gradual
development through successive geological periods. The geological
testimony is this: First, there were no animals having any structural
resemblance to the fishes prior to their creation, and when they appear
they are already in possession of the highest organization and the
largest cerebral development.

During the long periods of geological history there has been no advance
in this class of animals. The science testifies to no successive steps
here. "They stood at the head of the icthyic division at the outset; but
there has been, during these periods, a progressive _degeneracy_, so
that though all possessed a high organization at first, there is found
in the after creations a _succession of lapses_ until the division of
fishes now contains species ranking little above the earth-worm." "A
single well defined placoid fossil in the Bala limestone as fully proves
the existence of placoid fishes, during the period of its deposition, as
if the rock were made up of placoid fossils, for it is not a question of
numbers, but of rank." The question, now, comes home to us with all its
force, how did fishes of this high order come to exist before any of the
inferior class? Let some of our evolution savans answer.

The same thing may be said of other organic divisions. It has gone to
record that the shell-fish of the Silurian system are the lowest
division of the molluscous animals. While the statement is received as
true, it must be remembered that there is some diversity of structure in
this lower division, and that the earliest molluscs are not the lowest,
but the highest in the division. The most important point, however, is,
that while Brachiopoda were most abundant, the highest molluscs existed
also, their remains being found in the Bala limestone, which is the
lowest bed of molluscous fossils. (See Silurian System, p. 308.) The
number of these higher species is not important. They existed, few or
many, as early as any other of the mollusca. If the lower had not an
anterior existence, the higher were not developed from them. It is also
a conclusive argument against the system, that while the intermediate
mollusca are very numerous, the cephalopoda, which were so early
introduced, and are the higher forms that were so numerous at certain
times, are now narrowed down to a few species.

Lyell was the first to drop a word of caution against "inferring too
hastily from the absence of mammalian fossils in the older rocks