THE ANTHRAX FLY 



cell. The others, when they become perfect insects, have 

 implements for mining and demolishing. They have 

 stout mandibles, capable of digging the ground, of 

 pulling down clay partition-walls, and even of grinding 

 the Mason-bee's tough cement to powder. The Anthrax, 

 in her final form, has nothing like this. Her mouth is 

 a short, soft proboscis, good at most for soberly licking 

 the sugary fluid from the flowers. Her slim legs are so 

 feeble that to move a grain of sand would be too heavy a 

 task for them, enough to strain every joint. Her great 

 stiff wings, which must remain full-spread, do not allow 

 her to slip through a narrow passage. Her delicate suit 

 of downy velvet, from which you take the bloom by 

 merely breathing on it, could not withstand the contact 

 of rough tunnels. She is unable to enter the Mason- 

 bee's cells to lay her egg, and equally unable to leave it 

 when the time comes to free herself and appear in broad 

 daylight. 



And the grub, for its part, is powerless to prepare the 

 way for the coming flight. That buttery little cylinder, 

 owning no tools but a sucker so flimsy and small that it 

 is barely visible through the magnifying-glass, is even 

 weaker than the full-grown insect, which at least flies 

 and walks. The Mason-bee's cell seems to this creature 

 like a granite cave. How can it get out *? The problems 

 would be insoluble to these two incapables, if nothing 

 else played its part. 



[257] 



