Teacher's Leaflet, 769 



(i). Note how the spider gets the supporting Une between two points. 



(2). How it makes the frame work for holding the web in place. 



(3). How it makes the first radius. 



(4). How it makes the next radii and selects the point which is about 

 the center of the web. 



(5). How it keeps the line which it is spinning clear of the line it 

 walks upon. 



(6). After the radii are all made, are they fastened at the center? 



(7). How does the spider first begin to spin a spiral? 



(8). Are the lines of this spiral close together or far apart? 



(9). For what is this first spiral used? 



(10). Where does it begin to spin the permanent spiral? 



(11). Where does it walk when spinning it? 



(12). By the way it walks on the first spiral, do you think it is sticky 

 and elastic? 



(13).- What does it do with the first spiral while the second one is 

 being finished? 



(14). If the center of the web has a zigzag ribbon of silk, when was 

 it put on? 



(15). How many minutes .did it take the spider to complete the web? 



Facts for the Teacher. — The spider's method of making its first bridge is to place 

 itself upon some high point and lift its abdomen in the air and throw out on the 

 breeze a thread of silk; when this touches any object it adheres and the spider 

 draws in the slack until it is "taut" and then travels across this bridge which is 

 to support its web and makes it stronger by doubling the lines. From this line 

 it stretches other lines by fastening a thread to one point and then walking along 

 to some other point holding the line clear of the object on which it is walking by 

 means of one of its hind legs, of course spinning the thread as it goes. When the 

 second point is reached it pulls the line tight fastens it and then makes another. It 

 may make its first radius by dropping from its bridge to some point below, then 

 climbing back to the center it will fasten the line for another radius and spinning 

 as it goes walk down and out to some other point holding the thread clear and 

 then pulling it tight. Having thus selected the center of the web it goes back and 

 forth to it spinning lines until all of the radii are completed, and when they are 

 complete they are already fastened at the center. It then starts at the center and 

 spins a spiral laying it onto the radii thus making them firm. However, the lines 

 of this spiral are farther apart and much more irregular than the final spiral. Thus 

 far all of the threads it has spun are inelastic and not sticky ; and this first or 

 temporary spiral is used by the spider to walk upon when spinning the final spiral. 

 It begins the latter at the outer edge instead of at the center and works toward the 

 middle. As the second spiral progresses the spider with its jaws cuts away the 

 spiral which it first made and which it has used as a scaflfolding. A careful observer 

 may often see remnants of this first spiral on the radii between the lines of the 

 permanent spiral. The spider works very rapidly and will complete a web in a 

 very short time. 



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