Origin of Species Variorum

→ or some few 1859 1860 1861 1866 1869

OMIT 1872

→ groups of species 1861 1866 1869

species 1859 1860

groups or species 1872

→ and consequently that the transitional forms would often long remain confined to some one region; but 1861 1866 1869 1872

but 1859 1860

→ adaptation had once 1861 1866 1869 1872

had 1859 1860

→ be able to 1859 1860 1861 1866

OMIT 1869 1872

of forms, all of which

are

have

descended from some one progenitor, must have been an extremely slow process; and the

progenitors,

progenitors

must have lived long

~~ages~~

ages

before their modified descendants. But we continually

over-rate

overrate

the perfection of the geological record, and falsely infer, because certain genera or families have not been found beneath a certain stage, that they did not exist before that stage. In all cases positive palæontological evidence may be implicitly trusted; negative evidence is worthless, as experience has so often shown. We continually forget how large the world is, compared with the area over which our geological formations have been carefully examined; we forget that groups of species may elsewhere have long

existed

existed,

and have slowly

multiplied

multiplied,

before they invaded the ancient archipelagoes of Europe and

....

the United States. We do not make due allowance for the

~~enormous~~

enormous

intervals of

time,

time

which have

probably

....

elapsed between our consecutive formations,— longer perhaps in

some

most

many

cases than the time required for the accumulation of each formation. These intervals will have given time for the multiplication of species from some one →or some few

parent-form:

parent-forms;

and in the succeeding

formation,

formation

such →groups of species will appear as if suddenly created.

I may here recall a remark formerly made,

namely

namely,

that it might require a long succession of ages to adapt an organism to some new and peculiar line of life, for

instance

instance,

to fly through the air; →and consequently that the transitional forms would often long remain confined to some one region; but

that

that,

when this →adaptation had once been effected, and a few species had thus acquired a great advantage over other organisms, a comparatively short time would be necessary to produce many divergent forms, which would →be able to spread rapidly and widely throughout the world. Professor Pictet, in his