42 ANIMAL INTELLIGENCE. 



of their community after so prolonged an absence. Think- 

 ing that the facts could only be explained, either by all 

 the ants in the same nest having a peculiar smell, or by 

 all the members of the same community having a par- 

 ticular pass-word or gesture-sign, Sir John Lubbock, 

 with the view of testing this theory, separated some ants 

 from a nest while still in the condition of pupae, and, 

 when they emerged from that state as perfect insects, 

 transferred them back to the nest from which they had 

 been taken as pupae. Of course in this case the ants in 

 the nest could never have seen those which had been 

 removed, for a larval ant is as unlike the mature insect as 

 a grub is unlike a beetle ; neither can it be supposed that 

 a larva, hatched out away from the nest, should retain, 

 when a perfect insect, any smell belonging to its parent 

 nest — more especially as it had been hatched out by 

 ants in another nest ; ^ nor, lastly, is it reasonable to 

 imagine that the animal, while still a larval grub, can have 

 been taught any gesture-signal used as a pass-word by the 

 matured animals. Yet, although all these possible hypo- 

 theses seem to be thus fully excluded by the conditions 

 of the experiment, the result showed unequivocally that 

 the ants recognised their transformed larvae as native-born 

 members of their community. 



Lastly, Sir John Lubbock tried the experiment of 

 going still further back in the life-history of the ants 

 before separating them from the nest. For in September 

 he divided a nest into two halves, each having a queen. 

 At this season there were neither larvae nor eggs. The 

 following April both the queens began to lay eggs, and in 

 August — i.e. nearly a year after the original partitioning 

 of the nest — he took some of the ants newly hatched from 

 the pupae in one division, and placed them in the other 

 division, and vice versa. In all cases these ants were re- 

 ceived by the members of the other half of the divided 

 nest as friends, although if a stranger were introduced into 

 either half it was invariably killed. Yet the ants which 



^ It is to be noted that although ants will attack stranger ants 

 introduced from other nests, they will carefully tend stranger larvae 

 rjimilarly introduced. 



