12 MOSQUITOES 



puncture to a healthy individual. The best we can do, 

 then, is to say that the adult mosquitoes live indefinitely 

 — certainly, under favorable circumstances, even in sum- 

 mer, for several weeks — and that they may bite an indef- 

 inite number of times. 



Observations by Fermi and Lumbao on Onlex pipiois in 

 Italy led them to believe that this mosquito, after emerg-- 

 ing, devotes itself to blood-sucking and similar pleasant 

 occupations, but that egg-laying- only takes place after 

 from fifteen to twenty days, and that after egg-laying the 

 females die. This observation may be perfectly correct, 

 but it is contrary to the customary rule with insects, since 

 it is almost a law that after the issuing of the adults the 

 first and main business of life is the perpetuation of the 

 species. 



Transformations of Mosquitoes Artificiallj^ Hastened. 



In the summer of 1900, while engaged in making experi- 

 ments as to the insecticidal effect of creosote-oil poured 

 upon the surface of water in breeding-jars containing 

 mosquito larvae, I made what seems to me to be a most 

 interesting observation. In one battery jar containing 

 three quarts of water, eight j^ nearly full grown larvae of 

 Culex stimulans and C. 2^erturham were placed, and one- 

 fourth of an ounce of creosote-oil of a specific gravity 1.035 

 at 60° F. was i)oured. This was jar No. 1. In another 

 jar were two quarts of water in which were placed 150 

 larvae of the same species, all full grown or nearly so. 

 Upon this water, three-sixteenths of an ounce of a some- 



