admitted, we can easily understand why there should now be found
upon many mountains so great a number of crustacea and other marine
animals."

In the above extract, I have not merely enumerated the opinions and
facts which are confirmed by recent observation, suppressing all that
has since proved to be erroneous, but have given a faithful abridgment
of the entire treatise, with the omission only of Moro's hypothesis,
which Generelli adopted, with all its faults and excellences. The reader
will therefore remark, that although this admirable essay embraces so
large a portion of the principal objects of geological research, it
makes no allusion to the extinction of certain classes of animals; and
it is evident that no opinions on this head had, at that time, gained a
firm footing in Italy. That Lister and other English naturalists should
long before have declared in favor of the loss of species, while Scilla
and most of his countrymen hesitated, was perhaps natural, since the
Italian museums were filled with fossil shells belonging to species of
which a great portion did actually exist in the Mediterranean; whereas
the English collectors could obtain no recent species from such of their
own strata as were then explored.

The weakest point in Moro's system consisted in deriving _all_ the
stratified rocks from volcanic ejections; an absurdity which his
opponents took care to expose, especially Vito Amici.[80] Moro seems to
have been misled by his anxious desire to represent the formation of
secondary rocks as having occupied an extremely short period, while at
the same time he wished to employ known agents in nature. To imagine
torrents, rivers, currents, partial floods, and all the operations of
moving water, to have gone on exerting an energy many thousand times
greater than at present, would have appeared preposterous and
incredible, and would have required a hundred violent hypotheses; but we
are so unacquainted with the true sources of subterranean disturbances,
that their former violence may in theory be multiplied indefinitely,
without its being possible to prove the same manifest contradiction or
absurdity in the conjecture. For this reason, perhaps, Moro preferred to
derive the materials of the strata from volcanic ejections, rather than
from transportation by running water.

_Marsilli._--Marsilli, whose work is alluded to by Generelli, had been
prompted to institute inquiries into the bed of the Adriatic, by
di