How Animals Work. 



any insect that might blunder into the web would 

 easily be able to free itself. So now Madam Spider 

 must set to work to spin a spiral of viscid thread for 

 the capture of her prey. First of all, however, com- 

 mencing close to the point where her first few spiral 

 turns of thread end, she proceeds rapidly to work in 

 a spiral thread of ordinary silk with the successive 

 turns about as far apart as she can conveniently straddle 

 her legs, to form a kind of scaffolding, by clinging 

 to which she can put in the viscid spiral, which she 

 starts at the circumference and not at the hub of the 

 web. Now she becomes so closely absorbed in her 

 work that it is quite possible to watch her movements 

 with the aid of a hand magnifying glass without in 

 any way disturbing or alarming her. Her movements 

 become exceedingly careful and deliberate, though. by 

 no means slow. With one or both of her hind legs 

 she now proceeds to draw out from the spinnerets suc- 

 cessive lengths of a highly elastic line, which she stretches 

 just at the moment of fixing to a spoke or radius, and 

 then lets go with a snap. If we look at this viscid 

 spiral thread with a magnifying glass, we shall see that 

 it is beaded over with little sticky globules, which appear 

 to be arranged with remarkable regularity. 



Up to quite recent years it was thought that the 

 deposition of these sticky bead-like globules upon the 

 spiral line was a subsequent operation, and, in view 

 of their vast number and regularity, the circumstance 

 naturally excited much interest. It was estimated by 

 one authority that there were at least 120,000 viscid 

 globules in a fourteen-inch web, and yet the construc- 

 tion of this globule-bedecked spiral had only occupied 



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