BUILDING STONES 



albuminous matter contained in this secretion, a sort of 

 rapidly hardening cement, not unlike the adhesive substance 

 you can make by mixing quicklime with white of egg. 



The body of the male bee is covered with red down of 

 rather a bright tint, but in the female it is of a beautiful 

 velvety black, and the wings show a pleasing shade of deep 

 violet colour. It is the female alone who constructs the 

 nest. For this purpose she seeks out a dry spot, and scrapes 

 together a little heap of cement which she makes into a 

 pellet about the size of those used for shooting rabbits. 

 Carrying this in her jaws, she flies with it to the place she has 

 decided upon and on arriving there deposits her burden on 

 the wall and proceeds to fashion a rounded pad. From time 

 to time she fetches grains of sand and grit and embeds them 

 in the cement while it is still soft. 



In order to save labour and at the same time to economize 

 in the expenditure of mortar, the insect chooses coarse 

 materials, using large fragments of grit which are for her, 

 in proportion to her size, true building stones. She selects 

 them one by one with care, seeming to prefer those which 

 are very hard and have sharp corners so that when they are 

 fitted together they give support to each other and contribute 

 to the solidity of the whole structure. Beds of mortar, 

 sparingly spread between the stones, hold them firmly to- 

 gether. The outside of the mass thus takes on the appear- 

 ance of an irregularly built wall, such as you may see during 

 a country walk, the stones with all their natural irregularities 

 making a rough, uneven surface ; but the interior must be 

 smooth so as not to injure the tender skin of the grub, and 

 on that account it is plastered over with pure mortar. 

 Except for this, however, the chamber is finished off quite 

 carelessly, as though with heedless sweeps of the trowel, 

 and to make it more comfortable the grub, as soon as it has 



140 



