and marl was the bottom of the ocean which covered the old
world, and laid the foundation of a new. But in the saurian
period none of the contemporaries of. mankind seem to have
existed. Repeated revolutions <pf the earth appear to have
taken place between that age and the origin of the tribes
whichrare coeval with men. It is within this interval, that all
the numerous tribes of pachydermes, whose relics are found
in the gypsum of Paris, had the commencement and the termination
of their existence. Now if it be allowed to have
been a part of the order of things ip remote ages of the world,
that the creation, of- organized beings, either partially or universally,
should be renewed at different periods, as the sequel
of some great cataclysms, or, perhaps, in consequence h f sqm#
physical changes in the surface of our planet, which had rendered
it-an appropriate habitation for beings of a different organization
from those which had previously existed in it,, there
is nothing remote from this analogy in the supposition, that
after the last great deluge which has overwhelmed the
teihapov apovpav, a similar renovation should have taken place.
I do not profess to advocate either of these suppositions,
but have merely laid them before my readers, who wilJ -select
from them that which may be most satisfactory to them,
or discover, if they can, one that may be preferable to either*
BOOK II.
CONSIDERATIONS RELATIVE TO THE QUESTION,
WHETHER THE VARIOUS RACES OE MEN ARE OF ONE
OR OF SEVERAL SPECIES.-r-ANALOGICAL
INVESTIGATION.