INTELLIGENCE OF ANTS. 505 



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 pupae of 

 the vanquished nest in order to hatch them out as slaves. When these 

 pupae 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 JF. sanguinea the compara- 

 tively 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 mas- 

 ters carry their slaves in their jaws. On the other hand, F, riifescens 

 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 

 larvae, 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) 

 Lespes 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 mas- 

 ters bite the slaves when displeased with them. Forel and Darwin 

 have also confirmed these observations of Huber. Indeed, the struct- 

 ure of the mouth in F. rufescens is such as to render self -feeding diffi- 

 cult, if not physically impossible. Its long and narrow jaws, admira- 

 bly 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 in- 

 sects 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. 



When these ants want to bring home the leaves which they have bitten off 

 the trees, they do it by means of a column of these bugs, which go in pairs, 

 kept in order on either side by accompanying ants. They compel stragglers to 

 reenter the ranks^ and laggards to keep up by biting them. After the work is 

 done, the bugs are shut up within the colony and scantily fed. 



