SPIDERS' WEBS 



97 



prey. The temporary line or scaffolding is then cut 

 away. 



The whole process of making a web takes about half 

 an hour, and after finishing it the spider retires. Her 

 object now is to keep in touch with the movements of 

 the web. This she does through her feet, which are 

 sensitive to the slightest vibration, and her complex 

 nervous system probably enables her to interpret 

 each kind of vibration as 

 signifying a definite disturb- 

 ance. In response to the 

 tug she feels her action takes 

 several forms. It may be 

 that a gust of wind will 

 immediately destroy the web, 

 or that a large insect may 

 blunder into it. But in the 

 event of calm weather and no 

 accidents the advent of prey 

 may be, and no doubt is, 

 eagerly and confidently ex- 

 pected. Should a fly become 

 entangled, the spider is at 

 once aware, and adapts her 

 behaviour accordingly. She 

 evolves her stickiest silk, seizes the fly, and, running 

 round and round her prey, envelops it somewhat 

 as she spun the circular web lines. She now plunges 

 her poison-organs into the fly and proceeds to suck 

 its juices, thereafter casting out the skin and smoothing 



FIG. 22. Nest of Cave Spider 

 (Meta menardi}, to show the 

 way in which the eggs are 

 surrounded by silk and sup- 

 ported by a stalk. (From a 

 specimen in the Manchester 

 Museum. ) 



