MOSQUITOES. 337 



them. Tliese are in constant motion, and promote 

 a current of water, whicli is sent along to tlie mouth 

 of the mosquito *' wriggler," carrying tiny animals 

 and scraps of vegetable food. One can see them 

 moving along on their heads, feeding on the tiny 

 vegetable growths which flourish on the leaves of 

 the long, grass-like VaUisneria and other water 

 plants in the fish boAvls, or burrowing their heads 

 into the sediment at tlie bottom of the bowl. The 

 lieavier head and thorax form a good balance or 

 anchor, as tlie larva is feeding head downwards. It 

 moults six times, increasing in size after each moult. 

 It then pupates. 



The pupa (Plate 41, Fig. 6) is a curious little 

 object like a little ''water gnome," with its great 

 'Miead" (whicli is really tlie head and tliorax) and 

 its lai'ge, ear-like breathing tubes slit' down part 

 of one side and resembling "donkey's ears." These 

 are situated on the head of the active little pupa 

 instead of tlie tail (as was the case in the larva). 

 (Plate 41, Fig. 6 a and Fig. 4). Unlike most pupa% 

 it is very active ; but it cannot eat, because the 

 mouth parts and all its bod.y is covered by the 

 pupal sliell. (Note tliat the pupa is naked or free, 

 and not enclosed in a puparium.) As before men- 

 tioned, it breathes by means of a pair of tubes on 

 its head, and it has to come to the surface of the 

 water to get an air-supply. It moves about with 

 its head upwards, and by curling its body round 

 it gives a series of jerks, sends itself through the 

 Avater, and is called a "tumbler." Tlie abdomen 

 of the pupa tapers to the end, and terminates in 



