nforms me that he has watched the nests at various hours during May, June
and August, both in Surrey and Hampshire, and has never seen the slaves,
through 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 constantly seen bringing in materials for the nest, and
food of all kinds. During the present year, however, in the month {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 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 (instead of being carried by, as in the case of F.
rufescens) 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. 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 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. {222}

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 t