136 
ANIMAL INTELLIGENCE. 
seems to betoken no small knowledge of practical engineer- 
ing. 
Buchner, after quoting these cases, proceeds to say 
{loc. tit., p. 120), — 
The ants behaved in yet more ingenious fashion under the 
following very similar circumstances. Herr G. Theuerkauf, 
the painter (Wasserthorstr. 49, Berlin), writes to the author, 
November 18, 1875: ( A maple tree standing on the ground 
of the manufacturer, Vollbaum, of Elbing (now of Dantzic), 
swarmed with aphides and ants. In order to check the mis- 
chief, the proprietor smeared about a foot width of the ground 
round the tree with tar. The first ants who wanted to cross 
naturally stuck fast. But what did the next % They turned 
back to the tree and carried down aphides, which they stuck down 
on the tar one after another until they had made a bridge over 
which they could cross the tarring without danger. The above- 
named merchant, Vollbaum, is the guarantor of this story, 
which I received from his own mouth on the very spot whereat 
it occurred. 
Buchner also gives the following case on the authority 
of Karl Vogt {loc. cit p. 128). An apiary of a friend was 
invaded by ants : — 
To make this impossible for the future, the four legs of the 
beehive- stand were put into small, shallow bowls filled with 
water, as is often done with food in ant-infested places. The 
ants soon found a way out of this, or rather a way into their 
beloved honey, and that over an iron staple with which the 
stand was attached to a neighbouring wall. The staple was 
removed, but the ants did not allow themselves to be defeated. 
They climbed into some linden trees standing near, the branches 
of which hung over the stand, and then dropped upon it from 
the branches, doing just the same as their comrades do with 
respect to food surrounded by water, when they drop upon it 
from the ceiling of the room. In order to make this impos- 
sible, the boughs were cut away. But once more the ants 
were found in the stand, and closer investigation showed 
that one of the bowls w T as dried up, and that a crowd of ants 
had gathered in it. But they found themselves puzzled how to 
go on with their robbery, for the leg did not, by chance, rest on 
the bottom of the bowl, but was about half an inch from it. 
The ants were seen rapidly touching each other with their 
antennae, or carrying on a consultation, until at last a rathe] 
