in.] VISION. 89 



such circumstances, if she had been much guided by 

 sight, she could not of course have had any difficulty 

 in finding her way to the nest. As a matter of fact, 

 however, she was entirely at sea, and after wandering 

 about for some time, got back to the nest by another 

 and very roundabout route. I then again varied the 

 experiment as follows. I placed the food in a small 

 china cup on the top of the pencil, which thus formed 

 a column seven and a half inches high. When the 

 ant once knew her way, she went very straight to and 

 from the food. I then moved the pencil six inches. This 

 puzzled her very much : she went over and over the 

 spot where the pencil had previously stood, retraced 

 her steps several times almost to the nest, and then 

 returned along the whole line, showing great perseverance, 

 if not much power of vision. She found it at last, but 

 only after many meanderings. 



I repeated the observation on three other ants with 

 the same result : the second was seven minutes before she 

 found the pencil, and at last seemed to do so accidentally ; 

 the third actually wandered about for no less than half 

 an hour, returning up the paper bridge several times. 



Let us compare this relatively to man. An ant 

 measuring, say one-sixth of an inch, and the pencil being 

 seven inches high, it is consequently forty-two times 

 as long as the ant. It bears, therefore, somewhat the 

 same relation to the ant as a column two hundred and 

 fifty feet high does to a man. The pencil having been 

 moved six inches, it is as if a man in a country he 

 knew well would be puzzled at being moved a few 

 hundred feet ; or, if put down in a square containing 

 less than an acre, could not find a column two hundred 



