the whole
newer newer 1861 |
of the newer 1866 1869 1872 |
Palæozoic
formation. formation. 1861 | formations. 1866 1869 1872 |
In many regions the metamorphic and granitic
areas areas 1861 | rocks 1866 1869 1872 |
would be
greatly increased in size, if we could remove greatly increased in size, if we could remove 1861 |
seen to be much more widely extended, if 1866 1869 |
found much more widely extended than they appear to be, if 1872 |
all the sedimentary beds
which which 1861 |
were removed which 1866 1869 1872 |
rest unconformably on them, and which
at the line of junction have not been metamorphosed, showing that they at the line of junction have not been metamorphosed, showing that they 1861 |
OMIT 1866 1869 1872 |
could not have formed part of the original mantle under which
the the 1861 | they 1866 1869 1872 |
granitic rocks granitic rocks 1861 | granitic rocks 1866 1869 1872 |
were crystallized. Hence it is probable that in some parts of the world whole
formations, formations, 1861 1866 | formations 1869 1872 |
marking at least sub-stages in the several successive geological epochs, marking at least sub-stages in the several successive geological epochs, 1861 1866 |
OMIT 1869 1872 |
have been completely denuded, with not a wreck left behind. |
|
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
....... 1861 1866 1869 1872 | most 1859 1860 |
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 the productions 1859 1860 1861 | the productions 1866 1869 1872 |
on the shores of a continent when first broken up into an archipelago), and consequently during subsidence, though there will be much extinction,
few few 1861 1866 1869 1872 | fewer 1859 1860 |
new varieties or species will be formed; and it is during these very periods of subsidence, that
our great deposits rich our great deposits rich 1859 1860 1861 1866 |
the deposits which are richest 1869 1872 |
in fossils have been accumulated. Nature may almost be said to have guarded against the frequent discovery of her
fine transitional fine transitional 1861 | transitional 1859 1860 |
or linking forms. ↑Subtitle not present 1859 1860 1861 |
On
the
Absence
of
Numerous
Intermediate
Varieties
in
any
one
Single
Formation
.
1866 1869 1872 |
|
From
these several these several 1861 1866 1869 1872 | the foregoing 1859 1860 |
considerations considerations 1859 1860 1861 | considerations, 1866 1869 1872 |
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
much more much more 1861 1866 1869 1872 | more 1859 1860 |
difficult to
|