Origin of Species Variorum

→ for many generations a 1872

a 1859 1860 1861 1866 1869

→ breed— 1872

breed for many generations— 1859 1860 1861

breed for many generations — 1866 1869

→ remnant 1872

very small proportion 1859 1860 1861 1866 1869

→ removed by some 1869 1872

some 1859 1860 1861 1866

→ the character in question 1869 1872

there 1859 1860 1861 1866

→ lying latent, and 1869 1872

a tendency to reproduce the character in question, which 1859 1860 1861 1866

→ is developed. 1869 1872

gains an ascendancy. 1859 1860 1861

gains an ascendency. 1866

→ With 1869 1872

For instance, it is probable that in each generation of 1859 1860 1861 1866

→ for instance, which very rarely produces 1869 1872

which produces most rarely 1859 1860 1861 1866

→ bird, it is probable that there is a latent tendency 1872

and black-barred bird, there has been a tendency 1859 1860 1861 1866

bird, it is probable that a latent tendency exists 1869

→ to produce blue plumage. 1869 1872

in the plumage to assume this colour. 1859 1860 1861 1866

↑ 3 blocks not present in 1859 1860 1861 1866 1872; present in 1869

The possibility of characters long lying latent can be understood according to the hypothesis of pangenesis, which I have given in another work. The abstract improbability of a latent tendency being transmitted through a vast number of generations, is not greater than than of quite useless or rudimentary organs being thus transmitted. A mere tendency to produce a rudiment is indeed sometimes inherited.

→ The 1872

This view is hypothetical, but could be supported by some facts; and I can see no more 1859 1860 1861 1866

→ being transmitted through a vast 1872

to produce any character being inherited for an endless 1859 1860 1861 1866

→ is not greater than that of 1872

than in 1859 1860 1861 1866

→ similarly transmitted. 1872

as we all know them to be, thus inherited. 1859 1860 1861 1866

→ A 1872

Indeed, we may sometimes observe a 1859 1860 1861

Indeed, we may sometimes observe that a 1866

→ is indeed sometimes thus inherited. 1872

inherited: for instance, in the common snapdragon (Antirrhinum) a rudiment of a fifth stamen so often appears, that this plant must have an inherited tendency to produce it. 1859 1861

inherited: for instance, in the common snap-dragon (Antirrhinum) a rudiment of a fifth stamen so often appears, that this plant must have an inherited tendency to produce it. 1860

is inherited. 1866

→ to be 1872

on my theory, to have 1859 1860 1861 1866

on our theory, to be 1869

→ the varieties of two or more 1866 1869 1872

a variety of one 1859 1860 1861

→ each other, or that a variety of one species would resemble in certain 1872

in some of its 1859 1860 1861

each other, or that a variety of one species would resemble in some of its 1866

each other, or that a variety of some one species would resemble in certain 1869

→ and distinct species,— 1872

species; 1859 1860 1861

and distinct species, — 1866 1869

→ according to our 1869 1872

on my 1859 1860 1861 1866

→ exclu- sively due to analogous variation 1872

thus gained 1859 1860 1861 1866 1869

I presume that no one will doubt that this is a case of reversion, and not of a new yet analogous variation appearing in the several breeds. We

may

may,

think

think,

confidently come to this conclusion, because, as we have seen, these coloured marks are eminently liable to appear in the crossed offspring of two distinct and differently coloured breeds; and in this case there is nothing in the external conditions of life to cause the reappearance of the

slat-blue,

slaty-blue,

with the several marks, beyond the influence of the mere act of crossing on the laws of inheritance.

No doubt it is a very surprising fact that characters should

reappear

re-appear

after having been lost for many,

perhaps

probably

for hundreds of generations. But when a breed has been crossed only once by some other breed, the offspring occasionally show →for many generations a tendency to revert in character to the foreign →breed— some say, for a dozen or even a score of generations. After twelve generations, the proportion of blood, to use a common expression,

of any

from

one ancestor, is only 1 in 2048; and yet, as we see, it is generally believed that a tendency to reversion is retained by this →remnant of foreign blood. In a breed which has not been crossed, but in which both parents have lost some character which their progenitor possessed, the tendency, whether strong or weak, to reproduce the lost character

might

might,

be,

....

as was formerly remarked, for all that we can see to the contrary,

transmitted

be transmitted

for almost any number of generations. When a character which has been lost in a breed, reappears after a great number of generations, the most probable hypothesis is, not that

the offspring

one individual

suddenly takes after an ancestor →removed by some hundred

generations

gene- rations

generations,

distant,

....

but that in each successive generation →the character in question has been →lying latent, and at last, under unknown favourable conditions, →is developed. →With the barb-pigeon, →for instance, which very rarely produces a blue →bird, it is probable that there is a latent tendency in each generation →to produce blue plumage. ↑ →The abstract improbability

of such

a tendency →being transmitted through a vast number of generations, →is not greater than that of quite useless or rudimentary organs

being,

being

→similarly transmitted. →A mere tendency to produce a rudiment →is indeed sometimes thus inherited.

As all the species of the same genus are

supposed,

supposed

→to be descended from a common

parent,

progenitor,

it might be expected that they would occasionally vary in an analogous manner; so that →the varieties of two or more species would resemble →each other, or that a variety of one species would resemble in certain characters another →and distinct species,— this other species

being

being,

→according to our

view

view,

only a well-marked and permanent variety. But characters →exclu- sively due to analogous variation