Mary S. Claude, Natural History in Stories for Little Children, Londres, Addey, 1854, p. 62-64.
One fine summer day, Emily went out to walk on the bank of the river with her mama. Emily asked whether she might go down to the edge of the stream. Her mama told her that she might, and said she would sit under the trees and read while she played there. So Emily ran down and amused herself by throwing pebbles into the water.
In a little while she grew tired and sat down, and began to lift up some of the stones that lay just at the edge of the stream, and even quite in the water.
Presently she found what she called a curious little case, made up of the tiniest bits of gravel; so neat and close, she wondered how it could possibly be made. It was not more than an inch long, and not thicker than a straw.
Emily lifted up more of the stones, and found more curious little cases. They were not all alike ; some were made of bits of reeds and rushes, some of little shells, and some of sand wonderfully joined together.
Emily thought, when she had gathered a good many, she would take them to her mama and ask her what they were ; but when she took them up in her hand, she was startled to see them moving. There must be something living in the cases !
When she looked closer, she saw a little head peeping out, and part of a body aand some legs ; and the creature struggled to get along, dragging its house with it, though it moved but slowly.
Emily went at once to her mama, to ask her the name of these curious creatures that carried their houses about with them almost like the snails.
« They are called caddis-worms, » said mama.
« But how did the worms get these pretty little houses, mama ? » asked Emily.
Her mama told her that each little worm, soon after it was hatched, made its own house, patiently gathering all the tiny stones or bits of straw and fitting them together ; and that it line dit with a sort of silk, to make the inside smooth for its soft body.
There it lived for some time, and could crawl about at the bottom of the stream, and upon the water-plants, and even row itself on the water.
« What does it eat, mama ? asked Emily.
« It eats the leaves of the water-plants, and some kinds of little worms, » said her mama.
« Will it always live in the house ? » said Emily.
« No, » answered her mama, » when it is full grown, it fastens its house to some large stone by threads, and then closed theend of it with threads spun across and across, like a little net, through which the water can pass.