Origin of Species Variorum

→ in 1859 1860 1861

may be placed in 1866 1869 1872

→ I do not doubt that 1859 1860 1861

probably 1866 1869

OMIT 1872

→ be slowly 1859 1860 1861 1866 1869

it is probable, be 1872

↑ 2 blocks not present in 1859 1860 1861; present in 1866 1869 1872

Here is a better and real illustration: according to M. Verlot, some varieties of the double annual stock of various colours, from having been long carefully selected to the right degree, always produce by seed a large proportion of plants bearing double and quite sterile flowers; so that, if the variety had not yielded others, it would at once have become extinct; but it likewise always yields some single and fertile plants, which differ only in their power of producing which differ only in their power of producing two forms, from ordinary single varieties. Thus these single and fertile plants may be compared with the males and females of an ant-community, and the sterile double-flowered plants, which are regularly produced in large numbers, with the many sterile neuters of the same community.

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

As with the varieties of the stock, so with social insects, selection has been applied to the family, and not to the individual, for the sake of gaining a serviceable end.

→ Thus I believe it has been with social insects: a 1859 1860 1861 1866 1869

Hence we may conclude that 1872

→ has been advantageous to the community: 1859 1860 1861 1866 1869

have proved advantageous: 1872

→ of the same community 1859 1860 1861 1866 1869

have 1872

→ And I believe that 1859 1860 1861 1866 1869

OMIT 1872

→ until 1859 1860 1861 1866 1869

many times, until 1872

~~I have~~

I have

Such

such

faith →in the

power

powers

of selection, that →I do not doubt that a breed of cattle, always yielding oxen with extraordinarily long horns,

could,

could

→be slowly formed by carefully watching which individual bulls and cows, when matched, produced oxen with the longest horns; and yet no one ox

would

could

ever have propagated its kind. ↑ ↑ →Thus I believe it has been with social insects: a slight

modifications

modification

structure

structure,

of instinct,

instinct,

correlated with the sterile condition of certain members of the community, →has been advantageous to the community: consequently the fertile males and females →of the same community flourished, and transmitted to their fertile offspring a tendency to produce sterile members

with

having

the same

modifications.

modification.

→And I believe that

This

this

process

must have

has

been

repeated

repeated,

→until that prodigious amount of difference between the fertile and sterile females of the same species has been produced, which we see in

so many

many

social insects.

But we have not as yet touched on the climax of the difficulty; namely, the fact that the neuters of several ants differ, not only from the fertile females and males, but from each other, sometimes to an almost incredible degree, and are thus divided into two or even three castes. The castes, moreover, do not

commonly

generally

graduate into each other, but are perfectly well defined; being as distinct from each

other

other,

as are any two species of the same genus, or rather as any two genera of the same family. Thus in Eciton, there are working and soldier neuters, with jaws and instincts extraordinarily different: in Cryptocerus, the workers of one caste alone carry a wonderful sort of shield on their heads, the use of which is quite unknown: in the Mexican

Myrmecocystus,

Myrme- cocystus,