The Mankato free press. [volume] (Mankato, Blue Earth County, Minn.) 1879-1924, 1892-11-11
FORMATION OF CORAL
HOW THE POlYPS DO THEIR ST.
LENT YET LASTING WORK.


tiful Animal Vegetables.
The term coral insect" survives in
literature, although science discarded it
long ago. Possibly the idea of ''toil"
and patience" and building for the
future" as the lesson taught by the coral
insect, also survives to point moral and
adorn tale of the same order as one
praising the industry of the ant or the
bee Alas for old beliefs! Our grand
mothers were exhorted to reflect on the
vanity of the moth and the butterfly.
Now it is known that the moth and
the butterfly are among the chief agents
by which the most beautiful and fra
grant flowers are fertilized, and that
honey and perfume and color and fruit
largely depend upon the energy of the
insects formerly despised. The other
so called insects have no more energy
than simple vegetable existence. Their
toll is nothing greater than dying and
leaving their skeletons behind them.
But how beautiful are these skeletons,
or conglomerated accumulation of
myriads! And how beautiful and inter-
esting, too. the animal vegetables, or
rather fowerlike animals. "Sea anem-
ones" is the popular name given to the
whole tribe with their disklike mouths.
their petaloid tentacles, their stomach
suggesting seed vessels and their fixed
bases corresponding to stout stems, to
af hai,
rivaling the most gorgeous corollas ever
blown.
According to DR.. Gustav Eisen, there
are two kinds of corals of the sea anem-
one order-those which produce coral,
that is, the hard, calcareous formation,
and those which do not. The popular
term coral as applied to the accumu-
lated dead skeletons of the dead polyps,
is not strictly correct; coral. properly
speaking. refers also to the living ami
NAL.
The sea flower, although suggesting a
plantlike structure, is still true ami
NAL. 1t has a skin, also documentary
nerves. 1t can seize with its tentacles;
it can swallow and digest its food and
throw out the refuse from its mouth; it
can defend itself from it's enemies by
forcibly ejecting poison from its many
stings. 1t has some sensation. Quite a
number of species of polyps have rudi-
Fmentary eyes, arranged around their
circular edges like beads. The hardened
base of the sea flower corresponds to
skeleton in higher order of animal,
even though in some anemones the hard
ness may only be relative.
Coral animals of the sea anemone or
der reproduce their kind in several ways.
One is by ova, which develop perfect
polyps within the parent flower. An
other mode is by budding: still another
by tission. In the latter method new
mouth may form beside the old one in
the center of fringed disk which then
divides into disks, each surrounded by
its own tentacles and each leading to its
own closed sac. In the budding process
branches are thrown out, from which
spring new polyps. Tear one polyp to
pieces, and each piece may reproduce
all the parts it needs to form fresh
polyp.
The familiar tree coral is the result
of the budding process. The branches
below are the dead skeletons, above
which the living polyps have mounted.
The singular convulutions in ''brain
coral" were caused by fssion, one mouth
giving rise to strings Of others, which
never completely separated from each
other, and so left continuous line of
stony skeletons. 1t must not be sup
posed, however, that zoophytes of the
style of sea anemones are the only coral
producers. Some calcareous secretions
are left by animals related to the me-
dusae, or jellyfish. Other corals come
from the bryozoans, which look like pol
Ups, but really belong to the subking-
dom of mollusks. The bottom of the
sea is largely covered with deposits from
such animals. 1t is even believed that
in early times they made up the greater
part of limestone strata. Mention must
also be made of the beautiful and bril-
liant corallines, or vegetable corals, cal
careous seaweeds, which look like red,
white and yellow branched coral, but
which, properly speaking, are algae.
Corals of some kinds are found in all
seas. Those stony formations popularity
called corals are mostly produced within
the tropics. Probably the variety best
known is the red or pink coral, long es-
teemed for ornaments. This was found
in the Mediterranean from very early
period. Now, however, it has become
SO rare as to be practically extinct.
The specimens of coral seen in mu-
seums and private collections are of
course masses of dead skeletons. Hard
as rock they are, as might be expected,
when it is remembered that the famous
reefs of Florida and the Pacific islands
are built up of them-no credit to the
animals, however, despite the old tale.
Yet if the antiquated moral be lost, the
study of the calcareous formation is
none the less interesting.
There is the fungus coral, a dull gray
in color and shaped somewhat as the
umbrella of a mushroom, with ridges
running from the long mouthlike center
to the edge. The lace coral, of pure
white, with delicate wheels, indicates
Al.