The Life of the Fly 



curious gymnastic display, that of this soft, 

 hanging spine turning and swaying, while the 

 grapnels feel in every direction for a thread. 



All this labour results in a sort of casing 

 of little white cords. The work lacks firm- 

 ness and regularity. Nevertheless, judging 

 by the builder's methods, I can see that the 

 building would not be devoid of merit if the 

 materials gave it a better chance. The Cad- 

 dis-worm estimates the size of its pieces very 

 fairly; it cuts them all to nearly the same 

 length; it always arranges them crosswise on 

 the margin of the case; it fixes them by the 

 middle. 



Nor is this all: the manner of working 

 helps the general arrangement considerably. 

 When the bricklayer is building the narrow 

 shaft of a factory-chimney, he stands in the 

 centre of his turret and turns round and round 

 while gradually laying new rows. The Cad- 

 dis-worm acts in the same way. It twists 

 round in its sheath; it adopts without incon- 

 venience whatever position it pleases, so as to 

 bring its spinneret full-face with the point to 

 be gummed. There is no straining of the 

 neck to left or right, no throwing back of 

 the head to reach points behind. The animal 

 has constantly before it, within the exact 



192 



