50 
above mentioned was not materially changed, except that the num- 
ber of bugs had diminished still further, bemg now reduced, appa- 
rently, to about twenty per cent. of that occurring there on the 
25th of July. About two-thirds of those seen were pup, but in a 
half hour’s search only three adults were found. 
In other fields at this time most of the bugs were in the adult 
stage. Again, many were noticed dead behind the sheaths of the 
corn and many of the living ones were torpid and could easily be 
picked up or brushed about without their making active efforts to 
escape. I examined one of these torpid specimens in the third stage 
and found an excessive number of bacteria, rapidly multiplying, 
many of them being in long strings. I also crushed an active speci- 
men in the same stage, and found the parasites numerous but less 
abundant than in the preceding specimen, and none of them in 
strings. I also crushed a dead pupa obtained at the same time, 
still plump and fresh, and found immense numbers of the same 
bacteria, most of them occurring in pairs. I then crushed an active 
pupa which contained a great number of bacteria, many of them in 
fours; scarcely fewer, in fact, than in some dead bodies. 
In order to compare the condition of the insects in this field where 
they were apparently disappearing, with that obtaining in other 
situations, where no such disappearance was noticeable, I next col- 
lected a number of specimens from a small lot of corn, the stalks 
of which were nearly half covered to the ear with bugs. A few of 
these were adult, but nine-tenths of the remainder were pupe. Here 
and there a dead specimen was noticed, and some were apparently 
torpid. I crushed an active pupa upon the slide and found plenty 
of bacteria in its fluids, but clearly fewer than in the specimens 
examined from the other field. On the 28d I made a more exact 
comparison by examining in immediate succession the fluids from 
pupe taken from both fields. The specimen from a situation where 
the bugs were apparently dying was swarming with bacteria, while 
in the example from the other situation but few were found, proba- 
bly not a twentieth part of those in the individual just mentioned. 
On the 26th this observation was repeated. From a field where the 
bugs were abundant and active and where none were found dead, 
but all had reached the adult stage, I had some trouble to find any 
bacteria at all, but in an adult from Mr. ,Conner’s field they were 
very abundant indeed, at least twenty times as numerous as in the 
preceding specimen. A second observation only confirmed the other. 
In Conner’s field the insects were now still less numerous than before, 
about ten per cent. of those remaining being adult, and the others 
all in the pupa stage. On the 4th of September the bugs in this 
field did not seem to have further diminished in numbers, but were 
curiously retarded in development. Not more than twenty-five per 
cent. were adults, nearly all the others being pupe, with now and 
then one of the preceding stage. Only one or two were seen dead. 
In another field, from which collections were made for purposes of 
comparison, the specimens were nearly all adults. The bacteria 
were found perhaps more numerous in the bugs from Conner’s field 
than in those from the second, but there was at this time no great 
difference. On the 18th of September, specimens from Conner’s 
field contained few bacteria, although they were certainly present in 
