are Ferns; and the greatest part of the remainder
are, Cycadeae and Coniferae, with a few Lili-
aceae. More species of Cycadeae occur among
the fossils of this period, than are found living on
the present surface of the earth. They form more
than one third of the- total known fossil Flora of
the Secondary formations; whilst of our actual
vegetation, Cycadeae are not one two-thousandth
part.
The vegetation of the Third period approximated
closely to that of the existing surface of
the globe.
Among living families of plants, Sea weeds,
Ferns, Lycopodiaceae, Equisetaceae, Cycadeae
and Coniferae, bear the nearest relations to the
earliest forms of vegetation that have existed upon
our planet.
The family which has most universally pervaded
every stage of vegetation is that of Coniferae
; increasing in the number and variety of its
genera and species, at each successive change in
the climate and condition of the surface of the
earth. This family forms about one three-hundredth
part of the total number of existing vegetables.
Another family which has pervaded all the
Series of formations, though in small proportions,
is that of Palms.
The view we have taken, of the connexions between
the extinct and living systems of the vegetable
kingdom, supplies an extensive fund ol
arguments, and lays open a new and large field
of enquiry, both to the Physiologist, and to the
student in Physico-Theology.
In the fossil Flora, we have not only the existing
fundamental distinctions between Endogenous
and Exogenous plants, but we have also
agreement in the details of structure, throughout
numerous families, which indicates the influence
of the same Laws, that regulate the development
of the living members of the vegetable kingdom.
The remains of Fructification, also ; found occasionally
with the plants of all formations, shew
still further, that the principles of vegetable Reproduction
have at all times been the same.
The exquisite organizations which are disclosed
by the microscope, in that which to the naked
eye is but a log of Lignite, or a lump of Coal, not
only demonstrate the adaptation of means to ends,
but the application also of similar means, to effect
corresponding ends, throughout the several Creations
which have modified the changing forms of
vegetable life.
Such combinations of contrivances, varying
with the varied conditions of the earth, not only
prove the existence of a Designer from the existence
of method, and design ; but from the Connexion
of parts, and Unity of purpose, which
pervade the entirety of one vast, and complex,
but harmonious Whole, shew that One, and the
same Mind gave origin and efficacy to them all.