F. A. Pouchet, The Universe : The Infinitly Great and the Infinitely Litlle, Londres, Blackie & Son, 1871, pp. 213-214.

Sometimes also the Phryganea for so these prudent workmen are named construct their sentry-boxes of fresh-water shells; finally, at other times they cut up for this purpose slender herbs, and cover their whole body with them in such a manner, that at the bottom of a poll they look like tiny bottles of hay walking about of themselves, for we do not perceive the timid inhabitants. However, the common Phryganea (Phryganea communis) seems to give little head to the nature of the materials it employs, and willigly makes use of all it finds at hand. Having carefully extracted several of its larvae from their shelly sheaths, and afterwards placed them in vessels of water, the bottom of which was covered only with little pearls of various colours. I saw them immediately set to work to make a new residence, choosing here and there pearls of the most different hues, in such a way that when the construction was finished, each Phryganea’s dress resembled a little case in mosaic, promenading on the walls of my crystal case.