THE SPIDER. 561 



mal emits a polfon ; which, though harmlcfi to us, is 

 capable of inftLmtly deftroying its prey. 



But all thefe arms of the fpider, formidable as they 

 are, would prove infjfficient for procuring him fublill- 

 ence, did h^ not add ftratagem to force. Every one is 

 acquainted with his invention of fpreadmg a net for the 

 fly, an infe>5l which, without this artifice, mull for ever 

 Iiave efcaped him. The pofition of the fpider'a web is 

 generally well cliofen ; being placed either in the corners 

 of rooms, the fides of windows, or among the branches 

 of trees, where flies are moft frequent and plenty. 



For the conftruftion of this delicate engine, Nature 

 has fapplied thefe animals with a large portion of a glu- 

 tinous fubftance, which fne has granted them tlie po:ver 

 of fpinning into a thread fo delicate, that ninety of tliem 

 tvi^ifted together are only equal in thicknefs to that of the 

 common (ilk worm. Every thread of the common fpi- 

 der's web, though fcarcely vifible hy the naked eye, is 

 compofed of a vaH; number of (lender filaments joined to- 

 gether. The inllruments of this delicate operation are 

 five dugs or teats, with fmall orifices, capable of being 

 contra6led or dilated, according to the finenefs of the in- 

 tended thread. 



After the net has been thus formed, the next care of 

 its owner is to provide a proper retreat, from v.'hich he 

 may furvey the whole, and obferve the fuccefs of his ow;i 

 artifice. Some threads being in contact with his bodj', 

 whenever the web is touched from without, he inftantly 

 feels the motion, and accordingly prepares either for at- 

 tack or defence. If the infe(5l invading his territories 

 prove a fly, he immediately failles forth, and de\our3 th:; 

 devoted prey with all that ferocity which dillinguifties 



Vol. III. 4 B ' ^ ths 



