GEOMETRICAL SPIDERS 89 



4. The temporary spiral. 



5. The viscid spiral. 



I have some remarks to make on each step in this 

 work. It is a fabric worthy of our note. The 

 strength of its transparent filaments, the geometrical 

 accuracy of its lines, the subtlety of its device and 

 the unerring certainty of its power cannot but excite 

 our wonder and admiration. To produce such a 

 consummate work needs the skill of a master-hand 

 moved by a geometrical sway. I will endeavour to 

 disclose the nature of this handiwork, to show how all 

 this accuracy is attained. I hope to demonstrate how 

 the spider works ; how it measures its equal angles ; 

 draws its perfect parallels ; secures its equidistant 

 lines ; how it achieves all this mathematical accuracy 

 which, woven into its architecture, makes for the 

 beauty, the perfection and the certainty of its 

 snare. 



First with respect to the construction of the founda- 

 tion-lines, the fact of most interest is the ingenious 

 manner in which the spider pays out its filament to the 

 wind. The spider does not act altogether haphazard, 

 allowing the filament to trail away from the spinnerets 

 in search of a chance attachment. It shows some 

 method even in this simple act. It supports the 

 thread with the claws of its second tarsus and tests its 

 every quiver and motion. With the filament curved 

 over the tip of its tarsus, it is really fishing for an 

 attachment, using the most delicate of lines and the 

 most sensitive of fingers. But the filament itself is 

 more worthy of notice. It is specially adapted to its 

 peculiar purpose. Not only is it light and slender, fit 

 to be supported on a gentle breeze, but the spider ha^ 



