Reflections upon Insect Psychology 



perfectly convinced. The Mason-bees, there*, 

 fore, shall supply me with the materials for 

 this chapter also. 



A few words, before I begin, about the 

 works. The Mason-bee of the Sheds utilizes, 

 first of all, the old galleries of the clay nest, a 

 part of which she good-naturedly abandons to 

 two Osmiae, her free tenants: the Three- 

 horned Osmia and Latreille's Osmia. These 

 old corridors, which save labour, are in great 

 demand; but there are not many vacant, as the 

 more precocious Osmiae have already taken 

 possession of most of them; and therefore the 

 building of new cells soon begins. These 

 cells are cemented to the surface of the nest, 

 which thus increases in thickness every year. 

 The edifice of cells is not built all at once: 

 mortar and honey alternate repeatedly. The 

 masonry starts with a sort of little swallow's 

 nest, a half-cup or thimble, whose circumfer- 

 ence Is completed by the wall against which it 

 rests. Picture the cup of an acorn cut in two 

 and stuck to the surface of the nest : there you 

 have the receptacle in a stage sufficiently ad- 

 vanced to take a first Instalment of honey. 



The Bee thereupon leaves the mortar and 

 busies herself with harvesting. After a few 

 i6s 



