176 
Psyche 
[October 
two or three inches only. The bugs appeared to be dead when 
first taken but they soon responded to the warmth of the hands 
as shown by slight movements. They were placed in collecting 
cans and by the time we returned to the laboratory they were 
fairly active. Transferred to water of room temperature, in a 
short while they were as active as those taken during the warmer 
part of the year. They were kept in a glass vessel in the lab- 
oratory for a period of several months, but died before an aqua- 
rium suitable for the deposition of eggs was provided. During 
this period they received an occasional feed of small sunfish and 
small catfish. 
On July first, 1923, a large Lethocerus nymph was secured 
from a small pond near University Farm campus. It was taken 
while dredging at the edge of a pond with a heavy water net. 
The nymph was feeding on a tadpole larger than itself and did 
not release its victim while it was being taken from the net and 
placed in a collecting can. In the laboratory it was placed in a 
glass vessel which was four inches deep and ten inches in dia- 
meter. This container was half filled with water and a little 
vegetation added. The nymph fed greedily upon beefsteak, 
grasshoppers, tadpoles, young frogs, young fish, flies and other 
things that were offered. On July fifth it molted. The cast 
skin measured dorsally as follows: Length along median line, 
33 mm.; width of head across eyes, 6 mm.; width of posterior 
margin of prothorax, 10 mm. ; width of posterior margin of meta- 
thorax, 14 mm.; width of abdomen across base of second seg- 
ment, 16 mm. (widest portion of bug). Immediately upon 
molting it was of a very delicate yellow and green color and 
seemed quite frail. It was so translucent that it was easy to see 
what was going on within the bug. When observed a few hours 
later it had taken on the color it had previous to molting. 
About seven hours after molting food was offered and it ate 
twelve large flies and two meadow grasshoppers. No doubt it 
it would have eaten more had they been offered. On the after- 
noon of the following day while out collecting, two tadpoles 
considerably larger than the nymph were secured, so one of these 
was offered. At the end of an hour nothing remained of the 
tadpole but the shriveled skin and some dark mud-like material 
