Percival W. Westell, Nature stalking for boys. Throught Field-Glass, Stereoscope and Camera, Londres, J.M. Dent, 1909.

The Boy-Scout.
Just look at the homes of the larvae when you next have an opportunity. Is it not remarkable that a mere grub should, by its own industry and perseverance, manage to build such a nice snug little house in which it can shield its soft body from ennemies, and live until such time as it emerges as the pefect Cadis fly?
These houses of the Caddis Fly larvae are of various kinds according to the species responsible for their construction. One kind builds a home of pieces of stick ; another uses sand, small, stones, and little shells ; another utilises dead leaves, and several seem to be very fond of ornamenting the front door with a shell of some small Fresh-water mollusc.
p. 56-57.

The Caddis Fly
The Caddis Fly I always recognise and remember as one of my earliest insect friends. I was much impressed in my youger days with the remarkable larval and pupal case that the larva constructs, and wondered a thousand tomes how it was possible for such a creature to construct such a home. The case is sometimes built uo of small sticks, and is embellished with a small shell , a stone, or some similar object. Other cases are composed of small stones, and adhering to these the tenanted shells of minute forms of shells-fish may be found. It is no uncommon sight to witness the larva of the caddis Fly travelling in one direction and the moluscs endeavouring to progress in an opposite one!…/…
p. 257 – 258.