ARTIFICIAL INFECTION FIELD EXPERIMENTS. 29 
It will not be necessary to give the field notes for all the localities 
in full, since a few will suffice to show how the work was conducted. 
Sumner County. — Attention was first called to the vicinity of Wel- 
lington, in which chinch bugs promised to be extremely troublesome. 
Collections of the bugs early in the spring confirmed the report. 
Sporotrichum was known to be present in the soil because of its 
presence in the bottle culture used as tests. 
The use of three wheat fields was kindly permitted by Messrs. 
Lynch, Banks, and Russell. Other farmers offered the use of their 
fields, but the three mentioned were found to be the most favorable 
in point of wheat prospects and numbers of bugs. The experiments 
on two of them will be described in detail. 
Experiments in Mr. Lynch? s field. — Two plots, 50 feet square and 
planted gridiron fashion, with a dwarf variety of beans, were set 
out about 150 yards apart in the wheat field northwest of the Lynch 
residence. The plots contained approximately the same number of 
bugs, but the wheat was ranker in one than in the other. It grew 
finally so tall and close that its shade greatly exceeded that given by 
the beans. The beans were sown in the latter part of April, but it 
was not until about May 18 that the plants were high enough to make 
sufficient shade. On May 18 the field was examined for chinch 
bugs dead of Sporotrichum that existed naturally in the soil. They 
were found in both plots ; also in other parts of the field. The part 
selected for artificial infection was near the center of the field, by an 
old strawstack. The check plot was that containing the ranker 
growth of wheat. Owing to the shade in the check, the conditions 
for fungus development were deemed better, but, on the other hand, 
the plot with the thinner growth contained more spores, owing to 
the artificial infection. About 20 dried petri-dish cultures were 
stirred into a bucket of dry soil, and the mixture, whitened with the 
spores, was sown along the wheat rows and under the beans. There 
was no doubt but that the swarms of bugs around the wheat came 
into close contact with the infection. In addition, they jostled almost 
continuously the whitened corpses of bugs, already dead of the Sporo- 
trichum disease. 
A shading experiment, in which straw was used, was conducted 
near the infected spot. Small piles of straw were laid both between 
the wheat rows and around the wheat. Fungus-infected earth was 
then liberally sown in the straw and under it. The straw was util- 
ized to keep the ground beneath moist, so that if bugs frequented 
the straw to any extent they would find conditions more favorable 
than out in the open. Many would contract the disease, perhaps, 
and then leaving the piles die in other locations, thus scattering the 
infection. 
On May 25 a second and thorough infection of the previously 
infected plot and straw piles was made. At the same time results 
