gradually degenerate and die out from the influence of the altered and
unfavourable physical conditions in which they were placed, and be
supplanted by immigrants of different species, and to which the new
conditions were more congenial?

The last, we confess, is the view to which we are most inclined--first,
because we think a transmutation of species, from a lower to a higher
type, has not been satisfactorily proved; and second, because of the
strong impression we entertain, that the universe, subject to certain
cyclical and determinate mutations, was made complete at first, with
self-subsisting provisions for its perpetual renewal and conservation.
We shall advert to this matter hereafter; but at present it is the
conclusions of the author of the _Vestiges_ that claim consideration. He
adopts the first interpretation of animal phenomena, namely, that there
has been a transmutation of species, that the scale of creation has been
gradually advancing in virtue of an inherent and organic law of
development. Nature, he contends, began humbly; her first works were of
simple form, which were gradually meliorated by circumstances favourable
to improvement, and that everywhere animals and plants exhibit traces of
a parallel advance of the physical conditions and the organic structure.
The general principle, he inculcates, is, that each animal of a higher
kind, in the progress of its embryo state, passes through states which
are the final condition of the lower kind; that the higher kinds of
animals came later, and were developed from the lower kinds, which came
earlier in the series of rock formations, by new peculiar conditions
operating upon the embryo, and carrying it to a higher stage. These
conclusions the author maintains geology has established, and of the
results thence derived he gives the subjoined recapitulation:--

"In pursuing the progress of the development of both plants and