Origin of Species Variorum

→ a 1859 1860 1861 1866 1869

for many generations a 1872

→ breed for many generations — 1866 1869

breed for many generations— 1859 1860 1861

breed— 1872

→ very small proportion 1859 1860 1861 1866 1869

remnant 1872

→ 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 a latent tendency exists 1869

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

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

→ to produce blue plumage. 1869 1872

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

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

re-appear

reappear

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 →a tendency to revert in character to the foreign →breed for many generations — some say, for a dozen or even a score of generations. After twelve generations, the proportion of blood, to use a common expression,

from

of any

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 →very small proportion 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,~~

be,

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

be transmitted

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

one individual

the offspring

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 a latent tendency exists in each generation →to produce blue plumage. 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