9 2 



THE STUDY OF INSECTS. 



parallel with the abdomen when at rest (Fig. 99) or are up- 

 tilted. The head is transverse, each eye being borne by a 

 lateral prolongation of the head. The females possess an 



FIG. 99. A damsel-fly. 



FIG. loo. Nymph of a 

 damsel-fly. 



FIG. 101. 

 Tracheal gill 

 of nymph of 

 damsel-fly. 



ovipositor by means of which the eggs are placed in the 

 stems of aquatic plants, sometimes beneath the surface of 

 the water. 



The name of the suborder is from the Greek zygon, 

 yoke, and pteron, wing ; it probably refers to the fact that 

 the wings are brought together when at rest. 



Unlike the dragon-flies, the damsel-flies are compara- 

 tively feeble in their flight. They are found near the 

 margins of streams and ponds, in which the nymph stages 

 are passed. 



The nymphs of damsel-flies (Fig. 100) possess leaflike 

 tracheal gills at the caudal end of the body. One of these 

 is represented greatly enlarged by Fig. 101. 



