442 HABITATIONS OF INSECTS. 



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 bestov/s 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 some- 

 times are more economical of their labour, and repair 

 old nests, for the possession of which they liave 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 apiarius, F.) both contrive to introduce 

 their eggs into the cells, and the larvae proceeding from 

 them devour their inhabitants*. 



Other bees of the same family 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 (A. ccerulescens, L.), 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. Apis bicornis selects the hol- 

 lows of large stones for the site of its dwelling; while 

 others prefer the holes in wood. 



The works thus far described require in general less 



^ Rcaum. vi. 57-88. Mon. Jp. Angl. i. 179. 



