HOW ANTS CARRY ON WAR 



tvvccn individuals of the two factions, yet they do 

 infallibly and instantly distinguish their nest-fellows 

 from the enemy. This is done by the antenna), which 

 are kept in constant motion, the tips describing sundry 

 curves. At a meeting between ants these organs touch 

 and embrace the face; if the parties be friends, they pass 

 on; if foes, they straightway begin to fight. The new- 

 comers, thronging to the battle-centre, where hundreds 

 are struggling in a heap that is chaos to human eyes, 

 but presents no difficulty to emmet senses, plunge into 

 the seething mass and instantly recognize and join com- 

 bat with their enemies. How is it done? 



Thirty-two years ago, during the summer of 1877, 

 while pondering this problem, it occurred to the writer 

 that this recognition was based upon a certain odor, 

 emitted in different degrees of intensity by the respective 

 factions, or upon two distinct characteristic party odors. 

 The degree of odor or difference in odors, he thought, 

 might be dependent upon some peculiarity in the phys- 

 ical condition or environment of the antagonists. Sup- 

 posing that there were any truth in this theory, it further 

 occurred to him that the presence of an artificial and 

 alien perfume strong enough to neutralize the distinctive 

 animal odors, or degrees of odor, and environ the com- 

 batants with a foreign and common odor, would have a 

 tendency to confuse the ants, and disturb or destroy 

 their recognition of the distasteful and exciting element. 

 In which case he conjectured that the result might be 

 their pacification and reconciliation. Experiments were 

 made to test this hypothesis. [McC. 17, p. 17.] 



A number of warring Tetramoriums, taken upon a 

 flower border, were placed together in a large glass 



vessel upon some soil. The jar was vigorously shaken 



221 



