ain as the destruction of a former and a
different order, and the extinction of a number of living forms which
have no types in being. In the oldest secondary strata there are no
remains of such animals as now belong to the surface; and in the rocks,
which may be regarded as more recently deposited, these remains occur
but rarely, and with abundance of extinct species;--there seems, as it
were, a gradual approach to the present system of things, and a
succession of destructions and creations preparatory to the existence of
man."[211]

In the above passages, the author deduces two important conclusions from
geological data: first, that in the successive groups of strata, from
the oldest to the most recent, there is a progressive development of
organic life, from the simplest to the most complicated
forms;--secondly, that man is of comparatively recent origin, and these
conclusions he regards as inconsistent with the doctrine, "that the
present order of things is the ancient and constant order of nature only
modified by existing laws."

With respect, then, to the first of these propositions, we may ask
whether the theory of the progressive development of animal and
vegetable life, and their successive advancement from a simple to a more
perfect state, has any secure foundation in fact? No geologists who are
in possession of all the data now established respecting fossil remains,
will for a moment contend for the doctrine in all its detail, as laid
down by the distinguished philosopher to whose opinions we have
referred: but naturalists, who are not unacquainted with recent
discoveries, continue to defend it in a modified form. They say that in
the first period of the world (by which they mean the earliest of which
we have yet brought to light any memorials), the vegetation was
characterized by a predominance of cryptogamic plants, while the animals
which coexisted were almost entirely confined to zoophytes, testacea,
and a few fish. Plants of a less simple structure, coniferae and cycadeae,
flourished largely in the next epoch, when oviparous reptiles began also
to abound. Lastly, the terrestrial flora became most diversified and
most perfect when the highest orders of animals, the mammalia and birds,
were called into existence.

Now in the first place, it may be observed, that many naturalists are
guilty of no small inconsistency in endeavoring to connect the phenomena
of the earliest vegetation with a nascent conditi