Origin of Species Variorum

→ in the struggle for life, that 1869 1872

that 1859 1860 1861 1866

→ otherwise they would 1869 1872

those which do not change will 1859 1860 1861 1866

→ enduring formations, rich in fossils, 1872

long-enduring fossiliferous formations 1859 1860 1861 1866

long-enduring formations, 1869

→ depends 1859 1860 1861 1866 1872

rich in fossils, depends 1869

→ subsiding areas, 1869 1872

areas whilst subsiding, 1859 1860 1861 1866

→ of time; consequently 1866 1869 1872

consequently 1859 1860 1861

→ progenitors; and organisms already differing would vary in a different manner. 1872

progenitors. 1859 1860 1861 1866

progenitors, and organisms already differing would vary in a different manner. 1869

→ all our fantail pigeons were 1869 1872

our fantail-pigeons were all 1859 1860 1861 1866

→ OMIT 1869 1872

by striving during long ages for the same object, 1859 1860 1861 1866

→ successive variations would almost certainly be in some degree different, and the newly-formed variety would probably 1869 1872

newly-formed fantail would be almost sure to 1859 1861 1866

newly-formed faintail would be almost sure to 1860

→ when 1866 1869 1872

does not reappear after 1859 1860 1861

→ never reappears; that is, 1866 1869 1872

or 1859 1860 1861

all-important relations of organism to

organism,

organism

→in the struggle for life, that any form which

does

did

not become in some degree modified and improved,

will

would

be liable to

....

exterminated.

extermination.

Hence we

can

....

see why all the species in the same region do at last, if we look to

wide

long

enough intervals of time, become

modified;

modified,

for →otherwise they would become extinct.

In members of the same class the average amount of change, during long and equal periods of time, may, perhaps, be nearly the same; but as the accumulation of →enduring formations, rich in fossils, →depends on great masses of sediment

having been

being

deposited on →subsiding areas, our formations have been almost necessarily accumulated at wide and irregularly intermittent

intervals;

intervals

→of time; consequently the amount of organic change exhibited by the fossils embedded in consecutive formations is not equal. Each formation, on this view, does not mark a new and complete act of creation, but only an occasional scene, taken almost at hazard, in

an ever

slowly changing drama.

We can clearly understand why a species when once lost should never reappear, even if the very same conditions of life, organic and inorganic, should recur. For though the offspring of one species might be adapted (and no doubt this has occurred in innumerable instances) to fill the

exact

....

place of another species in the economy of nature, and thus supplant it; yet the two forms— the old and the new— would not be identically the same; for both would almost certainly inherit different characters from their distinct →progenitors; and organisms already differing would vary in a different manner. For instance, it is

just

....

possible, if →all our fantail pigeons were destroyed, that

fanciers,

fanciers

→OMIT might make a new breed hardly distinguishable from

our

the

present

fantail;

breed;

but if the parent rock-pigeon were

also

likewise

destroyed, and

under

nature we have every reason to believe that

the

parent-form

will

generally

supplanted and exterminated by

its

their

improved offspring, it is

quite

....

in- credible

incredible

that a

fan- tail,

fantail,

identical with the existing breed, could be raised from any other species of pigeon, or even from

the

any

other well-established

races

race

of the domestic pigeon, for the →successive variations would almost certainly be in some degree different, and the newly-formed variety would probably inherit from its

new

....

progenitor some

slight

....

characteristic differences.

Groups of species, that is, genera and families, follow the same general rules in their appearance and disappearance as do single species, changing more or less quickly, and in a greater or lesser degree. A

group

group,

→when it has once

disappeared;

disappeared,

→never reappears; that is, its existence, as long as it lasts, is continuous. I am aware that there are some apparent exceptions to this rule, but the exceptions are surprisingly few, so

few,

few

that E. Forbes , Pictet, and