The giant orb-weaving spider Nephila clavipes stands 

 guard over her eggs, which are fastened to a leaf. 

 Until the spiderlets hatch, she lets her 8-foot web go 

 untended. ( Florida Everglades. Lorus and Margery 

 Milne) 



The orange-and-black garden spider Argiope auraniia 

 weaves a platform with zigzag runways at the center 

 of her spiral insect trap, and waits there until vibra- 

 tions tell her that a victim has blundered into the 

 tanglefoot. (Connecticut. Andreas Fciningcr) 



spider, often closed by a fitted lid, such as the trap- 

 door spiders produce. 



In and near the tropics of both the Old World and 

 the New, spiders of the genus Nephila weave orb 

 webs between tall trees. Some of these webs are eight 

 feet in diameter, and so sturdily constructed that they 

 sometimes catch small birds and bats as well as quite 

 hirge insects. When a victim blunders into the net, 

 Nephila behaves in much the same way as the smaller 

 but heavier garden spiders, such as Argiope (Plate 

 114). The orb-weaver runs to the side of the prey 

 and expertly rotates the captive in the net while 

 spraying over it multiple strands of silk that reduce 

 struggling and prevent escape. 



A spider has exquisite control over the spinnerets 

 from which the silk emerges. Every spider has three 

 or four different kinds available, each reaching the 

 outside world through a different shape of tube. One 

 product is the firm dry cord with which the orb- 

 weaver constructs the radial strands of her web — 

 lines that can be walked on without a foot adhering 

 to the silk. Ouite ditTerent is the sticky and elastic 

 thread which is used for the spiral of the orb web — 

 the tanglefoot to which victims will adhere. Far 

 finer strands are those by which a spider lets itself 

 down or which it pays out behind. These fibers are so 

 uniform in diameter and so unaffected by changes in 

 temperature and humidity that they have been in 

 considerable demand as material for the cross hairs 

 in telescopic sights. Still another kind of silk is the 

 material in which the eggs are encased. Often it is a 

 warm brown, or pink, or saffron yellow. 



The common house spider, Theiidion, hangs her 

 silken spherical cases full of eggs in the irregular nest 

 she constructs in some corner. She watches the egg 

 cases, for if one of them falls, she hurries down and 

 rescues it. Wolf spiders (Plates 109-1 12), such as the 

 common small Lycosa of beach and woodland and 

 the large Dolomedes of fresh-water margins, usually 

 affix the ball full of eggs to the spinnerets and drag it 

 after them wherever they go. Their eyes are useful in 

 finding insect prey which can be run down or pounced 

 upon, but a wolf spider seems to recognize her egg 

 ball only by touch. If she becomes separated from it 

 she pays no attention unless it chances to come into 

 contact with her hindmost legs or abdominal tip. Only 

 then will she fasten it in place and run off with it. 



Dolomedes not only runs dry-shod over the sur- 

 face of ponds after insects but occasionally creeps 

 down a plant stem or wharf piling into the water and 

 catches fish. During these underwater expeditions, 

 the spider's hairy body seems silvered by an air film 

 held among the bristles. The European water spider 

 Argyronecta takes additional advantage of this load 

 of air. The creature spins a dome-shaped nest in the 

 water of a pond, anchoring the dome to bottom vege- 

 tation with strong lines. Then, on trip after trip to the 



