etimes the same species is found in
different formations, having survived the great earth changes which the
record of the rocks indicates. There is an unbroken succession of animal
life from the beginning to the present epoch. Low down, where the
records of life begin, we find an era of backboneless animals only, and
the animal forms there found, though various, are all humble in their
respective lines of gradation.

The early fishes were low, both with respect to their class as fishes,
and the order to which they belong--that of the cartilaginous or gristly
fishes. In all the orders of ancient animals there is an ascending
gradation of character from first to last. Further, there is a
succession from low to high types in fossil plants, from the earliest
strata in which they are found to the highest. Several of the most
important living species have left no record of themselves in any
formation beyond what are, comparatively speaking, modern. Such are the
sheep and the goat, and such, above all, is our own species. Compared
with many humbler animals, man is a being, as it were, of yesterday.

Thus concludes the wondrous section of the earth's history which is told
by geology. It takes up our globe at an early stage in the formation of
its crust--conducts it through what we have every reason to believe were
vast spaces of time, in the course of which many superficial changes
took place, and vegetable and animal life was gradually evolved--and
drops it just at the point when man was apparently about to enter on the
scene. The compilation of such a history, from materials of so
extraordinary a character, and the powerful nature of the evidence which
these materials afford, are calculated to excite our admiration, and the
result must be allowed to exalt the dignity of science as a product of
man's industry and his reason.

It is now to be remarked that there is nothing in the whole series of
operations displayed in inorganic geology which may not be accounted for
by the agency of the ordinary forces of Nature. Those movements of
subterranean force which thrust up mountain ranges and upheaved
continents stand in inextricable connection, on the one hand, with the
volcanoes which are yet belching forth lavas and shaking large tracts of
ground, as, on the other, with the primitive incandescent state of the
earth. Those forces which disintegrated the early rocks, of which
detritus formed new beds at the bottom of the sea, are