corresponding beds will occur in a similar order; but, however great
may be the probability, no man can say with absolute certainty that the
beds in the two sections were synchronously deposited. For areas of
moderate extent, it is doubtless true that no practical evil is likely
to result from assuming the corresponding beds to be synchronous or
strictly contemporaneous; and there are multitudes of accessory
circumstances which may fully justify the assumption of such
synchrony. But the moment the geologist has to deal with large areas,
or with completely separated deposits, the mischief of confounding that
"homotaxis" or "similarity of arrangement," which 'can' be
demonstrated, with "synchrony" or "identity of date," for which there
is not a shadow of proof, under the one common term of
"contemporaneity" becomes incalculable, and proves the constant source
of gratuitous speculations.

For anything that geology or paleontology are able to show to the
contrary, a Devonian fauna and flora in the British Islands may have
been contemporaneous with Silurian life in North America, and with a
Carboniferous fauna and flora in Africa. Geographical provinces and
zones may have been as distinctly marked in the Paleozoic epoch as at
present, and those seemingly sudden appearances of new genera and
species, which we ascribe to new creation, may be simple results of
migration.

It may be so; it may be otherwise. In the present condition of our
knowledge and of our methods, one verdict--"not proven, and not
provable"--must be recorded against all the grand hypotheses of the
paleontologist respecting the general succession of life on the globe.
The order and nature of terrestrial life, as a whole, are open
questions. Geology at present provides us with most valuable