28 THE AQUARIUM, 



for deceit too. By a peculiar process of development 

 the lower jaws become converted into a mask provided 

 with a pair of pincers. This mask is attached to a long 

 jointed rod, by means of which it can be shot out some 

 distance from the head, and, when the prey has been 

 secured by the pincers, as quickly drawn back to the 

 insect's mouth. As we have before stated they are 

 exceedingly ravenous, and must be carefully looked after, 

 as they will attack and destroy young newts, if they have 

 the opportunity. But there is so much of interest attached 

 to them, that any trouble incurred in keeping them will 

 be fully repaid. 



Another group of insects inhabiting the water in their 

 early stages are known as Caddis-flies. Interesting as 

 the Dragon-fly larva is from its peculiar structure, the 

 Caddis-worm is perhaps more so, from its defenceless 

 nature. It has no powerful jaws, no special locomotive 

 apparatus, not even the tough integument in which the 

 Dragon-fly larva is encased. The Caddis-worm is totally 

 unprotected by nature, and its skin is of the very tenderest 

 description. But to remedy nature's oversight, our little 

 friend constructs itself a movable grotto impervious to the 

 attacks of inquisitive fish. This protection takes the form 

 of a cylinder, perfectly smooth within, and lined with a 

 dainty tapestry of silk, but without it is of the roughest de- 

 scription. To make it they collect little gravel-grains, 

 small snail-shells, bits of wood, leaves, &c., and fasten 

 them together by an insoluble glue. Different species 

 exhibit special preferences in regard to building material. 

 Thus Anabolia 7iervosa prefers coarsest grains of sand for 

 the construction of its tube, but it is always lightened by 

 a miniature log of wood running along the upper surface, 

 and overlapping in front, so that the tenant can put out 



