Bul. 1098, U. S. Dept. of Agriculture. PEATE IIE 
Fic. 1.—View along channel, Bayou Walnut, natural conditions, showing overhanging vege- 
tation and aquatic vegetationin bed. Surface of water in foreground covered with duckweed 
(Lemna spp.) and with aquatic plant, Jussiaea diffusa, in background. 
Fig. 2.—View across Bayou Walnut, natural conditions, showing absence of overhanging 
vegetation, with aquatic grass, Zizaniopsis miliacea, in bed. 
IMPOUNDING WATER TO CONTROL MALARIA MOSQUITOES. 
