INTELLIGENCE OF ANTS. 829 



It is remarkable that the military or driving ants of Africa exhibit 

 precisely similar devices for the bridging of streams as the Ecitons of 

 America, namely, by forming a chain of individuals over which the 

 others pass. By means of similar chains they also let themselves 

 down from trees. 



But of the Ecitons another and more recent observer gives an 

 account of a yet more remarkable device, although no doubt a de- 

 velopment of the one just described. This observer is Herr H. Krep- 

 lin, who lived for nearly twenty years in South America as an engineer, 

 and often had the opportunity of watching the Ecitons. He writes to 

 Buchner under date 1876 as follows : 



If the water-course be narrow, the thick-heads (officers) soon find trees, the 

 branches of which meet on the bank of either side, and after a short halt the 

 columns set themselves in motion over these bridges, rearranging themselves in 

 a narrow train with marvelous quickness on reaching the farther side. But, if 

 no natural bridge be available for the passage, thej 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 pusli 

 the front ones ever 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 off and begins the journey across, while the 

 ants left on the bank busily pull their bits of wood into the water and work at 

 enlarging the ferry-boat until it again breaks. This is repeated as long as an ant 

 remains on shore. 



I shall now bring these numerous instances to a close with a quota- 

 tion from Belt, which reveals in a most unequivocal manner astonish- 

 ing powers of observation and reason in the leaf -cutting ants of South 

 America, the general habits of which we have already considered : 



A nest was made near one of our tramways, and to get to the trees the ants 

 had to cross the rails, over which the wagons were continually passing and re- 

 passing. Every time they came along a number of ants were crushed to death. 

 They persevered in crossing for some time, but at last set to work and tunneled 

 underneath each rail. One day, when the wagons were not running, I stopped 

 up the tunnels with stones ; but although great numbers carrying leaves were 

 thus cut off from the nest, they would not cross the rails, but set to, work mak- 

 ing fresh tunnels beneath them. 



Such, then, are some of the more well-established facts regarding 

 the intelligence of ants, and taken altogether they certainly seem to 

 justify the remark of the most illustrious of naturalists, " The brain 

 of an ant is one of the most marvelous atoms of matter in the world, 

 perhaps more so than the brain of a man." Nineteenth Century. 



