THE HOME OF THE BEES. 375 
sides of their cells.” In three other cells “several hun- 
dred minute Ichneumons (Anthophorabia megachilis) — 
were seen, which came forth as soon as the cells were 
opened.” 
The habits of the little blue or green Mason-bees 
(Osmia), are quite varied. They construct their cells in 
the stems of plants and in rotten posts and trees, or, like 
Andrena, they burrow in sunny banks. An European 
species selects snail shells for its nest, wherein it builds its 
earthen cells, while other species nidificate under stones. 
Curtis found two hundred and thirty cocoons of a British 
species ( Osmia paretina), placed on the under side of a flat 
stone, of which one-third were empty. Of the remainder, 
the most appeared between March and June, males ap- 
pearing first; thirty-five more bees were developed the 
following spring. Thus there were three successive 
broods, for three succeeding years, so that these bees 
lived three years before arriving at maturity. This may 
account for*the insect years, which are like the “apple 
years,” seasons when bees and wasps, as well as other in- 
sects, abound in unusual numbers. 
Mr. G. R. Waterhouse, in the Transactions of the En- 
tomological Society of London, for 1864 (3d series, vol. 
2, p. 121), states that the cells of Osmia leucomelana 
“are formed of mud, and each cell is built separately. 
The female bee, having deposited a small pellet of mud in 
a sheltered spot between some tufts of grass, immediately 
commences to excavate a small cavity in its upper sur- 
face, Scraping the mud away from the centre towards the 
margin by means of her jaws. A small shallow mud-cup 
is thus produced. It is rough and uneven on the outer 
Surface, but beautifully smooth on the inner. On wit- 
essing thus much of the work performed, I was struck 
