U.S. B. F.—Doce. 874. PLATE II. 
FIG. 4—SPRAYING OIL ON AN ACID SWAMP IN WHICH FISH CAN NOT 
LIVE BUT WHICH SUPPORTS ANOPHELES LARVA. 
FIG. 5—SECTION OF CLEAN SHORE OF A POND WHERE MOSQUITO 
LARVA. WERE ABUNDANT BEFORE INTRODUCING TOP MINNOWS. 
FIG. 6—SHOWING GROWTH OF AQUATIC GRASS IN CORNER OF POND. 
SUCH GRASS FURNISHES EXCELLENT PROTECTION FOR MOSQUITO 
LARVA. 
