ORTHOPTERA 



371 



numbers of hungry foes are always on the watch to devour them. 

 So they set to work to protect themselves from assault. 



This they do by making a little " case " in which to live. The 

 material of which it is constructed varies greatly. Some caddis 

 grubs simply fasten two dead leaves together and live between 

 them. Some make a case of little stones, or grains of sand ; others 

 will have nothing but grass blades, or bits 

 of reed, which they carefully cut up into 

 suitable lengths. Others, again, prefer 

 the shells of minute water snails, and do 

 not seem to care in the least whether their 

 inmates are alive or not; so that, when 

 the case is finished, one sometimes sees 

 the inhabitants of the shells pulling in one 

 direction, while the caddis grub is dragging 



them in another! Caddis-FIy and Grubs 



In order that the grub may be able to i,caddis-Fiy;2,Grubincaseformed 

 retain its position within this case, the end °^ ^"^^ and dry pass stalks; 3, in 



. , r . _ , , . case formed of small stones; 4, incase 



of its body IS furnished with two strong formed of grass roots; 5, in case formed 



hooks, with which it clings so firmly that the °f »>■'"=■ 



body may be torn in two without causing them to loose their hold. 



When it has finished growing, the caddis grub retreats alto- 

 gether into its case and spins a close silken net-work over the 

 entrance. It then turns into a pupa, and can rest secure in its 

 artificial protection. 



When it leaves the chrysalis state and becomes a perfect insect 

 it does not eat, for it has no mouth ! But it never seems hungry. 

 Its life in this stage is very short, and after a few days it lays its 

 eggs and dies. 



ORTHOPTERA 



This order includes, with others, some groups, such as the true 

 May-flies, dragon-flies, and white ants, which used to be placed 

 in the Neuroptera. But as none of these undergo the complete 



