of coral islands, which are formed by those great coral reefs which are
known as the Bahama Banks. Twenty of them are uninhabited, and many of
them are mere reefs or keys.

These islands are very interesting from the fact that they have all been
built by the coral insects. Each of these tiny creatures gathers lime
from the water in which it lives or the food which it eats, and develops
from this a skeleton, which is the coral. They live in masses or
colonies, and throw out buds above them which form fresh coral insects.

These buds immediately set to work and gather lime to build up their
own skeletons. In time the old coral insects below die, leaving behind
them the hard limestone frame which they have built. The younger coral
above lives on, sending forth buds which in turn do their share of the
building, and in time,--in countless ages of time,--reefs and islands
rise out of the mighty depths of the sea, built by the untiring energy
of these marvellous little insects.

This rock building is still going on in the Bahama group, and some
geologists think that in ages to come the coral insects which are at
work on the Bahamas and those that are so busy on the Florida reefs will
build up a vast country where it is now sea, and that ages and ages
hence the Florida Keys, the Bahamas, and perhaps even the West Indian
Islands may be a part of the main land. While this is only a theory, it
should be interesting to you in making you realize that the building of
the world is going on now, from day to day, as steadily as it did in the
days when the bed of the Niagara River was carved out, and the wonders
of the Yellowstone Park were being created by the gradual working of the
waters. The forces of nature are building up and destroying to-day just
as steadily as when the world first began.