in,] INTELLIGENCE OF ANTS. 81 



then put a F. nigra from one of my nests to this food, 

 she began carrying it off, and by degrees a number of 

 friends came to help her. When about twenty-five 

 ants were so engaged, I moved the little paper bridge 

 slightly, so as to leave a chasm just so wide that the 

 ants could not reach across. They came to the edge 

 and tried hard to get over, but it did not occur to them 

 to push the paper bridge, though the distance was only 

 about one-third of an inch, and they might easily have 

 done so. After trying for about a quarter of an hour 

 they gave up the attempt, and returned home. This I 

 repeated several times. Then, thinking that paper was 

 a substance to which they were not accustomed, I tried 

 the same with a bit of straw one inch long and one- 

 eighth of an inch wide. The result was the same. I 

 repeated this twice. Again I placed particles of food 

 close to and directly over the nest, but connected with 

 it only by a passage several feet in length. Under these 

 circumstances it would be obviously a saving of time 

 and labour to drop the food on to the nest, or at any 

 rate to spring down with it, so as to save one journey. 

 But though I have frequently tried the experiment, my 

 ants never adopted either of these courses. I arranged 

 matters so that the glass on which the food was placed, 

 was only raised one-third of an inch above the nest. 

 The ants tried to reach down, and the distance was so 

 small that occasionally, if another ant passed underneath 

 just as one was reaching down, the upper one could step 

 on to its back, and so descend ; but this only happened 

 accidentally, and they did not think of throwing the 

 particles down, nor, which surprised me very much, 

 would they jump down themselves. I then placed a 



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