uctures fitted for simple conditions of life,
and in some cases will even degrade or simplify the organisation, yet
leaving such degraded beings better fitted for their new walks of life.
In another and more general manner, new species become superior to their
predecessors; for they have to beat in the struggle for life all
the older forms, with which they come into close competition. We may
therefore conclude that if under a nearly similar climate the eocene
inhabitants of the world could be put into competition with the existing
inhabitants, the former would be beaten and exterminated by the
latter, as would the secondary by the eocene, and the palaeozoic by
the secondary forms. So that by this fundamental test of victory in the
battle for life, as well as by the standard of the specialisation of
organs, modern forms ought, on the theory of natural selection, to
stand higher than ancient forms. Is this the case? A large majority of
palaeontologists would answer in the affirmative; and it seems that this
answer must be admitted as true, though difficult of proof.

It is no valid objection to this conclusion, that certain Brachiopods
have been but slightly modified from an extremely remote geological
epoch; and that certain land and fresh-water shells have remained nearly
the same, from the time when, as far as is known, they first appeared.
It is not an insuperable difficulty that Foraminifera have not, as
insisted on by Dr. Carpenter, progressed in organisation since even the
Laurentian epoch; for some organisms would have to remain fitted for
simple conditions of life, and what could be better fitted for this end
than these lowly organised Protozoa? Such objections as the above
would be fatal to my view, if it included advance in organisation as
a necessary contingent. They would likewise be fatal, if the above
Foraminifera, for instance, could be proved to have first come into
existence during the Laurentian epoch, or the above Brachiopods during
the Cambrian formation; for in this case, there would not have been time
sufficient for the development of these organisms up to the standard
which they had then reached. When advanced up to any given point, there
is no necessity, on the theory of natural selection, for their further
continued process; though they will, during each successive age, have to
be slightly modified, so as to hold their places in relation to slight
changes in their conditions. The foregoing objecti