A. W. Roberts, « A fresh water aquarium », New York, Harper’s Young People, vol. 1 n° 43, 24 août, Harper & Brother, 1880.
In the illustration are figured three kinds of caddis-worms. These worms are useful for consuming decaying animal matter. When a « cad » has grown too large for his house, he makes a little case of silk, which he covers at each end with pieces of leaves, wood, or straw, biting them to the right length ; some fasten on small bits of stone and shells. However rough the outsides of their houses may be, the insides are smooth, and lined with silk.