CG 
XEUROPTERA. 
wing. The insects, of which there are a great many 
British species, are well-known, both in their larval and 
perfect states to all anglers. Various forms are to be 
seen near every river and pond, of different sizes, some 
about an inch in length, others almost microscopic in 
size. Most of them are tolerably active runners, but 
their flight is, for the most part, heavy. These insects 
are all aquatic, the larvae forming for themselves little 
homes of dead sticks, stones, bits of grass, shells, grains 
of sand, etc,, in which they dwell. Some are active, and 
carry their houses about with them ; others attach them 
firmly to stones and other submerged bodies. The bodies 
of the larvae belonging to the larger species are thick 
and fat, and are favourite food for almost any kind of 
fish. The segments of the abdomen have white filaments, 
of various form, the external organs of respiration. The 
materials of these caddis’ houses are united by fine silken 
threads, spun from a spinneret on the animal’s labium. 
At the end of the tail there are two hook-like append- 
ages, by means of which the larva adheres firmly to the 
inside of its dwelling. Most of the larvae are herbivorous, 
though they will also eat other larvce, and have been 
known to prey upon each other when in confinement. 
When the larva wishes to pass into the pupa state, it 
closes up the ends of the tube with a sort of open-work 
fence of silk, which admirably serves the double purpose 
of keeping out enemies—saying “ not at home” to callers 
when the creature does not wish to be disturbed—and 
of allowing free access of water to the branchial append¬ 
ages which, in the pupa, resemble those of the larva. 
When ready to complete its final change, the pupa bites 
away the silken grating, and sets itself free; some 
