18G 
FLOATING EXPERIMENT. 
This experiment was begun August 3, 1894, with chinch-bugs 
colJected from the same field as those used in the immersion ex¬ 
periment. Bugs in various stages of development were selected 
and floated on the surface of rain water at a temperature of 70° 
Fab., in ordinary tumblers about two thirds filled. 
No. 1. Eighteen bugs just emerged fiom the egg were selected 
August 3, divided into three lots of six each, and floated on the 
surface of water at 8:45 a. m. They swam about for several 
minutes and then remained quiet as if dead, but when removed 
on a pencil point crawled away. Each lot was examined every 
fifteen minutes, and the first dead one was removed at 12:45 p. 
m. All were dead by 2:45, or seven hours from the time the ex¬ 
periment began. 
No. 2. Eighteen chinch-bugs of the first molt were divided into 
three lots, as above, and floated on the water at 9:15 a. m. They 
swam about for some hours, but at 5:15 p. m. were quiet. They 
were examined every thirty minutes, and not until 8:15 p. m. did 
any fail to crawl away almost immediately after being removed 
from the water, and then but one. At 11:15 six were very feeble, 
but they were just alive at 6 o’clock the following morning. None 
of the insects removed from the water at this time attempted to 
escape. At 7:15 a. m. eight were removed that showed no signs 
of life, and these did not revive when placed on a dry towel. At 
eight o’clock fourteen out of the eighteen were dead, and the re¬ 
maining four were dead at 8:45. From this it appears that chinch- 
bugs of the first molt will often remain alive on the surface of 
water for about twenty-three hours. 
No. 3. Three lots of chinch-bugs of the second molt, six in 
each lot, were floated August 3 at 9:30 a. m. They were exceed¬ 
ingly active, and three escaped an hour later. At 7:30 p. m. they 
were still active, and at 11:30 were in good condition but quiet. 
They were next observed at 6 o’clock the following morning, 
August 4, being then in good conditian and attempting to escape 
whenever anything was held in the water near them. They were 
examined every two hours during the day, and were still active at 
10 o’clock p. m. When examined the following morning, August 
5, at 7 o’clock, they were in fairly good condition. Three more 
bugs had made their escape thus leaving but twelve under observa¬ 
tion. These were examined every two hours, as before, and at 
3:20 p. m. four bugs showed signs of weakness. At 5:30 six others 
were about helpless, and barely moved when taken out of the 
water. At 7:30 all were dead, five of them having sunk to the 
bottom, It appears from the foregoing that bugs of the second 
molt will live for two and a half days on tbe surface of water. 
No. 4. August 3, at 4 p. m., three lots of six pupae each were 
placed on the surface of water. They were very active making 
every effort to escape, and w T ere still swimming at 7:30 p. m. 
They were next observed August 4, at 6:15 a. m., when they were 
still active and trying to escape, two having disappeared. They 
were observed at 10 a. m., 2 p. in., and 6 p. m, being still in 
