CHAPTER IX 



The Aerial Web Spinners 



IT 



J.HE VAST ASSEMBLAGE OF SPIDERS 



treated in this chapter are those that spin silk from their bodies 

 and produce many types of aerial webs. Whereas their relatives 

 developed alertness, speed, brute strength, and a minimum use of 

 silk, to become hunters, the sedentary types on their gossamer lines 

 swung far aside from that line of ecribellate spider evolution. Theirs 

 is a story of silk; on tiny claws that have become increasingly effec- 

 tive as hooks, they hang upside down from the threads of a circum- 

 scribed web, rarely leaving its confines voluntarily. Their sense of 

 sight is rather poor; for this deficiency they have compensated by 

 spinning expansive tangles, sheets, and formal web designs to enlarge 

 their area of action, the struggles of an insect in the farthest recesses 

 of the snare are communicated to them. Within the confines of 

 the web the sedentary spiders have become supreme autocrats. 



They are a motley crew running to all sizes and shapes. Many 

 are shy, lie immobile in the web, and when disturbed drop on drag- 

 line threads to the security of deep underbrush. Others stay hidden 

 away in retreats or under objects until their traps are touched by 

 small animals. Some are quite agile and run nearly as well as hunt- 

 ing spiders; others, in appearance well proportioned for running, 

 have legs too long and thin. A few specialize in inaction; they hang 

 like inanimate slivers or clods in their webs, to all intents part of 

 the debris that adheres to the lines. Others, possessing greatly 

 elongated abdomens that they wave gently back and forth, resemble 

 in form and action common caterpillars. Most are fat creatures 

 with short legs that seem molded for an acrobatic life. The great 

 majority are tiny and inoffensive; therefore they rarely come to our 

 notice; but some of the orb weavers are giants, in bulk exceeding 

 some large hunters. 



The webs of the sedentary spiders, displayed on every side in a 

 myriad of sizes and designs, vary from crude artistry to extraordi- 



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