MA Y-FLIES. 



105 



an uncouth, broad, flat, olive-coloured animal, having six sprawling legs, with 

 which it crawls, spider-like, about the mud at the bottom of ponds, or glides 

 by a singular mechanism through the water. The hinder extremity of the 

 body is furnished with several leaf-like appendages, capable of being brought 

 close together or opened at pleasure. These close the orifice of a cavity 

 whose sides are very muscular. When the insect wishes to move rapidly it 

 opens this cavity, which thus becomes filled with water, and then by a con- 

 traction of its walls the water is forcibly ejected in a stream, as from a syringe, 

 and thus the larva is propelled like a rocket, 

 with its legs closely packed against its sides. 

 The pupa only differs from the larva by hav- 

 ing the rudiments of wings attached to its 

 thorax; both are active and voracious, the 

 tyrants of the pool, devouring with ferocity 

 other insects, tadpoles, small newts, and even 

 fishes. These predatory habits are continued 

 in the perfect insect, whose sanguinary pro- 

 pensities are no less correctly expressed by 

 our term Dragon-Fly than its elegance and 

 grace by the French appellation Demoiselle. 

 It pursues gnats and flies in the air, eating them on the wing. It has been 

 seen to catch butterflies, and Mr. Gosse, to whose elegant pen we are indebted 

 for much of the above graphic account of their history, believes that they 

 sometimes pounce upon the fry of fishes when swimming at the surface. 



The May-Flies (Ephemera}* These insects have received their name 

 from the shortness of their existence in their perfect state, which is, indeed, so 



FIG. 94. PUPA OF DRAGON-FLY. 



FIG. 95. LARVA OF EPHEMERON, AND SECTION OF ITS CELL. 



brief that the same evening sun which sees their birth generally witnesses 

 their destruction. Their life, however, in the earlier stages of their growth 

 is of much longer duration. In their larva state they live in the water, lurk- 

 ing under stones, or residing in little holes that they excavate in the banks of 



, ephemeros, living but a day. 



