Origin of Species Variorum

→ trans- port,— 1869

transport,— a subject which has hardly ever been properly experimentised on; 1859 1860

transport,— a subject which has hardly ever been properly experimented on; 1861 1866

transport,— 1872

→ how 1859 1860 1861 1866 1869

and this is a very important consideration, how 1872

→ tracts,— 1869 1872

tracts, I think 1859 1860

tracts, 1861 1866

→ is not insuperable in 1869 1872

in 1859 1860 1861 1866

→ common parents. 1869 1872

the same parents, are not insuperable. 1859 1860 1861 1866

→ of all kinds, and 1869 1872

and 1859 1860 1861 1866

→ have changed very 1869 1872

change most 1859 1860 1861 1866

→ OMIT 1869 1872

I do not think that 1859 1860 1861 1866

→ far from insuperable; though 1869 1872

insuperable; though they often are 1859 1860 1861 1866

→ they are often great. 1869 1872

extremely grave. 1859

extremely great. 1860 1861 1866

→ a part the 1869

has been the influence of the modern 1859 1860 1861 1866

a part the last 1872

which I am fully convinced simultaneously affected the whole world, or at least great meridional belts. 1859 1860

which I am fully convinced simultaneously affected the whole world, or at least great longitudinal belts. 1861 1866

has played, which affected even the equatorial regions, and which, during the alternations of the cold in the north and south, allowed the productions of opposite hemispheres to mingle, and left some of them stranded on the mountain-summits in all parts of the world. 1872

→ the several species belong- ing to the same genus, 1869

allied species, 1859 1860 1861 1866

the several species belonging to the same genus, 1872

the many

and

....

curious means of occasional →trans- port,— if we bear in

mind,

mind

→how often a species may have ranged continuously over a wide area, and then have become extinct in the intermediate →tracts,— the

difficulties

difficulty

→is not insuperable in believing that all the individuals of the same species, wherever

located, have

found, are

descended from →common parents. And we are led to this conclusion, which has been arrived at by many naturalists under the designation of single centres of creation, by

some

various

general considerations, more especially from the importance of barriers →of all kinds, and from the analogical distribution of sub-genera, genera, and families.

With respect to

the

....

distinct species

belonging to

the same genus, which on

our

theory

~~must~~

must

have spread from one parent-source; if we make the same

allowances

allowance

as before for our ignorance, and remember that some forms of life →have changed very slowly, enormous periods of time

being

having been

thus granted for their migration, →OMIT the difficulties are →far from insuperable; though in this case,

and

in that of the individuals of the same species, →they are often great.

As exemplifying the effects of climatal changes on distribution, I have attempted to show how important →a part the Glacial

period,

period

→has played, which affected even the equatorial regions, and which, during the alternations of the cold in the north and south, allowed the productions of opposite hemispheres to mingle, and left some of them stranded in all parts of the world on the mountain-summits. As showing how diversified are the means of occasional transport, I have discussed at some little length the means of dispersal of fresh-water productions.

If the difficulties be not insuperable in admitting that in the long course of time

the

all the

individuals of the same species, and likewise of →the several species belong- ing to the same genus, have proceeded from