The Life of the Fly 



in danger of Inoculation by that whereon It 

 grows fat ? I dare not rely upon experiments 

 conducted by myself: my clumsy im.plements 

 and my shaky hand make me fear that, with 

 subjects so small and delicate, I might inflict 

 deep wounds which of themselves would bring 

 about death. 



Fortunately, I have a collaborator of in- 

 comparable skill in the parasitic Chalcidid. 

 Let us apply to her. To Introduce her germs, 

 she has perforated the maggot's paunch, has 

 even done so several times over. The holes 

 are extremely small, but the poison all around 

 is excessively subtle and has thus been able. In 

 certain cases, to penetrate. Now what has 

 happened? The pupae, all from the same ap- 

 paratus, are numerous. They can be divided 

 into three not very unequal classes, according 

 to the results supplied. Some give me the 

 adult Flesh-fly, others the parasite. The rest, 

 nearly a third, give me nothing, neither this 

 year nor next. 



In the first two cases, things have taken 

 their normal course: the grub has developed 

 Into a Fly, or else the parasite has devoured 

 the grub. In the third case, an accident has 

 occurred. I open the barren pupae. They 

 are coated Inside with a dark glaze, the re- 

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