178 ANIMAL INTELLiaENCE. 



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 save 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 1 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 coveired 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,^ 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. Id 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. ' Does the mason-bee act like a 

 machine,' says E. Menault, ' when it directs its work ac- 



* 3find in Animals, pp. 252-3. 



