48 VETERIKARY OPHTHALMOLOGY. 



from one another and the posterior by the fat belong- 

 ing to the membrana nictatans. They act according 

 to position, and, as I have demonstrated upon the board, 

 according to concerted action. 



Superior Oblique, or Great Oblique. — This arises 

 from the back of the orbit and passes forward against 

 the inner wall to pass through a strong flbro-cartilag- 

 inous pulley, which is attached to the frontal bone at 

 the base of the orbital process ; then, bending out- 

 ward, passes beneath the superior rectus neaiiits at- 

 tachment and inserts itself into the sclerotic between 

 the superior and external rectus. Consequently this 

 muscle pivots the eye inward and upward, carrying 

 the outer aspect of the globe upwards and its lower 

 part outwards. 



Inferior or Small Oblique Muscle. — Thicker and 

 shorter than the superior; is nearly parallel to the 

 reflected portion of the superior. Arises in the lachry- 

 mal fossa, passes outward and is inserted in the 

 sclerotic between the external and inferior recti. In 

 action it antagonizes the great oblique. The move- 

 ments of the bulbus correspond to a ball and socket 

 joint. The center of rotation is a short distance be- 

 hind the center of the eye. 



The oculo-motor nerve, or third pair, supplies all the 

 muscles of the eye except the external rectus and supe- 

 rior oblique, which are supplied by the sixth and fourth 

 pair respectively. These muscles are susceptible to 



