James George Needham, Elementary Lessons on Insects, Springfield (IL), Charles Thomas, 1928.
2. In aquaria watch the caddis-worms in portable case drag their lumbering houses about. See them retreat Inside when disturbed, and see them come out again. Some may br seen feeding on the plants present.
3. Pick up one of the larger cases containing an active larva, and drive the larva forward out of its case by poking a match stick into the case at the rear. Put the larva naked, into the water and observe what a helpless creature it is when deprived of its proper shelter.
4. If you have at hand the living larvae in cases of the form shown in figure 30, or any other similar large form, drive the larvae out of one case, and put it and another larva in a dish of water with a single case, and watch them strive or the possession of that case.
IV With a variety of cases at hand observe
- Their diversity in form.
- Their materials.
- Their manner of construction
Note that they all have a lining of silk.