Chap. VII. SLAVE-MAKING INSTINCT. 221 



of July, I came across a community with an unusually 

 large stock of slaves, and I observed a few slaves mingled 

 with their masters leaving the nest, and marching along 

 the same road to a tall Scotch -fir-tree, twenty-five yards 

 distant, which they ascended together, probably in search 

 of aphides or cocci. According to Huber, who had ample 

 opportunities for observation, in Switzerland the slaves 

 habitually work with their masters in making the nest, 

 and they alone open and close the doors in the morning 

 and evening ; and, as Huber expressly states, their 

 principal office is to search for aphides. This differ- 

 ence in the usual habits of the masters and slaves 

 in the two countries, probably depends merely on the 

 slaves being captured in greater numbers in Switzerland 

 than in England. 



One day I fortunately chanced to witness a migration 

 from one nest to another, and it was a most interesting 

 spectacle to behold the masters carefully carrying, as 

 Huber has described, their slaves in their jaws. Another 

 day my attention was struck by about a score of the 

 slave-makers haunting the same spot, and evidently not 

 in search of food ; they approached and were vigorously 

 repulsed by an independent community of the slave 

 species (F. fusca) ; sometimes as many as three of these 

 ants clinging to the legs of the slave-making F. san- 

 guinea. The latter ruthlessly killed their small oppo- 

 nents, and carried their dead bodies as food to their 

 nest, twenty-nine yards distant; but they were pre- 

 vented from getting any pupae to rear as slaves. I 

 then dug up a small parcel of the pupae of F. fusca 

 from another nest, and put them down on a bare spot 

 near the place of combat ; they were eagerly seized, 

 and carried off by the tyrants, who perhaps fancied 

 that, after all, they had been victorious in their late 

 combat. 



