scare the fishes. I know very well that it seems to you as if I was
washing or bathing all the time, but there! Some kind of a water-bug has
plumped right down onto my head, and left a lot of sticky sand on it,
that the water does not wash away.

Now don't be alarmed. I won't let you be swept from my back. I am only
going to wash my head. See me swim directly under this mass of sponge,
swaying out from a rock. There will be no bits of sand clinging to me
after I have been sponged a few moments.

Here is a sponge that looks as if almost as large as your sun when it
rises out of the water, but if you squeeze that fellow dry--the sponge,
not the sun--it will not begin to be the size it is now. You could press
it into a bowl of moderate size when dry, but then take it to the pump
or the faucet, fill it with water, and my, what a balloon!

Sponges were once called "worm-nests," and were thought to be a mere
kind of seaweed. But looked at under the sea, it would be known at once
that they are neither nest nor weed.

Once in awhile sponges seem to spring directly up from the mud without
anything to cling to, but generally they are fastened to rocks or large
stones, and spread out and out from them. Here they look so much like a
kind of herb, that Folks who make a study of things in nature, and are
called naturalists, for a long time took them to be a kind of sea-plant,
and for years it was a puzzle as to just what they were.

All are full of pores or layers of small cells, and some are quite
pretty from having a fringe about the cells like eyelashes. There are
others curiously shaped, looking like coral sprays, and here and there