ANTS, WASPS, AND BEES. 211 



excavate. Having drilled a cavity, they collect a 

 store of provender for their prospective young, on 

 which they deposit the egg. They then collect a 

 small quantity of clay mixed with sand, which they 

 knead together by the aid of a viscous secretion which 

 they disgorge, and this forms a concrete that hardens 

 rapidly and firmly. With this substance rolled up in 

 a ball within their mandibles they fly back to their 

 cavity and close the cell, separating it securely from 

 the next store of provision which is placed upon it 

 and upon which another egg is laid. Thus a second 

 and a third cell are formed and sealed up, and so on, 

 until the cavity is filled. 



Two beautiful little Hymenopterous insects (Chrysis 

 ignita and Chrysis cyanea) are parasites, bred at the 

 expense of these Carpenter Bees. 



The Mason Bees, of the genus Osmia, domicile 

 themselves in old walls, sandbanks, and decaying 

 willow stumps. They have been called Masons from 

 the habit they have of agglutinating particles of sand 

 or earth, mixed with minute pebbles scarcely larger 

 than grains of sand, or raspings of wood combined in 

 the same manner with a secretion which they emit, 

 and of which they form their cells. These cells are 

 rather rough externally, according to the nature of the 

 material of which they are composed, but they are 

 very smooth within. Where the cavity is restricted, 

 they place them end to end, but where it is more 

 roomy they affix them side by side, adapting them- 

 selves to the circumstances in which they may be 

 placed. The insects may be found frequenting many 

 kinds of flowers, especially those which are abundant 

 p ?. 



