THE DRAGON FLIES 71 



organ for seizing prey, the so-called mask, which is really 

 the labium, or second maxillae. It is furnished with mov- 

 able hooks at the end and is capable of being extended for 

 a considerable distance in front of the head. If an un- 

 wary insect ventures too near, the mask is shot out with 

 great rapidity and the insect pulled back to the mouth. 

 When at rest the mask is folded up under the head. 



FIG. 57. Dragon fly. (After Kennedy.) 



After a series of molts, during which the rudiments of the 

 wings are gradually developing, the larva becomes ready 

 for the final change into the imago or mature insect. 

 It then crawls out of the water, the skin splits down the 

 back and the dragon fly pulls itself out of the old 

 skin, shakes its wings dry and flies away. Upon a super- 

 ficial view there is little resemblance between the alert 

 and graceful movements of the one as it darts through the 

 air with the greatest quickness and precision, and the 



