NATURAL ENEMIES OF MOSQUITOES 159 



well in i)nrely fresh water. He has raised them to the 

 fourth generation in tubs and i^onds, and they will breed 

 readily in tubs or aquaria. As destroyers of eggs and 

 larvae, and adults as well, of such insects as infest and 



"J /ip"7"M^'",jiiiv"-iJ'i«'V'^>v--' y ' ' ,' 



Fig. 45. — Top-minnow {Gambusia affiiiis) ; male above ; female below ; 

 somewhat enlarged. (After Jordan and Evermann.) 



mutilate aquatic plants or lay their eggs in the water, Mr. 

 Seal finds these top-minnows vastly superior to any other 

 species of fish. Dr. H. F. Moore, of the United States 

 Commission of Fish and Fisheries, informs me that the 

 top-minnow, known scientifically as Gcunhusia affinis, is 



