Comparison with 1860 |
|
Successive formations are
separated separated 1859 1860 |
in most cases separated 1861 1866 1869 1872 |
from each other by enormous
blank intervals of time;
for
fossiliferous
formations, formations, 1859 1860 | formations 1861 1866 1869 1872 |
thick enough to resist future
degradation, degradation, 1859 1860 | degradation 1861 1866 1869 1872 |
can
be be 1859 1860 |
generally be 1861 1866 |
as a general rule be 1869 1872 |
accumulated only where much sediment is deposited on the subsiding bed of the sea. During the alternate periods of elevation and of stationary level the record will be
blank. blank. 1859 1860 1869 1872 | generally blank. 1861 1866 |
During these latter periods there will probably be more variability in the forms of life; during periods of subsidence, more extinction. |
|
With respect to the absence
of fossiliferous formations of fossiliferous formations 1859 1860 1861 |
of strata rich in fossils 1869 1872 |
OMIT 1866 |
beneath the
lowest Silurian strata, lowest Silurian strata, 1859 1860 1861 |
lowest Silurian strata 1866 |
Cambrian formation, 1869 1872 |
I can only recur I can only recur 1859 1860 1861 |
of formations rich in fossils of many kinds, I can recur only 1866 |
I can recur only 1869 1872 |
to the hypothesis given in the ninth
chapter.
↑1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | With respect to the lapse of time not having been sufficient since our planet was consolidated for the assumed amount of organic change, and this objection, as urged by Sir William Thompson , is probably one of the gravest as yet advanced, I can only say, firstly, that we do not know at what rate species change as measured by years, and secondly, that many philosophers are not as yet willing to admit that we know enough of the constitution of the universe and of the interior of our globe to speculate with safety on its past duration.
|
That the geological record is imperfect all will admit; but that it is imperfect to the degree which I require,
few will be inclined to admit. If we look to long enough intervals
of time, geology plainly declares that all species have
changed; and they have changed in the manner which my theory requires,
for they have changed slowly and in a graduated manner. We clearly see this in the fossil remains from consecutive formations invariably being much more closely related to each other, than are the fossils from formations distant from each other in time.
|
|
Such is the sum of the several chief objections and difficulties which may justly be
urged against my
theory; and I have now briefly recapitulated the answers and explanations which
can
be given
to them.
I have felt these difficulties far too heavily during many years to doubt their weight. But it deserves especial notice that the more important objections relate to questions on which we are confessedly ignorant; nor do we know how ignorant we are. We do not know all the possible transitional gradations between the simplest and the most perfect organs; it cannot be pretended that we
|
Successive formations are
in most cases separated in most cases separated 1861 1866 1869 1872 |
separated 1859 1860 |
from each other by
enormous enormous 1859 1860 1861 1866 | enormous 1869 1872 |
blank intervals of
time; time; 1859 1860 1861 1866 | time 1869 1872 |
for for 1859 1860 1861 1866 |
of great length; for 1869 1872 |
fossiliferous
formations formations 1861 1866 1869 1872 | formations, 1859 1860 |
thick enough to resist future
degradation degradation 1861 1866 1869 1872 | degradation, 1859 1860 |
can
generally be generally be 1861 1866 |
be 1859 1860 |
as a general rule be 1869 1872 |
accumulated only where much sediment is deposited on the subsiding bed of the sea. During the alternate periods of elevation and of stationary level the record will
be be 1859 1860 1861 1866 | generally be 1869 1872 |
generally blank. generally blank. 1861 1866 | blank. 1859 1860 1869 1872 |
During these latter periods there will probably be more variability in the forms of life; during periods of subsidence, more extinction. |
|
With respect to the absence
...OMIT 1866 |
of fossiliferous formations 1859 1860 1861 |
of strata rich in fossils 1869 1872 |
beneath the
lowest Silurian strata lowest Silurian strata 1866 |
lowest Silurian strata, 1859 1860 1861 |
Cambrian formation, 1869 1872 |
of formations rich in fossils of many kinds, I can recur only of formations rich in fossils of many kinds, I can recur only 1866 |
I can only recur 1859 1860 1861 |
I can recur only 1869 1872 |
to the hypothesis given in the
ninth ninth 1859 1860 1861 1866 1869 | tenth 1872 |
chapter. chapter. 1859 1860 1861 1866 1869 |
chapter; namely, that though our continents and oceans have endured for an enormous period in nearly their present relative positions, we have no reason to assume that this has always been the case; consequently formations much older than any now known may lie buried beneath the great oceans. 1872 |
↑1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | With respect to the lapse of time not having been sufficient since our planet was consolidated for the assumed amount of organic change, and this objection, as urged by Sir William Thompson , is probably one of the gravest as yet advanced, I can only say, firstly, that we do not know at what rate species change as measured by years, and secondly, that many philosophers are not as yet willing to admit that we know enough of the constitution of the universe and of the interior of our globe to speculate with safety on its past duration.
|
That the geological record is imperfect all will admit; but that it is imperfect to the degree
which I require, which I require, 1859 1860 1861 1866 |
required by our theory, 1869 1872 |
few will be inclined to admit. If we look to long enough
intervals intervals 1859 1860 1866 1869 1872 | in- tervals 1861 |
of time, geology plainly declares that
all species have all species have 1859 1860 1861 1866 |
species have all 1869 1872 |
changed; and they have changed in the manner
which my theory requires, which my theory requires, 1859 1860 1861 1866 |
required, 1869 |
required by the theory, 1872 |
for they have changed slowly and in a graduated manner. We clearly see this in the fossil remains from consecutive formations invariably being much more closely related to each other, than are the fossils from
formations distant from each other in time. formations distant from each other in time. 1859 1860 1861 1866 |
widely separated formations. 1869 1872 |
|
|
Such is the sum of the several chief objections and difficulties which may
justly be justly be 1859 1860 1861 1866 1869 | be justly 1872 |
urged against
my my 1859 1860 1861 1866 | the 1869 1872 |
theory; and I have now briefly recapitulated the answers and explanations
which which 1859 1860 1861 1866 1869 | which, 1872 |
can can 1859 1860 1861 1866 1869 |
as far as I can see, may 1872 |
be
given given 1859 1860 1861 1866 | given. 1869 1872 |
to to 1859 1860 1861 1866 | to 1869 1872 |
them. them. 1859 1860 1861 1866 | them. 1869 1872 |
I have felt these difficulties far too heavily during many years to doubt their weight. But it deserves especial notice that the more important objections relate to questions on which we are confessedly ignorant; nor do we know how ignorant we are. We do not know all the possible transitional gradations between the simplest and the most perfect organs; it cannot be pretended that we
|