146 The Book of Bugs. 



In some of these tubes in the ground spiders build a 

 sort of a Y with a trap-door shutting off one arm; it 

 works just the same as if they had thought it all out thus, 

 ' Now, some creature will chase me in here. I'll run up 

 the side arm and shut the trap after me. It will go on 

 down to the bottom, and I'll open the trap and there I'll 

 have him penned up, and I'll kill him when I get ready." 

 So also the spiders that do side-steps. They must rea- 

 son, or some ancestor must have reasoned for them thus: 

 ' All of our enemies figure that we will run forward. 

 Well, I'll just fool 'em. I'll take a hop to one side." 

 Also when the Ncphila plninipcs, a big black-and-yellow 

 person that hangs in her web in plain sight, sees an evil- 

 disposed bird making for her, what does she do? She 

 vanishes. Run? Never. She vanishes, I tell you. 

 Stays where she is, but goes out of sight. She shakes 

 her web so violently that instead of appearing to be a 

 big, fat, juicy spider there is only a haze where she was. 

 Pholcus, the long-legged cellar-spider that spins an ir- 

 regular web, in similar circumstances swings its body in 

 a circle so fast that it cannot be seen. Orb-weavers 

 scatter rubbish in their webs till they look like old things 

 that have been deserted two or three months, and then 

 they get in line with the chips and bits of bark that they 

 themselves have put there. The trick of imitating spots 

 on grass-stems, scales on trees, lichens and the like, is 

 wonderful. Some spiders have found it a paying proposi- 

 tion to look like the stamens and pistils of bright-colored 

 flowers. There they stand by the hour with their yellow 

 forelegs stuck up stiff into the air. A butterfly comes 

 along and alights to suck honey. He never gets away 

 alive. The resemblance is so close that botanists are de- 

 ceived. One kind of a spider spins a little round patch of 

 white silk on a leaf. It sits in the center. The outer edge 



