r 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
topographical records, but she has not the means of working them into a
universal history. Is such a universal history, then, to be regarded as
unattainable? Are all the grandest and most interesting problems which
offer themselves to the geological student essentially insoluble? Is he
in the position of a scientific Tantalus--doomed always to thirst for
a knowledge which he cannot obtain? The reverse is to be hoped; nay, it
may not be impossible to indicate the source whence help will come.

In commencing these remarks, mention was made of the great obligations
under which the naturalist lies to the geologist and paleontologist.
Assuredly the time will come when these obligations will be repaid
tenfold, and when the maze of the world's past history, through which
the pure geologist and the pure paleontologist find no guidance, will be
securely threaded by the clue furnished by the naturalist.

All who are competent to express an opinion on the subject are, at
present, agreed that the manifold varieties of animal and vegetable
form have not either come into existence by chance, nor result from
capricious exertions of creative power; but that they have taken place
in a definite order, the statement of wh