HUNGERFORD: AQUATIC HEMIPTERA. 249 
material being of plant origin. The presence of long filaments 
of Spirogyra, Zygnema and Oscillatoria cannot be accounted 
for in any incidental manner. The deliberate action of the 
bug in feeding on the chlorophyll of Spirogyra, as indicated 
above, is conclusive evidence of the herbivorous tendencies of 
these creatures. The presence of oligochzetes, nematodes, roti- 
fers and protozoa indicates that they consume the little ani- 
mals along with the plant matter. As a basis for the propa- 
gation of Corixids in artificial quarters, it has been discovered 
by experiment that a satisfactory food supply can be obtained 
by grinding the water-soaked leaves of cattail that have laid 
in the marsh over winter and allowing them to reach a state 
of balance. A brown flocculent mass is thus produced, in which 
develop a flourishing population of tiny organisms, both plant 
and animal. In such a culture Palmacoriva has been carried 
from egg to adult. 
