CHAPTER VII. 

 VISION. 



I. DISSECTION OF THE APPENDAGES OF THE EYE. 



Appliances. Fresh ox-eyes, including as much of the appendages 

 as possible; physiological operating case; dissecting board and pins, 

 such as used for frogs; dog, cat, or rabbit; bone forceps; injection 

 mass; syringe. 



Dissection. Follow Cunningham or Quain, vol. iii., part iii. 



(1) Before fixing the eye to the board make a careful examination 

 of the organ. 



(a) Trace the conjunctiva, describing its ocular and its palpebral 

 portions. Describe the plica semilunaris and the caruncula. Do 

 these two tissues have the same relative size in man and the ox? 

 Find and describe the* puncta lacrymalia. Find and describe the 

 openings of the lacrymal ducts. How many are there? Enumerate 

 the conjunctival landmarks which determine the inner from the outer 

 side of the eye. Enumerate the conjunctival landmarks which 

 determine the superior aspect of the eye. Is the eye which you 

 have a right eye or is it a left one? 



(6) Observe the appendages of the eye. Do you find a remnant 

 of the levator palpebrce muscle? Find the tar sal cartilages and the 

 remnant of the orbicularis palpebrarum muscle. Find openings of 

 the meibomian and of sebaceous glands. Find and describe the 

 lacrymal gland as to location and size. 



Find and cut off ends of the recti and oblique muscles of the eye. 



Describe location of the optic nerve with respect to the cornea. 



What traces have you found of the capsule of Tenon f 



Enumerate the new landmarks which determine the superior 

 aspect of the eye; the internal aspect. Are these extra landmarks 

 sufficient to determine whether the eye which you have is a right 

 or a left one? 



(2) Fix the eye to the board with the corneal surface down, pinning 

 down flaps of the conjunctiva for support. 



(a) Dissect out the four recti and the two oblique muscles. One 

 will find in the ox a rather heavy retractor muscle in close relation 

 to the optic nerve. This should be left undissected until the other 

 muscles are demonstrated. 



(6) Trace the intricate loculi of the capsule of Tenon. 



