53 
in progress, immense numbers of these Micrococci developed, many 
of them single or double, but most in chaplets, like strings of 
beads. Careful measurement of individuals showed their identity 
with those above described. 
At this time, the general disappearance of the chinch-bug, and the 
consequent difficulty of obtaining specimens for experiment, put a 
period to the investigation, and the solution of the questions stall 
remaining was necessarily postponed to another year. 
The studies here reported demonstrate the frequent association of 
a peculiar bacterium (Micrococcus), essentially parasitic in char- 
acter, in the intestines of the chinch-bug, with a general diminution 
of numbers among those affected, together with an apparent retard- 
ation of their development. They also show that this bacterium is 
easily cultivable in both vegetable and animal infusions, and pro- 
bably multiples spontaneously in the fluid exudations of corn-stalks 
punctured by the bugs. The final step of the proof that it injuri- 
ously affects its host is yet lacking, and cannot be supplied until 
an opportunity is had to expose the insect artificially to its influence. 
Besides this bacterium, another parasitic fungus, certainly de- 
structive in character, was found to infest the chinch-bug; and this 
seems to me more likely than the other to have been concerned in 
the wholesale disappearance of the bugs described by Dr. Shimer. 
I have already mentioned the occurrence of many dead specimens 
in a field at Jacksonville, attached to the stalks and leaves of the 
corn and buried in the silk. These were all embedded in a dense 
mat of white fungus threads, which sometimes almost hid the body. 
The general resemblance of this growth to the fungus which com- 
monly attacks flies in autumn, often fastening them to the window 
pane, and bursting from their bodies in the form of a white efflo- 
rescence, led me to suppose that this chinch-bug fungus was one of 
the same character, and not a simple mold, forming after death. 
The bugs affected were both pupe and adults. Subsequent study 
with the microscope demonstrated the correctness of the above sur- 
mise, as the fungus in question proved to belong to the same genus 
(Entomophthora) as that infesting flies; a fact of which I was as- 
sured by Prof. Burrill, to whom some specimens were submitted. 
It was not possible to determine the species of the fungus in the 
stage represented by my collections, but it was apparently different 
from that of the house-fly. Recent studies of these fungi by Euro- 
pean biologists have confirmed the prevailing opinion that they are 
true destructive parasites, the causes and not the consequences of 
disease and death. It seems not impossible that the white mold, of 
which Dr. Shimer speaks in the paragraph I have cited, was really 
this parasitic fungus; and if so, it was probably the cause of the 
epidemic disease which he describes. This fungus often runs its 
course to a fatal result, without making any external appearance, 
bursting forth only after death. It is vroper to say, however, that 
I also found three or four dead bugs at Normal, seemingly in the 
same condition as those above described, but which were really 
simply buried in a harmless meld, as was easily seen with the 
microscope. ~The parasitic forms are distinguished from the molds 
at a glance, by the fact that in the former the threads are not di- 
vided off into cells by cross partitions, as they are in the latter, 
—-4 
