ANATOMY OF THE EYE 23 



sphincter pupilte is a circular, flat body, located in the 

 stroma near the pupillary margin. This muscle con- 

 tracts the pupil. 



The posterior layer of pigment epithelium is con- 

 tinuous with that of the ciliary body and retina. It 



./ 



^ 



Fig. 8.-Eyeb.U of horse in orbit, slrowing shape of the iris and the corpora 



nigra 



extends to the anterior margin of the pupil, and in the 

 horse it is quite thick in the upper portion, forming 

 several prominent projections into the pupillary space. 

 These pigment bodies are known as the "corpora nigra," 



