THE BLUEBOTTLE 103 



stationary and impassive and is easily observed through 

 my lens. A movement on my part would doubdess 

 scare her ; but my restful presence gives her no anxiety. 

 I am nothing to her. 



The discharge does not go on continuously until the 

 ovaries are exhausted; it is intermittent and performed 

 in so many packets. Several times over, the Fly leaves 

 the bird's beak and comes to take a rest upon the wire- 

 gauze, where she brushes her hind-legs one against the 

 other. In particular, before using it again, she cleans, 

 smooths and polishes her laying-tool, the probe that 

 places the eggs. Then, feeling her womb still teeming, 

 she returns to the same spot at the joint of the beak. 

 The delivery is resumed, to cease presently and then be- 

 gin anew. A couple of hours are thus spent in alternate 

 standing near the eye and resting on the wire-gauze. 



At last it is over. The Fly does not go back to the 

 bird, a proof that her ovaries are exhausted. The next 

 day she is dead. The eggs are dabbed in a continuous 

 layer, at the entrance to the throat, at the root of the 

 tongue, on the membrane of the palate. Their number 

 appears considerable; the whole inside of the gullet is 

 white with them. I fix a little wooden prop between 

 the two mandibles of the beak, to keep them open and 

 enable me to see what happens. 



I learn in this way that the hatching takes place in a 

 couple of days. As soon as they are born, the young 

 vermin, a swarming mass, leave the place where they are 

 and disappear down the throat. 



The beak of the bird invaded was closed at the start, 



