The idea of a cat peeping out of a muff

AnonymeHints for the formation of a fresh-water aquarium, Londres, Society for Promoting Christian Knowledge, 1858, p. 107-108. 

We must not forget the Caddis-worm, the larva of several species of four-winged fly, Phryganea. These are to be found in abundance, at the bottom of running water, encased in tubes of gravel, small shells, &., or at the bottom of ponds, or creeping about upon the weeds, in houses made with particles of wood, the stems of aquatic plants, &. In a aquarium, they frequently repair their dwellings with particles cut from the silvery floating roots of water crowfoot, suggesting the idea of a cat peeping out of a muff.