500 THE POPULAR SCIENCE MONTHLY, 



that all the ants of the same community recognize one another as 

 friends, while an ant introduced from another nest, even though it be 

 an ant of the same species, is known at once to be a foreigner, and is 

 usually maltreated or put to death. Huber found that, when he re- 

 moved an ant from a nest and kept it away from its companions for a 

 period of four months, it was still recognized as a friend, and caressed 

 by its previous fellow-citizens after the manner in which ants show 

 friendship, viz., by stroking antennae. Sir John Lubbock, after re- 

 peating and fully confirming these observations, extended them as 

 follows : 



He first tried prolonging the period of separation beyond four 

 months, and found that it might be made more than three times as 

 long without the ants forgetting their absent friend. Thinking that 

 this fact could only be explained, either by all the ants knowing each 

 other's personal appearance, or by their all having a distinctive smell 

 peculiar to each nest, or by their all having a sign, like a pass-word, 

 differing in different nests. Sir John tried separating some ants from 

 a nest while still in the condition of larvae, and, when they emerged as 

 perfect insects, transferring them back to the nest from which they 

 had been taken as larvse. Of course, in this case the ants in the nest 

 could never have seeyi those which had been removed, for a larval ant 

 is as unlike the mature insect as a caterpillar is unlike a butterfly ; 

 neither can it be supposed that the larvae, thus kept away from the 

 nest, should retain, when hatched out as perfect insects, any smell be- 

 longing to their parent nest ; nor, lastly, is it reasonable to imagine 

 that the animals, while still in the condition of larval grubs, can have 

 been taught any gesture or sign used as a pass-word by the matured 

 animals. Yet, although all these possible hypotheses seem to be thus 

 fully excluded by the conditions of the experiment, the result showed 

 unequivocally that the ants all recognized their transformed larvae as 

 native-born members of their community. 



Next, therefore. Sir John Lubbock tried dividing a nest into two 

 parts before the queen ants had become pregnant. Seven months after 

 the division the queens laid their eggs, and five months later these 

 eggs had developed into perfect insects. lie then transferred some of 

 these young ants from the division of the nest in which they had been 

 born to the division in which they had never been, even in the state 

 of the QQQ. Yet these ants also were received as friends, in marked 

 contrast to the reception accorded to ants from any other nest. It 

 therefore seems to be blood-relationship that ants are able, in some 

 way that is as yet wholly inexplicable, to recognize. It ought, how- 

 ever, to be remembered in this connection that, in an experiment made 

 by Forel on slave-making ants, it was proved that they almost instan- 

 taneously recognized their own slaves from other slaves of the same 

 species and this after their slaves had been kept away from the nest 

 for a period of four months. 



