340 T'hWisDouof GOD Part II. 

 the Wifdom of Nature among a thoufand others, 

 of which we perceive not the Contrivance, be- 

 caufe we underftand them only by the Effeds, of 

 which we know not the Caufes j but we here treat 

 of a Machine, all the Parts whereof are vifible, 

 and which need only to be look'd upon to difco- 

 ver the reafon of its Motion and Adion. 



This internal Eye-lid in Birds is a membranous 

 Part, which is extended over the Cornea when it 

 is drawn upon it like a Curtain by a little Cord or 

 Tendon, and which is drawn back again into the 

 great Corner of the Eye, to uncover the Cornea^ 

 by the means of the very ftrong Ligaments that it 

 has, and which in drawing it back towards its 

 Origin do fold it up ; it made a Triangle when 

 extended, and it had the Figure of a Crefcent 

 when folded up; its B a/Is (which is its Origin) 

 was toward the great Corner of the Eye, at the 

 edge of the great Circle, which the Sclerotica 

 forms when it is flatted before, making an Angle 

 with its anterior Part, that is, the Cornea^ which 

 is raised like a Hill upon it; the Bafis, which is 

 the Part immoveable, and faften^'d to the edge of 

 the Sclerotica^ did take up more than a third Part 

 of the Circumference of the great Circle of the 

 Sclerotica ; the fide of the Triangle, which is to- 

 ward the little Corner of the Eye, and Is move- 

 able, was reinforced with a Border, which fup- 

 plies the place of the 'TarfuSy and which is black 

 in moft Quadrupeds ; this fide of the Eye-lid is 

 that which is drawn back into the Corner of the 

 2 Eye, 



