Origin of Species Variorum

→ in the Old World could 1859 1860

in the Old World can 1861 1866

can 1869 1872

→ hotter than any 1859 1860 1861 1866

OMIT 1869 1872

→ yet 1859 1860 1861 1866

hotter than any in the New World, but 1869

hotter than any in the New World; but 1872

→ or flora. 1859 1860 1861 1866

different from that of the surrounding districts; for it is very rare to find a group of organisms confined to a small area, having conditions peculiar in only a slight degree. 1869

different from that of the surrounding districts; for it is rare to find a group of organisms confined to a small area, of which the conditions are peculiar in only a slight degree. 1872

→ inhabit a 1859 1860 1861

are separated by a space of ten degrees of latitude and live under a 1866

are separated by a space of ten degrees of latitude and are exposed to 1869 1872

→ climate, and they will be found 1859 1860 1861

climate, yet they are 1866

conditions, yet they are 1869

conditions; yet they are 1872

→ climate. Analogous facts could be given with respect to the inhabitants of the sea. 1859

climate. 1860 1861 1866 1869 1872

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

Analogous facts could be given with respect to the inhabitants of the sea.

small areas →in the Old World could be pointed out →hotter than any in the

Old

New

World

World,

→yet these are not inhabited by a

~~peculiar~~

peculiar

fauna →or flora. Notwithstanding this

general parallelism

parallelism

in the conditions of the Old and New Worlds, how widely different are their living productions!

In the southern hemisphere, if we compare large tracts of land in Australia, South Africa, and western South America, between latitudes

25°

and

35°,

we shall find parts extremely similar in all their conditions, yet it would not be possible to point out three faunas and floras more utterly dissimilar.

Or,

again,

again

we may compare the productions of South America south of lat.

35°

with those north of

25°,

which consequently →inhabit a considerably different →climate, and they will be found incomparably more closely related to each

other

other,

than they are to the productions of Australia or Africa under nearly the same →climate. Analogous facts could be given with respect to the inhabitants of the sea. ↑

A second great fact which strikes us in our general review is, that barriers of any kind, or obstacles to free migration, are related in a close and important manner to the differences between the productions of various regions. We see this in the great difference

nearly all the terrestrial productions of the New and Old Worlds, excepting in the northern parts, where the land almost joins, and where, under a slightly different climate, there might have been free migration for the northern temperate forms, as there now is for the strictly arctic productions. We see the same fact in the great difference between the inhabitants of Australia, Africa, and South America under the same

latitude;

latitude:

for these countries are almost as much isolated from each other as is possible. On each continent, also, we see the same fact; for on the opposite sides of