338 SPECIAL INSTINCTS. [Chap. VIII. 



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 fonnd a few slaves in all. Males and 

 fertile females of the slave species (F. fusca) are fonnd 

 only in their own proper communities, and have never 

 been observed in the nests of F. sanguinea. The slaves 

 are black ami 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 ener- 

 getically 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 might behave differently when more numerous; 

 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 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 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 Ihe same road to a tall Scotch-fir-tree, 



