Origin of Species Variorum

→ suppose 1859 1860 1861 1866 1869

in addition suppose 1872

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

Mr. Bates, in his most interesting 'Naturalist on the Amazons,' has described some analogous cases.

→ parents, 1859 1860 1861 1866

ants or parents, 1869 1872

→ jaws having a 1859 1860 1861 1866 1869

OMIT 1872

→ simultaneously 1859 1860 1861 1866 1872

at the same time 1869

→ from being the most useful to the community, 1859 1860 1861

OMIT 1866 1869 1872

→ in greater and greater numbers 1859 1860 1861

in greater and greater numbers, 1869 1872

OMIT 1866

→ until 1859 1860 1861 1869 1872

in greater and greater numbers, until 1866

→ Thus, 1859 1860 1861

I have now explained how, 1866 1869 1872

house,

house

of whom many were five feet four inches high, and many sixteen feet high; but we must →suppose that the larger workmen had heads four instead of three times as big as those of the smaller men, and jaws nearly five times as big. The jaws, moreover, of the working ants of the several sizes differed wonderfully in shape, and in the form and number of the teeth. But the important fact for us is,

that,

that

though the workers can be grouped into castes of different sizes, yet they graduate insensibly into each other, as does the widely-different structure of their jaws. I speak confidently on this latter point, as

Sir J.

Mr.

Lubbock made drawings for

me,

with the camera

lucida,

lucida

of the jaws which I

~~had~~

had

dissected from the workers of the several sizes. ↑

With these facts before me, I believe that natural selection, by acting on the fertile →parents, could form a species which should regularly produce neuters,

~~either~~

either

all of large size with one form of jaw, or all of small size with →jaws having a widely different

jaws;

structure;

or lastly, and this is

the

our

climax of difficulty, one set of workers of one size and structure, and →simultaneously another set of workers of a different size and structure;— a graduated series having

first been

been first

formed, as in the case of the driver ant, and then the extreme

forms

forms,

→from being the most useful to the community, having been produced →in greater and greater numbers through the

survival

natural selection

of the parents which generated

them,

them;

→until none with an intermediate structure were produced.

→Thus, as I believe, the wonderful fact of two distinctly defined castes of sterile workers existing in the same nest, both widely different from each other and from their parents, has originated. We can see how useful their production may have been to a social community of

ants,

insects,

on the same principle that the division of