92 
and corn fields, of fungus cultures and of chinch-bugs dead with 
disease and bearing the characteristic fungus in a fruiting condition. 
One series of such experiments was made on the University Experi¬ 
ment Station farm, at Urbana, and others were set on foot at several 
points in Southern Illinois, each being followed up by repeated visits 
made to ascertain the result. 
The opportunity was improved during these visits to examine also 
several experiments made by farmers of our acquaintance with ma¬ 
terial obtained from the office under such conditions and management 
as to give them positive value. 
Additional laboratory experiments directed to special ends were 
named on during some weeks by the aid of Miss Nettie A^ers, 
then an assistant in the bacteriological laboratory of the Univer¬ 
sity of Illinois. Artificial cultures, under varying conditions, of 
the Sporotrichum characteristic of the chinch-bug disease were 
made by Miss Ayers, and the results of such cultures were tested 
upon chinch-bugs, living and dead, upon cabbage worms both 
living and dead, and upon a variety of other insects, these exper¬ 
iments being so managed that the conditions under which they 
were made were precisely subject to our control. 
In addition to these various experiments with the contagion 
method, I made at Urbana this summer a thorough test of cer¬ 
tain measures for the arrest and destruction of chinch-bugs as 
they moved from wheat to corn in early June and July. 
The entire series, for 1894, of these experimental studies in the 
laboratory and in the field are here reported, whether made under 
the immediate auspices of the Agricultural Experiment Station, 
or as a part of the regular work of the State Laboratory of Nat¬ 
ural History. 
GENERAL DISCUSSION OF RESULTS. 
The more important results of the season’s experiments which 
have an economic value may be briefly summarized in the follow¬ 
ing terms: . , 
1. The white muscardine will not spread among vigorous chinch- 
bugs in the field in very dry weather to an extent to give this 
disease any practical value as a means of promptly ariesting seii- 
ous chinch-bug injury under such conditions. (See Nos. 55 to 
58, and 61, 62, 77, etc.) On the contrary, even when it has ap¬ 
peared spontaneously, or as a result of artificial measuies for its 
introduction, it may be completely arrested by dry weather, re¬ 
maining in abeyance at least until the weather changes. (See No. 
53, June 5 and June 20; No. 55, June 7, June 19, and August 8, 
No. 57, concluding discussion; and Nos. 60, 63, 69, etc. ) # 
2. It is most likely to “catch” in low spots, where the soil is 
kept somewhat moist by dense vegetation, a mat of fallen herbage, 
or the like. Shocks of corn, especially when the crop is cut early, 
furnish excellent places for the development of this disease.^ (See 
No. 55, June 20; No. 57, September 18, 19, and 28; and Nos. 76 
and 77.) Indeed, the presence in any field, of spots especially 
favorable to the growth of the Sporotrichum infection seemed, ac- 
