76 DRAGON FLIES VS. MOSQUITOES. 



May flies (Ephemeridse), seem only to reach tlie last stage 

 for the purpose of procreating their species, so compara- 

 tively short is its duration. The writer has, however, some 

 years previously made some experiments at carrying the 

 larvse of many aquatic neuroptera through to the perfect 

 stage ; and the results of these, coupled with some subse- 

 quent attempts to obtain oviposition, may serve to answer 

 the present purpose. 



In the spring and summer of 1S75, while at home ujion 

 my father's farm in Suffolk County, Long Island, which 

 borders for some half mile upon the Connecticut River, 

 I constructed three cages for the rearing of any insect 

 whose larval stage was confined to the watei-. The sides 

 of two of these were of board, sixteen inches in width and 

 five feet in length, placed one fiiot apart and kept in posi- 

 tion by fi)ur narrow pieces of scantling nailed at right 

 angles to the ends, top and bottom. Painted wire cloth 

 was fastened to the ends of the cages by wooden cleats, to 

 allow the passage of water. Escape of the larvse by bur- 

 • rowing was prevented by a fringe of tin projecting several 

 inches from the bottom of the cages ; and the cover of each 

 consisted of two painted wire screens which could be 

 raised independently for the purpose of keeping a portion 

 of the imagines confined while others were being removed. 

 The third cage was similar in construction, but having 

 three timqs the width. Weights prevented the cages from 

 floating when in position. One cage was placed in a shal- 

 low arm of the river, so that the current would readily flow 

 through it, leaving some four or five inches projecting above 

 the surface, affording space for the imagines to expand their 

 wings. The second cage was similarly placed in the stag- 

 nant water of a M'ide, shallow ditcli in an adjoining bog 



