attack a nest of F. fusca in a body; there is a great fight with much slaughter, and, if victorious, the slave-makers carry off the pupæ of the vanquished nest in order to hatch them out as slaves. When these pupæ hatch out, the young slaves begin their life of work, and seem to regard their masters' home as their own, for they never attempt to escape, and they fight in defense of the nest should it be attacked. The work that devolves upon the slaves differs according to the species which has enslaved them. In the nests of F. sanguinea the comparatively few captives are kept exclusively as household slaves, all the out-door work of foraging, slave-capturing, etc., being performed by the masters; and when for any reason a nest has to migrate, the masters carry their slaves in their jaws. On the other hand, F. rufescens assigns a much larger share of work to the slaves, which they capture in much larger numbers to take it. In this species the masters do no work whatsoever, unless the capturing of slaves be regarded as such. Therefore the whole community is entirely dependent upon its slaves; the masters are not able to make their own nests, to feed their own larvæ, or even to feed themselves; they die of starvation in the midst of favorite food if a slave should not be present to hand it in proper form. In order to confirm this observation (originally due to Huber) Lespès placed a piece of moistened sugar near a nest of these slave makers. It was soon found by one of the slaves, which gorged itself and returned. Other slaves then came out and did likewise. Some of the masters next came out, and by pulling the legs of the feeding slaves reminded them that they were neglecting their duty. The slaves then immediately began to serve their masters to the sugar. Had they not done so, there is no doubt they would have been punished, for the masters bite the slaves when displeased with them. Forel and Darwin have also confirmed these observations of Huber. Indeed, the structure of the mouth in F. rufescens is such as to render self-feeding difficult, if not physically impossible. Its long and narrow jaws, admirably adapted to pierce the head of an enemy, do not admit of being used for feeding unless liquid food is poured into them from the mouth of a slave.
Ants do not appear to be the only animals of which ants make slaves; for there is at least one case in which these wonderful insects enslave insects of another species, which may therefore be said to stand to them in the relation of beasts of burden. The case to which I allude stands upon the authority of Audubon, who says that he has seen certain leaf-bugs used as slaves by ants in the forests of Brazil.