and geologist. When we
consider that we have at hand only a soft, gelatinous covering,
stretched on a hard, stony frame-work--that the material on which this
animal substance exists is furnished by the sea in which it lives--we
can not but be surprised at the smallness of the means which nature uses
for the execution of her great designs. But time compensates for the
insignificance of the means employed, and the continued activity of
nature's architects, during continuous ages, accomplishes these
stupendous results, which have at various times excited the wonder of
the navigator, and aroused the attention of the naturalist. Many
examples of these are to be found in the Pacific Archipelago. Seas and
shallows, once navigable, become in the process of time so filled by
these living animals, as to become impassable, their stony skeletons
forming hard, massy rocks and impenetrable barriers, which, rising from
the bottom of the sea and shallows, constitute solid masonry of living
stones.

But besides thus aggregating in the neighborhood of land and continents,
formations similarly produced are constantly met with during the
circumnavigation of the globe. Not only barriers and reefs owe their
origin to these humble means, but large lands, stretching for miles in
the centre of the ocean, rise gradually from beneath the surface of the
sea, and, becoming clothed with verdure and vegetation, at last offer a
resting-place for the daring seafarer. But now occurs the interesting
question, How happens it that these islands are found in situations
where the sea is too deep to allow of any animal life to exist? And yet
these corals must have grown upward from some resting-place. The
researches of Darwin have shown that the greatest depth in which corals
live, is between thirty and forty fathoms beneath the surface of the
sea; hence it is absolutely certain that for every island some
foundation must exist in the sea for these reef-building animals to
attach themselves to. Such foundation, from the observation of Darwin,
would appear to be provided by submarine mountains which have gradually
subsided into the sea, having originally existed above its surface. Upon
these foundations the reef-building saxigenous corals have become
attached, and slowly accumulating in large numbers, and gradually
depositing their carbonate of lime, during the lapse of ages, by degrees
construct these large piles, which, at last emerging from the ocean's
boso