THE SEXSES. 



695 



white fibrous tissue, with some elastic fibres near the inner surface, 

 arranged in variously disposed and interlacing layers. Many of the 

 bundles of fibres cross the others almost at right angles. It is strong, 



Ciliary muscle 



Ciliary process 



Canal of Petit 



Cornea 



Anterior chamber 



Lens 



Iris 



Ciliary process 

 Ciliary muscle 



Fig. 406. Seciton of the anterior four-fifths of the eyeball. 



tough, and opaque, and not very elastic. It is separated from the 

 choroid by a considerable lymphatic space (periclioroidal), and this is in 

 connection with smaller spaces lined with endothelium in the sclerotic 

 coat itself. There is a lymphatic space also outside the sclerotic sepa- 

 rating it from a loose investment of connective tissue called the capsule 

 of Tenon. The innermost layer is made up of loose connective tissue 

 and pigment-cells, and is called the lamina fusca. 



Structure of the Cornea. The cornea is a transparent membrane 

 which forms a segment of a smaller sphere than the rest of the eyeball, 



Fig. 407. Vertical section of rabbit's cornea, a, Anterior epithelium, showing the different 

 shapes of the cells at various depths from the free surface ; 6, portion of the substance of 

 cornea. (Klein.) 



and is let in, as it were, into the sclerotic with which it is continuous 

 all round. It is covered by laminated epithelium (#, fig. 407), consist- 



