The Life of Spiders 



name the notched ione. (Fig. 190.) This method of fastening 

 the spiral line adds greatly to the strength of this region of the 

 web. 



The spiral guy-line.— After the completion of the centre of 

 the web, the next step is to stay the radii by a spiral line, which 

 is a continuation of the line of the notched zone, and which ex- 

 tends spirally over the entire area that is to be occupied by the 

 orb. As the function of this line is merely to hold the radii 

 in place during subsequent operations in the making of the web 

 1 have called it the spiral guy-line. The turns of this spiral are 

 as far apart as the spider can conveniently reach and it crosses 

 the radii at right angles (Fig. 190 bis). In Fig. 191 which rep- 

 resents a web at a somewhat later stage in its construction, 

 four or five turns of the spiral guy-line can be seen between the 

 hub and the outer completed portion of the web. 



The viscid spiral. — All of the threads spun up to this stage 

 in the construction of the web, excepting the attachment disks 

 by which threads are anchored, are dry and inelastic. The spider 

 now proceeds to stretch upon the radii a viscid and elastic line, 

 which is the most important part of the web, the other lines being 

 merely a framework to support it. In spinning the viscid line 

 the spider begins at the outer margin of the orb, and passing 

 around it fastens this line to each radius as it goes. At first 

 the spider does not pass entirely around the web but makes a 

 greater or less number of loops on the lower part of the web. In 

 the web represented by Fig. 191, which was the web of a spider 

 that makes an incomplete orb, there are many of these loops; 

 but in most orb-webs there are only a few, the spider passing 

 entirely around the web after making a few loops. 



The turns of the viscid spiral are placed quite close together 

 and the spiral guy-line is cut away turn by turn as the viscid spiral 

 approaches it. The remnants of the spiral guy-line remain 

 attached to the radii and form a series of minute specks which 

 can be seen in large webs after their completion (Fig. 188). 



In spinning the viscid line the spider fastens it to a radius 

 by means of a small attachment disk; and then moves on pulling 

 out the thread from the spinnerets; but before the thread is fast- 

 ened to another radius the spider takes hold of it with either 

 the claws or with a spine of one hind leg and straightening out 

 this leg pulls out from the spinnerets more of this thread; the 



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