LANGUAGE. 93 



yards to the rear, and the column at that point commenced 

 retreating." 



On arriving at a stream of water, the marching cokimn 

 first endeavours to find some natural bridge whereby to cross 

 it. Should no such bridge be found, " they travel along the 

 bank of the river until they arrive at a flat sandy shore. Each 

 ant now seizes a bit of dry wood, pulls it into the water and 

 mounts thereon. The hinder rows push the front ones farther 

 out, holding on to the wood with their feet and to their 

 comrades with their jaws. In a short time the water is 

 covered with ants, and when the raft has grown too large to 

 be held together by the small creatures' strength, a part breaks 

 itself off, and begins the journey across, while the ants left 

 on the bank pull the bits of wood into the water, and work 

 at enlarging the ferry-boat until it breaks again. This is 

 repeated as long as an ant remains on shore." * 



So much, then, to give a general idea of the extent to 

 which co-operation is exhibited by Ecitons — a fact which must 

 be taken to depend upon some system of signs. Turning next 

 to still more definite evidence of communication, Mr. Hague, 

 the geologist, writing to Mr. Darwin from South America, says 

 that on the mantel-shelf of his sitting-room there were three 

 vases habitually filled with fresh flowers. A nest of red ants 

 discovered these flowers, and formed a line to them, constantly 

 passing upwards and downwards between the mantel-shelf 

 and the floor, and also between the mantel-shelf and the 

 ceiling. For several days in succession Mr. Hague frequently 

 brushed the ants in great numbers from the wall to the floor, 

 but, as they were not killed, the line again reformed. One 

 day, however, he killed with his finger some of the ants upon 

 the mantel-shelf "The efi"ect of this was immediate and 

 unexpected. As soon as those ants which were approaching 

 arrived near to where their fellows lay dead and suffering, 

 they turned and fled with all possible haste. In half an hour 

 the wall above the mantel-shelf was cleared of ants. During 

 the space of an hour or two the colony from below continued 

 * Krcplin, quoted liy Ijliclincr. 



