CHAPTER II 



flies with aquatic larv^ 



The Gnat (Culex) 



Small stagnant pools and ditches are the favourite 

 haunts of the larvse and pupae of the Gnat. A ditch 

 in a wood choked with fallen leaves is one of the best 

 hunting grounds, and in the summer months they 

 may be found by the thousand in such places. 



The larva, when at rest, floats at the surface of the 



water. Its head, which is provided with vibratile 



organs suitable for sweeping minute particles into the 



mouth, is directed downwards, and, when examined 



by a lens in a good light, appears to be bordered 



below by a gleaming band. There are no thoracic 



limbs. The hind limbs, which are long and hooked 



in the burrowing Chironomus larva, and reduced to 



a hook-bearing sucker in Simulium, now disappear 



altogether. A new and peculiar organ is developed 



from the eighth segment of the abdomen. This is a 



cylindrical respiratory siphon, traversed by two large 



air-tubes, which are continued along the entire length 



of the body, and supply every part with air. The 



H 



