Origin of Species Variorum

↑ 1 blocks not present in 1861 1866 1869 1872; present in 1859 1860

Although naturalists very properly demand a full explanation of every difficulty from those who believe in the mutability of species, on their own side they ignore the whole subject of the first appearance of species in what they consider reverent silence.

→ fall away 1859 1860 1861 1866 1869

in favour of community of descent become fewer in number and less 1872

→ groups. 1859 1860 1861 1866 1869

groups. Fossil remains sometimes tend to fill up very wide intervals between existing orders. 1872

→ a very early 1869 1872

an embryonic 1859 1860 1861 1866

→ class. 1859 1860 1861 1866 1869

great class or kingdom. 1872

→ OMIT 1861 1866 1869 1872

germinal vesicles, their 1859 1860

→ their liability to injurious influences. 1861 1866 1869 1872

reproduction. 1859 1860

axiom "of least action" leads the mind more willingly to admit the smaller number; and certainly we ought not to believe that innumerable beings within each great class have been created with plain, but deceptive, marks of descent from a single parent. ↑

It may be asked how far I extend the doctrine of the modification of species. The question is difficult to answer, because the more distinct the forms are which we

may

....

consider, by so much the arguments →fall away in force. But some arguments of the greatest weight extend very far. All the members of whole classes

can be

are

connected together by

chains

a chain

of affinities, and all can be

classed

classified

on the same principle, in groups

sub-ordinate

subordinate

to →groups. Fossil remains sometimes tend to fill up very wide intervals between existing orders. Organs in a rudimentary condition plainly show that an early progenitor had the organ in a fully developed

condition;

state;

and this in some

instances necessarily

cases

instances

implies an enormous amount of modification in the descendants. Throughout whole classes various structures are formed on the same pattern, and at →a very early age the

species

embryos

closely resemble each other. Therefore I cannot doubt that the theory of descent with modification embraces all the members of the same →class. I believe that animals

have

are

descended from at most only four or five progenitors, and plants from an equal or lesser number.

Analogy would lead me one step

further,

farther,

namely, to the belief that all animals and plants

have

are

descended from some one prototype. But analogy may be a deceitful guide. Nevertheless all living things have much in

common,

common,—