Mary Pirie, Familiar Teachings on Natural History : A Book for the Use of schools, Aberdeen, Lewis Smith, 1864, p. 168.

The caddis worm is the larva of the caseworm fly, and is well known to anglers, as affording them a choice bait. It is found in brooks and running streams, where it makes itself a curiously-formed cell, in which it takes up its abode, while  awaiting its transformation to the winged state. In the construction of this cell, it makes choice of a number of tiny shells and small stones, with which it sets about forming its tube-like dwelling, which is about the size of a wheat-straw, and equally smooth and uniform in the interior.