HOUSE-CARRIERS UNDER WATER 



301 



yonder pool and laid upon the snow. I have a number 

 of these cases before me as I write, and they are really 

 beautiful works of insect art. As a rule, each species of 

 caddis is true to some particular whim in building or in 

 the choice of materials for its domicile. Here are two 

 individuals that seem to have taken a hint from the 

 bag-worm, and think there is nothing to compare with 

 sticks and leaves. Their cases are about an inch and a 

 half long. Another has carefully selected tubular pieces 

 of floating grass stems or straws, enlarging the tube as 

 its growth requires by slitting up the side and fitting in 



a strip of new material ; afterwards, perhaps, decorating 

 the exterior with a few stray chips or pebbles. 



But the most interesting of all are the dwellings of 

 the stone-builders, actual mosaic tubes of carefully- 

 selected pebbles, all joined edge to edge, and neatly 

 closed at the rear opening by a nicely- fitted pebble 

 of larger size. And one there is, the glassy abode of 

 the smaller caddis, a perfect marvel of mosaic art. A 

 small, slightly curved tube about three-quarters of an 

 inch in length (shown directly above the stick case in 



