nditions. We may infer, then, that the
strata deposited next after the almost "azoic" strata, would contain the
remains of invertebrata, allied to those found near the shores of
Australia and South America. Of such invertebrate remains, the lower
beds would furnish comparatively few genera, and those of relatively low
types; while in the upper beds the number of genera would be greater,
and the types higher: just as among the fossils of our Silurian system.
As this great geologic change slowly advanced through its long history
of earthquakes, volcanic disturbances, minor upheavals and
subsidences--as the extent of the archipelago became greater and its
smaller islands coalesced into larger ones, while its coast-line grew
still longer and more varied, and the neighbouring sea more thickly
inhabited by inferior forms of life; the lowest division of the
vertebrata would begin to be represented. In order of time, fish would
naturally come later than the lower invertebrata; both as being less
likely to have their ova transported across the waste of waters, and as
requiring for their subsistence a pre-existing Fauna of some
development. They might be expected to make their appearance along with
the predaceous crustaceans; as they do in the uppermost Silurian rocks.
And here, too, let us remark, that as, during this long epoch we have
been describing, the sea would have made great inroads on some of the
newly-raised lands which had remained stationary; and would probably in
some places have reached masses of igneous or metamorphic rocks; there
might, in course of time, arise by the decomposition and denudation of
such rocks, local deposits coloured with oxide of iron, like our Old Red
Sandstone. And in these deposits might be buried the remains of the fish
then peopling the neighbouring sea.

Meanwhile, how would the surfaces of the upheaved masses be occupied? At
first their deserts of naked rocks would bear only the humblest forms of
vegetal life, such as we find in grey and orange patches on our own
rugged mountain sides; for these alone could flourish on such surfaces,
and their spores would be the most readily transported. When, by the
decay of such protophytes, and that decomposition of rock effected by
them, there had resulted a fit habitat for mosses; these, of which the
germs might be conveyed in drifted trees, would begin to spread. A soil
having been eventually thus produced, it would become possible for
plants of h