A FIRM FOUNDATION 



series, is very thick, and is clearly intended to protect the 

 contents of the tube against damage from without. 



Each chamber is furnished with a collection of pollen in 

 the midst of which the bee disgorges a little honey, which 

 filters and penetrates amongst the grains and forms a 

 nutritious pulp. The egg is deposited with one end em- 

 bedded in this sweet cake, and thus it comes about that the 

 grub is born with its mouth in the midst of plenty and is 

 able to commence the serious business of eating without 

 the necessity of changing its position. When it has consumed 

 the whole store of food it spins a cocoon, from which there 

 emerges in due course an adult Osmia, whose active life 

 endures scarcely a single year. 



One of the most plentiful of English insects is the little 

 yellow-banded black wasp called Odynerus murarius which 

 may be observed on sunny days flitting about sand-banks, 

 busily engaged in burrowing and building. This wasp is 

 an excavator as well as a mason, and it works on a very 

 curious and ingenious plan, for as it burrows in the ground 

 it makes tiny bricks of the material it digs out of the hole, 

 and builds them up in the form of a round tower about the 

 mouth of the nest. About June and the early part of July 

 you may frequently see these strange chimney-like structures 

 projecting from the surface of sand-banks which are exposed 

 to the glare of the sun. The Odynems chooses hard, 

 compact sand for its operations sand which is almost as 

 hard as stone, and on which it is difficult to make any 

 impression with your fingers. In this it displays much 

 wisdom, for the building that is founded upon rock is 

 proverbially more likely to stand than one raised upon 

 loose sand; while, as for the burrow, it is even more im- 

 portant that the ground should be fairly solid, for other- 

 wise there would be every likelihood of the sides of the 



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