ANTS GENERAL INTELLIGENCE. 141 



workers, which are the most intelligent members of the 

 community. 



Injury of the brain causes, as in higher animals, 

 tetanic spasms and involuntary reflex movements, followed 

 by stupefaction. 



An ant, whose brain has been perforated by the pointed 

 mandibles of an amazon, remains as though nailed to its place ; 

 a shudder runs from time to time through its body, and one of 

 its legs is lifted at regular intervals. It occasionally makes a 

 short and quick step, as though driven by an unseen spring, 

 but, like that of an automaton, aimless and objectless. If it is 

 pulled, it makes a movement of avoidance, but falls back into 

 its stupefied condition as soon as it is released. It is no longer 

 capable of action consciously directed to a given object; it 

 neither tries to escape, nor to attack, nor to go back to its 

 home, nor to rejoin its companions, nor to walk away ; it feels 

 neither heat nor cold, it knows neither fear nor desire for food. 

 It is merely an automatic and reflex machine, and. is exactly 

 similar to one of those pigeons from which Flourens removed 

 the hemispheres of the cerebrum. Just in the same way behaves 

 the body of an ant from which the head has been taken away. 

 In the numerous fights between amazons and other ants, count- 

 less cases have been observed of slight injury to the brain, 

 which have caused the most remarkable phenomena. Many of 

 the wounded were seized with a mad rage, and flung them- 

 selves at every one that came in their way, whether friend or 

 foe. Others assumed an appearance of indifference, and walked 

 serenely about in the midst of the fighting. Others exhibited 

 a sudden failure of strength ; but they still recognised their 

 enemies, approached them, and tried to bite them in cold 

 blood, in a way quite foreign to the behaviour of healthy ants. 

 They were also often observed to run round and round in a 

 circle, the motion resembling the manege, or riding-school 

 action of mammals, when one of the crura cerebri has been 

 removed. 



If an ant is cut in half through the thorax, so that the great 

 nerve ganglia of the pro-thorax remain untouched, the behaviour 

 of the head shows that intelligence also remains untouched. 

 Ants mutilated in this way try to go forwards with their two 

 remaining legs, and beg with their antennae for their com- 

 panions' aid. If one of these latter lets itself be stopped, then 

 we observe a lively interchange of thanks and sympathy ex- 

 ] ressed by the actively moving antennae. Forel placed near to 



