Old photographic films

Laurence E. Palmer, « The smaller creature of quiet water », Ithaca (New York), Cornell Rural School Leaflet, vol. XIV, n°2, novembre 1920, pp. 127-128. 

If you pick up a bunch of rubbish in a pond, you may sometimes be surprised to see a piece of grass get up and walk off. Look at it closely and you will se a head and some legs at one end. A bunch made of pieces of plant material is often found fastened together like a little log cabin. Watch it and you may see it move off too. All of these are different kinds of caddis worms and they will give you a great deal of fun as they usually build their houses right before your eyes in an aquarium, providing you take them out of their old houses and give them the material for making new ones.


Sometimes it is fun, instead of giving one of the larger caddis worms grass stems with which to build a home, to give it some narrow strips of clear material like old photographic films that have had the dark parts removed by warm water. When the caddis worm builds a house of this material, be is perfectly happy even though he is living in a house through the walls of which you can see.