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Rural School Leaflet 



are the orb webs, the most perfect structures made by living creatures, 

 except by the hand of man. Each species constructs its own kind of 



orb web, but the general plan is 

 similar. The spider first constructs 

 the framework of the supporting 

 lines ; the outer part of this frame- 

 work is irregular and holds the 

 web in place, but the central part 

 is very regular, being constructed 

 like a wheel with many lines radi- 

 ating from the center. All of the 

 threads of the framework are dry 

 and will not adhere to anything 

 that touches them, nor will they 

 stretch. But after the wheel 

 framework is constructed, the spider 

 places on the radiating lines a 

 spiral thread, which is sticky and 

 elastic so that it will adhere to and 

 entangle any insect touching it. 

 Many of the orb weavers spin a zigzag ribbon across the center of 

 their webs to make them stronger. Some species reside at the 

 center of the web, while others have a retreat near the edge of the 

 web. But, in either case, the resting spider has in its claws one 

 or more lines connected with the web, and through them receives warning 

 when an insect is entrapped and jars the net. One 

 of the most interesting observations to be made in 

 the field is to watch a spider construct an orb web. 

 This may be seen easily in the morning or late 

 in the afternoon on summer days. 



Diagram of an orb web 



THE KINDS OF SPIDERS MOST COMMONLY SEEN 



The web weavers. — These have been described just 

 above and there are a large number of species that 

 construct the snares. These include the cobweb 

 weavers, in the comers of ceilings or cellars ; the fun- 

 nel-web weavers, which spin their sheets of web on 

 the grass; the curled-thread weavers, which spin ir- 

 regular webs over weeds and flowers, especially the 

 goldenrod and wild plants ; and the orb-web weavers. 



The crab spiders. — These spin no webs, but lie in wait for their prey 

 They are crab-like in appearance and move backward as readily as forward 



The garden spider; an orb 

 weaver. The black-and- 

 gold spider that makes 

 the egg sac shown sus- 

 pended in the goldenrod 



