haracteristic names. In this
epoch of the world's history we see the first approach to a condition of
things resembling that now prevailing, and Sir Charles Lyell has
most fitly named its three divisions, the "Eocene," or the dawn, the
"Miocene," meaning the continuance and increase of that light, and
lastly, the "Pliocene," signifying its fulness and completion. Above
these deposits comes what has been called in science the present
period,--_the modern times_ of the geologist,--that period to which man
himself belongs, and since the beginning of which, though its duration
be counted by hundreds of thousands of years, there has been no
alteration in the general configuration of the earth, consequently no
important modification of its climatic conditions, and no change in the
animals and plants inhabiting it.

I have spoken of the first of these periods, the Azoic, as having been
absolutely devoid of life, and I believe this statement to be strictly
true; but I ought to add that there is a difference of opinion among
geologists upon this point, many believing that the first surface of our
globe may have been inhabited by living beings, but that all traces
of their existence have been obliterated by the eruptions of melted
materials, which not only altered the character of those earliest
stratified rocks, but destroyed all the organic remains contained in
them. It will be my object to show in this series of papers, not only
that the absence of the climatic and atmospheric conditions essential
to organic life as we understand it, must have rendered the previous
existence of any living beings impossible, but also that the
completeness of the Animal Kingdom in those deposits where we first
find organic remains, its intelligible and coherent connection with the
successive creations of all geological times and with the animals now
living, affords the strongest internal evidence that we have indeed
found in the lower Silurian formations, immediately following the Azoic,
the beginning of life upon earth. When a story seems to us complete and
consistent from the beginning to the end, we shall not seek for a first
chapter, even though the copy in which we have read it be so torn and
defaced as to suggest the idea that some portion of it may have been
lost. The unity of the work, as a whole, is an incontestable proof that
we possess it in its original integrity. The validity of this argument
will be recognized, perhaps, only by tho