Contributions to the theory of natural selection. A series of essays ... By Alfred Russel Wallace ...

22 ON THE LAW WIHICH HAS REGULATED
they differ considerably in their fossils, and you may
then get some notion of how small a portion of the
whole we know.
But yet more important is the probability, nay
almost the certainty, that whole formations containing the records of vast geological periods are entirely
buried beneath the ocean, and for ever beyond our
reach. Most of the gaps in thb geological series
may thus be filled up, and vast numbers of unknown and unimaginable animals, which might help
to elucidate the affinities of the numerous isolated
groups which are a perpetual puzzle to the zoologist,
may there be buried, till future revolutions may
raise them in their turn above the waters, to afford
materials for the study of whatever race of intelligent beings may then have succeeded us. These considerations must lead us to the conclusion, that our
knowledge of the whole series of the former inhabitants of the earth is necessarily most imperfect and
fragmentary -as much so as our knowledge of the
present organic world would be, were we forced to
make our collections and observations only in spots
equally limited in area and in number with those
actually laid open for the collection of fossils. Now,
the hypothesis of Professor Forbes is essentially one
that assumes to a great extent the completeness of
our knowledge of the whole series of organic beings
which have existed on the earth. This appears to
be a fatal objection to it, independently of all other
considerations, It may be said that the same ob