64 The Structure and Habits of Spiders. 



After going round a few times, this spiral 

 crosses the one that was spun first, or would, 

 if the spider allowed it to ; but, as she comes 

 to the old spiral, she bites it away, leaving 

 only little rags, Fig. 22, b, attached to the rays, 

 which may be seen in the finished web. By 

 beginning thus at the outside, the spider is 

 able to cover the whole web with adhesive 

 threads, and, without stepping on it, take her 

 usual place in the centre. She usually is care- 

 ful enough to spin beforehand a thread from 

 the .centre to her nest, and sometimes stays 

 there, with one foot on the thread, so as to 

 feel if any thing is caught in the web. When 

 she feels a shake, she runs down to the centre, 

 feels the rays to see where the insect is, and 

 runs out, and seizes it, or ties it up as de- 

 scribed on page 43. We have described the 

 web as consisting of one regular spiral ; but 

 this is seldom the case. It is usually wider 

 on one side than the other, or below than 

 above, as in Fig. 28, where outside the spirals 

 are several loops going partly round the web. 

 The web of Zilla consists entirely of such 

 loops going three-quarters round the web, and 



