240 FLASHLIGHTS ON NATURE 



is a portrait of the larva in his full-grown stage, 

 near the surface of the water. He is about 

 half an inch long, and nimble as a squirrel. You 

 will observe on his head a sort of big moustache, 

 set with several smaller bristles. This moustache 

 (which consists for science of a pair of mandibles) 

 is kept always in constant and rapid motion ; its 

 use is to create an eddy or continuous current 

 of water ; which brings very tiny animals and 

 other objects of food within reach of the voracious 

 larva's mouth ; for young or old, your mosquito 

 is invariably a hungry subject. In point of fact, 

 you may say that these hairy organs are the 

 equivalents of hands with which the larva feeds 

 himself. They vibrate ceaselessly. 



At the opposite end of the body, you will 

 observe, there are two other organs, both equally 

 interesting. One of them, which goes straight 

 up to the surface of the water, and protrudes 

 above it, is the larva's breathing-tube ; for the 

 mosquito breathes, at this stage, not with his head 

 but with his tail ; this ingenious mechanism I 

 will explain further presently. The other organ, 

 which in the illustration (No. 4) goes off to the 

 left, and has four loose ends visible, serves its 

 owner as a fin and rudder. It is the chief organ 

 of locomotion the oar or screw by whose means 

 the larva darts with lightning speed through the 

 water, and alters his direction with such startling 

 rapidity. You will note that it is not unlike the 

 screw of a steamer, and it answers for the animal 

 the same general purpose. How effectual it is 



