Origin of Species Variorum

→ of strata rich in fossils 1869 1872

of fossiliferous formations 1859 1860 1861

OMIT 1866

→ Cambrian formation, 1869 1872

lowest Silurian strata, 1859 1860 1861

lowest Silurian strata 1866

→ I can recur only 1869 1872

I can only recur 1859 1860 1861

of formations rich in fossils of many kinds, I can recur only 1866

→ 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.

→ required by our theory, 1869 1872

which I require, 1859 1860 1861 1866

→ species have all 1869 1872

all species have 1859 1860 1861 1866

→ required, 1869

which my theory requires, 1859 1860 1861 1866

required by the theory, 1872

→ widely separated formations. 1869 1872

formations distant from each other in time. 1859 1860 1861 1866

→ can 1859 1860 1861 1866 1869

as far as I can see, may 1872

→ are not 1869

do not 1859 1860 1861 1866

are by no means sufficient to 1872

→ sufficient to overthrow 1869

overthrow 1859 1860 1861 1866 1872

deposited on the subsiding bed of the sea. During the alternate periods of elevation and of stationary level the record will

generally be

generally blank.

blank.

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 strata rich in fossils beneath the →Cambrian formation, →I can recur only to the hypothesis given in the

tenth

ninth

→chapter. ↑ That the geological record is imperfect all will admit; but that it is imperfect to the degree →required by our theory, few will be inclined to admit. If we look to long enough

in- tervals

intervals

of time, geology plainly declares that →species have all changed; and they have changed in the manner →required, 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 →widely separated formations.

Such is the sum of the several chief objections and difficulties which may

be justly

justly be

urged against

the

theory; and I have now briefly recapitulated the answers and explanations

which,

which

→can be

given

given.

....

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 know all the varied means of Distribution during the long lapse of years, or that we know how imperfect

is the

the

Geological

Record.

Record

~~is.~~

is.

Grave

Serious

as these several

difficulties

objections

are, in my judgment they →are not →sufficient to overthrow