We now enter upon a new great epoch in the history of our globe.
There was now dry land. As a consequence of this fact, there was
fresh water, for rain, instead of immediately returning to the sea,
as formerly, was now gathered in channels of the earth, and became
springs, rivers, and lakes. There was now a theatre for the
existence of land plants and animals, and it remains to be inquired
if these accordingly were produced.

The Secondary Rocks, in which our further researches are to be
prosecuted, consist of a great and varied series, resting, generally
unconformably, against flanks of the upturned primary rocks,
sometimes themselves considerably inclined, at others, forming
extensive basin-like beds, nearly horizontal; in many places, much
broken up and shifted by disturbances from below. They have all been
formed out of the materials of the older rocks, by virtue of the
wearing power of air and water, which is still every day carrying
down vast quantities of the elevated matter of the globe into the
sea. But the separate strata are each much more distinct in the
matter of its composition than might be expected. Some are siliceous
or arenaceous (sandstones), composed mainly of fine grains from the
quartz rocks--the most abundant of the primary strata. Others are
argillaceous--clays, shales, &c., chiefly derived, probably, from the
slate beds of the primary series. Others are calcareous, derived
from the early limestone. As a general feature, they are softer and
less crystalline than the primary rocks, as if they had endured less
of both heat and pressure than the senior formation. There are beds
(coal) formed solely of vegetable matter, and some others in which