Origin of Species Variorum

→ old 1859 1860 1861 1866 1872

of these old 1869

→ parent-forms having occasionally 1859 1860 1861 1866

forms having 1869

forms have 1872

→ will give to us 1859 1860 1861 1866

constitute 1869

these constitute 1872

→ on my theory 1859 1860 1861 1866

OMIT 1869 1872

→ by 1859 1860 1861 1866 1869

as at present by 1872

→ but such richness in species, as I find after some investigation, does not commonly fall to the lot of aberrant genera. 1859 1860 1861 1866

or by one or two. 1869

or by two or three. 1872

→ failing groups 1859 1860 1861 1866

forms which have been 1869 1872

→ preserved by some unusual coincidence of favourable circumstances. 1859 1860 1861 1866

still preserved under unusually favourable conditions. 1869 1872

→ of the bizcacha to Marsupials 1859 1860 1861 1866

OMIT 1869 1872

→ are due on my theory 1859 1860 1861 1866

must be due in accordance with our view 1869 1872

→ in common. 1859 1860 1861 1866

from a common progenitor. 1869 1872

→ have had a character in some degree intermediate 1859 1860 1861

naturally have been more or less intermediate in character 1866 1869 1872

→old and intermediate →parent-forms having occasionally transmitted to the present day descendants but little modified, →will give to us our so-called osculant or aberrant

species.

groups.

The more aberrant any form is, the greater must be the number of connecting forms which →on my theory have been exterminated and utterly lost. And we have some evidence of aberrant

groups

forms

having suffered severely from extinction, for they are

almost always

generally

represented by extremely few species; and such species as do occur are generally very distinct from each other, which again implies extinction. The genera Ornithorhynchus and Lepidosiren, for example, would not have been less aberrant had each been represented by a dozen

species,

species

instead of →by a single

one,

one;

→but such richness in species, as I find after some investigation, does not commonly fall to the lot of aberrant genera. We can, I think, account for this fact only by looking at aberrant

groups

forms

as →failing groups conquered by more successful competitors, with a few members →preserved by some unusual coincidence of favourable circumstances.

Mr. Waterhouse has remarked that, when a member belonging to one group of animals exhibits an affinity to a quite distinct group, this affinity in most cases is general and not special: thus, according to Mr. Waterhouse, of all Rodents, the bizcacha is most nearly related to Marsupials; but in the points in which it approaches this order, its relations are general, and not to any one marsupial species more than to another. As

these

the

points of affinity →of the bizcacha to Marsupials are believed to be real and not merely adaptive, they →are due on my theory to inheritance →in common. Therefore we must suppose either that all Rodents, including the

biz- cacha,

bizcacha,

branched off from some

~~very~~

very

ancient Marsupial, which will →have had a character in some degree intermediate with respect to all existing Marsupials; or