Peyssonel's doctrine that corals are the work of animal organisms has
been part of the body of established scientific truth.

Peyssonel, in the extract from his memoir already cited, compares the
flower-like animal of the coral to a "poulpe," which is the French
form of the name "polypus,"--"the many-footed,"--which the ancient
naturalists gave to the soft-bodied cuttle-fishes, which, like the
coral animal, have eight arms, or tentacles, disposed around a central
mouth. Réaumur, admitting the analogy indicated by Peyssonel, gave the
name of _polypes_, not only to the sea-anemone, the coral animal, and
the fresh-water _Hydra_, but to what are now known as the _Polyzoa_,
and he termed the skeleton which they fabricate a "_polypier_" or
"polypidom."

The progress of discovery, since Réaumur's time, has made us very
completely acquainted with the structure and habits of all these
polypes. We know that, among the sea-anemones and coral-forming
animals, each polype has a mouth leading to a stomach, which is open
at its inner end, and thus communicates freely with the general cavity
of the body; that the tentacles placed round the mouth are hollow, and
that they perform the part of arms in seizing and capturing prey. It
is known that many of these creatures are capable of being multiplied
by artificial division, the divided halves growing, after a time, into
complete and separate animals; and that many are able to perform a
very similar process naturally, in such a manner that one polype may,
by repeated incomplete divisions, give rise to a sort of sheet,
or turf, formed by innumerable connected, and yet independent,
descendants. Or, what is still more common, a polype may throw out
buds, which are converted into polypes, or branches bearing polypes,
until a tree-like mass, sometimes of very considerable size, is