40 THE WHITE-FUNGUS DISEASE IN KANSAS. 
a plausible explanation at least, since our tests in nearly every case 
yielded negative results. But when large quantities of the fungus 
were introduced the results remained unchanged ; no epidemic could 
be started. It seems evident, therefore, that the failure of an out- 
break to occur was not always due to the lack of the fungus, but to 
some other factor as yet unknown. 
If these two places in Anderson County are representative of those 
in which spontaneous outbreaks do not seem to occur, then it is evi- 
dent that artificial infection does not produce such outbreaks or any 
beneficial effects that are commensurate with the amount of fungus 
introduced and the time and expense necessary in introducing it. 
Corn-infection experiments at Cherry vale. — The field work at 
Chereyvale was more extended than at Independence and the climatic 
conditions were more favorable, especially during the first part of 
the work. The fields selected were owned by Mr. Metcalf and Mr. 
Botkins. They were separated by a wheat field, from which chinch 
bugs migrated. By the 21st of June about the first 20 rows of corn 
were badly infested. Two plots of corn were selected in the Metcalf 
field, at opposite ends of the corn rows nearest the wheat. The plots 
were surrounded by ridge barriers on which crude oil was placed. 
Each area had about as many bugs in it as the other. Both were very 
badly infested, and the corn gave promise of being quickly killed 
unless the bugs were exterminated. One of the plots was artificially 
infected with fungus culture. The spores were mixed with earth 
and dusted on the bugs. Some of the dried cultures were used with- 
out an admixture of earth. The insects swarmed on the corn in such 
compact bunches that large numbers could be easily dosed with 
fungus spores. Practically all of the bugs in the plot had an appli- 
cation of Sporotrichum. The other plot was used as a check. Each 
plot was about 40 feet long and included three rows of corn. The 
experiment continued for a week, or until the corn was completely 
killed out. The bugs were unhurt and finally escaped over the 
barrier and scattered into the new corn. 
A new type of experiment was then tried, the chief merit being the 
maintenance of extremely humid conditions. The other factors, large 
numbers of bugs and intensity of infection, were still at hand. The 
experiment consisted of cutting corn badly infested with bugs and 
piling it in heaps, bugs and all. In the Metcalf field about a dozen 
stalks composed each. The top soil under each pile was removed to 
expose the damper subsoil, which thus assisted in preserving the 
dampness. The bugs repaired to the lower portions of the piles as 
soon as they were made, and there, with the moisture from the leaves, 
from the ground, or from the rain, or artificial watering, the humidity 
was high enough to insure propagating of the fungus. 
