Origin of Species Variorum

→ and at that time less differentiated vertebrate 1869 1872

vertebrate 1859 1860 1861

and then less differentiated vertebrate 1866

→ for instance 1872

as in that of 1859 1860 1861 1866

as with 1869

→ and only partially 1866 1869 1872

but 1859 1860 1861

→ still 1869 1872

from other groups, as all would blend together by steps as fine as those between the finest existing varieties, nevertheless 1859 1860

from other groups, as all would blend together by steps as fine as those between existing varieties, nevertheless 1861

from other groups, as all would be blended together by steps as fine as those between existing varieties, nevertheless 1866

→ with every 1869 1872

Every intermediate link between these eleven genera and their primordial parent, and every intermediate 1859 1860 1861 1866

→ OMIT 1869 1872

of their descendants, may be supposed to be 1859 1860 1861 1866

→ not greater than 1869 1872

to be as fine as 1859 1860 1861 1866

→ and descendants. 1869 1872

or these parents from their ancient and unknown progenitor. 1859 1860 1861 1866

→ would be natural; for, on 1869 1872

on 1859 1860 1861 1866

→ for instance, from A, 1869 1872

from A, or from I, 1859 1860 1861 1866

→ Assuredly we shall 1869 1872

We shall certainly 1859 1860

We shall assuredly 1861 1866

difficulty which naturalists have experienced in describing, without the aid of a diagram, the various affinities which they perceive between the many living and extinct members of the same great natural class.

Extinction, as we have seen in the fourth chapter, has played an important part in defining and widening the intervals between the several groups in each class. We may thus account

even

....

for the distinctness of whole classes from each other— for instance, of birds from all other vertebrate animals— by the belief that many ancient forms of life have been utterly lost, through which the early progenitors of birds were formerly connected with the early progenitors of the other →and at that time less differentiated vertebrate classes. There has been

less entire

less complete

much less

extinction of the forms of life which once connected fishes with batrachians. There has been still less

within

some

other

whole

classes, →for instance the Crustacea, for here the most

wonder-fully

wonderfully

diverse forms are still

tied

linked

together by

long,

long

→and only partially

broken,

broken

chains

chain

of affinities. Extinction has only

separated

defined the

the groups:

groups:

it has by no means made them; for if every form which has ever lived on this earth were suddenly to reappear, though it would be quite impossible to give definitions by which each group could be

distinguished

distinguished,

→still a natural classification, or at least a natural arrangement, would be possible. We shall see this by turning to the

diagram:

diagram;

the letters, A to L, may represent eleven Silurian genera, some of which have produced large groups of modified

descendants.

descendants,

→with every link in each branch and sub-branch →OMIT still alive; and the links →not greater than those between

the finest

existing

varieties. In this case it would be quite impossible to give

any

....

definition

definitions

by which the several members of the several groups could be distinguished from their more immediate

parents;

parents

→and descendants. Yet the

natural

....

arrangement in the diagram would still hold

good;

good

and,

and

→would be natural; for, on the principle of inheritance, all the forms

descended

descended,

→for instance, from A, would have something in common. In a tree we can

specify

distinguish

this or that branch, though at the actual fork the two unite and blend together. We could not, as I have said, define the several groups; but we could pick out types, or forms, representing most of the characters of each group, whether large or small, and thus give a general idea of the value of the differences between them. This is what we should be driven to, if we were ever to succeed in collecting all the forms in any

class

one class

which have lived throughout all time and space. →Assuredly we shall never succeed in making so perfect a collection: nevertheless, in certain classes, we are tending

towards

this

direction;

end;

and Milne Edwards has lately insisted, in an able paper, on