70 
conidia from the atomizer. The culture remained about ten days in a 
room at 10° C., under cover in the tin boxes previously described and 
then the plants were set out in the field. 
In ten experiments with oats, always with a sowing of 100 grains, 
the result was on an average 17 to 20 per cent, of smutty panicles. 
The infected barley remained entirely sound. 
II. In the following series of experiments the grains which barely 
showed rootlets were placed on the earth and so covered with a thin 
layer of soil, at most Jem. thick, that only the emerging points of the 
seedlings were exposed and were infected by means of the atomizer, 
consequently the infection only reached the sheath leaf. The shoots 
were infected in the youngest stage when they had pushed out of the 
earth about Jem. 
In seven experiments with oats, each of 100 grains, the result was 
not more than 5 x>er cent, of smutty plants. The barley remained 
entirely sound. 
III. The infection was made as in I on uncovered plants, the shoots 
of which were about lj-2 cm long, but did not yet show any opened 
sheath leaf. 
Here in eight experiments with oats the result fell back to 2 per cent, 
of smutty x>lants; barley sound. 
IV. Infection as in II, the sheath leaf only infected, the remaining 
parts of the seedlings covered with soil, but the shoot of the same length 
as in HI. 
In three exx^erimeuts with oats there was 1 x^er cent, of smutty plants ; 
in two experiments none were obtained ; barley sound. 
V. Infection of uncovered seedlings with sheath leaf already pushed 
through. 
In two experiments with oats the result was 1 x>cr cent, of smutty 
I>lants, in two others, none; barley sound. 
VI. Experiments with infected soil in which the unsprouted grains 
were sown. 
In five exx^eriments with oats the result amounted 4 to 5 x^er cent, of 
smutty plants; barley sound. 
VII. Experiments with an abundantly infected mixture of soil and 
fresh horse dung, in which the unsprouted grains were sowed. 
Here in three exx)eriments with oats the result rose to 40 to 46 x^er 
cent.; in three additional experiments, which were not conducted in a 
cool room, there was 27 to 30 x>er cent, of smut; barley again entirely 
sound. 
VIII. Experiments with conidia, which had been cultivated ten 
months, generation after generation, in nutrient solutions, and which 
ceased to grow out into threads after the exhaustion of the solutions, 
infection of young seedlings lying uncovered on the earth in first stage 
of germination, as in I. 
The result was negative. In two series of experiments there was in 
