Part I. //? /^^ C R E A T ro N. 151 



The Fins, madeofgriftly Spokes, or Rays, con- 

 neded by Membranes, lb that they may be' con- 

 traded, or extended iike Womens Fans, and fur- 

 niflied with Mufcles for Motion, ferve partly 

 for Progreffion, but chiefly to hold the Body up- 

 right; which appears in that when they are cut 

 off, it wavers to and fro, and fo foon as the Fifh . 

 dies, the Belly turns upwards. The great 

 Strength by which Fifhes dart themfelves for- 

 * ward with incredible Celerity, like an Arrow 

 out of a Bow, lies in their Tails, their Fins, 

 mean time, left they (hould retard their Motion, 

 being held clofe to their Bodies. And therefore 

 almoft the whole Mufculous Fleih of the Body 

 is beftow'd upon the Tail and Back, and ferves 

 for the Vibration of the Tail, the Heavlnefs and 

 Corpulency of the Water requiring a great Force 

 to divide it. 



In Cetaceous Fiflies, or, as the Latim call 

 them, * Sea-Beafts, the Tail hath a dif- ^ 

 ferent Pofition from what it hath in all MarL^^ 

 other Fifties ; for whereas in thefe it is 

 ereded perpendicular to the Horizon, in them it 

 lies parallel thereto, partly to fupply the Ufeof 

 the hinder Pair of Fins which thefe Creatures 

 lack, and partly to raife and deprefs the Body at 

 pleafure. For it being necelTary that thefe Fifties 

 ihould frequently afcend to the Top of the Water 

 to breathe, or take in and let out the Air, it was 

 fitting and convenient that they ftiould be pro- 

 vided with an Organ to facilitate their Afcent 

 and Defcent as they had Occafion. And as for 

 their turning of their Bodies m the Water, they 



L 4 muft 



