Economy of Energy 



favourite building-yards, A solitary and in- 

 dustrious worker, she bores, bit by bit, cir- 

 cular passages the width of one's thumb, as 

 clear-cut as though they were made with an 

 auger. A heap of saw-dust accumulates on 

 the ground and bears witness to the severity 

 of the task. Usually, the same aperture is 

 the entrance to two or three parallel corri- 

 dors. With several galleries there is accom- 

 modation for the entire laying, though each 

 gallery is quite short; and the Bee thus avoids 

 those long series which always create difficult- 

 ies when the moment of hatching arrives. 

 The laggards and the insects eager to emerge 

 are less likely to get in each other's way. 



After obtaining the dwelling, the Carpen- 

 ter-bee behaves like the Osmia who is in pos- 

 session of a reed. Provisions are collected, 

 the egg is laid and the chamber is walled in 

 front with a saw-dust partition. The work 

 is pursued in this way until the two or three 

 passages composing the house are completely 

 stocked. Heaping up provisions and erecting 

 partitions are an invariable feature of the 

 Xylocopa's programme; no circumstance can 

 release the mother from the duty of provi- 

 ding for the future of her family, in the mat- 



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