SPIDERS. 113 



104. As the thread issues from the spinnerets, the spider 

 guides it with its hind pair of feet, and these are curiously 

 adapted for the purpose not only of holding and guiding the 

 thread, but also of enabling the spider to run rapidly across 

 its nets without getting entangled, while other animals be- 

 come helplessly ensnared in attempting the same thing. 



The ends of the legs terminate in three claws, a pair of 

 larger ones generally notched like a comb, and a third one 

 like a spine which acts as a thumb. Other notched spines 

 or hairs also aid in securing a hold upon the web, and even 

 if these fail to secure a footing, the leg itself is covered with 

 long stiff bristles pointing downward which are sure to catch 

 in the web. The two large notched claws, as well as the 

 other claw and spines, are highly polished, and consequently 

 present no roughened surface to which the thread will 

 adhere. 



The following figure (Fig. 110) represents the end of a 

 spider's leg magnified, showing the arrangement of hooks 

 and claws. 



t m o 



FIG. 110. END OF A COMMON GARDEN SPIDER'S LEG MAGNIFIED. o, Outer Claws; ?/i, 



Middle Claw ; t, Toothed Hairs. 



105. By observing the spiders which build their nets 

 across the openings of windows and in other convenient 



