THE EYE. 145 



EXTERNAL PARTS OF THE EYE. 



The eye of the rabbit may be used, but that of the ox is 

 better. 



1. Observe the clear front part of the eye, the cornea. 

 Note its shape. Its wider end was at the inner angle 

 of the eyelids. 



2. Around the cornea find a whitish membrane, the 

 conjunctiva, which a short distance back from the 

 cornea separates from the eyeball to turn forward 

 and line the eyelid. 



3. The severed muscles of the eyeball, a mass of fat 

 which forms a cushion for the eye, and other tissue, 

 should be trimmed away leaving the optic nerve, 

 which enters the eye below and outside of the centre 

 of its posterior surface ; the place of entrance of the 

 optic nerve, together with the shape and natural 

 position of the cornea, will serve to distinguish the 

 right and left eyes. 



4. Place the eye in its natural position, and make draw- 

 ings of it as seen from the front, from behind, being 

 still careful to have it right side up, and from one 

 side, naming the parts, and stating whether it be the 

 right or the left eye. 



DISSECTION OF THE EYE. 



1. Lay the eye on a plate with the cornea uppermost. 

 Hold the eye firmly with the thumb and fingers of 

 one hand ; with the thumb and forefinger of the 

 other hand hold one blade of the scissors half an 

 inch from its tip ; with a steady motion push the 

 blade horizontally through the cornea near its edge. 



