NEUKOPTERA. 



139 



nished armour, gemmed with green and gold and black ; 

 their gorgeous wings, like films of living glass stretched 

 over net-work (to compare with which, the finest lace is 

 but a sorry piece of workmanship), proclaim them tyrants 



Fig. 93.— duagox-flv, 



of the air, and monarchs of the insect world. Yet in the 

 earlier stages of their existence, these splendid creatures 

 arrayed in humbler guise inhabited some neighbouring 

 pool or ditch ; the larva is 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 proj)elled 

 through the water with its legs closely packed against its 

 sides. The pupa only differs from the larva by having 

 the rudiments of wings attached to its thorax ; both are 



