l of the sea, and
yet the luxuriant vegetation with which they are covered gives them an
imposing appearance.

But this is not the end of the story. Travelling inland from the
shore-bluffs, we cross a low, flat expanse of land, the Indian
hunting-ground, which brings us to a row of elevations called the
Hummocks. This hunting-ground, or Everglade as it is also called, is an
old channel, changed first to mud-flats and then to dry land by the same
kind of accumulation that is filling up the present channels, and the
row of hummocks is but an old Coral Reef with the Keys or islands of
past days upon its summit. Seven such Reefs and channels of former times
have already been traced between the shore-bluffs and Lake Okee-cho-bee,
adding some fifty thousand years to our previous estimate. Indeed, upon
the lowest calculation, based upon the facts thus far ascertained as to
their growth, we cannot suppose that less than seventy thousand years
have elapsed since the Coral Reefs already known to exist in Florida
began to grow. When we remember that this is but a small portion of the
peninsula, and that, though we have not yet any accurate information as
to the nature of its interior, yet the facts already ascertained in the
northern part of this State, formed like its Southern extremity of Coral
growth, justify the inference that the whole peninsula is formed of
successive concentric Reefs, we must believe that hundreds of thousands
of years have elapsed since its formation began. Leaving aside, however,
all that part of its history which is not susceptible of positive
demonstration in the present state of our knowledge, I will limit my
results to the evidence of facts already within our possession; and
these give us as the lowest possible estimate a period of seventy
thousand years for the formation of that part of the peninsula which
extends south of Lake Okee-cho-bee to the present outer Reef.

So much for the duration of the Reefs themselves. What, now, do they
tell us of the permanence of the Species by which they were formed? In
these seventy thousand years has there been any change in the Corals
living in the Gulf of Mexico? I answer, most emphatically, _No_.
Astraeans, Porites, Maeandrinas, and Madrepores were represented by
exactly the same Species seventy thousand years ago as they are now.
Were we to classify the Florida Corals from the Reefs of the interior,
the result would correspond exactly to a classification fou