96 OUR INSECT FRIENDS AND FOES 



When the larva has been successfully removed 

 from its case, it should be placed in a shallow 

 dish or glass tank of water ; together with a 

 supply of pieces of stick, dead leaves, sand 

 grains, or other material similar to that employed 

 in the construction of the case from which it has 

 been extracted. The larva will at once begin 

 to select from the materials provided such 

 portions as may meet its requirements, and pro- 

 ceed to form them into a new sheath around its 

 body, the whole operation of building the new 

 case taking from one to three or four hours. 

 Reaumur, who did so much to awaken an 

 interest in, and advance the study of, insect life, 

 has left a singularly clear and interesting account 

 of his observations of the Caddis-fly in all the 

 stages of its life, and gives the following sum- 

 mary on the peculiarities of the perfect insect : 

 " The Caddis-fly exhibits some marked peculi- 

 arities of its own. In the classification of Flies, 

 we might assign to them the name of papilio- 

 naceous, that is, Flies which at first sight resemble 

 Butterflies. These papilionaceous Flies have 

 four wings, of which only the two upper are 

 visible when the insect is at rest. In this posi- 

 tion the upper wings are nearly flat above, then 

 they bend at an angle and slope downwards. 

 These two upper wings are moderately trans- 

 parent, but appear opaque when they overlie 

 the others. It is their opacity which causes 

 them to resemble Butterflies' wings, but on 

 close examination we see that they have none 

 of the scales which are characteristic of the 

 wings of Lepidoptera. The lower wings are 



