ned devonian or
carboniferous, silurian or devonian, cambrian or silurian.

This truth is further illustrated in a most interesting manner by
the impartial and highly competent testimony of M. Pictet, from whose
calculations of what percentage of the genera of animals, existing in
any formation, lived during the preceding formation, it results that in
no case is the proportion less than 'one-third', or 33 per cent. It is
the triassic formation, or the commencement of the mesozoic epoch, which
has received the smallest inheritance from preceding ages. The other
formations not uncommonly exhibit 60, 80, or even 94 per cent. of genera
in common with those whose remains are imbedded in their predecessor.
Not only is this true, but the subdivisions of each formation exhibit
new species characteristic of, and found only in, them; and, in
many cases, as in the lias for example, the separate beds of these
subdivisions are distinguished by well-marked and peculiar forms of
life. A section, a hundred feet thick, will exhibit, at different
heights, a dozen species of ammonite, none of which passes beyond its
particular zone of limestone, or clay, into the zone below it or into
that above it; so that those who adopt the doctrine of special creation
must be prepared to admit, that at intervals of time, corresponding with
the thickness of these beds, the Creator thought fit to interfere with
the natural course of events for the purpose of making a new ammonite.
It is not easy to transplant oneself into the frame of mind of those who
can accept such a conclusion as this, on any evidence short of absolute
demonstration; and it is difficult to see what is to be gained by so
doing, since, as we have said, it is obvious that such a view of the
origin of living beings is utterly opposed to the Hebrew cosmogony.
Deserving no aid from the powerful arm of Bibliolatry, then, does the
received form of the hypothesis of special creation derive any support
from science or sound logic? Assuredly not much. The arguments
brought forward in its favour all take one form: If species were not
supernaturally created, we cannot understand the facts 'x' or 'y', or
'z'; we cannot understand the structure of animals or plants, unless we
suppose they were contrived for special ends; we cannot understand the
structure of the eye, except by supposing it to have been made to see
with; we cannot understand instincts, unless we suppose animals to have
been miracul