108 ON THE HABITS OF ANTS. [LECT. 



intelligent to appreciate, still less to remember it, the 

 pupae which were entrusted to ants from another nest 

 would have the password, if any, of that nest : and not 

 of the one from which they had been taken. Hence, if 

 the recognition were effected by some password, or sign 

 with the antennae, they would be amicably received in 

 the nest from which their nurses had been taken, but 

 not in their own. I therefore took a number of pupae 

 out of some of my nests of Formica fusca and Lasius 

 niger, and put them in small glasses, some with ants 

 from their own nest, some with ants from another nest 

 of the same species. The result of my observations was 

 that 32 ants belonging to Formica fusca and Lasius 

 niger, removed from their nest as pupae, attended by 

 friends, and restored to their own nest, were all amicably 

 received. 



What is still more remarkable : of 22 ants belong- 

 ing to Formica fusca, removed as pupae, attended 

 by strangers, and returned to their own nest, 20 were 

 amicably received, though in several cases after some 

 hesitation. As regards one, I was doubtful : this last 

 was crippled in coming out of the pupa case, and to this 

 perhaps her unfriendly reception may have been due. 

 Of the same number of Lasius niger, developed in the 

 same manner, from pupae tended by strangers belonging 

 to the same species, and then returned into their own 

 nest, 17 were amicably received, three were attacked, 

 and about two I felt doubtful. 



On the other hand, 15 specimens, belonging to the 

 same species, removed as pupae, tended by strangers 

 belonging to the same species, and then put into the 

 strangers' nest, were all attacked. 



