William Ray Allen, A nature sketchbook twenty talks on the everday life roudabout, Lexington, Department of University Extension, 1936, p. 47.
Among the most interesting are the caddis-flies, whose larvae live on the bottoms of ponds and streams. They build for themselves a tube like a chimney. Sometimes the chimney is built of small sticks, other species use tiny pebbles, others fine sand.
Other species make the tube of bits of dead leaf pasted together. We shall later discuss the way of the dragonfly nymph, one of the most interesting..