HUNGERFORD: AQUATIC HEMIPTERA, 243 
for they continued to sweep in dead rotifers and protozoa along 
with green plant cells. 
Spirogyra Culture. 
It has been stated elsewhere in this paper that Corixids are 
very largely herbivorous; that the digestive tracts have been 
found to contain much chlorophyll. But the finding of pebbles 
in the stomachs of fishes is not taken as conclusive evidence 
that pebbles form their food supply. So with the boatmen. 
The writer felt that chlorophyll might be eaten by herbivores 
and these herbivores by Corixids, and the digestive tracts of 
the boatmen would be green. Moreover, even the carmine 
experiment cited above might be subject to criticism by those 
who had not made direct observations. Such skeptics might 
say that the carmine could be ingested by worms, amcebee, 
etc., and thus, through the eating of these organisms by 
Corixids, get into the stomachs. The contention that Corixids 
are largely herbivorous, is obvious to‘any who repeat these ex- 
periments for themselves, but to the writer’s mind, nothing 
seals the incontestibility of the facts like the following dem- 
onstration. This demonstration has been repeated a number 
of times with three or four species of Corixids. Here are the | 
notes on the first experiment: 
Washed a species of Spirogyra repeatedly in tap water until 
every organism perceptible under the low-power compound 
was removed, then placed a few filaments of this in a small 
Petrie dish and added an adult Palmacorixa buenoi. It began 
feeding at once and worked contentedly. It gathered up the 
green filaments, singly or by the half dozen, and slowly worked 
them backwards, using its pale like hands, to manipulate the 
algal threads which it pressed to its mouth. So intent was 
this bug upon the business in hand, that it was content to lie 
upon its back and eat, so every detail visible with a high-power 
binocular was seen. For thirty minutes this bug fed most in- 
-dustriously. The spiral filament, moved from front to rear by 
the hand-over-hand movement of the fore | mbs, was pressed 
to the face, the cell punctured and the green matter with- 
drawn. See plate XXX. Thus the threads of Spirogyra that 
were passed between the mouth and the pale of the bug were 
transformed from threads bright with green spirals to empty 
_and transparent filaments. After a half hour’s feeding, the bug 
q 
