THE WOOD ANT. 123 



rapid communications with each other, mostly by means 

 of their antennae, which pat and stroke those of their 

 gossip with surprising quickness, the whole transaction 

 irresistibly reminding the observer of the Oriental 

 method of conducting sales or barters by means of the 

 hands. The antennae, whose precise function is still 

 rather obscure, are employed not only for actual com- 

 munication with other ants, but to ascertain whether a 

 companion has passed over a certain spot. This 

 peculiar instinct is mostly exercised among trees. The 

 ant roads seem even to extend themselves to the summit 

 of trees, being generally confined to one side of the 

 trunk, and ramifying to the very tips of the leaves, as 

 may be seen by means of a good field-glass. Ants may 

 be seen passing and repassing upon the trees as briskly 

 as upon the ground, and it is notable that when they 

 get among the small branches an ant will not go where 

 another has preceded it, making itself aware of the cir- 

 cumstance by the tapping of the antennae upon the 

 bark. 



The object of this tree-haunting habit is twofold , 

 firstly that the individual may obtain food for itself, 

 and secondly that it may bring in subsistence for the 

 community. Its own nourishment is chiefly obtained 

 from the aphides which swarm on many trees, and 

 which have the power of exuding a saccharine fluid 

 from a pair of minute tubes near the extremity of the 

 body. When the aphides are very plentiful the sweet 

 juice falls on the leaves, and is popularly known as the 



