274 HYMBNdPTERA. 
constructed in the same manner, in con- 
tact with the first ; six or eight cells, 
which this industrious little mason huilds 
in as many days, compose a nest ; and 
outside of the whole she adds a rough 
coat of coarser sand, so that the entire 
fabric appears like a stone projecting from 
the wall. 
Lucy. It is most surprising how so 
many curious circumstances were ever 
found out. 
Mother, We are indebted for these 
details to the patient and indefatigable 
attention of various naturalists ; but 
chiefly to Reaumur, a French philosopher, 
who flourished in the beginning of the 
last century. 
Lucy, As you say, mamma, that 
every insect has its enemies, I suppose 
even the stone house of the mason bee 
does not entirely protect it ? 
Mother. You are very right, Lucy ; 
there is a species of ichneumon, which is 
provided with a boring machine, that can 
pierce through the artificial stone into the 
