SLA VE~MAKING INSTINCT. 257 



rey and Hampshire, and has never seen the slaves, though 

 present in large numbers in August, either leave or enter 

 the nest. Hence, he considers them as strictly household 

 slaves. The masters, on the other hand, may be con- 

 stantly seen bringing in materials for the nest, and food of 

 all kinds. During the year 1860, however, in the month 

 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, the slaves in Switzerland 

 habitually work with their masters in making the nest, 

 and they alone open and close the doors in tlie morning and 

 evening; and, as Huber expressly states, their principle 

 office is to search for aphides. This difference in the usual 

 habits of the masters and slaves in the two countries, prob- 

 ably depends merely on the slaves being captured in greater 

 numbers in Switzerland than in England. 



One day I fortunately witnessed a migration of F. san- 

 guina from one nest to another, and it was a most interest- 

 ing spectacle to behold the masters carefully carrying their 

 slaves in their jaws instead of being carried by them, as in 

 the case of F. rufescens. 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 independ- 

 ent community of the slave-species (F. fusca); sometimes 

 as many as three of these ants clinging to the legs of the 

 slave-making F. sanguinea. The latter ruthlessly killed 

 their small opponents and carried their dead bodies as 

 food to their nest, twenty-nine yards distant; but they were 

 prevented from getting any pupae to rear as slaves. I then 

 dug up a small parcel of the pupa3 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. 



At the same time I laid on the same place a small parcel 

 of the pupse of another species, F. flava, with a few of 

 these little yellow ants still clinging to the fragments of 



