The Geometry of the Epeira's Web 



point the explanation is acceptable. The 

 Spider, for her part, will have none of it. Un- 

 related to the appendix-lacking, corkscrew- 

 twirling Worm, she is nevertheless familiar 

 with the logarithmic spiral. From the cele- 

 brated curve she obtains merely a sort of 

 framework; but, elementary though this 

 framework be, it clearly marks the ideal 

 edifice. The Epeira works on the same prin- 

 ciples as the Mollusc of the convoluted shell. 



The Mollusc has years wherein to construct 

 its spiral and it uses the utmost finish in the 

 whirling process. The Epeira, to spread her 

 net, has but an hour's sitting at the most, 

 wherefore the speed at which she works com- 

 pels her to rest content with a simpler pro- 

 duction. She shortens the task by confining 

 herself to a skeleton of the curve which the 

 other describes to perfection. 



The Epeira, therefore, is versed in the geo- 

 metric secrets of the Ammonite and the 

 Nautilus pompilus; she uses, in a simpler 

 form, the logarithmic line dear to the Snail. 

 What guides her? There is no appeal here to 

 a wriggle of some kind, as in the case of the 

 Worm that ambitiously aspires to become a 

 Mollusc. The animal must needs carry within 



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