INSECTA: NEUROPTERA 



299 



foul, or if the air in it has been driven out by boiling, the 

 larva comes to the surface and projects its tail into the air, 

 which it takes direct into the rectum. A full-grown larva, 

 instead of drawing in air through its tail, may make use of 

 its thoracic spiracles, for these are open at this stage, though 

 closed in the young larva. 



j_. The sudden ejection of water from the large 



anal chamber will often cause the larva to dart 



Pig. 221. — Two Aeschna Larvae hunting Tadpoles in a Poui. 



A^ With mask, M, bent back under the head ; iJ, with mask extended and holding 



a tadpole in its "forceps." 



quickly forward through the water. When a captured larva 

 is first set free from the hand into a bowl of water, it will 

 often suddenly eject this anal jet, which may spurt up into 

 the air for several inches. 



The Dragon-fly larva is a very active hunter, 

 Canture stalking its prey unperceived owing to its dull 

 coloration and its stealthy movements. Any soft- 

 bodied aquatic creatures are attacked by it, even fish larger 

 than itself. It has a most efficient weapon for seizing its 

 prey in the so-called "mask" or modified lower lip. 



The labium has developed into a single, jointed, arm-like 



