in.] THE STING. POISON. 95 



that the ants with stings must have a great advantage 

 over those with none. In some cases, however, 

 the poison is so strong, that it is sufficient for it to 

 touch the foes to place them hors de combat, or at least 

 to render them incapacitated, with every appearance 

 of extreme pain. Such species have the abdomen 

 unusually mobile. 



The species of Lasius make up in numbers what they 

 want in strength. Several of them seize an enemy at 

 the same time, one by each of her legs or antennas, 

 and when they have once taken hold they will suffer 

 themselves to be cut in pieces rather than let go. 



Polyergus rufescens, the celebrated slave-making or 

 Amazon ant, has a mode of combat almost peculiar to 

 herself. Her jaws are very powerful, and pointed. If 

 attacked if, for instance, another ant seizes her by 

 a leg she at once takes her enemy's head into her 

 jaws, thus generally making her quit her hold. If 

 she does not, the Polyergus closes her mandibles, so 

 that the points pierce the brain of her enemy, paralysing 

 the nervous system. The victim falls in convulsions, 

 setting free her terrible foe. In this manner a com- 

 paratively small force of Polyergus will fearlessly 

 attack much larger armies of other species, suffering 

 itself scarcely any loss. 



I have elsewhere discussed the relations of flowers 

 to insects, especially to bees, and particularly the 

 mode in which flowers have been modified, so that 

 the bees might transfer the pollen from one to another. 

 Ants are also, as mentioned in the preceding lecture, 

 of considerable importance to plants, especially in keep- 

 ing down the number of insects which feed on them. 



