s were living he would be the first to renounce
the notions which he promulgated. For he imagined the habitable world to
have been for a certain time limited to one small tract, the only
portion of the earth's surface that was as yet laid bare by the
subsidence of the primaeval ocean. In this fertile spot he supposed the
originals of all the species of plants which exist on this globe to have
been congregated together with the first ancestors of all animals and of
the human race. "In qua commode habitaverint animalia omnia, et
vegetabilia laete germinaverint." In order to accommodate the various
habitudes of so many creatures, and to provide a diversity of climate
suited to their several natures, the tract in which the creation took
place was supposed to have been situated in some warm region of the
earth, but to have contained a lofty mountain range, on the heights and
in the declivities of which were to be found all temperatures and every
climate, from that of the torrid to that of the frozen zone.[948]

That there never was a universal ocean since the planet was inhabited,
or, rather, since the oldest groups of strata yet known to contain
organic remains were formed, is proved by the presence of terrestrial
plants or by indications of shores in all the older formations; and if
this conclusion was not established, yet no geologist could deny that,
since the first small portion of the earth was laid dry, there have been
many entire changes in the species of plants and animals inhabiting the
land.

But, without dwelling on the above and other refuted theories, let us
inquire whether some hypothesis cannot be substituted as simple as that
of Linnaeus, to which the phenomena now ascertained in regard to the
distribution both of aquatic and terrestrial species may be referred.
The following may, perhaps, be reconcileable with known facts:--Each
species may have had its origin in a single pair, or individual, where
an individual was sufficient, and species may have been created in
succession at such times and in such places as to enable them to
multiply and endure for an appointed period, and occupy an appointed
space on the globe.

In order to explain this theory, let us suppose every living thing to be
destroyed in the western hemisphere, both on the land and in the ocean,
and permission to be given to man to people this great desert, by
transporting into it animals and plants from the eastern hemisphere, a
strict proh