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ARACHNIDS, CENTIPEDES, AND MILLIPEDES— ARTHROPODS 



and run away only to return and repeat the process over and over again, 

 each time getting a little nearer to the female. In preparation for this 

 occasion the male has already removed a ball of sperms from his re- 

 productive organs and is carrying it in his pedipalps. After repeated 

 approaches in which the female does not attempt to capture him, the 

 male finally approaches close enough to tuck the ball of sperms into her 

 seminal receptacle. Then, again he turns and rushes away, but this 

 time the female is likely to pursue him and may overtake him and eat 

 him. This is where the black widow gets her name — she is black and 



I'hvto bv Lee Passmore 



Fig. 14.2. Female and male black widow spiders. It is easy to understand why the 

 male runs from his larger, cannibalistic mate after insemination is accomplished. 



may become a self-made "widow" by this action. Later she will lay 

 the eggs and spin a web around them to form an egg case. She will 

 defend this viciously against any intruders. 



The little spiders hatch within the case and soon break out and climb 

 on their mother's back. Female spiders are frequently seen with their 

 backs covered with tiny spiders clinging onto the hairs. In some spe- 

 cies, they are known to eat their mother before scattering out to shift 

 for themselves. Distribution among spiders is an important thing, for if 

 a hundred or more all set up housekeeping in the same vicinity there 

 would be serious competition for food. Here, again, the web comes in 

 handy. The little spiders climb the nearest tree or other elevation and 



