49 
Hx'J 
ivere rapidly multiplying, in a bug which had been confined with- 
>ut food in a bott e tor five days. The specimen was sluggish, 
:>ut could still walk. A\ ith a view to locating more exactly their 
irmcipal seat in the body, I crushed the head, thorax and abdomen 
>r another upon separate slides. Very few bacteria were found in 
he head. Ihey were much more abundant in the thorax but not 
learly so common as in the abdomen, the fluids of which were lit¬ 
erally swarming with them. From this observation it seemed prob¬ 
able that they occurred chiefly m the alimentary canal. To satisfy 
nyseh more exactly upon this point, I dissected, on the 15th, a pupa 
rom Champaign, which had been kept without food since the 9th. I 
■eparated the entire alimentary canal, with trifling injury, until I*at- 
empted to detach it from the body at the vent. As soon as the needles 
jenetrated the rectum, I noticed the escape of an extremely viscid 
1-1 li 1C i- ^ delicate film on the surface of the water in 
mich the dissection was made. This fluid was seen by a power of about 
ixty diameteis to contain numerous minute cell-like bodies, which un- 
ter a high power appeared to be globular masses of bacteria. This 
iscid him so interfered with the needles and entangled the tissues 
hat the posterior portion of the intestine was torn to fragments 
including the Malpgliian tubes, but the hard structures were removed 
rom the. slide, and the cell in which the dissection was made, to¬ 
other with its contents, mounted, for study. Upon pressure with 
he cover glass, globular masses of bacteria were seen escaping from 
he stomach, similar in all respects to those previously studied, 
mrnense numbers of free specimens occurred everywhere on the 
hide, but scarcely anything else. 
On the 16th of August; in a field of corn near Normal, belonging 
o Mr. Conner, from which most of these specimens had been^ol> 
amed, the chinch-bugs were evidently much less numerous than a 
ortnight previously, and they were also apparently greatly retarded in 
I levelopment. Not over ten per cent, had reached the pupa stage, 
rmd no adults had as yet appeared, while in other fields not far 
distant, ninety per cent, w^ere pupae, and many were winged. In the 
ormer field several dead bugs were found behind the sheaths of the 
orn of all ages and sizes, but the mortality had evidently chiefly 
effected the older bugs. Several were collected, both dead and alive, 
j nd studied as usual. The fluids of one freshly dead were swarm- 
ug with bacteria, as were also those of another in the third stage, 
filich was still alive, but had a swollen and unhealthy look. Taking 
t for granted that bacteria were most abundant in the alimentary 
I anal, if not strictly confined to it, I next, on the same day, suc- 
| essfully dissected the pupa of a chinch-bug which had been for 
hree days in confinement. I removed the alimentary canal as far 
s the Malpghian tubes, divided it in the middle, and placed the two 
I -arts upon different slides. Bacteria were present in both slides, 
at much the most abundant in that containing the posterior part 
f the. intestine. They were nearly or quite as abundant in the 
fater in which the dissection had been made, a fact probably due 
3 the rupture of the alimentary canal during dissection. These 
acteria were evidently rapidly multiplying, occurring on both slides 
a zoogloea-like masses, and also in strings, of a length to simulate 
acilli. On the 22d of August, the condition of things in the field 
