// ATER-BOATMAN — CADDIS-FLY— DRAGON-FLY 37 1 



end of the body to the breathing-apertures on the thorax. The insect may. indeed, 

 often be seen passing its hind-legs like the bow of a violin, across the back of its 

 body, in order to force the air in one or other direction into the grooves, where the 

 rows of bail's separate for its admission. 



caddis fi Many representatives of the group of insects known as 



Neuroptera frequent the banks of streams, and when young live 

 in water. Nearly every angler is familiar with caddis-worms, which are insect- 

 larvae living in eases of their own making, the materials used being fragments of 

 shells, sand, sticks, and leaves. These larvae, which are mainly carnivorous, though 

 occasionally feeding on vegetable matter, cling by little side-hooks to their dwell- 

 ing, from which only the fore part of the body protrudes; and in this way they 

 creep about in the water, retiring into their artificial shells at the slightest touch, 

 and closing the opening in front with the horny head-shield. The caddis-flies, to 



% 



THE WATER-BOATMAN. 



which these larvae pertain, constitute the subgroup Trichoptera, and are character- 

 ised by the presence of transverse veins on both pairs of wings, as well as by the 

 hind-paii- folding up like a fan so as to be covered, as with a roof, by the front-pair. 

 As full-grown insects they live on the juices of flowers, and are often known as 

 water-moths, owing to their moth-like appearance. 

 Dr Another sub-group (Odonata) is represented by the dragon-flies, 



which also live when young in the water. These active insects are 

 specially characterised by well-developed mouth-organs, and the two pairs of long 

 and gauzy wings, which are almost equal in size, as well as by the presence of three 

 joints in the feet. Swift in flight and predaceons in habit, they skim the water like 

 swallows, the females often dropping their eggs as they dip their tails in the water. 

 They live on aquatic insects and fish-spawn; and as larvpe have a large lower lip, 

 divided into two sections, bearing on the end a pair of pincer-like hooks, which may 

 be placed over the face when the insect is resting so as to form a kind of mask. On 



