Origin of Species Variorum

→ new varieties arising, which have 1859 1860 1861 1866

having 1869 1872

→ would naturally oftenest give rise to 1859 1860 1861 1866

would be the most likely to give birth to the greatest number of 1869

give birth to the greatest number of 1872

→ and 1861 1866 1869 1872

in their own homes, and are 1859 1860

→ compared with other less dominant plants, producing 1866

having produced 1859 1860

compared with other plants within their own homes, having produced 1861

producing 1869 1872

→ or on the gradual acclimatisation of new species to the various climates through which they have to pass, but 1866

but 1859 1860

or on the gradual acclimatisation of new species to the various climates through which they must pass, but 1861

and on the gradual acclimatisation of new species to the various climates through which they might have to pass, but 1869 1872

→ course of time 1866 1869 1872

long run 1859 1860 1861

→ spreading. 1859 1860 1861 1866

spreading and would ultimately prevail. 1869 1872

other causes more or less local and temporary, but depend on general laws which govern the whole animal kingdom." M. Barrande has made forcible remarks to precisely the same effect. It is, indeed, quite futile to look to changes of currents, climate, or other physical conditions, as the cause of these great mutations in the forms of life throughout the world, under the most different climates. We must, as Barrande has remarked, look to some special law. We shall see this more clearly when we treat of the present distribution of organic beings, and find how slight is the relation between the physical conditions of various

countries

countries,

and the nature of their inhabitants.

This great fact of the parallel succession of the forms of life throughout the world, is explicable on the theory of natural selection. New species are formed by →new varieties arising, which have some advantage over older forms; and

the

those

forms, which are already dominant, or have some advantage over the other forms in their own country, →would naturally oftenest give rise to new varieties or incipient

species;

for

these

latter

must

victorious

still

higher

degree

order

preserved

and

survive.

We have distinct evidence on this head, in the plants which are dominant, that is, which are commonest →and most widely diffused, →compared with other less dominant plants, producing the greatest number of new varieties. It is also natural that the

domi- nant,

dominant,

varying, and far-spreading species, which

have already

already have

invaded to a certain extent the territories of other species, should be those which would have the best chance of spreading still further, and of giving rise in new countries to

other new

new

varieties and species. The process of diffusion

would

may

often be very slow,

~~being~~

being

depending

dependent

on climatal and geographical changes,

on strange accidents, →or on the gradual acclimatisation of new species to the various climates through which they have to pass, but in the →course of time the dominant forms

would

will

generally succeed in →spreading.