B0MBUS. 
317 
quired. A vaulted covering and sides is thus formed 
or extended within the cavity by the plaiting or wreath¬ 
ing together of these sprigs of moss, and the inside of 
which is further strengthened by being plastered with a 
coating of the pseudo-wax, which, however, smells much 
like true wax, and with which the lower loose filaments 
of the moss are intermingled, that one cannot be sepa¬ 
rated from the other without tearing the whole to pieces. 
Thus ingeniouslv do these insects enclose their home. 
These nests are not always on the surface, but often 
cavities of the necessary size are thus lined, and then 
they are doubly secure. Within these nests, with the 
increase of the population the number of the cocoons of 
course increases, as they are never used twice over, ex¬ 
cepting that when they are conveniently situated for the 
purpose they are converted into honey pots. Thus 
sometimes several layers are formed of these irregularly- 
placed cocoons, of which the longest diameter is, how¬ 
ever, always perpendicular to the horizon. In this way 
B. muscorum , senilis, fragrans , and others build. Some 
use a naked cavity, and merely secure it in its crevices 
from the filtering intrusion of rain or other water, the 
closing patches being formed of the usual waxy material. 
This is the practice of B. terrestris , which associates the 
largest communities of all; and B. lapidarius seeks 
cavities among stones or in the earth, and forms a nest 
of a regular oval, but merely clothes the sides, which is 
done by bits of moss and grass carried carefully home. 
The domestic arrangements within are much the same 
in all, the prolific females and the neuters being the 
labourers, which perform all the duties of building, the 
collecting and caring for the young, the function of the 
males being limited to the perpetuation of the species. 
