fixed
habitations; the materials, too, out of which the different cases are
constructed, are different, sometimes they are bits of gravel, or
sand, wood, leaves, grass, the empty shells of various fresh-water
molluscs. The fragments of stick and the small bits of gravel are held
together by a kind of cement which the larva spins from his mouth.
Sometimes we may meet with cases made of sand, having on either side
long slender bits of rush or stick. A lady once took a number of the
larvae out of their cases, and placed them in a vessel of water with
various materials, such as coloured glass, cornelian, agate, onyx,
brass filings, coralline, tortoiseshell; and these little maggoty
things made use of and built their houses out of them. The perfect
insect has four wings; and from these being closely covered with
hairs, the order to which they belong has received the name of
_Trichoptera_, which means "having hairy wings." You must know many of
these insects; they are very common near ponds and streams; generally
they fly in a zig-zag fashion, and have the appearance of moths.

[Illustration: _a, b, c, d._ Larva, cocoon, nympha, and insect of
Caddis-fly.]

Ah! here is a splendid bed of the forget-me-not growing on this bank
near the stream. Look at the blue enamel-like flowers, each with a
yellow centre-eye; the leaves are bright green and rather rough. There
are other species very much resembling this one you may often see in
hedgerows and fields; but they are generally smaller plants; this one
is the true forget-me-not. There are several stories about the origin
of the name. Here is one:--Many years ago, a lady and knight were
wandering by a river; the lady espied these bright blue flowers, on a
small islet I suppose, in the deep river, and wished to possess them.
Her lover immediately plunged in and plucked the plants, but the
strength of the stream was too much for him on his return. With a
great effort, however, he threw the flowers on the bank, exclaiming
"Forget-me-not," and sank!

"But the lady fair of the knight so true
Still remember'd his hapless lot;
And she cherish'd the flower of brilliant hue
And she braided her hair with the blossoms blue,
And she call'd it 'Forget-me-not.'"

We must proceed on our walk and not linger too long here, though, I
must own, it is hard to tear oneself away from the banks of a
gently-flowing river. So good-by to

"That blue and bright-eyed flowret