A NATURAL HISTORY 



The Gills of Fifh have an alternate Motion of Dilatation and 

 Compreffion ; when they dilate their Gills, the Water is taken 

 in i when they contra6i them, 'tis expelled again. Thus the 

 Water is carried in by the Mouth, and carried off again (ftript 

 of its Air) by the Gills, which perform the Office of Lungs. Their 

 fucking Water is Breathing, and their Food as little of Water, 

 perhaps, as other Creatures ufe. 



SERPENTS willfwim in all Liquids j this appears in the 

 Experiment made by a learned Italian, who put a Serpent into a 

 large Glafs-VefTel of Wine, where it lived fwimming about fix 

 Hours; and when it was by force immerfed and kept under that 

 Liquid, it lived only about one Hour and a half. He put ano- 

 ther in common Water, where it lived three Days; but when 

 it was kept under Water, it lived only about twelve Hours *, 



Some Serpents are reptitious, creep on the Belly, and fome 

 have Feet; the Form of their Legs is peculiar, and different in 

 divers Species, whence the flow Motion of fome, and wonderful 

 Agility and Swiftnefs in others: Their Feet are fome cloven (as it 

 were) into Hoofs, others divided into Claws, with Variety of dif- 

 ferent Nails to anfwer the feveral Purpofes of Life ; among them 

 are Flying Serpents : for which purpofe, they are furniflied with 

 Wings to buoy themfelves up in the fluid Air, whereby they 

 keep their Bodies on a due Balance in their Motion. 



Serpents are provided with Tails of different Length 

 and Size ; thefe alfo are neceffary to adjufl their Motion, and 

 guard them againfl Stimulation of Flies. In winged Serpents, the 

 Tail ferves as a Rudder to govern them in flying through the Air; 

 and, in the marine Serpents, they fcrve as Oars. But another fays.,, 

 the flying of a Bird, in effect, is quite a different Motion from 

 the failing of a Ship : Birds don't vibrate their Wing-s towards the 

 Tail, as Oars are flruck towards the Stern, but waft them down- 

 ward ; nor does the Tail of the Bird cut the Air at right Angles, 

 fts the Rudder does the Water, but is difpofed horizontally, and 

 preferves the fame Situation what way foever the Bird turns-)-. 



They are painted with Variety of Colours, as red, black, 

 white, brown, green 3 the Compofition of thefe, in fome of their 

 Garnitures, forms Beauties exquifitely fine. Some of them have 

 very little Eyes, others large ones : Some wound with their Teeth, 



others 



* Fr. "Redi. Exj^er. circa res nat. p. 170. f Borelli. 



