370 THE WORLD OF ANIMAL LIFE 



NEUROPTERA 



This order is the last great group of insects whose life-history 

 embraces the three conditions of metamorphosis, namely, larval, 

 pupal, and •' perfect " forms. This group includes the caddis-flies, 

 the scorpion-fly, the alder-fly, the ant-lion, and the lace-wings. 

 But the caddis-flies, of which a considerable number of species are 

 known, are made into a sub-order termed Trichoptera, while the 

 rest are grouped together as the flat-winged sub-order Planipennia. 



CADDIS-FLIES 



It is a bright, sunny afternoon in early summer, and we are 

 walking along the bank of a small stream. Suddenly, from the 

 long herbage just in front of us, there rises a little brown-winged 

 insect, which looks very much like a moth. Its flight, however, 

 is not at all like that of a moth. Let us follow it and try to find 

 out what it is. Now it has settled upon a blade of grass, and we 

 walk cautiously up to it, when we find that it is not a moth but 

 a Caddis-Fly. 



It again rises into the air and flies off in the direction of the 

 stream, where it alights upon the water, and runs along the surface 

 as if it were on dry land, leaving a track behind, like the " wake " 

 made by a boat. Suddenly it disappears from sight; but, on 

 looking more closely, we can see it creeping down the stem of one 

 of the water plants. It has gone under the water to lay its eggs. 



There is a little pale-green object at the end of its body. 

 That is its egg-bag, which it is about to fasten to some leaf near 

 the bottom of the water. 



In a few days' time the eggs hatch, and out come a number of 

 very small grubs. Now these grubs are somewhat like the hermit 

 crab. The front part of their body is encased in a coat of shelly 

 armour, while the hinder part is soft and quite unprotected. The 

 little creatures seem quite aware of this, and also of the fact that 



