INSTINCT 221 



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 com- 

 munity with an unusually large stock of slaves, and I observed a 

 few slaves mingled with their masters leaving the nest, and march- 

 ing 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 opportuni- 

 ties for observation, the slaves in Switzerland 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 ex- 

 pressly states, their principal office is to search for aphides. This 

 difference 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 witnessed a migration of F. sanguinea 

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

 dependent 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 op- 

 ponents 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 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. 



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

 pupae of another species, F. flava, with a few of these little yellow 

 ants still clinging to the fragments of their nest. This species is 

 sometimes, though rarely, made into slaves, as has been described 

 by Mr. Smith. Although so small a species, it is very courageous, 

 and I have seen it ferociously attack other ants. In one instance I 

 found to my surprise an independent community of F. flava under 

 a stone beneath a nest of the slave-making F. sanguinea; and 

 when I had accidentally disturbed both nests, the little ants at- 

 tacked their big neighbors with surprising courage. Now I was 

 curious to ascertain whether F. sanguinea could distinguish the pu- 

 pae of F. fusca, which they habitually make into slaves, from those 



