iro NATURAL HISTORY OF AQUATIC INSECTS CH. 



short Norwegian summer often thicken the air of the 

 Tromsdal a wild valley within the Arctic Circle, 

 practically uninhabited either by man or probably by 

 beast how few are ever likely to taste blood ! " l Sir 

 James Ross and his men found it necessary in their 



A B 



FIG. 29. Antennae of Gnat. A, male; B, female. 



polar expedition to wear gauze over their faces in the 

 summer months as a defence against Gnats. 



o 



The irritation caused bv the bite of the Gnat has 



j 



naturally led to the belief that poison is injected 

 into the wound. Whether this is true or not cannot 

 be positively stated. No poison gland has hitherto 

 been demonstrated, and there is some reason to 

 believe that the irritation of the wound is slight in 

 1 A. D. Michael, in Natural Science, Vol. I. p. 203. 



