even
entered your dreams, or a poet's, as you may find alive at the bottom of
the sea, in the live flower-gardens of the sea-fairies.

There will be shoals of fish, too, playing in and out, as strange and
gaudy as the rest,--parrot-fish who browse on the live coral with their
beak-like teeth, as cattle browse on grass; and at the bottom, it may be,
larger and uglier fish, who eat the crabs and shell-fish, shells and all,
grinding them up as a dog grinds a bone, and so turning shells and corals
into fine soft mud, such as this stone is partly made of.

But what happens to all the delicate little corals if a storm comes on?

What, indeed? Madam How has made them so well and wisely, that, like
brave and good men, the more trouble they suffer the stronger they are.
Day and night, week after week, the trade-wind blows upon them, hurling
the waves against them in furious surf, knocking off great lumps of
coral, grinding them to powder, throwing them over the reef into the
shallow water inside. But the heavier the surf beats upon them, the
stronger the polypes outside grow, repairing their broken houses, and
building up fresh coral on the dead coral below, because it is in the
fresh sea-water that beats upon the surf that they find most lime with
which to build. And as they build they form a barrier against the surf,
inside of which, in water still as glass, the weaker and more delicate
things can grow in safety, just as these very Encrinites may have grown,
rooted in the lime-mud, and waving their slender arms at the bottom of
the clear lagoon. Such mighty builders are these little coral polypes,
that all the works of men are small compared with theirs. One single
reef, for instance, which is entirely made by them, stretches along the
north-east coast of Australia for nearly a thousand miles. Of this you
must read some day in Mr. Jukes's _Voyage of H.M.S. "Fly_." Every island
throughout a great part of the Pacific is fringed round each with its
coral-reef, and there are hundreds of islands of strange shapes, and of
Atolls, as they are called, or ring-islands, which are composed entirely
of coral, and of nothing else.

A ring-island? How can an island be made in the shape of a ring?

Ah! it was a long time before men found out that riddle. Mr. Darwin was
the first to guess the answer, as he has guessed many an answer beside.
These islands are each a ring, or nearly a ring of coral, with smooth
shallow water inside