REPORT ON MOSQUITOES. 133 



pupae were hatching. After twenty-four hours the conditions 

 were unchanged ; but some of the larvae had pupated and some 

 adults had emerged. After seventy-two hours there were some 

 dead larvae in all the jars ; but the fewest in Jars 1-3 ; many more 

 larvae had changed to pupie and more adults had emerged. After 

 ninety-six hours more larvae had pupated and adults had 

 emerged; the majority of the remaining larvae were dead; but 

 there were two or three in each of Jars 1-6 and one in each one of 

 Jars 7 and 8 still active. The experiment was ended at this point 

 with several larvae still active in a check jar, in which develop- 

 ment did not take place as rapidly as in the experiment jars. The 

 water in all the experiment jars was more or less thoroughly 

 cleared, while that in the check jar retained the characteristic 

 cloudy appearance of the pool breeding liquid. 



Experiment ./; with full grown larvcC and pupae of Ciilex can- 

 tator breeding in brackish water on the Newark meadows. They 

 were placed with the water in which they were found in three 

 jars and enough copper sulphate was added to give the following 

 proportions : 



Jar I — I part of copper sulphate in goo of water. 

 Jar 2 — I " " " " " 442 " 

 Jar 3—1 " " '■ " " 308 " 



Half an hour after adding the copper sulphate the water beg'an 

 to clear; twenty-four hours thereafter the water was clear^ with 

 the larvae and pupae in apparently healthy condition. After forty- 

 eight hours almost everything was dead, only a few larvae — three 

 in Jar i, and two in Jars 2 and 3 — and pup^ were still alive when 

 the experiment ended. The larvae and pupae in a check jar, which 

 retained the characteristic cloudy appearance, were in good con- 

 dition when the experiment closed. 



Experiment 5." with larva? and pupae of mostly Ciilcx canto tor 

 and a few of Citlex soUicitans breeding in brackish water on the 

 Newark meadows. These were placed in four jars in the natural 

 breeding water and enough copper sulphate was added to give the 

 following proportions : 



Jar I — I part of copper sulphate in 4466 of water. 

 Jar 2—1 " " " " " 2233 " 

 Jar 3-1 " " " " " 1488 " " 

 Jar 4 — I " " " " " 1 1 16 " " 



Twenty-four hours after adding the copper sulphate many 

 adults had emerged and the smaller larvae were dead in all the 

 jars. A few of the larger larvae were dead in Jar 3 and all the 

 larvae were dead or dying in Jar 4. After forty-eight hours 



