And if you choose to say that it was the deluge which carried these
shells away from the sea for hundreds of miles, this cannot have
happened, since that deluge was caused by rain; because rain
naturally forces the rivers to rush towards the sea with all the
things they carry with them, and not to bear the dead things of the
sea shores to the mountains. And if you choose to say that the
deluge afterwards rose with its waters above the mountains, the
movement of the sea must have been so sluggish in its rise against
the currents of the rivers, that it could not have carried, floating
upon it, things heavier than itself; and even if it had supported
them, in its receding it would have left them strewn about, in
various spots. But how are we to account for the corals which are
found every day towards Monte Ferrato in Lombardy, with the holes of
the worms in them, sticking to rocks left uncovered by the currents
of rivers? These rocks are all covered with stocks and families of
oysters, which as we know, never move, but always remain with one of
their halves stuck to a rock, and the other they open to feed
themselves on the animalcules that swim in the water, which, hoping
to find good feeding ground, become the food of these shells. We do
not find that the sand mixed with seaweed has been petrified,
because the weed which was mingled with it has shrunk away, and this
the Po shows us every day in the debris of its banks.

Other problems (992-994).