XXI EXPERIMENTS 297 



detach pollen, and sooner or later effaces it. It is 

 therefore in the very middle of the thorax — between 

 the wings — that I drop the gummed chalk. 



In such work it is hardly possible to wear gloves. 

 The fingers require all their dexterity to seize the 

 mason bee with sufficient delicacy, and to master 

 her struggles without rough pressure. It is evident 

 that if nothing else be gained, one is sure of stings ; 

 with a little address they can generally be avoided, 

 but not always ; one must take them with resigna- 

 tion. Besides, a mason bee's sting is by no means 

 so painful as that of a hive bee. The white spot 

 dropped on the thorax — off goes the mason bee, and 

 the mark dries as she goes. 



The first time I tried the experiment I took 

 two mason bees busy at their nests on the boulders 

 covering the alluvial lands along the Aygues, not 

 far from Serignan, and carried them to my home at 

 Orange, where I freed them after marking each. 

 According to the Ordnance map the distance be- 

 tween the two places is about four kilometres in a 

 right line. The captives were freed in the evening 

 at an hour when bees begin to leave off work, so 

 it was likely that my two would spend the night 

 somewhere near. 



The next morning I returned to the nests. It 

 was still too cold, and work was suspended. When 

 the dew was dried the masons set to work. I saw 

 a bee, but without the white spot, taking pollen to 

 one of the two nests whence had come the travellers 

 whom I expected. A stranger, having found the 

 cell unoccupied, and having expatriated the owner, 

 had established herself there, unaware that it was 



