Origin of Species Variorum

→ from ordinary single varieties only 1869

only 1866

OMIT 1872

→ the two forms. 1869

OMIT 1872

two forms, from ordinary single varieties. 1866

→ the fertile plants 1869

these single and fertile plants 1866

These latter, by which alone the variety can be propagated, 1872

→ producing single flowers may 1869

may 1866 1872

→ of an ant-community, 1866 1869

ants, 1872

→ sterile double-flowered plants, which are regularly produced in large numbers, 1866 1869

double sterile plants 1872

↑ 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

plants.

plants,

~~which~~

which

~~differ~~

differ

→from ordinary single varieties only

~~their~~

their

~~power~~

power

~~producing~~

producing

→the two forms.

~~Thus~~

Thus

→the fertile plants →producing single flowers may be compared with the

fertile male

males

and

female

females

→of an ant-community, and the →sterile double-flowered plants, which are regularly produced in large numbers, with the

~~many sterile~~

many sterile

neuters of the same community. ↑ →Thus I believe it has been with social insects: a slight

modifications

modification

structure

structure,

instinct,

of 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

many

so 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

Myrme- cocystus,

Myrmecocystus,

the workers of one caste never leave the nest; they are fed by the workers of another caste, and they have an enormously developed abdomen which