24 MOSQUITOES or NORTH AMERICA 



life-history of Culex pipiens, are wonderfully characteristic, exquisite in execu- 

 tion, and stand unsurpassed to this day. Like De Geer, he found the Aedes 

 larvas which appear in the early spring in snow-water, although, like that 

 author, he failed to realize that they were different from the rain-barrel mos- 

 quitoes, assuming that they were the first of a series of generations produced 

 through the warmer months. He is quite pardonable in this, as the error per- 

 sists with many even to this day. 



Kleemann calculated that there could be three generations of mosquitoes 

 during a season. After speaking of the retarded development of the larvae, when 

 confined in a small receptacle, he says (free translation) : 



" However, in this year 1763, with long-continued warm spring weather, I 

 found this out in the following manner : I had already found these worms, full 

 grown, in a wooden vat in which rain-water had been caught, at the beginning 

 of June, and soon brought some of them to transformation. On this account I 

 emptied it out and left it standing for some days without water. Towards the 

 end of the month, however, I had it again filled with clean water and at the be- 

 ginning of July found very many mosquito eggs therein, which brood then came 

 to completion at the beginning of August, Thereupon I emptied the vat once 

 more and again filled it with clean water, and also found in this, after some days, 

 mosquito eggs which hatched in the middle of September, Even in October of 

 this year I have still found mosquito eggs, the worms of which, however, at 

 present (towards the end of this month) do not incline to transform : therefore 

 I believe that they will hibernate without food and only transform in the spring ; 

 as I have also found the like full-grown worms already in April and May in the 

 swamps of the forests ; yes, even in March of this year, on a bright day, I have 

 caught a male mosquito which I could not take for a hibernated one but for one 

 freshly issued.'' 



As above stated, the other general accounts of the last century followed 

 Eeaumur, and the life-history of Culex pipiens was not restudied until 1896, 

 and of other mosquitoes not until several years after this. Since 1900 the whole 

 civilized world has been turning out mosquito literature, good, bad, and in- 

 different; papers descriptive of new species have multiplied, many accounts of 

 habits have been published, and much space has been devoted to the subject of 

 internal anatomy, so that since that date the bibliography of mosquito literature 

 has run into many thousands of titles. 



