Coral and Coral Reefs | Page 4

the creature, of its
internal substance, by the deposit in the body of a material which is
exceedingly common, not only in fresh but in sea water, and which is
specially abundant in those waters which we know as "hard," those
waters, for example, which leave a "fur" upon the bottom of a tea-kettle.
This "fur" is carbonate of lime, the same sort of substance as limestone
and chalk. That material is contained in solution in sea water, and it is
out of the sea water in which these coral creatures live that they get the
lime which is needed for the forming of their hard skeleton.
But now what manner of creatures are these which form these hard
skeletons? I dare say that in these days of keeping aquaria, of

locomotion to the sea-side, most of those whom I am addressing may
have seen one of those creatures which used to be known as the "sea
anemone," receiving that name on account of its general resemblance,
in a rough sort of way, to the flower which is known as the "anemone";
but being a thing which lives in the sea, it was qualified as the "sea
anemone." Well, then, you must suppose a body shaped like a short
cylinder, the top cut off, and in the top a hole rather oval than round.
All round this aperture, which is the mouth, imagine that there are
placed a number of feelers forming a circle. The cavity of the mouth
leads into a sort of stomach, which is very unlike those of the higher
animals, in the circumstance that it opens at the lower end into a cavity
of the body, and all the digested matter, converted into nourishment, is
thus distributed through the rest of the body. That is the general
structure of one of these sea anemones. If you touch it it contracts
immediately into a heap. It looks at first quite like a flower in the sea,
but if you touch it you find that it exhibits all the peculiarities of a
living animal; and if anything which can serve as its prey comes near
its tentacles, it closes them round it and sucks the material into its
stomach and there digests it and turns it to the account of its own body.
These creatures are very voracious, and not at all particular what they
seize; and sometimes it may be that they lay hold of a shellfish which is
far too big to be packed into that interior cavity, and, of course, in any
ordinary animal a proceeding of this kind would give rise to a very
severe fit of indigestion. But this is by no means the case in the sea
anemone, because when digestive difficulties of this kind arise he gets
out of them by splitting himself in two; and then each half builds itself
up into a fresh creature, and you have two polypes where there was
previously one, and the bone which stuck in the way lying between
them! Not only can these creatures multiply in this fashion, but they
can multiply by buds. A bud will grow out of the side of the body (I am
not speaking of the common sea anemone, but of allied creatures) just
like the bud of a plant, and that will fashion itself into a creature just
like the parent. There are some of them in which these buds remain
connected together, and you will soon see what would be the result of
that. If I make a bud grow out here, and another on the opposite side,
and each fashions itself into a new polype, the practical effect will be
that before long you will see a single polype converted into a sort of

tree or bush of polypes. And these will all remain associated together,
like a kind of co-operative store, which is a thing I believe you
understand very well here,--each mouth will help to feed the body and
each part of the body help to support the multifarious mouths. I think
that is as good an example of a zoological co-operative store as you can
well have. Such are these wonderful creatures. But they are capable not
only of multiplying in this way, but in other ways, by having a more
ordinary and regular kind of offspring. Little eggs are hatched and the
young are passed out by the way of the mouth, and they go swimming
about as little oval bodies covered with a very curious kind of hairlike
processes. Each of these processes is capable of striking water like an
oar; and the consequence is that the young creature is propelled through
the water. So that you have the young polype floating about in this
fashion, covered by its 'vibratile cilia', as