238 ABOUT SPIDERS AKD THEIR WEBS. 



is elastic as well as adhesive, the insect is detained 

 long enough to enable the spider to seize and kill it. 



Sometimes the victim is strong enough to make the 

 spider fear to grapple it in the usual way. In such 

 eases, it casts a cloud of silken fibres over the insect, 

 and by means of its forelegs rolls it over and over, 

 enveloping it so completely that it cannot be seen 

 through its silken shroud. Here, again, the elasticity 

 of the silk comes into operation, and holds the captive 

 so firmly that even a bee or a wasp has no chance of 

 escaping, but is utterly helpless, with its wings and legs 

 swathed firmly to the body. 



Another curious example of this elasticity may 

 sometimes be seen on stormy days, when the wind is 

 so violent as to threaten destruction to the webs, 



The spider begins by attaching additional "guy" 

 ropes in different directions, but if these should not be 

 sufficient, it has recourse to a singularly ingenious expe- 

 dient. Attaching a thread to the lower part of the web, 

 the spider lowers itself to the ground, where it searches 

 for a piece of stick or a stone which it thinks suitable for 

 its purpose. Carrying this burden to the thread by 

 which it had lowered itself, it ascends a few inches, fastens 

 the stone to the thread, and then leaves it swinging in 

 the air. 



No better plan could be adopted by the most expe- 

 rienced engineer, and it is wonderful to see how exactly 

 the spider adapts the weight to the work which it has to 

 perform. 



