epochs thus
implied, there existed an ocean, tides, winds, waves, rain, rivers. The
agencies by which the denudation of continents and filling up of seas
have all along been carried on, were as active then as now. Endless
successions of strata must have been formed. And when we ask--Where are
they? Nature's obvious reply is--They have been destroyed by that
igneous action to which so great a part of our oldest-known strata owe
their fusion or metamorphosis.

Only the last chapter of the Earth's history has come down to us. The
many previous chapters, stretching back to a time immeasurably remote,
have been burnt; and with them all the records of life we may presume
they contained. The greater part of the evidence which might have served
to settle the Development-controversy, is for ever lost; and on neither
side can the arguments derived from Geology be conclusive.

"But how happen there to be such evidences of progression as exist?" it
may be asked. "How happens it that, in ascending from the most ancient
strata to the most recent strata, we _do_ find a succession of organic
forms, which, however irregularly, carries us from lower to higher?"
This question seems difficult to answer. Nevertheless, there is reason
for thinking that nothing can be safely inferred from the apparent
progression here cited. And the illustration which shows as much, will,
we believe, also show how little trust is to be placed in certain
geological generalizations that appear to be well established. With this
somewhat elaborate illustration, to which we now pass, our criticisms
may fitly conclude.

* * * * *

Let us suppose that in a region now covered by wide ocean, there begins
one of those great and gradual upheavals by which new continents are
formed. To be precise, let us say that in the South Pacific, midway
between New Zealand and Patagonia, the sea-bottom has been little by
little thrust up toward the surface, and is about to emerge. What will
be the successive phenomena, geological and biological, which are
likely to occur before this emerging sea-bottom has become another
Europe or Asia? In the first place, such portions of the incipient land
as are raised to the level of the waves, will be rapidly denuded by
them: their soft substance will be torn up by the breakers, carried away
by the local currents, and deposited in neighbouring deeper water.
Successive small upheavals will bring new and larger