i So ANTS. 



as a demonstration of reasoning power. One observer who placed 

 tobacco juice aero-- tbc path of some ants that were attending aphids 

 on a tree and saw the \\orkers cast pellets of earth on the liquid, con- 

 cluded that they \\ere intentionally building a bridge, and therefore 

 credited them with a high degree of intelligence, whereas they were 

 merely exercising one of their customary reflexes and happened to 

 use enough earth to enable them to cross the obstacle and reach their 

 charges. 



When a colony is attacked by alien ants or disturbed by larger 

 organism-, the character of the reaction varies with the specie's and the 

 >ixe of the community. The workers of large colonies are usually ag- 

 gressive. tlne of small colonies are timid and resort to more passive 

 means of defence. Usually the most immediate response, at least on 

 the part of a considerable portion of the colony, is precipitate flight 

 into the surrounding vegetation. This is invariably the resort of small 

 colonies of fleet-footed ants. Others, like Myrmecina and the smaller 

 species of the slow-footed Attii, " feign death " after the manner of 

 weevils or " skip-jack " beetles. They roll themselves up and remain 

 motionless for a time. In this posture the opaque, rough-bodied species 

 of Cyphomyrmex, Tntchinynnc.v and Mycocc punts are almost indis- 

 tinguishable from particles of earth or sand. 



Several species with peculiar mandibles manage to escape from 

 their enemies bv leaping. In Odoiitoinachits, the " tic-ant " of the 

 tropics, for example, the linear mandibles are inserted close together 

 at their bases and provided along their inner edges with a few sense- 

 hairs which are nearly as long as the mandibles. When the ant is 

 excited it opens its mandibles to their utmost extent, till they form 

 together a straight line at right angles with the long axis of the body. 

 Then as soon as a hard object is touched by the sense-hairs the blades 

 are suddenly closed, striking the object with their tips with sufficient 

 force to throw the insect backwards into the air for a distance of 

 several inches. This habit is also exhibited by other genera and species 

 with similar mandibles, for example by Anochctns sedilloti ( W rough- 

 ton. 1892), Stniinigcn\s salicns (Mayr, 18920, 189317) and probably 

 also by Daccton and Acanthognathus. According to Emery (1893/2) 

 the large-eyed Brazilian Gigantiops destructor is able ''to leap from 

 twig to twig." and an Indian ant with extraordinary mandibles, Har- 

 pc(/natluis cnicntittus, is said to leap forward like a grass-hopper to a 

 distance of eighteen inches ( Wroughton). 



In many species the tough integument or specially developed spines 

 are an important means of defense. The workers of the large species 

 of Atta and Acroniynnc.v bristle with hard spines and tubercles, and 



