The Geometry of the Epeira's Web 



But we must not rely too mudi on this rule, 

 say others. TTie Angular Epeira, the Pale- 

 tinted Epeira and the Diadem Epeira, or 

 Cross Spider, aU three more or less short- 

 limbed, rival the Banded Epeira in the spac- 

 ing of their lime-snares. The last two 

 even dispose them with greater Intervening 

 distances. 



We recognize in another respect that the 

 organization of the animal does not imply an 

 unmutable type of work. Before beginning 

 the stidcy spiral, the Epeirae first spin an 

 auxiliary intended to strengthen the stays. 

 This spiral, formed of plain, non-glutinous 

 thread, starts from the centre and winds in 

 rapidly-widening circles to the circumference. 

 It is merely a temporary construction, where- 

 of nau^t but the central part survives when 

 Ae Spider has set its limy meshes. The 

 second spiral, the essential part of the snare, 

 proceeds, on the contrary, in serried coils from 

 the circumference to the centre and is com- 

 posed oitirely of viscous cross-threads. 



Here we have, following one upon the 



other, by a sadden alteration of the machine, 



two volutes of an entirely different order as 



regards direction, the number of whorls and 



38S 



