Origin of Species Variorum

→ populi , 1861 1872

populi, 1866 1869

→ very imperfect and simple, 1859 1860 1861

imperfect and simple, 1866

perfect and complex, 1869

complex and perfect can be shown to exist, 1872

→ can be shown to exist; 1859 1860 1861 1866

can be shown to exist, 1869

as is certainly the case; 1872

→ if 1859 1860 1861 1866 1872

as is certainly the case; if 1869

→ does vary ever so slightly, 1859 1860 1861

does vary ever so slightly 1866

ever slightly varies, 1869

ever varies 1872

→ or modification in the organ be ever 1859 1860 1861 1866

should ever be 1869

should be 1872

→ real. 1859 1860 1861 1866 1869

as subversive of the theory. 1872

→ several facts make me suspect that nerves sensitive to touch may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound. 1861

several facts make me suspect that any sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound. 1859 1860

as some of the lowest organisms, in which nerves cannot be detected, are known to be sensitive to light, it does not seem impossible that certain elements in their tissues or sarcode should have become aggregated and developed into nerves endowed with special sensibility to its action. 1866

as some of the lowest organisms, in which nerves cannot be detected, are known to be sensitive to light, it does not seem impossible that certain elements in the sarcode, of which they are mainly composed, should become aggregated and developed into nerves endowed with this special sensibility. 1869

as some of the lowest organisms, in which nerves cannot be detected, are capable of perceiving light, it does not seem impossible that certain sensitive elements in their sarcode should become aggregated and developed into nerves, endowed with this special sensibility. 1872

→ in each case 1859 1860 1861 1866

OMIT 1869 1872

→ species 1859 1860 1861

other species and genera 1866 1869 1872

→ from the earlier stages of descent, 1859 1860 1861 1866

OMIT 1869 1872

suppose that the

eye

eye,

with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest

~~possible~~

possible

degree. When it was first said that the sun stood still and the world turned round, the common sense of mankind declared the doctrine false; but the old saying of Vox → populi , vox

Dei,

Dei ,

as every philosopher knows,

cannot

can never

be trusted in science.

Yet

....

reason

Reason

tells me, that if numerous gradations from

imperfect

simple

perfect

and

simple

imperfect

complex

eye to one →very imperfect and simple, each grade being useful to its possessor, →can be shown to exist; →if further, the eye →does vary ever so slightly, and the variations be inherited,

which

likewise certainly

certainly

the case; and if

such

any

variations

variation

→or modification in the organ be ever useful to

any

animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could

have been

formed by natural selection, though insuperable by our imagination,

cannot

should not

can hardly

be considered →real. How a nerve comes to be sensitive to light, hardly concerns us more than how life itself

~~first~~

first

originated; but I may remark

that,

that

→several facts make me suspect that nerves sensitive to touch may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound.

searching

looking

for the gradations

through

which

any

organ in any species has been perfected, we ought to look exclusively to its lineal

progenitors;

ancestors;

but this is scarcely ever possible, and we are forced →in each case to look to →species of the same group, that is to the collateral descendants from the same

~~original~~

original

parent-form, in order to see what gradations are possible, and for the chance of some gradations having been transmitted →from the earlier stages of descent, in an unaltered or little altered

condition.

condi- tion.