HABITATIONS OF INSECTS. 249 



mansions of her offspring. For this she usually selects an angle, sheltered 

 by any projection, on the south side of a stone wall. Her next care is to 

 provide materials for the structure. The chief of these is sand, which she 

 carefully selects grain hy grain from such as contains some mixture of earth. 

 These grains she glues together with her viscid saliva into masses the size 

 of smalt shot, and transports by means of her jaws to the site of her castle. 1 

 With a number of these masses, which are the artificial stone of which her 

 building is to be composed, united by a cement preferable to ours, she first 

 forms the basis or foundation of the whole. Next she raises the walls of a 

 cell, which is about an inch in length, and half an inch broad, and, before its 

 orifice is closed, in form resembles a thimble. This, after depositing an egg 

 and a supply of honey and pollen, she covers in, and then proceeds to the erec- 

 tion of a second, which she finishes in the same manner, until the whole num- 

 ber, which varies from four to eight, is completed. The vacuities between 

 the cells, which are not placed in any regular order, some being parallel to the 

 wall, others perpendicular to it, and others inclined to it at different angles, 

 this laborious architect fills up with the same material of which the cells 

 are composed, and then bestows upon the whole group a common cover- 

 ing of coarser grains of sand. The form of the whole nest, which when 

 finished is a solid mass of stone so hard as not to be easily penetrated with 

 the blade of a knife, is an irregular oblong of the same colour as the sand, 

 and to a casual observer more resembling a splash of mud than an artificial 

 structure. These bees sometimes are more economical of their labour, and 

 repair old nests, for the possession of which they have very desperate com- 

 bats. One would have supposed that the inhabitants of a castle so fortified 

 might defy the attacks of every insect marauder. Yet an Ichneumon and 

 a beetle (Clerus apiarius) both contrive to introduce their eggs into the 

 cells, and the larvae proceeding from them devour their inhabitants. 2 



Other bees of the same group with that last described use different 

 materials in the construction of their nests. Some employ fine earth made 

 into a kind of mortar with gluten. Another (Osmia* ccerulescens), as we 

 learn from De Geer, forms its nest of argillaceous earth mixed with chalk, 

 upon stone walls, and sometimes probably nidificates in chalk pits. O. 

 bicornis, according to Reaumur, selects the hollows of large stones for the 

 site of its dwelling ; but in England seems to prefer rotten posts and 

 palings, in which it bores upwards, and then forms the partitions of its cells 

 of clay and sand glued together. One species of this genus (0. gallaruni) 

 saves itself trouble by placing its cells in an abandoned gall of the oak, and 



1 Reaumur plausibly supposes that it has been from observing this bee thus 

 loaded that the tale mentioned by Aristotle and Pliny, of the hive-bee's ballasting 

 itself with a bit of stone previously to flying home in a high wind, has arisen. 



8 Reaum. vi. 5788. Mon. Ap". Angl. i. 179. According to M. Goureau, Reaumur 

 and succeeding entomologists have always confounded under Megachile muraria two 

 very distinct species. The first, which he considers the true one, constructs its nest 

 in April, selecting the exposed surface of a rock, stone, or wall (not an angle), 

 and preferring solitary places distant both from the noise of the abode of man and 

 from the habitations of its own tribe ; whereas the other, which does not begin its 

 nest till the end of May or beginning of June, always places it in the angle of some 

 wall or pilaster, &c. of a building, seeming to prefer inhabited houses and to be near 

 others of its species, close to whose nests it often places its own. (Ann. Soc. Ent. 

 de France, ix. 118.) 



3 Apis. **. c. 2. i. K. 



