DIPTERA. 



173 



shrill small triimi)et of the little pest, to ward off such a 

 despicable foe; too soon our legs and hands and face, 

 pierced to the blood, covered with lumi^s and painful 

 swellings, proclaim the efficiency of the dreadful weapon. 

 Neither heat nor cold seems to affect these tormentors of 

 the human race. In Lapland they swarm to such an 

 extent during certain periods of the year, that there is 

 neither rest nor sleep for the inhabitants indoors or out, 

 unless in the suffocation of thick smoke, or under the 

 defence of a thick unguent composed of grease, tar, and oil. 



The transformations of the common gnat . 

 (culex pipiens), are well worthy of om* atten- 

 tion, and may be observed in any water 

 butt. The female gnat, descending from 

 her aerial dance among the slanting beams 

 of sunset, alights cautiously on the surface 

 of the water, where the lightness of her 

 body, and the expanse covered by her slen- 

 der feet, prevent her not only from sink- 

 ing, but even from becoming wetted. She 

 then crosses her hind legs, thus making a 

 sort of frame in which her eggs are de- 

 posited, in the shape of a little boat, so fig. 132.— lakva of 

 buoyant and so repellant to the water that '^^^'^■ 



it is impossible to sink it. In the course of a couple 

 of days the eggs, thus left to float, are hatched, and the 

 larvae escape ; they may then be seen wriggling about 

 ^vith considerable agility, now descending, now ascending 



Fig. 133. — e.*cape of gxat from its pupa-case. 



slowly to the sm-face, where they hang suspended from a 

 little tube affixed to their tail, through which they breathe 



