138 ANIMAL INTELLIGENCE. 



he found his provisions in the safe swarming with ants as 

 before, and on investigating their mode of access to them 

 found — 



Proceeding along the whitewashed wall a string of ants 

 going and coming from the outer door to a height of four feet 

 on my wall, and corresponding with that of the safe ; and look- 

 ing between it and the wall, I discovered the secret — the bridge 

 which these persevering little insects had made. It consisted of 

 a broken bit of straw, which rested with one end on a mud 

 buttress fixed to the wall, and the other on the overhanging or 

 projecting top of the safe, which came within an inch and a half 

 of the wall. So they must have carried the straw up from the 

 floor, and resting their end of it on the support they had pre- 

 pared, let it fall until its other end reached the safe, and then 

 crossed and completed the structure, for it was fastened at both 

 ends with the mortar composed of their saliva and fine earth. 

 Ruthlessly I destroyed the bridge, and moving the safe farther 

 from the wall, managed to prevent their inroads for that season 

 at least. Since then I have frequently seen short bridges, com- 

 posed entirely of the concrete or mortar which the white ants 

 use to cover up their workings, extending from a damp earthen 

 wall to anything not more than three-quarters of an inch 

 from it. 



Of the Ecitons Mr. Belt says : — 



I shall relate two more instances of the use of a reasoning 

 faculty in these ants. I once saw a wide column trying to pass 

 along a crumbling, nearly perpendicular slope. They would 

 have got very slowly over it, and many of them would have 

 fallen, but a number having secured their hold, and reaching 

 to each other, remained stationary, and over them the main 

 column passed. Another time they were crossing a watercourse 

 along a small branch, not thicker than a goose-quiU. They 

 widened this natural bridge to three times its width by a 

 number of ants clinging to it and to each other on each side, 

 over which the column passed three or four deep; whereas 

 excepting for this expedient they would have had to pass over 

 in single file, and treble the time would have been consumed. 

 Can it be contended that such insects are not able to determine 

 by reasoning powers which is the best way of doing a thing ? 



Another observer, writing from the same part of the 

 world to Biichner, gives a still more wonderful account of 

 the ingenuity of Ecitons in crossing water. This observer 



