Ill 



PRACTICAL ZOOLOGY 



Fig. sy. — Photograph of a spider at the center of its web. (After Burlend.) 



in all directions. The spider lives on the underside, back down- 

 ward. 



3. The round webs are made of threads radiating from a 

 common center and crossed by circular loops and spirals, part of 

 which are adhesive (Fig. 59). 



