Origin of Species Variorum

→ those naturally and those artificially produced, 1866 1869 1872

natural and artificial, 1859 1860 1861

→ has at some periods probably been 1866 1869 1872

is probably 1859 1860 1861

→ species have 1866 1869 1872

the number of species has 1859 1860 1861

→ i.e. 1866 1869 1872

i . e . 1859

I. e. 1860 1861

belief that each new variety, and ultimately each new species, is produced and maintained by having some advantage over those with which it comes into

compe- tition;

competition;

and the consequent extinction of

less-favoured

the less-favoured

forms almost inevitably follows. It is the same with our domestic

productions:

productions;

when a new and slightly improved variety has been raised, it at first

supplants

generally supplants

the less improved varieties in the same neighbourhood; when much improved it is transported far and near, like our short-horn cattle, and takes the place of other breeds in other countries. Thus the appearance of new forms and the disappearance of old forms, both →those naturally and those artificially produced, are bound together. In

certain

....

flourishing groups, the number of new specific forms which have been produced within a given time →has at some periods probably been greater than

that

the number

of the old

forms

specific forms

which have been exterminated; but we know that →species have not gone on indefinitely increasing, at least during the later geological

periods,

epochs,

that

that,

looking to later

times

times,

we may believe that the production of new forms has caused the extinction of about the same number of old forms.

The competition will generally be most severe, as formerly explained and illustrated by examples, between the forms which are most like each other in all respects. Hence the improved and modified descendants of a species will generally cause the extermination of the parent-species; and if many new forms have been developed from any one species, the nearest allies of that species, → i.e. the species of the same genus, will be the most liable to extermination. Thus, as I believe, a number of new species descended from one species, that is a new genus, comes to supplant an old genus, belonging to the same family. But it must often have happened