.

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
provable"--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 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 palaeontologist.
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 palaeontologist 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 which order is what men of science term a natural
law. Whether such a law is to be regarded as an expression of the mode of
operation of natural forces, or whether it is simply a statement of the
manner in which a supernatural power has thought fit to act, is a
secondary question, so long as the existence of the law and the
possibility of its disc