THE MAY-FLIES AND THE DRAGON-FLIES 27 



the anterior and posterior wings, and by the presence of 

 abdominal filaments. From the earliest nymph stage to the 

 imago there is quite a clearly marked though gradual change 

 of form, or metamorphosis. 



To-day I saw the dragon-fly 



Come from the wells where he did lie. 



An inner impulse rent the veil 



Of his old husk : from head to tail 



Came out clear plates of sapphire mail. 



He dried his wings : like gauze they grew ; 



Thro' crofts and pastures wet with dew 



A living flash of light he flew. TENNYSON. 



Dragon-Flies. The dragon-flies (Libel'lula, Fig. 15) are 

 familiar insects found flying over the surface of still or run- 

 ning water. They feed on other insects, which they capture 

 on the wing. They are lovers of the sunshine, and are most 

 active in the brightest and hottest part of the day. The larger 

 kinds hawk freely over the surface of the water at some dis- 

 tance above it, often far out from the shore, where their range 

 of vision is unobstructed ; while the smaller and weaker kinds 

 keep closer to the shore and the protection of vegetation. All 

 are voracious feeders, destroying large quantities of flies and 

 mosquitoes. Many superstitions have become associated with 

 them in different parts of the country ; in the North it is 

 believed that they sew up the mouths and ears of children ; 

 in the South, that they bring dead snakes to life. It is, per- 

 haps, needless to say that they are harmless. The head is 

 made up almost entirely of the great, staring, compound 

 eyes, which shine like fire as the dragon-fly moves about. 

 The mouth has strong jaws, somewhat resembling the power- 

 ful mandibles of the locusts. The wings are large, with 

 many veins, and are moved by powerful muscles ; but the legs 

 are slender and small, as the dragon-flies are preeminently 

 creatures of the air. The long and slender abdomen is used 

 to balance the insect in its headlong flight. 



