ike a cup divided by a number of radiating partitions towards the
outside; and that cup is formed of carbonate of lime, only not stained
red, as in the case of the red coral. And all these cups are joined
together into a common branch, the result of which is the formation of
a beautiful coral tree. This is a great mass of madrepore, and in the
living state every one of the ends of these branches was terminated by
a beautiful little polype, like a sea anemone, and all the skeleton
was covered by a soft body which united the polypes together. You must
understand that all this skeleton has been formed in the interior of the
body, to suit the branched body of the polype mass, and that it is as
much its skeleton as our own bones are our skeleton. In this next coral
the creature which has formed the skeleton has divided itself as it
grew, and consequently has formed a great expansion; but scattered
all over this surface there were polype bodies like those I previously
described. Again, when this great cup was alive, the whole surface was
covered with a beautiful body upon which were set innumerable small
polype flowers, if we may so call them, often brilliantly coloured;
and the whole cup was built up in the same fashion by the deposit of
carbonate of lime in the interior of the combined polype body, formed
by budding and by fission in the way I described. You will perceive that
there is no necessary limit to this process. There is no reason why we
should not have coral three or four times as big; and there are certain
creatures of this kind that do fabricate very large masses, or half
spheres several feet in diameter. Thus the activity of these animals
in separating carbonate of lime from the sea and building it up into
definite shapes is very considerable indeed.

Now I think I have said sufficient--as much as I can without taking you
into technical details, of the general nature of these creatures which
form coral. The animals which form coral are scattered over the seas of
all countries in the world. The red coral is comparatively limited, but
the polypes which form the white coral are widely scattered. There
are some of them which remain single, or which give rise to only small
accumulations; and the skeletons of these, as they die, accumulate upon
the bottom of the sea, but they do not come to much; they are washed
about and do not adhere together, but become mixed up with the mud of
the sea. But there are certain parts