Origin of Species Variorum

→ having been effected through 1869 1872

being effected by 1859 1860 1861 1866

→ ordinary animal, 1869 1872

animal in the ordinary state, 1859 1860 1861 1866

→ which were 1869 1872

of structure, this being 1859 1860 1861 1866

→ and that these 1869 1872

which 1859 1860 1861 1866

→ inherited structure which are correlated with 1869 1872

structure which have become correlated to 1859 1860 1861 1866

rendered sterile is a difficulty; but not much greater than that of any other striking modification of structure; for it can be shown that some insects and other articulate animals in a state of nature occasionally become sterile; and if such insects had been social, and it had been profitable to the community that a number should have been annually born capable of work, but incapable of procreation, I can see no

very great

especial

difficulty in this →having been effected through natural selection. But I must pass over this preliminary difficulty. The great difficulty lies in the working ants differing widely from both the males and the fertile females in structure, as in the shape of the

thorax

thorax,

and in being destitute of wings and sometimes of eyes, and in instinct. As far as instinct alone is concerned, the

prodigious

wonderful

difference in this respect between the workers and the perfect females, would have been

far

....

better exemplified by the hive-bee. If a working ant or other neuter insect had been an →ordinary animal, I should have unhesitatingly assumed that all its characters had been slowly acquired through natural selection; namely, by

....

individual

individuals

having been born with

some

....

slight profitable

modification

modifications,

→which were inherited by

its

the

offspring,

offspring;

→and that these again varied and

were again

again were

selected, and so

on wards.

onwards.

But with the working ant we have an insect differing greatly from its parents, yet absolutely

sterile,

sterile;

so that it could never have transmitted successively acquired modifications of structure or instinct to its progeny. It may well be asked how is it possible to reconcile this case with the theory of natural selection?

First, let it be remembered that we have innumerable instances, both in our domestic productions and in those in a state of nature, of all sorts of differences of →inherited structure which are correlated with certain ages, and

with

either sex. We have differences correlated not