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and shutting close. The latter serves to exclude the 

 bright light of the day, the former to take in the faint 

 rays of the night, thereby enabling them to see and 

 catch their prey when there is no light discernable to 

 us. 



Thus cats can so close their pupil as to admit but a 

 Single ray of light ; and again, by throwing all open, 

 they can take in all the faintest rays ; which is an in- 

 comparable provision for creatures that have occasion 

 to watch their prey both by day and night. 



But beside this, in cats and other nocturnal animals, 

 there is a sort of carpet at the bottom of the eye, which 

 gives a kind of radiation on the pupil, thereby enabling 

 them to see in the dark. 



To preserve this tender organ, many creatures have 

 a membrane, which is not commonly perceived, where, 

 with they can at pleasure cover the eye, without too 

 much hindering the sight, being both transparent and 

 strong, so that it is a kind of moveable cornea. 



Providence is conspicuous in furnishing frogs with 

 this ; for as they live in watry places which generally 

 abound in plants that have sharp edges or points, and 

 as the frog goes on, not by walking but by leaping, if 

 he were not so furnished, he must either shut his eyes, 

 and so leap blindfold, or run many risques by leaving 

 them open ; but this membrane guards the eyes with- 

 out blinding him, and as soon as the occasion for it is 

 over, he draws it back into a little cell. Many birds 

 also, as they must fly between trees and bushes, arc 

 provided with the same membrane, and so is the rein* 

 deer. 



6. The comparative anatomy of the Ear, yields 

 abundant instances of the Creator's wisdom. In birds 

 the outward ear is close and covered, not protuberant, 

 as that would obstruct their flight. In beasts, its 

 form is agreeable to the posture and motion of the 

 body, but admirably varied in the several species ac. 

 cording to their various occasions. In some, as the 

 hare, it is large, open, and erectj by which means 



