desolate
void and aeriform deep to that now before us secular refrigeration
must have been steadily in progress. Let us also observe here that the
earliest fractures of the crust would determine the first coast lines,
and the first slopes along which sedimentary matter would descend from
the land and be deposited in the sea. They would also modify the
direction of the ocean currents. Thus the deposition of new formations
would be directed by these old lines, as would also to some extent the
course of all subsequent fractures and plications. Thus it happens
that the lines of outcrop of the oldest rocks first raised out of the
waters already marked out the forms of the continents, and that the
later formations appear rather as fillings-up and extensions of the
skeleton established by the first dry land. Farther, the lines of
plication first established along the borders of the continents formed
resisting walls along which, in the continued contraction of the
earth, pressure was exerted from the ocean bed, widening and elevating
these lines of upheaval, and still farther fixing the general forms of
the continents, and giving variety to their surfaces. In the progress
of geological time there have also been successive depressions and
re-elevations of the continental plateaus, subjecting them alternately
to the wearing and disintegrating action of the atmosphere and its
waters, and to the influence of waves and ocean currents, and
especially to that of the deep-seated polar currents which have
throughout geological ages been loading the submerged areas of the
earth's surface with the products of the waste caused by frost and ice
in the polar regions. These causes again have been progressively
increasing the oblateness of the earth's figure, and, along with the
slackening of its rotation, preparing the way for those periodical
collapses in the equatorial and temperate regions which form the
boundaries of some of our most important geological periods.[86]
Throughout all these changes the great general plan of the continents,
first sketched out when the "foundations of the earth" were laid,
before Eozoic time, was being elaborated.

The same creative period that witnessed the first appearance of dry
land saw it also clothed with vegetation; and it is quite likely that
this is intended to teach that no time was lost in clothing the earth
with plants--that the first emerging portions received their vegetable
tenants as they bec