Origin of Species Variorum

→ With respect to the effects of this intercrossing, it 1860 1861 1866

It 1869 1872

→ remembered 1860 1861 1866

borne in mind 1869 1872

→ examples: 1860 1861 1866

illustrations of the foregoing remarks: 1869 1872

→ there are 26 land-birds; of these 21 (or perhaps 23) 1866 1869 1872

nearly every land-bird, but only two out of the eleven marine birds, 1860

there are 26 land-birds; of these, 21 (or perhaps 23) 1861

→ whereas of the 11 1861 1866 1869 1872

and it is obvious that 1860

→ only 2 are peculiar; and it is obvious that marine birds only 2 are peculiar; and it is obvious that marine birds could 1866

could 1860

only 2 are peculiar; and it is obvious that marine birds could 1861 1869 1872

→ more easily 1860 1861 1866

much more easily and frequently 1869 1872

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

Thus in the Galapagos Islands nearly every land-bird, but only two out of the eleven marine birds, are peculiar; and it is obvious that marine birds could arrive at these islands more easily than land-birds.

→ one endemic land-bird; 1860 1861 1866

one endemic land bird; 1859

a single endemic land-bird; 1869 1872

→ occasionally visit 1866

during their great annual migrations, visit either periodically or occasionally 1859 1860 1861

occasionally or even frequently visit 1869 1872

→ by 1859 1860 1861 1866

from the neighbouring continents with 1869 1872

→ struggled together in their former homes, and have 1859 1860 1861 1866

struggled together, and 1869

there struggled together, and have 1872

→ adapted to each other; and when settled in their new homes, each kind will have been kept by the others to its proper place and habits, and will consequently have been little liable to modification. 1866

adapted to each other; and when settled in their new homes, each kind will have been kept by the others to their proper places and habits, and will consequently have been little liable to modification. 1859 1860 1861

adapted; hence when settled in their new homes, each kind would be kept by the others to its proper place and habits, and would consequently be but little liable to modification. 1869

co-adapted. 1872

→ from 1860 1861 1866 1869

often arriving from 1872

→With respect to the effects of this intercrossing, it should be →remembered that the offspring of such crosses would

~~almost~~

almost

certainly gain in vigour; so that even an occasional cross would produce more effect than might

~~at first~~

at first

have been

anticipated.

I will

give a few →examples: in the Galapagos Islands →there are 26 land-birds; of these 21 (or perhaps 23) are

peculiar;

peculiar,

→whereas of the 11 marine birds →only 2 are peculiar; and it is obvious that marine birds only 2 are peculiar; and it is obvious that marine birds could arrive at these islands →more easily than land-birds. ↑ Bermuda, on the other hand, which lies at about the same distance from North America as the Galapagos Islands do from South America, and which has a very peculiar soil, does not possess →one endemic land-bird; and we know from Mr. J. M.

Joness

Jones's

admirable account of Bermuda, that very many North American

birds,

birds

→occasionally visit this island. Almost every year, as I am informed by Mr. E. V. Harcourt, many European and African birds are blown to Madeira; this island is inhabited by 99 kinds, of which one alone is peculiar, though very closely related to a European form; and three or four other species are confined to this island and to the Canaries. So that

these two

the

the two

Islands

islands

of Bermuda and Madeira have been stocked →by birds, which for long ages have →struggled together in their former homes, and have become mutually →adapted to each other; and when settled in their new homes, each kind will have been kept by the others to its proper place and habits, and will consequently have been little liable to modification. Any tendency to modification

will,

would

will

also,

also

have been

checked by intercrossing with the unmodified

immigrants,

immigrants

→from the mother-country.

Madeira,

Madeira

again,

again

is inhabited by a wonderful number of peculiar land-shells, whereas not one species of sea-shell is

confined

peculiar

to its