ARACHNIDA 127 



the ground line, is always passed out as the spider flees. 

 After danger is past, the spider is able to return quickly 

 and easily to its web by taking in the ground line. 



The chief enemies of spiders are the mud-dauber wasps. 

 One of these agile insects is able to pull an orb-weaver 

 from its web and fly away without being entangled. The 

 luckless victim of the raid is rendered torpid by stinging 

 and used to provision the little earthen cells in which the 

 wasp's eggs are laid. The spider guards against the wasp's 

 attacks by spinning an irregular tangle of threads on all 

 sides of its orb. These outlying lines impeded the prog- 

 ress of winged aggressors, or by their vibrations at least 

 give warning that an attack is impending. 



Spiders are subject to certain parasites and diseases 

 which sap their vitality or destroy them outright. Such 

 afflictions are more prevalent during damp weather. For 

 'many reasons rain is one of the spider's chief obstacles to 

 success in life. Raindrops or heavy dews break down the 

 web and on this account continual repairs are necessary. 



Race Preservation. Spiders are of two sexes, male or 

 female. The latter is larger and spins the more perfect 

 webs. When mature the little male frequents the webs of 

 females in search of a mate (Fig. 59). The males of some 

 species go through various fantastic courting activities, 

 such as dancing, posturing, and posing before the female. 

 Being a chosen suitor is a somewhat doubtful honor, how- 

 ever, for the female often eats the male, sometimes even 

 before she has been fertilized. 



After a female has received sperm cells for fertilizing 

 her eggs, she usually makes elaborate preparations for 

 cocooning. Some species of spiders carry their cocoons 

 about in their jaws, or attach them to their abdomens; 

 others hide them away under stones or logs. The orb- 

 weaver goes to some sheltered nook in low vegetation and 

 fastens her cocoon to the plants (Fig. 59). The gauzy 

 structure is pear-shaped and hangs free from surrounding 

 objects, suspended by silken threads. In the center is a 



