See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1866
1869
1872

varieties 1859 1860 1861 1866 1869
natural and domestic varieties 1872

Time .— 1859 1860 1861
Time, as inferred from the rate of Deposition and extent of Denudation . 1866
Time, as inferred from the rate of Deposition and extent of Denudation . 1869
Time , as inferred from the rate of Deposition and extent of Denudation . 1872

3 blocks not present in 1859 1860 1861 1866; present in 1869 1872
We can best gain some idea of past time by knowing the agencies at work, and learning how much of the surface of the land has been denuded, and how much sediment has been deposited. As Lyell has well remarked, the extent and thickness of our sedimentary formations are the result and the measure of the denudation which the earth's crust has elsewhere undergone. Therefore a man should examine for himself the great piles of superimposed strata, and watch the rivulets bringing down mud, and the waves wearing away the sea-cliffs, in order to comprehend something about the duration of past time, the monuments of which we see all around us.

genus, by differences not greater than we see between the varieties of the same species at the present day; and these parent-species, now generally extinct, have in their turn been similarly connected with more ancient
forms;
species;
and so on backwards, always converging to the common ancestor of each great class. So that the number of intermediate and transitional links, between all living and extinct species, must have been inconceivably great. But assuredly, if this theory be true, such have lived upon
this
the
earth.
On
On
the
the
Lapse
lapse
of
of
Time .—
Independently of our not finding fossil remains of such infinitely numerous connecting links, it may be
objected
objected,
that time
cannot
will not
have sufficed for so great an amount of organic change, all changes having been effected
very
very
slowly.
slowly
through
through
natural
natural
selection.
selection.
It is hardly possible for me
even
even
to recall to the
reader
reader,
who
is
may
not
be
be
a practical geologist, the facts leading the mind feebly to comprehend the lapse of time. He who can read Sir Charles Lyell's grand work on the Principles of Geology, which the future historian will recognise as having produced a revolution in natural science,
and yet
yet
does not admit how
incomprehensively
incomprehensibly
incomprehensibly
vast have been the past periods of time, may at once close this volume. Not that it suffices to study the Principles of Geology, or to read special treatises by different observers on separate formations, and to mark how each author attempts to give an inadequate idea of the duration of each
formation,
formation
or even
of each
each
stratum. A man must for years examine for himself great piles of superimposed strata, and watch the sea at work grinding down old rocks and making fresh sediment, before he can hope to comprehend anything of the lapse of time, the monuments of which we see around us.