Planorbis vortex

Reginald A.R. Bennett, « The Fresh Water Aquarium »The Boys Own Paper, Londres, n° 1079, 16 septembre, 1899, pp. 812-815.

The larva being a choices morsel much appreciated by fishes, etc., finds it necessary to protect himself from those who would devour it. This it does by constructing a case to hold its soft body. These case are made out of all sorts of things. In the picture you will see the one on the left has made his out of small shells, principally those of the Planorbis vortex, or other small Planorbes, while the one on the right has made his one out of little bits of grass stem or vegetable branches of woods. If the larvaa are caught (they usually abound in almost any ditch or pond) and place in a veasel with beads, etc., in it, after gently depriving them of their former cases, they will at once begin to construct new cases with the materials provided, and thus you will get some very curious habitations indeed. In the aquarium the Caddis-worms will not do any harm to anything, but will feed on the plants, unless they come across a piece of decaying animal matter, when they may condescend to eat that. The different species of Caddis-fly larvae make cases of different materials; thus one can distinguish the kind of fly by the materials of which it makes its home.