58 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



near tlic liuli wIktc the spider waits, is eonniuinly t\\u[v long ^'nougli to 

 allow tlie active ereature to reach ami secure her victim, when eai)ture is 

 desirable. When for any reason eai)ture is not desirable or prudence sug- 

 gests caution, tlie nearness of the spider to an insect tlius arrested on tlie 

 naked radii lyings it within her vision, which at the best seems to be 

 limited. On tlie contrary, insects who strike upon the outer margin are 

 not only detained by the viscid beads, but made comparatively harmless. 

 T). The Free Zone gives the further advantage of allowing the s})ider 



easy access to the under part of the 

 snare, a convenience which is some- 

 times imi>ortant. It is perhaps worth 

 noting here that vertical snares wliicb 

 have an open hub appear quite com- 

 monly to liave no free zone, tliat 

 jiart of the web being occupied by 

 the notched zone prolonged to tlie 

 inner boundary of the spirals. ^ Thus in either case, although by an inter- 

 esting variation in spinning habit, the way is left open for tlie spider to 

 pass from one side of her orb to tlie other. I have watched with great 

 interest the agility of a large Argiope in swinging herself from one side 

 of her shield to the other when threatened by danger. I could always by 

 demonstrations with finger or pencil cause her to change sides. This was 

 done invariably by crawling through the free zone. The space seemed over 

 small to give passage to such a large creature, but the elasticity of the 

 threads readily permitted the transfer, 

 which was made with remarkable deft- 

 ness and dexterity. 



The chief purpose of the Notched 

 Zone seems to be to strengthen the 



•KT ^ , , "*'*'g1j, and particularly to brace 



Notched Tin- •..• ^i 



Zone '^ "^ position the radii 



before the spirals are wrought 



in. My observations indicate that the 



notched spirals are invariably woven 



in before the beaded spirals. The outer 



or diverging ends of the radii being supiwrted by the Foundation lines, 



the inner or converging ends by the notched space, the spicier begins to 



lay in her foundation spirals from the inner margin of the spiral simce, 



working toward the circumference. Thus her operations are conducted 



somewhat after the architectural modes of a human builder erecting a 



large scaffolding. 



' I make this statement with some qualifications and cannot positively s:iy tluit it is true 

 •of all snares witli open hubs. Th.it it is with niaiiy I know. The jujint is mw fur furtlicr in- 

 vestigation. 



