
the spores. The disease did not show itself with the above named plant- as 
host. This is an interesting fact for the reason that PammeP found spores very 
similar to those of this species of Helminthosporium upon fescue grass in the 
fall of 1909, near one of the affected barley plots. 
These experiments were discontinued after the seedlings had attained a height 
of ten inches. The results of the above experiments show conclusively that 
the disease can be transmitted by the seed. Further than this the experiments 
indicate that this species occurs upon the barley plant alone. 
FURTHER OBSERVATIONS. 
In the spring of 1910, there was a resumption of experimental work on this 
fungus at the Gilbert Farm near Elgin, 111. Twenty-two varieties taken from 
the infected plots of the year before, on the college farm, were furnished to 
me by Mr. Burnett. Frequent observations were "made during the growing 
period, but there was no indication of the disease. On examining the straw 
later, I was unable to find any spores of Helminthosporium. The same thing 
was true of the plots at Ames, for that year. The reason for this, is the fact 
that the season of 1910 was unusually dry. Not until the following fall was 
there any sign of the presence of the Late Blight. At that time, through the 
effect of the fall rains, the disease was abundant upon volunteer plants. The 
season of 1911 showed very little of this fungus disease as compared to the 
season of 1909. The abundance and wide spread character of the “Blight” 
during 1909 shows that a moist humid atmosphere is an important factor in 
dissemination. 
CULTURAL CHARACTERS AND METHODS. 
Leaves infected with H. teres were placed in sterile petri dishes, where the 
moisture was excessive, for the purpose of developing a copious supply of 
spores. Inside of seven days, the conidia had formed to such an extent that a 
brownish black appearance was imparted to the leaf. In ascertaining the re- 
