Origin of Species Variorum

→ local; and lastly, although each species must have passed through numerous transitional stages, it is probable that the periods, during which each underwent modification, though many and long as measured by years, have been short in comparison with the periods during which each remained in an unchanged condition. 1866 1869 1872

local. 1859 1860 1861

→ OMIT 1866 1869 1872

must have tended to make the geological record extremely imperfect, and 1859 1860

must have made the geological record extremely imperfect, and 1861

→ find many links— we do not find 1869 1872

not find 1859 1860

find 1861 1866

→ interminable 1859 1860 1869 1872

many links between the members of the same group— we do not find interminable 1861

many links between the species of the same group— we do not find interminable 1866

→ Cambrian 1869 1872

first bed of the Silurian 1859 1860 1861 1866

→ We now know that at least one animal did then exist; but I 1869 1872

I 1859 1860 1861

We now know that animals, and probably plants, lived at an epoch immensely remote, long anterior to the primordial zone of the Silurian system, but I 1866

→ OMIT 1866 1869 1872

as far as we can see, 1859 1860 1861

→ extended for an enormous period, 1866 1869 1872

for an enormous period extended, 1859 1860 1861

→ commencement of the Cambrian system; 1869 1872

Silurian epoch; 1859 1860 1861

commencement of the Silurian epoch; 1866

→ only as remnants 1866 1869 1872

all be 1859 1860 1861

→ agree admirably with 1872

seem to me simply to follow on 1859 1860 1861 1866 1869

→ variation and natural 1872

natural 1859 1860 1861 1866 1869

and

frequently, and

have oftenest given rise to new species;

and

....

that varieties have at first

often

....

been →local; and lastly, although each species must have passed through numerous transitional stages, it is probable that the periods, during which each underwent modification, though many and long as measured by years, have been short in comparison with the periods during which each remained in an unchanged condition.

All

....

these

These

causes

causes,

taken conjointly, →OMIT will to a large extent explain

why

why— though

we do →find many links— we do not find →interminable varieties, connecting together all

the

....

extinct and existing forms

of life

....

by the finest graduated steps. It should also be constantly borne in mind that any linking

varieties

variety

between two

or more

....

forms, which might be found, would be ranked, unless the whole chain could be perfectly restored, as

so many

new and distinct species; for it is not pretended that we have any sure criterion by which species and varieties can be discriminated.

He who rejects

these

this

views

view

the

nature

imperfection

of the geological record, will rightly reject

the

whole theory. For he may ask in vain where are the numberless transitional links which must formerly have connected the closely allied or representative species, found in the

several

successive

stages of the same great

formation.

formation?

He may disbelieve in the

enormous

immense

intervals of time which

have

must have

elapsed between our consecutive formations; he may overlook how important a part migration

must have

has

played, when the formations of any one great

region

region,

alone,

....

that

those

of Europe, are considered; he may urge the apparent, but often falsely apparent, sudden coming in of whole groups of species. He may ask where are the remains of those infinitely numerous organisms which must have existed long before the →Cambrian system was

deposited:

deposited?

→We now know that at least one animal did then exist; but I can answer

this latter

the above

this last

question only

hypothetically,

....

saying

supposing

that →OMIT where our oceans now extend they have →extended for an enormous period, and where our oscillating continents now stand they have stood

ever

....

since the →commencement of the Cambrian system; but

that

that,

long before that

period,

epoch,

the world

may have

....

presented a

wholly

widely

different aspect; and that the older continents, formed of formations older than any known to us,

may

exist

now →only as remnants in a metamorphosed condition, or

may

....

lie

buried

wholly buried

still buried

under the ocean.

Passing from these difficulties,

all

....

the other great leading facts in palæontology →agree admirably with the theory of descent with modification through →variation and natural selection. We can thus understand how it is that new species come in slowly and successively; how species of different classes do not

necessarily,

necessarily

change