22, THE UNIVERSITY SCIENCE BULLETIN. 
Notonecta, the little Plea, and Corixids in both numbers and 
variety were here. Ranatra and Nepa, too, came into the 
catch often enough to call them plentiful. Of all the places 
the writer has ever collected, this pool in late fall and early 
winter has been the best collecting. 
East of the Field Station there is a little stretch of water, 
connected with the Fall Creek outlet, in which there is a 
dense growth of water shamrock in summer. In midsummer 
the floating leaves of this plant make footing for the surface 
forms such as Mesovelias, Microvelias and Hebrids. In earli- 
est spring the brown tangle of the stems of the previous year’s 
growth harbored hundreds of Notonecta variabilis. These 
scattered to other regions for breeding purposes and were 
not abundant in June. 
Bool’s Backwater: A very few minutes brisk walk east of 
the Insectary at Cornell takes one about the border of the 
Beebe Lake and across a couple blocks of Forest Home to a 
steep bank overlooking a strip of land bordering an abandoned 
channel of Fall Creek. This old channel can be followed to its 
junction with Fall Creek at its upper end. Near this point 
arises the first of a series of clear pools which are fed by 
seepage from Fall Creek, by springs or by both, and which, 
in turn, overflow to form a little brook that trickles along over 
large water-worn stones covered by vast quantities of brown 
gelatinous growths of diatoms, to come finally to the quiet 
body of water filling the old channel for a considerable dis- 
tance back from its union with Fall Creek, due to the dam- 
ming of the latter a short way below. This is Bool’s Back- 
water. Its waters are fresh but still, and great beds of Elodea 
and Chara occupy ever-increasing areas as the season ad- 
vances. The bottom is somewhat muddy and the shallow mar- 
gins deeply covered with a flocculent organic ooze, ideal food 
for the boatmen. And here, indeed, two species of Corixids 
were to be taken in countless numbers. Because of this fact 
and its accessibility, this place was chosen for daily observa- 
tion and notes taken on these frequent visitations are else- 
where recorded. 
Ringwood Hollow: A series of interesting pools and marshy 
meadows in Ringwood Hollow were visited at rather frequent 
intervals throughout the season. These were reached by a short 
ride on the train, followed by perhaps three miles of walking. 
