se naturalists to whom the
Animal Kingdom has begun to appear as a connected whole. For those who
do not see order in Nature it can have no value.

For a table containing the geological periods in their succession, I
would refer to any modern text-book of Geology; or to an article in the
"Atlantic Monthly" for March, 1862, upon "Methods of Study in Natural
History," where they are given in connection with the order of
introduction of animals upon earth.

Were these sets of rocks found always in the regular sequence in which I
have enumerated them, their relative ago would be easily determined, for
their superposition would tell the whole story: the lowest would, of
course, be the oldest, and we might follow without difficulty the
ascending series, till we reached the youngest and uppermost deposits.
But their succession has been broken up by frequent and violent
alterations in the configuration of the globe. Land and water
have changed their level,--islands have been transformed to
continents,--sea-bottoms have become dry land, and dry land has sunk
to form sea-bottom,--Alps and Himalayas, Pyrenees and Apennines,
Alleghanies and Rocky Mountains, have had their stormy birthdays since
many of these beds have been piled one above another, and there are but
few spots on the earth's surface where any number of them may be found
in their original order and natural position. When we remember that
Europe, which lies before us on the map as a continent, was once an
archipelago of islands,--that, where the Pyrenees raise their rocky
barrier between France and Spain, the waters of the Mediterranean and
Atlantic met,--that, where the British Channel flows, dry land united
England and France, and Nature in those days made one country of
the lands parted since by enmities deeper than the waters that run
between,--when we remember, in short, all the fearful convulsions that
have torn asunder the surface of the earth, as if her rocky record
had indeed been written on paper, we shall find a new evidence of the
intellectual unity which holds together the whole physical history
of the globe in the fact that through all the storms of time the
investigator is able to trace one unbroken thread of thought from the
beginning to the present hour.

The tree is known by its fruits,--and the fruits of chance are
incoherence, incompleteness, unsteadiness, the stammering utterance of
blind, unreasoning force. A coherence that binds all the geolog