ENGINEERING SKILL OF SPIDERS. 



209 



show a continuous power to adapt the sphmingwork to its environment. 

 This seems to be done almost unconsciously. If this view be true the lack 

 of mathematical symmetry may prove the presence of a higher skill rather 

 than the reverse. 



The query was started in my mind whether spiders dwelling along the 

 seashore or in wind swept heights might not have developed some special 

 habit of resisting the extraordinary danger to their snares by some extraor- 

 dinary protection. But I have not found evidence favoring such a sug- 

 gestion. I have only one example that looks at all in that direction. 



Fir;. 201. Orbweb (A) among rocks, braced against sea wind. B, braces; C, C, connecting line 



or trapline to the den, D. 



Among the rocks around the lighthouse at Annisquam on Ipswich Bay, 

 Massachusetts, I found a large orb of Epeira sclopetaria spun within a 

 few feet of the surf, and stayed in the peculiar manner which is repre- 

 sented in Fig. 201. The snare was in a sort of gully or canal between the 

 granite boulders on the shore, through which the wind blew 

 stron S 1 y as tnrou gh a funnel. Across this little gully and exposed 

 to ^ ie ^ u ^ f rce an d suction of the wind the orbweb was built 

 and stayed upon the side of one of the rocks, as at A. Farther 

 along, a few lines were stretched across the opening, fastened to rocks on 

 either side as at B, and upon this a line, CC, was suspended, attached at one 



Snare. 



