8 MOSQUITOES 



scale in glass vessels have shown that the larvne of Culex 

 will exist for some little time in wet mud and that some 

 of them Avill successfully transform after water has been 

 added, but in no case were we able to revive larv?e in 

 mud from which the water had been drawn off for more 

 than forty-eight hours, and after twenty-four hours only 

 a small proportion of the larvae revived. These results 

 accord very accurately with those reached by English 

 observers in Africa, and, in fact, accurate observations 

 have not carried the larvae out of water alive for more 

 than forty-eiglit hours. The impression to the contrary 

 has probably been gained from observations on pools 

 which in realit}^ did not entirely dry up. Mr. C. A. 

 Sperry, of Chicago, has made observations upon a pond 

 which dried up and in Avhich he could find no dead larvae, 

 but he writes that after a week it rained and as soon as 

 the rain stopped he found the mosquito larvae all through 

 the water as lively as ever, and they began to issue as 

 adults in about a week from that time. Mr. Benjamin S. 

 Pascal, of Newfield, N. J., has sent to me an account of 

 observations of his own which indicate to him that mos- 

 quitoes may breed in grass or moist earth. 



In the summer of 1900, I watched a slowlj^ evaporating 

 pool with great interest. It contained a surface area of 

 about twentj^-four square feet, and was fed entirely by 

 rain-water and surface drainage. It was well stocked 

 with mosquito larvae, and after a long drought the water 

 was observed to have evaporated almost entirely, onh^ a 

 small puddle remaining in the centre, which contained at 

 the outside only three or four cubic inches of water. It 



