CHAPTER XII. 



THE CHOROID. 



The Choroid is a thin, dark-colored membrane situated 

 between the sclera and the retina. Extends from corpus 

 cili are to the optic nerve. Made up of vessels, pigment, 

 and some connective tissue. The blood comes from 

 the short posterior ciliary arteries which anastomose 

 with the long posterior and anterior ciliary arteries. 

 The veins begin as capillaries and take on a peculiar 

 form. Kesemble as much as anything else a weeping 

 willow, and these uniting, form the venae vorticose, 

 emptying into tlie ophthalmic vein. The anterior 

 ciliary vein drains the anterior portion. The long 

 and short ciliary nerves form plexuses in the 

 choroid and contain a number of ganglionic cells. 

 Between the retina and choroid there is a layer 

 of pigmented epithelium. The inner face of the 

 choroid is not uniform in color, being perfectly 

 black in the lower part of the eye. This is abruptly 

 terminated at a horizontal line about the eighth or 

 ninth part of an inch above the optic papilla. From 

 this line on the segment of a circle from j*^ to ^% of an 

 inch in height, it shows most brilliant colors; at first 

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