The Life of the Fly 



at work, entering her galleries at one time 

 with her harvest of pollen-dust and at another 

 with her little bale of cotton. Might not 

 these autumnal Bees be themselves exploited 

 by the Anthrax, the same that selected the 

 Osmia as her victim a couple of months earl- 

 ier? This would explain the presence of the 

 Anthrax-flies whom I now see fussing about. 

 A little reassured by this conjecture, I take 

 my stand at the foot of the rock, under a broil- 

 ing sun ; and, for half a day, I follow the 

 evolutions of my Flies. They flit quietly in 

 front of the slope, at a few inches from the 

 earthy covering. They go from one orifice to 

 the next, but without even penetrating. For 

 that matter, their big wings, extended cross- 

 wise even when at rest, would resist their en- 

 trance into a gallery, which is too narrow to 

 admit those spreading sails. And so they ex- 

 plore the cliff, going to and fro and up and 

 down, with a flight that is now sudden, now 

 smooth and slow. From time to time, I see 

 the Anthrax quickly approach the wall and 

 lower her abdomen as though to touch the 

 earth with the end of her ovipositor. This 

 proceeding takes no longer than the twinkling 

 of an eye. When it is done, the insect alights 



elsewhere and rests. Then it resumes its sober 



90 



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