Origin of Species Variorum

→ I am inclined to believe, has 1859 1860 1861

has probably 1866 1869 1872

→ separated 1859 1860

in most cases separated 1861 1866 1869 1872

→ for 1859 1860 1861 1866

of great length; for 1869 1872

→ be 1859 1860

generally be 1861 1866

as a general rule be 1869 1872

→ of fossiliferous formations 1859 1860 1861

of strata rich in fossils 1869 1872

OMIT 1866

→ lowest Silurian strata, 1859 1860 1861

lowest Silurian strata 1866

Cambrian formation, 1869 1872

→ 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

→ 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.

→ which I require, 1859 1860 1861 1866

required by our theory, 1869 1872

→ all species have 1859 1860 1861 1866

species have all 1869 1872

→ which my theory requires, 1859 1860 1861 1866

required, 1869

required by the theory, 1872

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

widely separated formations. 1869 1872

→ can 1859 1860 1861 1866 1869

as far as I can see, may 1872

improved;

proved;

and when they

have

spread,

and are

discovered in a geological formation, they

~~will~~

will

appear as if suddenly created there, and will be simply classed as new species. Most formations have

been,

been

intermittent in their accumulation; and their

duration

duration,

→I am inclined to believe, has been shorter than the average duration of specific forms. Successive formations are →separated from each other by

~~enormous~~

enormous

blank intervals of

time

time;

→for fossiliferous

formations

formations,

thick enough to resist future

degradation

degradation,

can →be 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

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 fossiliferous formations beneath the →lowest Silurian strata, →I can only recur 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 →which I require, few will be inclined to admit. If we look to long enough

in- tervals

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

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.~~

them.

I have felt these difficulties far too heavily during many years to