NATURAL ENEMIES OF MOSQUITOES 159 



well in purely fresh water. He has raised them to the 

 fourth generation in tubs and ponds, and they will breed 

 readily in tubs or aquaria. As destroyers of eg-gs and 

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





Fig. 45. — Top-minnow {Gambusia affinis) ; 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 anj^ 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 Gatnhuaia affinis, is 



