Weavers and Spinners. 



when this is accomplished she places the winding zigzag 

 band in position between two central spokes of the 

 web. The snare completed, the spider takes up her 

 station, head downwards, upon the central shield, in 

 which position she is ready to drop from her snare 

 should danger threaten, or to rush upon any unfortu- 

 nate insect blundering into her web. The zigzag ribbon 

 is not merely ornamental, but serves to strengthen the 

 snare and probably provide a reserve supply of silk, 

 should an emergency arise calling for an instant supply 

 beyond the powers of the spider's spinnerets. There is 

 a Mauritian spider which constructs a snare with zigzag 

 bands similar to those of the Basket Argiope, and uses 

 them as a reserve supply of silk for enveloping partly 

 entangled insects whose struggles are too vigorous to 

 succumb to the rather scanty supply of thread emitted 

 from its spinnerets at the time of capture. By this 

 means this spider has been seen to overcome a grass- 

 hopper much more powerful than itself by dexter- 

 ously throwing, with the aid of its hind leg, portions of 

 the zigzag ribbon of silk over its writhing, violently 

 kicking victim. 



In Texas there lives a most remarkable spider which 

 first constructs a horizontal orb web, and then pro- 

 ceeds to convert it into a perfectly formed dome. The 

 spider accomplishes this by attaching threads to various 

 points on the upper surface of the horizontal wheel, the 

 central portion of which is gradually pulled up until 

 the height of the dome is nearly equal to the diameter 

 of its base. The snare, however, does not consist of 

 this alone ; for when that has been completed, the spider 

 forms a perfect sheet of irregular lines beneath it, while 



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