380 INViiETEBRATES. 



Tkey are exceedingly ravenous ; they fall witn the greatest 

 fury on all their fellow-insects, and indiscriminately devour them. 

 Their tail is cloven, which has led many to believe they are pro- 

 vided with a sting. Hence, too, they have received the name of 

 Iwrse-stingers. 



The great dragon-fly is remarkable for the celerity and vigor 

 of its flight. On one occasion a great dragon-fly was seen gently 

 flying near a pond in search of its prey, when, on seeing a butter- 

 fly, it suddenly caught it, and then sat down composedly on a twig 

 and eat it piecemeal. 



The Caddis-fly. — This fly is well known to every angler 

 both in its larva and in its perfect state. The larva is a soft white 

 worm, of which fishes are exceedingly fond, and it therefore re- 

 quires some means of defence. It accordingly actually makes foi 

 itself a movable house of sand, small stones, straws, bits of shells, 

 or even small living shells, in which it lives in perfect security, 

 and crawls about in search of food, dragging its house after it. 

 When it is about to become a pupa, it spins a strong silk grating 

 over the entrance of its case, so that the water necessary for its 

 respiration can pass through, but at the same time all enemies are 

 kept out. When the time for its change has arrived, the pupa 

 bites through the grating, rises to the surface, and crawls out of 

 the reach of the water, which would soon be fatal to it. The skin 

 then splits down the back, and the perfect insect emerges. 



The Ant-lion. — This insect, in its perfect form, although it 

 is very elegant, exhibits no peculiarity worthy of notice, but in its 

 larva state its habits are so extraordinary as to have excited general 

 attention. As it is slow and awkward in its movements, it has 

 recourse to stratagem for capturing the agile insects on which it 

 feeds. Choosing a light sandy soil, it digs for itself a conical pit, 

 at the bottom of which it conceals itself, leaving only its jaws ex- 

 posed. When an unwary insect approaches too near the edge of 

 the pit, the sand gives way, and down rolls the insect into the very 

 teeth of the concealed Ant-lion, who instantly pierces its prey with 

 its calliper-shaped fangs, and sucks out its juices through the jaws, 

 which are hollow. Should, however, the Ant-lion miss its prey, 



