124 
ANIMAL INTELLIGENCE, 
the larvae at a. When the ants had made a number of 
journeys over cda and back again, he raised the block c D 
so that there was an interval of an inch between the 
end of the block d and the larvae at A. 
The ants kept on coming, and tried hard to reach down 
from D to A, which was only just out of their reach. . . . After 
a while they all gave up their efforts and went away, 
losing their prize in spite of most earnest efforts, because it 
did not occur to them to drop of an inch. At the mo- 
ment when the separation was made there were fifteen ants on 
the larvae. These could, of course, have returned if one had 
stood still and allowed the others to get on its back. This, 
however, did not occur to them ; nor did they think of letting 
themselves drop from the bottom of the paper (p) on to the 
nest. Two or three, indeed, fell down, I have no doubt by 
accident ; but the remainder wandered about, until at length 
most of them got into the water. 
In another experiment he interposed a light straw 
bridge on the way between the nest and the larvse, and 
when the ants had well learnt the way, he drew the 
bridge a short distance towards the nest, so that a small 
chasm was made in the road. The ants tried hard and 
ineffectually to reach across it, but it did not occur to 
them to push the straw into its original position. 
The following experiment is still more illustrative of 
the absence of intelligence, because the adjustive action 
required would not demand the exercise of such high 
powers of imagination and abstraction as would have been 
required for the moving forwards of the paper drawbridge . 
To test their intelligence I made the following experiments : 
I suspended some honey over a nest of Lasius Jtavus 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 re- 
moved 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 
