Origin of Species Variorum

→ vertebrate 1859 1860 1861

and then less differentiated vertebrate 1866

and at that time less differentiated vertebrate 1869 1872

→ as in that of 1859 1860 1861 1866

as with 1869

for instance 1872

→ but 1859 1860 1861

and only partially 1866 1869 1872

→ 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 blend together by steps as fine as those between the finest existing varieties, nevertheless 1859 1860

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

still 1869 1872

circuitous lines of affinity of various lengths (as may be seen in the diagram so often referred to), mounting up through many predecessors. As it is difficult to show the blood-relationship between the numerous kindred of any ancient and noble

family

family,

even by the aid of a genealogical tree, and almost impossible to do

this

without this aid, we can understand the

extra- ordinary

extraordinary

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~~

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 →vertebrate classes. There has been

less complete

much less

less entire

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

within

some

whole

other

classes, →as in that of the Crustacea, for here the most

wonderfully

wonder-fully

diverse forms are still

linked

tied

together by

....

long

long,

→but

broken,

broken

chain

chains

of affinities. Extinction has only

defined the

separated

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

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