Origin of Species Variorum

→ which 1872

must either have appeared at an earlier period than usual, or, if not so, the differences must 1859 1860 1861 1869

which give value to each breed, and which 1866

→ accumulated by man's selection, and which give value to his breeds, do not generally appear 1872

inherited, not at the corresponding, but 1859 1860 1861

accumulated by man's selection, have not generally first appeared 1866

inherited, not at a corresponding, but 1869

→ early period of life, and are inherited at a corresponding not early period. 1872

earlier age. 1859 1860 1861 1869

early period of life, and have been inherited by the offspring at a corresponding not early period. 1866

→ two principles 1869 1872

facts and the above two principles— which latter, though not proved true, can be shown to be in some degree probable— 1859 1860 1861

facts and the above two principles 1866

→ OMIT 1869 1872

on my theory 1859 1860 1861 1866

→ ancient form and 1869 1872

one parent-species, and of which the several new species have become 1859 1860 1861 1866

→ for different 1869 1872

in accordance with their diverse 1859 1860 1861 1866

→ in the several species at a not early 1869 1872

at a rather late 1859 1860 1861 1866

→ will have been but little modified, and they will still 1872

of the new species of our supposed genus will manifestly tend to 1859 1860 1861 1866

will be left but little modified and will 1869

→ widely distinct structures and to whole 1869 1872

whole families or even 1859 1860 1861 1866

→ to a remote progenitor, may have become, through 1869 1872

in the parent-species, may become, by 1859

in the parent-species, may have become, by 1860 1861 1866

→ principles 1869 1872

principles— namely of each successive modification supervening at a rather late age, and being inherited at a corresponding late age— 1859 1861 1866

principles— namely of each successive modification supervening at a rather late age, and being inherited at a corre- sponding late age— 1860

→ will not have been much modified in 1869 1872

in 1859 1860 1861 1866

→ forms; although in each form the fore-limb will differ greatly in the adult state. 1872

descendants of the parent-species will still resemble each other closely, for they will not have been modified. 1859 1860 1866

descendants of the parent species will still resemble each other closely, for they will not have been modified. 1861

forms; although in each the embryonic fore-limb will differ greatly from that in the adult. 1869

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

But in each individual new species, the embryonic fore-limbs will differ greatly from the fore-limbs in the mature animal; the limbs in the latter having undergone much modification at a rather late period of life, and having thus been converted into hands, or paddles, or wings.

→ long-continued use or disuse 1872

long-continued exercise or use on the one hand, and disuse on the other, 1859 1860 1861

long-continued exercise or disuse 1866

moreover, long-continued use or disuse 1869

→ had in modifying the limbs or other parts of any species, this will chiefly or solely have affected it when nearly mature, when it was compelled to use its 1872

in modifying an organ, such influence will mainly affect the mature animal, which has come to its 1859 1860 1861

had in modifying an organ, such influence will mainly affect the mature animal, which has come to its 1866

had in modifying the limbs or other parts of animals, this will chiefly or solely have affected them when mature and when they had to use their 1869

→ OMIT 1869 1872

of activity and has 1859 1860 1861 1866

→ have been transmitted to the offspring 1872

be inherited 1859 1860 1861 1866

be transmitted to the offspring 1869

→ not be modified, or 1872

remain unmodified, or 1859 1860 1861 1866

not 1869

→ will be modified only 1872

be modified 1859 1860 1861 1866 1869

→ in a slight degree, through the effects of the increased use or disuse of parts. 1872

in a lesser degree, by the effects of use and disuse. 1859 1860 1861 1866

or will be modified in a less degree. 1869

→ With some animals 1872

In certain cases 1859 1860 1861 1866

In other cases 1869

→ variations may have supervened 1869 1872

steps of variation might supervene, from causes of which we are wholly ignorant, 1859 1860 1861 1866

→ may have been 1869 1872

might be 1859 1860 1861 1866

→ of these cases, 1872

case (as with the short-faced tumbler) 1859 1860 1861 1866

case, as we have seen with the short-faced tumbler, 1869

→ parent-form, as we have seen with the short-faced tumbler. 1872

parent-form. 1859 1860 1861 1866 1869

→ And 1869 1872

We have seen that 1859 1860 1861 1866

→ or in certain sub-groups alone, 1872

of animals, 1859 1860 1861 1866

or sub-groups, 1869

→ land-shells, fresh-water crustaceans, 1866 1869 1872

and 1859 1860 1861

→ some 1869 1872

with a few 1859 1860 1861 1866

→ such groups not passing through 1872

these cases not undergoing 1859 1860 1861 1866

these groups not passing through 1869

→ OMIT 1866 1869 1872

or closely resembling their parents from their earliest age, 1859 1860 1861

the characteristic differences →which have been →accumulated by man's selection, and which give value to his breeds, do not generally appear at

a very

→early period of life, and are inherited at a corresponding not early period. But the case of the short-faced tumbler, which when twelve hours old

had acquired

possessed

its proper

proportions,

characters,

proves that this is not the universal rule; for here the characteristic differences must either have appeared at an earlier period than usual, or, if not so, the differences must have been inherited, not at

the

corresponding, but at an earlier age.

Now let us apply these →two principles to species in a state of nature. Let us take a

genus

group

of birds, descended →OMIT from some →ancient form and modified through natural selection →for different habits. Then, from the many slight successive

steps of

....

variation

variations

having supervened →in the several species at a not early age, and having been inherited at a corresponding age, the young →will have been but little modified, and they will still resemble each other much more closely than do the

adults,

adults,—

just as we have seen

with

the

case

breeds

pigeons.

the pigeon.

We may extend this view to →widely distinct structures and to whole classes. The fore-limbs, for instance, which

served

once served

as legs →to a remote progenitor, may have become, through a long course of modification, adapted in one descendant to act as hands, in another as paddles, in another as wings;

and

but

on the above two →principles the fore-limbs →will not have been much modified in the embryos of

the

these

several →forms; although in each form the fore-limb will differ greatly in the adult state. ↑ Whatever

influence,

influence

→long-continued use or disuse may have →had in modifying the limbs or other parts of any species, this will chiefly or solely have affected it when nearly mature, when it was compelled to use its full powers →OMIT

had to

gain

their

its

own living; and the

effect

effects

thus produced will →have been transmitted to the offspring at

the

corresponding

mature

nearly mature