NEAR RELATIVES OF INSECTS. 241 



at once killing it in preparation for the feast. In locating 

 the exact place of the insect in its web, the spider appears 

 to use the sense of touch, telling from this sense which 

 thread is vibrating, and thus running small risk of losing 

 its victim. 



Not all spiders spin webs to trap their prey. Some 

 of them stalk their victims through the grass or in the 

 usual lurking places of insects in barn or house. One of 

 the light-colored crab spiders was recently observed to 

 run down the cord of a window curtain, and pounce upon 

 a luckless fly, sunning itself on the cord. These crab 

 spiders seem to be less afraid of human beings than are 

 most spiders. The author has several times offered one 

 of them a fly and it accommodatingly stood still and let its 

 human friends see it eat. When a second fly was offered, 

 it seized the second and at the same time attempted to 

 hold on to the first. 



The trap-door spiders live in sandy or clayey soils, 

 and instead of spinning webs they stalk their prey and 

 then take it to their home to eat it at their leisure. 

 Their home is one of the most perfect places of abode 

 made by the Arthropoda. It consists of a burrow dug 

 in the fine clay soil, and lined with a soft silken lining, 

 the product of the spider's own industry. The opening 

 to the burrow is closed by a lid, which fits tightly over the 

 opening and is made of silken threads and soil, so disposed 

 over and among them that the top of it looks exactly 

 like the ground about the nest or burrow. The lid is 

 hung to the side of the burrow by a hinge also made of 

 the silk threads. When disturbed on the hunt, instead 

 of standing and showing fight, these spiders run to the 

 mouth of their burrow, pop inside, turn partly around, 

 and hold to their trap door with the two front claws while 



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