The Grey Flesh-Flies 



is still projecting. The head is not the head 

 of a Fly, but a queer, enormous mitre, spread- 

 ing at the base into two red skull-caps, which 

 are the eyes. To split her cranium in the mid- 

 dle, shunt the two halves to the right and 

 left and send surging through the gap a 

 tumour which staves the barrel with its pres- 

 sure : this constitutes the Fly's eccentric 

 method. 



For what reason does the hernia, once the 

 keg is staved, continue swollen and projecting? 

 I take it to be a waste-pocket into which the 

 insect momentarily forces back its reserves of 

 blood in order to diminish the bulk of the 

 body to that extent and to extract it more 

 easily from the nymphal slough and after- 

 wards from the narrow channel of the shell. 

 As long as the operation of the release lasts, 

 it pushes outside all that it is able to inject of 

 its accumulated humours; it makes itself small 

 inside the pupa and swells into a bloated de- 

 formity without. Two hours and more are 

 spent in this laborious stripping. 



At last, the Fly comes into view. The 



wings, mere scanty stumps, hardly reach the 



middle of the abdomen. On the outer edge, 



they have a deep notch similar to the waist of 



a violin. This diminishes by just so much the 



249 



