72 FISHING GOSSIP. 



insects of the spring, any more than all the Ephe- 

 ineridfe are limited to the existence of a single day. 

 The history of the Phryganidse forms one of not the least 

 strange chapters among the manifold wonders of ento- 

 mology. The mature female insect generally deposits 

 her eggs on the leaf of a tree overhanging the water. 

 Here the eggs are retained by a kind of glutinous 

 substance until hatched, when the larvae, strange 

 little six-footed creatures, drop off into the water. In 

 this new element, each larva, prompted by the un- 

 erring instinct of nature, commences to collect around 

 it a case composed of parts of plants, leaves, pieces 

 of stick, small stones, sand, and even small fluviatile 

 shells with their living inmates. These, materials are 

 collected and secured by loose threads of a glutinous 

 kind of silk spun from the mouth, as practised by 

 several caterpillars. The larva first collects a suf- 

 ficiency of materials before it attempts to enclose 

 itself, for it is obvious that the longer it builds, the 

 less constructive action it can maintain. A remarkable 

 instance of adaptation of materials is seen in those 

 cases constructed of small stones, of all shapes, full 

 of angles and irregularities, out of which the larva 

 forms a tube as straight, smooth, and uniform in the 

 inside as a gun-barrel. Nor is this all ; as the case 

 is a movable house, which the insect drags about at 

 will, the under surface must be as smooth and free 

 from projecting inequalities as the inside. The larva, 



