Of the Polype'i Armu 37 



s extended, are feeii at confiderable Diflances 

 from each other ; but when it is (hortned 

 they come quite clofe together, and render 

 it almoft opake. 



Your own Defcrlption, Sir, of all this 

 Is fo expreffive, that I beg leave to copy 

 it from the aforequoted Fhilofophical T^ranf- 

 aSions^ Page 427. ** Each Arm con- 

 " fifts of feveral Rows of Knots or fmall 

 *^ Papillce joyned together by a tranfparent 

 ** membranous Subftance, and which is en- 

 *' dued with a moft exquifite Power of Ex- 

 *' tenfion and Contraction : fo as thereby to 

 *' bring any of thofe Knots nearer toge- 

 ^' ther, or fet them farther afunder, and 

 " that in every poiTible Direilion, whereby 

 '* the Animal is able to bend any of thefe 

 " Arms in any part, and all Sorts of Ways." 



As the Arm is capable of great and gra- 

 dual Extenfions and Contractions, its Ap- 

 pearance is very difterent in different Degrees 

 of fuch Extenfion or Contradion. When 

 extended to the utm^oft Stretch, its Finenefs 

 is exquiiitely delicate, and it looks like a 

 String of Beads, or knotted Thread, with 

 the Beads or Knots widely diftant one from 

 another. When it is about half extended, it 

 much refembles the Chejiille * Women ufe in 

 their Works, which they erroneoufly call 



* The French Word Chejiille fignifies a Caterpillar, and 

 not a ^nail. 



D 3 ^naiL 



