SPIDERS. 



193 



ever an insect falls into the pit, the Ant-lion seizes and 

 devours it. 



Caddice Flies. 



These Insects are the most interesting while in the 

 larva state. They live at the bottom of ponds and 



Fig- 339- — Caddice Fly. 



streams, in cases which they construct of bits of wood 

 or grasses, of grains of sand, or of fragments of broken 

 shells, and which are lined with silk spun from their 

 mouths. They sometimes load one side of the case with 

 heavier pieces, in order to keep that side downward. 



SPIDERS AND SCORPIONS, OR ARACHNIDS. 

 Spiders. 



Spiders have the body divided into only two well- 

 marked portions, — the head and the hind body. They 

 have eight legs, and two palpi or feelers resembling 

 legs, but no wings, and do not change form from the 

 young to the adult state. Most kinds feed upon insects. 



Many Spiders have, at the hind part of their body, a 

 most wonderful organ, called the spinneret, by which 

 the delicate threads of the spider web are spun. It 

 consists of four to six knobs, with a thousand or more 



NAT. HIST. AN. — I3 



