the remains before they had time to decay. On the
other hand, as long as the bed of the sea remained stationary, THICK
deposits could not have been accumulated in the shallow parts, which are
the most favourable to life. Still less could this have happened during
the alternate periods of elevation; or, to speak more accurately, the
beds which were then accumulated will have been destroyed by being
upraised and brought within the limits of the coast-action.

Thus the geological record will almost necessarily be rendered
intermittent. I feel much confidence in the truth of these views, for
they are in strict accordance with the general principles inculcated
by Sir C. Lyell; and E. Forbes independently arrived at a similar
conclusion.

One remark is here worth a passing notice. During periods of elevation
the area of the land and of the adjoining shoal parts of the sea will
be increased, and new stations will often be formed;--all circumstances
most favourable, as previously explained, for the formation of new
varieties and species; but during such periods there will generally be
a blank in the geological record. On the other hand, during subsidence,
the inhabited area and number of inhabitants will decrease (excepting
the productions on the shores of a continent when first broken up into
an archipelago), and consequently during subsidence, though there will
be much extinction, fewer new varieties or species will be formed; and
it is during these very periods of subsidence, that our great deposits
rich in fossils have been accumulated. Nature may almost be said to have
guarded against the frequent discovery of her transitional or linking
forms.

From the foregoing considerations it cannot be doubted that the
geological record, viewed as a whole, is extremely imperfect; but if we
confine our attention to any one formation, it becomes more difficult
to understand, why we do not therein find closely graduated varieties
between the allied species which lived at its commencement and at its
close. Some cases are on record of the same species presenting distinct
varieties in the upper and lower parts of the same formation, but, as
they are rare, they may be here passed over. Although each formation has
indisputably required a vast number of years for its deposition, I can
see several reasons why each should not include a graduated series
of links between the species which then lived; but I can by no
means pretend to assign due