438 HABITATIONS OF INSECTS. 



What then becomes of it ? you will ask. It is impossible 

 that it should make its escape through eleven superincum- 

 bent cells without destroying the immature tenants ; and 

 it seems equally impossible that it should remain patiently 

 in confinement below them until they are all disclosed. 

 This dilemma our heaven-taught architect has provided 

 against. With forethought never enough to be admired 

 she has not constructed her tunnel with one opening only, 

 but at the further end has pierced another orifice, a kind 

 of back-door, through which the insects produced H)y the 

 first-laid eggs successively emerge into day. In fact, all 

 the young bees, even the uppermost, go out by this road ; 

 for, by an exquisite instinct, each grub, when about to 

 become a pupa, places itself in its cell with its head down- 

 wards, and thus is necessitated, when arrived at its last 

 state, to pierce its cell in this direction a . 



Ceratina albilabris of Spinola, who has given an inter- 

 esting account of its manners, forms its cell upon the 

 general plan of the bee just described, but, more econo- 

 mical of labour, chooses a branch of briar or bramble, 

 in the pith of which she excavates a canal about a foot 

 long and one line, or sometimes more, in diameter, with 

 from eight to twelve cells separated from each other by 

 partitions of particles of pith glued together 5 . 



Such are the curious habitations of the carpenter bees. 

 Next I shall introduce you to the not less interesting 

 structures of another family which carry on the trade of 

 masons, (Megachile muraria,) building their solid houses 

 solely of artificial stone. The first step of the mother bee 

 is to fix upon a proper situation for the future mansion of 



a Reaum. vi. 39-50. Mon. Ap. Angl. i. 189. Apis. **. *. 2. /3. 

 b Ann. du Mus. x. 236. 



