ORGANS OF SPECIAL SENSE. 



347 



aqueous humor and perforated by the pupil ; and the ciliary liga- 

 ment and muscle at the junction of the two. 



THE CHOROID is a dark, reddish-brown, highly vascular 

 membrane, lining the sclerotic coat from the optic nerve to the 

 ciliary ligament, where it projects backward in a number of 

 processes, the ciliary processes. It is in contact externally with 

 the sclerotic, to which it is attached by the membrana fusca, and 

 internally with the retina. 



10. 



FIG. 157. 



Vessels of the eye. A, conjunctival vessels; B, anterior ciliary 

 vessels; C, vena vorticosa; D, posterior ciliary arteries; E, central 

 retinal vessels. (Ball.) 



The structure consists chiefly of a dense capillary net-work. 



The choroid proper consists of an external and an internal 

 layer, and is separated from the sclerotic by the lamina supra 

 choroidea, continuous with the lamina fusca of the sclerotic, and 

 from the pigmentary layer of the retina by the lamina vitrea. 



The external layer consists of a capillary net-work, derived 

 from, the larger branches of the short ciliary arteries, inclosing 

 between the meshes large, star-shaped pigment cells, which are 

 connected together by a delicate stroma. They terminate in the 



