50 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



some nearby floating object (as a bit of cardboard in the aquarium), 

 but usually in a very short time it is able to fly, and immediately is 

 gone. Sometimes, however, mosquitoes in culture appear to have 

 much difficulty in finally extracting their legs; often they fall over 

 on the surface of the water, and some perish in this position with 

 their tarsi still held in the pupal sheaths. It is probable that in such 

 cases the larvae were not properly nourished. 



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Fig. 18. — An adult female of Aedes aegypti emerging from the submerged 

 pupal cuticle ; and the open thorax of the discarded pupal cuticle of Anopheles 

 quadrimaculatus. 



A remarkable thing about the mosquito is that, after its whole 

 previous life spent in the water, on emergence from the pupa it is 

 at once at home in the air. Without a flutter of the wings or any 

 practice trial, it makes a perfect takeoff, flight, and distant landing. 

 During the pupal stage, therefore, the mosquito has not only been 

 equipped with a complete mechanical apparatus of flight, but in its 

 nervous system a mechanism of control has been fully elaborated. 

 Compare this with the difficulty the young human has in learning even 

 to walk, but of course his ancestors did not always walk upright on 

 two legs. 



