179 
of 1894. Although the primary object of the egg experiment was 
to determine the number of eggs deposited by a female, several 
other points relative to the life history of this insect have been 
cleared up by it. 
The immersion experiment, though fairly satisfactory, was con¬ 
ducted with no little difficulty, as many of the immersions, espe¬ 
cially of adults, necessitated frequent examination during the late 
hours of the night. The floating and confinement experiments were 
conducted at the same time. 
r 
EGG EXPERIMENT. 
As the primary object of this experiment was to determine tie 
number of eggs deposited by a single female, the bugs were 
selected with great care. A quantity of them were collected from 
corn on the Agricultural Experiment Station grounds July 18 and 
brought to the insectary. Males and femrles just emerged from 
the pupal stage, still retaining the yellowish or bleached appear¬ 
ance characteristic of chinch-bugs which have recently molted for 
the last time, were selected and placed on the Setaria in the cages. 
These consisted of six ordinary five-inch flower pots filled with 
carefully screened garden soil, free from sand and particles of for¬ 
eign material, in which a plant of fox-tail grass (beicivia glciucci) 
had been set July 14, four days prior to the admission of the 
chinch-bugs. Each plant was then covered with a common three- 
inch flint-glass lamp chimney with smooth top, over which a piece 
of Swiss muslin was drawn and kept in place with a strong rub¬ 
ber band a quarter of an inch wide. One of these cages is repre¬ 
sented in Plate XL 
Six such cages were stocked July 18. 
No. 1 was started with a single female and two males, but owing 
to an accident one male escaped July 22. It will be seen from 
the table following that the female in this cage produced the 
greatest number of eggs, laying two hundred and thirty-seven from 
July 24 to September 4, thus averaging a little more than five 
eggs per day. I am of the opinion, however, that a chinch-bug 
does not deposit its eggs every day, but at intervals of three to 
five days. 
The total number of eggs taken from behind the leaf sheaths of 
the Setaria was one hundred. These were usually behind sheaths 
near the ground, and were deposited in clusters, ten to fifteen eggs 
being often attached side by side. One hundred and twelve were 
taken from the ground at depths varying from one eighth to 
three fourths of an inch. They were usually found singly; very 
rarely in clusters. They were scattered indiscriminately in the 
earth in the cage, the greatest number, however, being among the 
roots near the base of the plant. Twenty-five young bugs were 
also removed from the cage. These were from eggs that had been 
overlooked, or that were so placed behind leaf sheaths that they 
could not be removed without injuring the plant. The eggs were 
taken out of this cage every four to six days, care being taken 
each time to remove the parent insects before the examination was 
