Origin of Species Variorum

→ few: the masters determine when and where a new nest shall be formed, and when they migrate, the masters carry the slaves. 1860 1861 1866 1869

few. 1859

few: 1872

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

The masters determine when and where a new nest shall be formed, and when they migrate, the masters carry the slaves.

making slaves. Let it be observed what a contrast the instinctive habits of F. sanguinea present with those of the

continental F.

rufescens. The latter does not build its own nest, does not determine its own migrations, does not collect food for itself or its young, and cannot even feed itself: it is absolutely dependent on its numerous slaves. Formica sanguinea, on the other hand, possesses much fewer slaves, and in the early part of the summer extremely →few: the masters determine when and where a new nest shall be formed, and when they migrate, the masters carry the slaves. ↑ Both in Switzerland and England the slaves seem to have the exclusive care of the larvæ, and the masters alone go on slave-making expeditions. In Switzerland the slaves and masters work together, making and bringing materials for the

nest:

nest;

both, but chiefly the slaves, tend, and

milk,

milk

as it may be called, their aphides; and thus both collect food for the community. In England the masters alone usually leave the nest to collect building materials and food for themselves, their slaves and larvæ. So that the masters in this country receive much less service from their slaves than they do in Switzerland.

By what steps the instinct of F. sanguinea originated I will not pretend to conjecture. But as ants, which are not

slave-makers

slave-makers,

will, as I have seen, carry off

the pupæ

pupæ

of other species, if scattered near their nests, it is possible that

pupæ

such pupæ

originally stored as food might become developed; and the

ants

foreign ants

thus unintentionally reared would then follow their proper instincts, and do what work they could. If their presence proved useful to the species which had seized them— if it were more

advan- tageous

advantageous

to this species to capture workers than to procreate them— the habit of collecting

pupæ,

pupæ

originally for

food,

food

might by natural selection be strengthened and rendered permanent for the very different purpose