U. S. B. F.—Doc. 874. : PLATE V. 
FIG. 13.-TALL RUSHES AND GRASSES WHICH DO NOT PROVIDE PRO- 
TECTION FOR MOSQUITO LARVAE. 
FIG. 14—POND SUPPORTING DENSE VEGETATION CONSISTING PRIN- 
CIPALLY OF SMART WEEDS WHICH DO NOT PROVIDE PROTECTION 
FOR MOSQUITO LARVA. 
FIG. 15.—SECTION OF POND SHOWING ABUNDANT GROWTH OF TALL 
VEGETATION WHICH DOES NOT PROVIDE MUCH PROTECTION FOR 
MOSQUITO LARVA, 
