THE SENSES. 



5ST 



by amoeboid movement from one branched space into another. At its 

 posterior surface the cornea is limited by the posterior elastic lamina, or 

 membrane of Descemet, the inner layer of which consists of a single 

 stratum of epithelial cells (Fig. 391, d). 



Nerves. The nerves of the cornea are both large and numerous: they 

 are derived from the ciliary nerves. They traverse the substance of the 



FIG. 393. Vertical section of rabbit's^ cornea, a. Anterior epithelium, showing the different 

 shapes of the cells at various depths from the free surf ace; 6, portion of the substance of cornea 

 (Klein.) 



cornea, in which some of them terminate, in the direction of its anterior 

 surface, near which the axis cylinders break up into bundles of very deli- 

 cate beaded fibrillse (Fig. 391): these form a plexus immediately beneath 

 the epithelium, from which delicate fibrils pass up between the cells anas- 

 tomosing with horizontal branches, and forming a deep intra-epithelial 



Fin. 394. Horizontal preparation of cornea of frog; showing the network of branched cornea, 

 corpuscles. The ground substance is completely colorless, x 400. (Klein.) 



plexus, from which fibres ascend, till near the surface they form a super- 

 ficial intra-epithelial network. 



Structure of the Choroid Coat (tunica vasculosa).This coat of the 

 eyeball is formed by a very rich network of capillaries (chorio-capillaris) 

 outside which again are connective-tissue layers of stellate pigmented 

 cells, suprachoroidea (Fig. 392) with numerous arteries and veins. It is 



