
— 
poy 
s 

368 THE INSECT WORLD. 
that the head of the young is always turned downwards, in 
such a way that it is by the bottom of its cell that it comes 
out. The bottom of the first is very near the surface of the 
wood, so that the insect it encloses has only a thin layer of wood 
to pierce through in order to set itself free. Hach one of 
those which are born next has only to pierce the floor of its 
hiding-place to find the road before them free. The Xylocope 
Serial 
} ma fl if: 
A leesiiscal 





Fig, 340.—Mason Bee and Nest. 
pass the winter in the pupa state, and the perfect insects, with 
wings of a beautiful metallic violet, appear in the spring, but are 
not found in this country. 
Other solitary bees have their hind legs unsuited for the gather- 
ing of pollen, but have the rings of the abdomen furnished with 
hairs for that purpose. Such are the Mason bees of Réaumur, 
belonging to the genera Osmia and Chalicodoma,* which build their 
nests against walls of tempered earth, which become very hard. 
* At a meeting of the Entomological Society of London, Feb. 18th, 1867, Mr. 
Newman exhibited the lock of a door, one of several which, in 1866, were found at 
the Kent Waterworks, Deptford, to be completely filled and choked up with nests of 

