284 HABITATIONS OF INSECTS. 



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

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

 of small shot, and transports by means of her jaws to the site of her cas- 

 tle.^ Witli a number of tliese 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 erection of a second, which she finishes in the same 

 manner, until the whole number, which varies from four to eight, is com- 

 pleted. 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 covering 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 color as the sand, and to a casual observer more 

 resembling a splash of mud than an artificial structure. These bees some- 

 times are more economical of their labor, and repair old nests, for the pos- 

 session of which they have very desperate combats. 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 api- 

 arius) both contrive to introduce their eggs into the cells, and the larvae 

 proceeding from them devour their inhabitants.^ 



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^ carulescens) , 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. 

 hicornis. according to Reaumur, selects the hollows of large stones for the 

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

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

 of clay and sand glued together. One species of this genus (O. gallarum) 

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

 and others select, with the like object, empty snail-shells.'' One remarka- 

 ble peculiarity of some of these insects is, that they conceal the place 

 where their cells are situated with some extraneous material. Thus O. 

 gallarum hides the galls it has adopted by glueing round them oak leaves, 



> 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. 



2 Reaum. vi. 57—88. Mim. Ap. Aagl. i. 179. According to M. Goureau, Reaumur and 

 succeeding entomologists have always confounded under Megachile muraria two very dis- 

 tinct species. The first, which he 9onsiders the true one, constructs its nest in April, — 

 selecting the exposed surface of a rock, stone, or wall (not an angle), and preferring soli- 

 tary 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. S. K. * Westwood, Mod. Class, of Ins. ii. 274. 



