178 
ANIMAL INTELLIGENCE. 
the floor and roof of which were made of glass, that is of a body 
which the bees use very unwillingly for the attachment of their 
combs, on account of its smoothness. Thus the possibility of 
building as usual from above downwards, and also from below 
upwards, was taken away from them ; they had no point of sup- 
port savfc the perpendicular walls of their dwelling. They 
thereupon built on one of these walls a regular stratum of 
cells, from which, building sideways, they tried to carry the 
comb to the opposite side of the hive. To prevent this Huber 
covered that side also with glass. But what way out of the 
difficulty was found by the clever insects % Instead of building 
further in the projected direction, they bent the comb round at 
the extreme point, and carried it at a right angle towards one 
of the inner sides of the hive which was not covered with glass, 
and there fastened it. The form and dimensions of the cells 
must necessarily have been altered thereby, and the arrange- 
ment of their work at the angle must have been quite different 
from the usual. They made the cells of the convex side so 
much broader than those of the concave that they had a 
diameter two or three times as great, and yet they managed to 
join them properly with the others. They also did not wait to 
bend the comb until they came to the glass itself, but recog- 
nised the difficulty beforehand, 1 which had been interposed by 
Huber while they were building with a view to overcome the 
first difficulty. 
Special Habits. 
The Mason-Bee . — This insect closes the roof of its 
larval cell with a kind of mortar, which sets as hard as 
stone. A little hole, closed only with soft mud, is, how- 
ever, left in one part of the roof as a door of exit for the 
matured insect. It is said that when a mason-bee finds 
an old and deserted nest, it saves itself the trouble of 
making a new one — utilising the ready-made nest after 
having well cleaned it. In Algiers the mason-bees have 
been observed in this way to utilise empty snail-shells. 
According to Blanchard, some individuals avoid the labour 
of making their own nests or houses for their young, by 
possessing themselves of their neighbours* houses either 
by craft or by force. 4 Does the mason-bee act like a 
machine, 9 says E. Menault, 4 when it directs its work ac* 
1 Mind in Animal s, pp, 252-3. 
