EVEN IF BROUGHT UP SEPARATELY. 147 



cases, amicably received ants bred from its own pupae 

 but tended by ants from 60, it showed itself fiercely 

 hostile to ants from pupae born in nest 60, even when^ 

 these had been tended by ants from nest 36. Nest 60, 

 again, behaved in a similar manner ; amicably receiving, 

 as a general rule, its own young, even when tended 

 by ants from 36 ; and refusing to receive ants born in 

 nest 36, even when tended by specimens from nest 60. 

 - These experiments seem to indicate that ants of the 

 same nest do not recognise one another by any pass- 

 word. On the other hand, they seem to show that if ants 

 are removed from a nest in the pupa-state, tended by 

 strangers, and then restored, some at least of their rela- 

 tives are puzzled, and for a time doubt their claim to con- 

 sanguinity. I say some, because while strangers under 

 the circumstances would have been immediately at- 

 tacked, these ants were in every case amicably received 

 by the majority of the colony, and it was sometimes 

 several hours before they came across one who did not 

 recognise them. 



In all these experiments, however, the ants were 

 taken from the nest as pupae, and though I did not 

 think the fact that they had passed their larval existence 

 in the nest could affect the problem, still it might do 

 so. I determined therefore to separate a nest before 

 the young were born, or even the eggs laid, and then 

 ascertain the result. Accordingly I took one of my nests 

 of F. fusca, which I began watching on Sept. 13, 1878, 

 and which contained two qveens, and on February 8, 



