work, they did nothing; they could not even feed themselves, and many
perished of hunger. Huber then introduced a single slave (F. fusca), and
she instantly set to work, fed and saved the survivors; made some cells and
tended the larvae, and put all to rights. What can be more extraordinary
than these well-ascertained facts? If we had not known of any other
slave-making ant, it would have been hopeless to speculate how so wonderful
an instinct could have been perfected.

Another species, Formica sanguinea, was likewise first discovered by P.
Huber to be a slave-making ant. This species is found in the southern
parts of England, and its habits have been attended to by Mr. F. Smith, of
the British Museum, to whom I am much indebted for information on this and
other subjects. Although fully trusting to the statements of Huber and Mr.
Smith, I tried to approach the subject in a sceptical frame of mind, as any
one may well be excused for doubting the existence of so extraordinary an
instinct as that of making slaves. Hence, I will give the observations
which I made in some little detail. I opened fourteen nests of F.
sanguinea, and found a few slaves in all. Males and fertile females of the
slave-species (F. fusca) are found only in their own proper communities,
and have never been observed in the nests of F. sanguinea. The slaves are
black and not above half the size of their red masters, so that the
contrast in their appearance is great. When the nest is slightly
disturbed, the slaves occasionally come out, and like their masters are
much agitated and defend the nest: when the nest is much disturbed, and
the larvae and pupae are exposed, the slaves work energetically together
with their masters in carrying them away to a place of safety. Hence, it
is clear that the slaves feel quite at home. During the months of June and
July, on three successive years, I watched for many hours several nests in
Surrey and Sussex, and never saw a slave either leave or enter a nest. As,
during these months, the slaves are very few in number, I thought that they