Origin of Species Variorum

→ With 1859 1860 1861

When we reflect on 1866 1869 1872

→ and imperfectly given, which show that there is much graduated diversity 1859 1860

and imperfectly given, which show how much graduated diversity 1861

and imperfectly, with respect to the wide, diversified, and graduated range of structure 1866

with respect to the wide, diversified, and graduated range of structure 1869 1872

→ in 1859 1860 1866 1869 1872

there is in 1861

→ living crustaceans, and bearing 1859 1860

our existing crustaceans, and bearing 1861

the existing Articulata; and when we bear 1866

the lower animals; and when we bear 1869 1872

→ living animals is in proportion to 1859 1860 1861

all living forms must be in comparison with 1866 1872

all the forms now living must be in comparison with 1869

→ I can see no 1859 1860 1861

the difficulty ceases to be 1866 1869 1872

→ difficulty (not more than in the case of many other structures) 1859 1860 1861

(not more so than in the case of many other structures) 1866

OMIT 1869 1872

→ if 1859 1860 1861 1866

ought not to hesitate to go one step further, if 1869 1872

→ descent, ought not to hesitate to go further, and 1859 1860 1861

descent with modification, ought not to hesitate to go further, and 1866

descent with modification; he ought 1869

modification through natural selection; he ought 1872

→ the eye of 1859 1860 1861 1866

OMIT 1869 1872

→ might 1859 1860 1861 1866

eye might 1869

eye might thus 1872

→ by natural selection, 1859 1860 1861 1866 1869

OMIT 1872

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

It has been objected that in order to modify the eye and still preserve it as a perfect instrument, many changes would have to be effected simultaneously, which, it is assumed, could not be done through natural selection; but as I have attempted to show in my work on the variation of domestic animals, it is not necessary to suppose that all the modifications were simultaneous, if they were extremely slight and gradual.

→ His reason ought to conquer his imagination; though 1859 1860 1861

To arrive, however, at a just conclusion regarding the formation of the eye, with all its marvellous yet not absolutely perfect characters, it is indispensable that the reason should conquer the imagination; but 1872

→ any degree of hesitation in extending 1859 1860 1861

others hesitating to extend 1872

→ a 1859 1860

spaces filled with fluid, and with a 1861 1866 1869 1872

→With these facts, here

given

given much

~~far~~

far

too

briefly,

briefly

→and imperfectly given, which show that there is much graduated diversity →in the eyes of →living crustaceans, and bearing in mind how small the number of →living animals is in proportion to those which have become extinct, →I can see no very great →difficulty (not more than in the case of many other structures) in believing that natural selection

may have

has

converted the simple apparatus of an optic

nerve,

nerve

~~merely~~

merely

coated with pigment and invested by transparent membrane, into an optical instrument as perfect as is possessed by any member of the

~~great~~

great

Articulate

Class.

class.

He who will go thus far, →if he

should find

finds

find

on finishing this

volume

treatise

that large bodies of facts, otherwise inexplicable, can be explained by the theory of →descent, ought not to hesitate to go further, and to admit that a structure even as perfect as →the eye of an

eagles

eagle's

eagle

→might

have been

formed,

formed

→by natural selection, although in this case he does not know

~~any of~~

any of

the transitional

steps.

states.

grades.

↑ →His reason ought to conquer his imagination; though I have felt the difficulty far too keenly to be surprised at →any degree of hesitation in extending the principle of natural selection to

such

startling

a length.

lengths.

It is scarcely possible to avoid comparing the eye

with

a telescope. We know that this instrument has been perfected by the long-continued efforts of the highest human intellects; and we naturally infer that the eye has been formed by a somewhat analogous process. But may not this inference be presumptuous? Have we any right to assume that the Creator works by intellectual powers like those of man? If we must compare the eye to an optical instrument, we ought in imagination to take a thick layer of transparent tissue, with →a nerve sensitive to light beneath, and then suppose every part of this layer to be continually changing