SPIDERS AND THEIR IVEB-MAKING 201 



between the bushes tliemselves, in fences, in open door- 

 ways, or wherever in the garden a convenient framework 

 presents itself. They are characterized by their circular 

 outline, within which are disposed numerous radii and a 

 series of concentric circular or spiral threads. The cir- 

 cular snare is usually placed within an irregular triangle, 

 or quadrangle, or polygon, which is held in shape and 

 position by stout stay-lines fastened to the adjacent 



Fig. 161. ViG. 162. 



Fig. 161.— An orb-web of Argiope; this web may be from one to two feet 



in diameter. (After iUcCook.) 

 Fig. 162.— Diagram of (one-half) an orb-web; f.s, free space; s.s, spiral 



space; ^.i, "central space; f.z, free zone; n.z, notched zone; h, hub. 



(After McCook. ) 



branches, or fence-rails, or door-frames, or whatever 

 serves as a framework for it. The webs vary greatly in 

 size, the largest being sometimes a foot and a half to two 

 feet in diameter. The spiders which spin them are called 

 garden-spiders or orb-web weavers, and most of them are 

 highly colored, and have a nearly spherical abdomen. 

 They may be found "hanging head downwards, usually 

 near the center of the net; others have a retreat near one 

 edge of the net, in which they hang back downwards. 

 While resting in these retreats they keep hold of some of 



