Adolphe Boucard,A Manual of Natural History, London, Thomas Murby, 1876, p. 134.
We meet with larvae in ponds which drag after them a case about three-quarters of an inch long. When they walk about with their house, they put out their head and legs, and when they are alarmed they hide in it.
These are Phryganea, or caddis-flies, in the larva state. These cases are formed of the materials which the insect finds near it ; perhaps small stones, or shells, or else small twigs or pieces of leaves which the larva cuts for itself. All these objects are joined with threads of fine silk. The phryganeae are always very curious objects to observe in an aquarium, and they can be made to construct beautiful cases by pulling a larva out of its case, and putting it into a vessel with glass beads, when it will use them to construct a new house, if it can find nothing more suitable.