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VETERINARY OPHTHALMOLOGY. 



ciliary arteries form .the circulus iridis major by unit- 

 ing with the branches of the anterior ciliary arteries. 

 Prom these we have branches which form another 

 ring, the circulus iridis minor, formed by anasto- 

 mosing. The major is formed at the ciliary region. 

 The minor gives off capillaries, which in turn become 

 veins, and, the circulation being established, is re- 

 turned in the same manner as above described. The 



Fig. 44. 



iris regulates the amount of light admitted to the 

 eye's interior, and by excluding peripheral rays ad- 

 mits of acute vision. 



Iritis. — Inflammation of the iris is the result of in- 

 juries, cold, rheumatics, extension of inflammation from 

 other parts, etc. Three principal divisions: (1) plastic, 

 (2) purulent, and (3) serous, but a description of one 



