92 SPIDER GOSSIP, 



thread and trusts herself on the extremely fragile bridge thus 

 formed. The distances crossed in this way are often very 

 considerable, five or six yards being frequently measured, and the 

 web in the middle of the space looks most curious. Having, in 

 one way or the other, begun her operations and formed the frame, 

 doubling or trebling its threads for strength's sake, the spider draws 

 a thread across it, which is also doubled. Then it finds the 

 middle of this, and fastening a thread there, from that point walks 

 up to the top of the frame, always letting out thread as it goes. 

 Going a little way along the frame, its fastens the loose thread to 

 it, and returns to the centre by means of this new thread, which it 

 doubles in the act of returning. This forms a second radius, and 

 perhaps a third may be made in the same direction. But the 

 fourth, at any rate, will be taken in the opposite direction, other- 

 wise the centre piece would be pulled out of position by the 

 strain of elastic threads all on one side of it. A fifth will be put 

 across to another part of the frame, in order that the pull on the 

 centre may be kept equal all around, and so the litde animal goes 

 on, until the number of the radii is complete. This number 

 varies considerably. In a small web of E. diadema I have 

 counted as few as twenty-five ; in a web a little larger, forty-three ; 

 yet in an unusually large web with sixty-three rings to it, I found 

 only thirty-two. 



The radii are non-adhesive, and therefore cannot catch flies, 

 so, as soon as they are finished, the spider proceeds to lay upon 

 them a series of concentric " rings " (if one may call them so) of 

 sticky thread. These " rings " are really all one endless thread, 

 not complete circles, and they might be regarded as turns of an 

 infinite curve, if the radii did not break them into angles. People 

 suppose that a spider's sticky threads do not stick to the insect 

 that makes them. This is quite a mistake. They adhere to a 

 spider as closely as they do to a fly — if they happen to touch. 

 So mark the wonderful instinct of the spider. The radii are too 

 far apart at their extremities for the spider to step from one to 

 another, but, by beginning at the centre of the web where the 

 spaces between the radii are narrow, it goes round and round with 

 its ring-thread easily enough, and, when the spaces get too broad 

 to stride over, it uses the thread fixed the last time it came round, 



