Eric Tavernier, Trout Fishing from all Angles, Londres, Seely, Service & Co., 1933, p. 127-128.

Life for the caddis thereafter consists in feeding on microscopic algae, minute organisms and dead animal matter and in enlarging its home to fit its growth ; this is done by biting off the small end of the case and by extending the large rends according to it needs. The narrow end of the case is closed by a grating or is reduced to a pin-hole, which allows free passage of water without exposing the tenant to danger from its ennemies at the rear. The materials of which the caddis constructs its house are manifold : fine sand, minute pebbles, shells, twigs, plant-stems, leaves and many other river-bed debris are cleverly fastened outside a silken cocoon which is first of all spin as a foundation. Examples of some styles of architecture are here shown.