212 INTELLIGENCE IN INSECTS 
bridge consisting of a strip of paper 2/3 inch long and 1/3 
inch wide. Having then put a Lasius niger from one of 
my nests to these larve, she began carrying them off, and 
by degrees a number of friends came to help her. I then, 
when about twenty-five ants were so engaged, moved the 
little paper bridge slightly, so as to leave a chasm, just so 
wide that the ants could not reach across. They came and 
tried hard to do so; but it did not occur to them to push the 
paper bridge, though the distance was only about 1/3 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 1 inch long and 1/8 inch wide. The result was the 
same. I repeated this more than once. 
‘“‘Again I suspended some honey over a nest of Lasius 
flavus at a height of about 1/2 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 1/3 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 antenne; 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 themselves 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. 
