240 SPECIAL INSTINCTS. 



So utterly helpless are the masters, that when Huber shut 

 up thirty of them without a slave, but with plenty of food 

 which they liked best, and with their own larvae and pupae 

 to stimulate them to 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 extraordi- 

 nary 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. I/uring the months of June and July, on three 

 successive years, I watched for many hours several nests in 

 Surrey aJnd 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 might behave differently when 

 more nuxnerous ; but Mr. Smith informs 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, though present in. large numbers in August, either 



