83 
itself derived immediately from the Thaxter tube already mentioned. 
Twenty grubs were dusted April 19 with spores from this growth 
and placed in an earthen vessel, which was filled with leaf mold 
and sunk in the earth. Grubs died in this lot April 23, 25, and 
27, most of them becoming firm to the touch and of a dusky 
brownish hue. The record shows the death of thirteen of 
this experimental lot up to May 20, at which time ants invaded 
the cage and the experiment was discontinued. Five dead speci¬ 
mens, transferred to damp sand May 30, simply decayed without 
visible fungous growth. Only two of the lot, in fact, formed a 
mycelium, and none matured spores. 
No. 86. November 25. Agar cultures in test-tubes infected 
from No. 20. Nwember 29, culture growing, but agar not 
yet tinted. December 1, growing slowly, with red discoloration of 
the medium. December 5, spores formed. December 8, spores 
becoming yellowish and beginning to ripen. December 12, spores 
abundant and seemingly ripe. 
THE YEAR 1893. 
During 1893, the year of the great Columbian Exposition at 
Chicago, the office force was so largely engaged in the prepara¬ 
tion, installation, and supervision of the exhibit required of us by 
law, that comparatively little could be done with experimental 
work, and this little only during the latter part of the season. 
The experiments with insect diseases were eighteen in number, 
the first made April 6—an infection experiment with Isana leprosa , 
i applied to pupae of the tomato worm (Protoparce), the re¬ 
sult of which served to support the conclusions drawn from the 
work of the previous year with regard to the promise of this 
fungus species. The remaining experiments were all made with 
Sporotrichum globuliferum, and all but one upon the chinch-bug. 
A general contagion box was established July 1 (experiment 2) 
and kept in operation until September 6, its product being dis¬ 
tributed to correspondents of the office for use in the field. 
Nos. 3-9 of the list for this year are small laboratory infection 
experiments, all of which were carried far enough to indicate suc¬ 
cessful inoculation with the fungus, when the contents of the 
boxes were united with those of the larger box just mentioned. 
No. 10 was a laboratory contagion experiment, the spores for 
which were derived from dead chinch-bugs kindly sent me by 
Professor Snow, of Kansas; and Nos. 12-18 were field infection 
experim-mts in Southern Illinois, only one of which (L8) gave the 
slightest evidence of a useful result. The single plant-louse con¬ 
tagion experiment (No. 11) was unsuccessful. 
DETAILED DESCRIPTION OF EXPERIMENTS -1893. 
No. 1. April 6. An infection experiment upon Sphinx pupae 
with spores of [sarici leprosa from agar culture of 1892, not more 
definitely described. Two pupae brought in from the field, appar¬ 
ently of the tomato Sphinx (Protoparce), were treated by rubbing 
