nto view the very foundation; and
during the process of exposure the superior beds must not be entirely
swept away by denudation.

In the first place, the chances are as three to one against the mere
emergence of the mass above the waters, because three-fourths of the
globe are covered by the ocean. But if it be upheaved and made to
constitute part of the dry land, it must also, before it can be
available for our instruction, become part of that area already surveyed
by geologists; and this area comprehends perhaps less than a tenth of
the whole earth. In this small fraction of land already explored, and
still very imperfectly known, we are required to find a set of strata,
originally of limited extent, and probably much lessened by subsequent
denudation.

Yet it is precisely because we do not encounter at every step the
evidence of such gradations from one state of the organic world to
another, that so many geologists embrace the doctrine of great and
sudden revolutions in the history of the animate world. Not content with
simply availing themselves, for the convenience of classification, of
those gaps and chasms which here and there interrupt the continuity of
the chronological series, as at present known, they deduce, from the
frequency of these breaks in the chain of records, an irregular mode of
succession in the events themselves both in the organic and inorganic
world. But, besides that some links of the chain which once existed are
now clearly lost and others concealed from view, we have good reason to
suspect that it was never complete originally. It may undoubtedly be
said, that strata have been always forming somewhere, and therefore at
every moment of past time nature has added a page to her archives; but,
in reference to this subject, it should be remembered that we can never
hope to compile a consecutive history by gathering together monuments
which were originally detached and scattered over the globe. For as the
species of organic beings contemporaneously inhabiting remote regions
are distinct, the fossils of the first of several periods which may be
preserved in any one country, as in America, for example, will have no
connection with those of a second period found in India, and will
therefore no more enable us to trace the signs of a gradual change in
the living creation, than a fragment of Chinese history will fill up a
blank in the political annals of Europe.

The absence of any deposits of import