in
his structure the perfection of that type in which, from the earliest
ages, nature had been working with reference to some future development,
and as _therefore_ a foreordained existence. "The recognition of an
ideal exemplar for the vertebrated animals proves," he says, "that the
knowledge of such a being as man must have existed before man appeared.
For the Divine mind that planned the archetype also foreknew all its
modifications. The archetypal idea was manifested in the flesh under
divers modifications, upon this planet, long prior to the existence of
those animal species that actually exemplify it." So far Owen. And not
less wonderful is the conclusion at which Agassiz has arrived, after a
survey of the geologic existences, more extended and minute, in at least
the ichthyic department, than that of any other man. "It is evident," we
find him saying, in the conclusion of his recent work, "The Principles
of Zoology,"[20] "that there is a manifest progress in the succession of
beings on the surface of the earth. This progress consists in an
increasing similarity to the living fauna, and among the vertebrates,
especially in their increasing resemblance to man. But this connection
is not the consequence of a direct lineage between the faunas of
different ages. There is nothing like parental descent connecting them.
The fishes of the Palaeozoic age are in no respect the ancestors of the
reptiles of the Secondary age, nor does man descend from the mammals
which preceded him in the Tertiary age. The link by which they are
connected is of a higher and immaterial nature; and their connection is
to be sought in the view of the Creator himself, whose aim in forming
the earth, in allowing it to undergo the successive changes which
geology has pointed out, and in creating successively all the different
types of animals which have passed away, _was to introduce man upon the
surface of our globe_. MAN IS THE END TOWARDS WHICH ALL THE ANIMAL
CREATION HAS TENDED FROM THE FIRST APPEARANCE OF THE FIRST PALAEOZOIC
FISHES." These, surely, are extraordinary deductions. "In thy book,"
says the Psalmist, "all my members were written, which in continuance
were fashioned when as yet there was none of them." And here is natural
science, by the voice of two of its most distinguished professors,
saying exactly the same thing.

Of the earliest known vertebrates,--the placoidal fishes of the Upper
Silurian rocks,--we possess only fragments,