XXI EXPERIMENTS 301 



colony of Chalicodoma sicula in full activity. I can 

 draw at pleasure on the populous city. The insect 

 is small — less than half the size of C. muraria ; no 

 matter — all the more merit if it can traverse the four 

 kilometres which I have in reserve for it, and find its 

 nest. I took forty, isolating them as usual in paper 

 cones. 



A ladder was placed against the wall in order to 

 reach the nest ; it was to be used by my daughter 

 Aglae, to allow her to mark the exact instant when 

 the first one returned. I set the clock on the 

 mantelpiece and my watch together, that I might 

 compare the moment of departure and arrival. Then 

 I carried off my forty captives to the spot where 

 Chalicodoma muraria works beside the Aygues. The 

 expedition had a double scope — to observe Reaumur's 

 mason bee and set the Sicilian one free. The latter 

 would have to fly back four kilometres. 



At length my prisoners were released — all marked 

 with a large white dot in the middle of the thorax. 

 It is not for nothing that one successively handles 

 forty wrathful Hymenoptera which forthwith unsheath 

 and make play with their poisoned stings. Before 

 the mark could be made, too often the stab was given, 

 and my burning fingers moved in self-defence some- 

 times against my will ; I handled them with more 

 consideration for myself than for the insect, and 

 sometimes squeezed my bees too hard. To experi- 

 ment in order to lift a small corner of the veil 

 that covers a truth is a beautiful and noble thing, 

 which can enable one to brave many perils, yet 

 surely one may show a little impatience if in a brief 

 space of time one's finger tips get stung forty times. 



