The Mason-Wasps 



crowd, the grey visitors waited near the 

 threshold for a less busy moment. No harm 

 came to them. 



Inside the establishment, the same peace- 

 ful relations prevail. In this respect I have 

 the evidence of my excavations. In the un- 

 derground charnel-house, so rich in Fly- 

 grubs, I find no corpses of adult Flies. If 

 the strangers were slaughtered in passing 

 through the entrance-hall or lower down, 

 they would fall to the bottom of the burrow 

 promiscuously with the other rubbish. Now 

 in this charnel-pit, as I said, there are never 

 any dead Volucellae, never a Fly of any sort. 

 The incomers, therefore, are respected. 

 Having done their business, they go out un- 

 scathed. 



This tolerance on the part of the Wasps 

 is surprising. And a suspicion comes to 

 one's mind: can it be that the Volucella and 

 the rest are not what the accepted theories 

 of natural history call them, namely, enemies, 

 grub-killers sacking the Wasps'-nest? We 

 will look into this by examining them when 

 they are hatched. Nothing is easier, in Sep- 

 tember and October, than to collect the 

 Volucella's eggs in such numbers as we 

 please. They abound on the outer surface 

 of the Wasps'-nest. Moreover, as with the 

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