THE LEAF-CUTTER BEES. 279 



to six) as the body-whorl will contain, when the 

 aperture is carefully closed with pellets of clay, sticks, 

 and small pebbles, fastened together with a glutinous 

 secretion. In the larger snails, the Bee, having a 

 greater space to fill up, places two, three, or even four 

 cells together, the number increasing as she ap- 

 proaches the mouth. The O. parietina, a species 

 which has only been found in the North of England 

 and in Scotland, makes no regular nest, but attaches 

 numerous pellets of pollen to the lower surface of stones 

 lying upon the ground, and in these lays her eggs. 



The species of the genus Megachile, which is nearly 

 allied to Osmia, exhibit a peculiarity in the structure 

 of their dwellings which must not be passed over. 

 They form burrows in various situations, some species 

 selecting banks for this purpose, whilst others prefer 

 the dead trunks of trees, rotten posts, &c. ; and the 

 common species, M. centuncularis , which may be con- 

 stantly observed in our gardens in the summer, 

 appears to form its nest in all these situations indif- 

 ferently. When the burrow is completed, the Bee 

 lines it with pieces of leaves, which she cuts out in 

 the form of the segment of a circle by means of her 

 jaws, as neatly and almost as rapidly as it could be 

 done with a pair of scissors. Hence these Bees are 

 denominated Leaf- cutter Bees ; and they are also called 

 Upholste7'er Bees by some writers, from their Hning 

 the walls of their nests with a sort of tapestry"^. 

 Their favourite leaves are those of the rose and la- 



* The Megachile (Anthocopa) Popaveris uses the scarlet petals 

 of the common poppy for lining its nest ; a tasteful material, which 

 especially justifies the application to it by Reaumur of the name 

 Upholsterer Bee. It has been said to occur in this country, 

 but apparently upon insufficient grounds. 



