Origin of Species Variorum

→ but to this subject I shall have to return 1859 1860

so that here again we have undoubted evidence of change, though not strictly of variation, 1861 1866

so that here again we have undoubted evidence of change 1869 1872

→ following 1859 1860

direction required by my theory; but to this latter subject I shall have to return in the following 1861 1866

direction required by the theory; but to this latter subject I shall have to return in the following 1869

direction required by the theory; but to this latter subject I shall return in the following 1872

→ One other consideration is worth notice: 1859 1860 1861

OMIT 1866 1869 1872

→ probably 1859 1860

highly probable that 1861 1866

probable 1869 1872

→ those which have 1859 1860 1861 1866

that those which have 1869

that those which 1872

↑ 1 blocks not present in 1859 1860 1861; present in 1866 1869 1872

It is a more important consideration, clearly leading to the same result, as lately insisted on by Dr. Falconer, namely, that the periods during which species have been undergoing modification, though very long as measured by years, have probably been short in comparison with the periods during which these same species remained without undergoing any change.

→ in the case of 1859 1860 1861 1866 1869

with 1872

→ effected by palæontologists. 1859 1860 1861 1866 1869

done. 1872

yet are far more closely

allied

to each other than are the species found in more widely separated formations; →but to this subject I shall have to return in the →following chapter.

→One other consideration is worth notice:

With

with

animals and plants that

~~can~~

can

propagate rapidly and

are

not

wander much,

highly locomotive,

there is reason to suspect, as we have formerly seen, that their varieties are generally at first local; and that such local varieties do not spread widely and supplant their parent-forms until they have been modified and perfected in some considerable degree. According to this view, the chance of discovering in a formation in any one country all the early stages of transition between any two

such forms,

forms,

is small, for the successive changes are supposed to have been local or confined to some one spot. Most marine animals have a wide range; and we have seen that with plants it is those which have the widest range, that oftenest present varieties; so

that,

that

with shells and other marine animals, it is →probably →those which have had the widest range, far exceeding the limits of the known geological formations of Europe,

~~which~~

which

have oftenest given rise, first to local varieties and ultimately to new species; and this again would greatly lessen the chance of our being able to trace the stages of transition in any

ony

one

geological formation. ↑

It should not be forgotten, that at the present day, with perfect specimens for examination, two forms can seldom be connected by intermediate

varieties,

varieties

and thus proved to be the same species, until many specimens

are

have been

collected from many places; and →in the case of fossil species this

can

could

rarely be →effected by palæontologists. We shall, perhaps, best perceive the improbability of our being enabled to connect species by

numerous

numerous,

fine,

intermediate

intermediate,

fossil links, by asking