Origin of Species Variorum

→ remembered 1860 1861 1866

borne in mind 1869 1872

→ examples: 1860 1861 1866

illustrations of the foregoing remarks: 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

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

→ and it is obvious that 1860

whereas of the 11 1861 1866 1869 1872

→ could 1860

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

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

→ 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

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

occasionally visit 1866

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 their proper places and habits, and will consequently have been little liable to modification. 1859 1860 1861

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; 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

→ far more easily than land- shells, across three or four hundred miles of open sea. 1860

far more easily than land-shells, across three or four hundred miles of open sea. 1859 1861 1866

across three or four hundred miles of open sea far more easily than land-shells. 1869 1872

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

peculiar,

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,

→during their great annual migrations, visit either periodically or occasionally this island. Madeira does not possess one peculiar bird, and many European and African birds are almost every year blown there, as I am informed by Mr. E. V. Harcourt. So that

the two

the

these 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 their proper places 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

peculiar

confined

to its

shores;

shores:

now, though we do not know how sea-shells are dispersed, yet we can see that their eggs or larvæ, perhaps attached to

sea-weed

seaweed

or floating timber, or to the feet of wading-birds, might be transported →far more easily than land- shells, across three or four hundred miles of open sea.