Arachnida. 



57 



the conspicuous webs. These kinds lead a rather seden- 

 tary life, preferring to set traps for their game rather than 

 actively hunt for it. 



The spinning apparatus consists externally of two or 

 three pairs of short segmented appendages under the tip 

 of the abdomen. Each of these spinnerets has many short, 

 hairlike projections, with a perforation at the tip of each. 



FIG. 41. THE SPINNERETS OF THE COMMON GARDEN SPIDER. 



Within the abdomen are glands which secrete a liquid sub- 

 stance of which the web is made. When the spider wishes 

 to spin it presses the spinnerets against some surface, and 

 the exuded liquid adheres ; then as the liquid is drawn out 

 into a slender thread it hardens as it is drawn, making a 

 thread often of hundreds of strands united. The feet of 

 the spiders have blunt claws with a series of teeth, by 

 means of which they can easily walk on the web without 

 tearing it. In spinning the webs with radiating and concen- 

 tric lines, such as we have often noticed, the spider first 

 spins a few foundation threads, then the radiating threads. 



