174 UTIIEK MEMBK118 OF THE CLASS — INSECTA 



doctors," etc. (Fig. 114). They have long, slender bodies 

 ;ind two pairs of strong, transparent wings of about equal 

 size and with many longitudinal and cross \-eins. When 

 flying, they tlart swiftly back anrl forth over the water; 

 but when they alight, they sit motionless — most spe- 

 cies with outspread 

 wings — on the dry, 

 ])i'ojecting stems of 

 plants. They ha\'e 

 powerful jaws and 

 great round eyes, 

 and live upon other 

 insects caught while 

 on the wing. Most 

 of their prey they 

 capture and hold 

 with their legs and 

 eat while flying. 



The eggs of dragon 

 flies are either at- 

 tached to the stems 

 of water plants be- 

 low the surface of 

 the water or are laid 

 loo.'^ely in the watei-, 

 or, in some cases, 

 are inserted within 

 the tissues of the plant stems. They hatch into ferocious 

 nymphs with strong jaws and enormous appetites. The 

 nymphs live upon other aquatic insects, as the larvif of 

 mosqiutocs, for example, which they devour greedily when 

 tilt'}' ai'c tu be fuimd. 



on fli(-s. 



