ing of the globe
during geological time.

There seems, then, no escape from the admission that neither physical
geology, nor palaeontology, possesses any method by which the absolute
synchronism of two strata can be demonstrated. All that geology can
prove is local order of succession. It is mathematically certain that,
in any given vertical linear section of an undisturbed series of
sedimentary deposits, the bed which lies lowest is the oldest. In any
other vertical linear section of the same series, of course,
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 palaeontology 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 Palaeozoic 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
proveable"--must be recorded against all the grand hypotheses of the
palaeontologist 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
topographical records, but she has not the means of working them up into
a universal history. Is such a universal history, then, to be regarded
as unattaina