Origin of Species Variorum

→ difficulties 1866 1869

difficulties are removed on the view here given 1859 1860 1861

the difficulties 1872

→ identical and allied 1869 1872

allied 1859 1860 1861 1866

→ now live so widely separated 1869 1872

live 1859 1860 1861 1866

→ south, and sometimes 1869 1872

southern temperate zones and 1859 1860 1861

southern tem- perate zones and 1866

→ intermediate mountain-ranges, are removed on the views above given. 1869 1872

mountains of the intertropical regions. 1859 1860 1861

mountains of the intertropical regions, are removed on the views above given. 1866

↑ 3 blocks not present in 1859 1860 1861 1869 1872; present in 1866

It is extremely difficult to understand how a vast number of peculiar forms confined to the tropics could have been therein preserved during the coldest part of the Glacial period. The number of forms in Australia, which are related to European temperate forms, but which differ so greatly that it is impossible to believe that they could have been modified since the Glacial period, perhaps indicates some much more ancient cold period, even as far back as the miocene age, in accordance with the recent speculations of certain geologists. So again, as I am informed by Mr. Bates, the strongly marked character of several species of Carabus, inhabiting the southern parts of America, indicates that their common progenitor must have been introduced at some early period; and other analogous facts could be given.

→ OMIT 1869 1872

during the recent Glacial period 1866

→ OMIT 1869

nor the reason 1866

>We cannot say 1872

→ OMIT 1869

groups of forms, and 1866

forms, whilst 1872

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

Very many difficulties remain to be solved.

→ We cannot say 1869

I do not pretend to indicate the exact lines and means of migration, or the reason 1859 1860 1861

→ forms, whilst 1869

groups of forms, and 1859 1860 1861

→ The existence, 1869

But the existence of several quite distinct species, belonging to genera exclusively confined to the south, 1859 1860 1861 1866

The existence 1872

northern and southern temperate zones, and on the intertropical mountains.

When,

When

during the height of the Glacial

period,

period

the ocean-currents were widely different to what they now are, some of the inhabitants of the temperate seas might have reached the equator; of these a few would perhaps at once be able to migrate southward, by keeping to the cooler currents, whilst others might remain and survive in the

colder

cooler

depths

depths,

until the southern hemisphere was in its turn subjected to a glacial climate and permitted

their further progress; in nearly the same manner as, according to Forbes, isolated spaces inhabited by Arctic productions exist to the present day in the deeper parts of the

northern temperate

temperate

seas.

I am

very far

far

from supposing that all →difficulties in regard to the

range

distribution

and affinities of the →identical and allied

species

species,

which →now live so widely separated in the

northern

north

and →south, and sometimes on the →intermediate mountain-ranges, are removed on the views above given. ↑ The exact lines

and means

....

of migration →OMIT cannot be

indicated;

indicated.

→OMIT

why

certain

species

and

not

others

have

migrated;

why

certain

species

have

been

modified

and

have

given

rise

new

→OMIT

others

have

remained

unaltered.

↑ →We cannot say why certain species and not others have migrated; why certain species have been modified and have given rise to new →forms, whilst others have remained unaltered. We cannot hope to explain such facts, until we can say why one species and not another becomes naturalised by

man's

mans

agency in a foreign land; why one

ranges

species ranges

twice or thrice as far, and is twice or thrice as common, as another species within their own homes.

Various special difficulties also remain to be

solved;

solved:

for instance, the occurrence, as shown by Dr. Hooker, of the same plants at points so enormously remote as Kerguelen Land, New Zealand, and Fuegia; but icebergs, as suggested by Lyell, may have been concerned in their dispersal. →The existence,