NATURE'S CRAFTSMEN 



spirals that wind their way over the radii to the central 

 shield. Scoop out a section thereof with a glass cup 

 and examine it with your hand-lens as it is out-stretched 

 across the mouth of the vessel. Every spiral thread is 

 covered with minute beads. Touch your pencil to this 

 spot. See! Your pearly beads have disappeared; and 

 as you withdraw your pencil you perceive that they 

 have melted into a viscid liquid that has caused the 

 silken threads to stick tightly to the pencil. You 

 cannot release it without breaking a gap into the web. 

 It is this armature of viscid beads that makes Argiope's 

 web effective in so entangling insects within the lines 

 that they are usually at her mercy, and escape only by 

 uncommon vigor or a rare chance. The dews of sum- 

 mer gather upon these viscid beads and their connecting 

 threads, forming strings of minute translucent spheres 

 that in the changing lights of morning glisten like 

 diamonds. It is not inapt to compare such a dew- 

 bespangled orb web to a jewelled necklace, for truly 

 fair lady never hung a,bout her neck one more lovely 

 in form or more artistic in construction. Thus seen, 

 there are few objects in nature more striking and beau- 

 tiful than Argiope's snares; but they are terrible engines 

 of destruction to the unfortunates who fall into their 

 embrace. 



Another feature of this remarkable structure, which 

 we are studying here in the tall growth of the brook- 

 side, now catches our eye. The spider's silken shield, 

 or mattress, is placed, as a rule, above the centre of her 

 orb. On either side of it are thrown out strong inter- 

 lacing cords which form an open canopy that serves as 

 fender or protective wings. Insects striking against 

 these are suddenly arrested and are apt to flutter down 



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