THE HOUSE-SPIDER. 477 



by any human artist in this circumstance, that, in our 

 work, the threads extended in length are interlaced 

 with those that are carried on transversely ; whereas 

 the threads of a Spider's woof only cross the threads 

 of the warp, and are glued to them in the points 

 where they mutually touch, and are not either in- 

 serted or interwoven. 



The threads along the border of the work are 

 doubled or trebled, by the Spider's opening all her 

 teats at once, and glueing several threads one over 

 another ; sensible that the extremity of the web 

 ought to be hemmed and fortified to preserve it 

 from being torn : she likewise further secures and 

 supports it with strong loops, or double threads, 

 which she fixes all around it, and which hinder it 

 from being the sport of the winds. 



From time to time she finds it necessary to clear 

 away the dust, which would otherwise incommode 

 her web, and she sweeps the whole by giving it a 

 shake with her paw ; but in doing this she so nicely 

 proportions the force of the blow to the strength of 

 the work that nothing is ever broken. 



From all parts of the web are drawn several 

 threads, which terminate like rays in a centre at 

 the place of her concealment. The vibration of 

 any of these threads is communicated to her, and 

 gives her notice whenever there is game in the net, 

 and accordingly she springs upon it in an instant. 

 She derives another advantage from this retreat un- 

 der her web, and that is the opportunity it affords 

 of feasting on her prey in full security ; and besides 

 this it gives her the power of concealing. the carcas- 



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