248 WANT OF INGENUITY 



Then, thinking that paper was a substance to which 

 they were not accustomed, I tried the same with a bit 

 of straw 1 inch long and ^ inch wide. The result was 

 the same. I repeated this more than once. 



Again I suspended some honey over a nesL of 

 Lasius fiavus at a height of about ^ an inch, and 

 accessible only by a paper bridge more than 10 feet 

 long. Under the glass I then placed a small heap of 

 earth. The ants soon swarmed over the earth on to the 

 glass, and began feeding on the honey. I then 

 removed a little of the earth, so that there was an 

 interval of about ^ of an inch between the glass and 

 the earth ; but, though the distance was so small, they 

 would not jump down, but preferred to go round by the 

 long bridge. They tried in vain to stretch up from the 

 earth to the glass, which, however, was just out of their 

 reach, though they could touch it with their antennae; 

 but it did not occur to them to heap the earth up a 

 little, though if they had moved only half a dozen 

 particles of earth they would have secured for them- 

 selves direct access to the food. This, however, never 

 occurred to them. At length they gave up all attempts 

 to reach up to the glass, and went round by the paper 

 bridge. I left the arrangement for several weeks, but 

 they continued to go round by the long paper bridge. 



Again I varied the experiment as follows : — Having 

 left a nest without food for a short time, I placed some 

 honey on a small wooden brick surrounded by a little 

 moat of glycerine ^ an inch wide and about -Jj of 



