56 ANIMAL BIOLOGY 



cleaning up his own back yard and by covering cisterns 

 and wells with the finest meshed netting ; for the insistent 

 mosquito has been known to make its way through ordinary 

 wire netting. Fish and dragon flies are also important 

 helps to man, since these animals devour great numbers 

 of larvae, pupae, and adult insects; yet at best they can 

 hardly be counted as efficient means of ridding swamps of 

 mosquito pests. 



Anopheles, Culex, and Stegomyia lay their eggs in the same 



FIG. 39. Staten Island marshes after drainage. 



kind of stagnant pools, and the proper filling, draining, or 

 screening of these pools or their treatment with kerosene, 

 will destroy the one as well as the other. When this is ac- 

 complished, malaria and yellow fever, as has been con- 

 clusively demonstrated by the work of Americans on Staten 

 Island, New Orleans, Cuba, and Panama, will practically 

 disappear. 



