THE EYE AND ITS APPENDAGES. 



341 



anterior lamellae, in which they form net-works. Immediately 

 beneath the anterior elastic membrane the smaller fibres form the 

 dense subbasilar plexus, while under the epithelium the finest 

 fibrillae constitute the subepithelial plexus, from which delicate 

 naked axis-cylinders ascend and enter the epithelium, to end between 

 the cells as the intra-epithelial plexus. 



THE SCLERA. 



The sclera is composed of the same elements as is the substantia 

 propria of the cornea, but they are less regularly disposed and lack 

 the remarkable transparency of the latter. 



The ground-substance is made up of interlacing bundles of 

 gelatin-yielding fibrous tissue mingled with elastic fibres ; the fibrous 

 bundles are arranged as two principal sets, those extending longi- 

 tudinally or meridionally and those running transversely or 

 equatorially. 



The interfascicular interspaces are occupied by the stellate 

 connective-tissue plates, which correspond closely to the corneal 

 corpuscles ; in addition, a few small wandering cells are usually 

 present. The sclerotic and cho- 

 roid coats are united by a layer FIG. 368. 

 of loose connective tissue, the 

 lamina suprachoroidea, the 

 extensive interfascicular clefts of 

 which form part of the sub- 

 scleral lympl\-space. 



The suprachoroidal tissue 

 consists of many imperfect la- 

 mellae composed of a fibro- 

 elastic groundwork support- ^ 

 ing irregular groups of flattened 

 endothelioid connective-tissue 

 plates ; the broad trabeculae join 

 one another at various angles, 

 and include the imperfectly sep- 

 arated compartments of the gen- 

 eral lymph-space. The larger 

 partitions convey the numerous 

 vascular and nervous trunks in 

 their course to and from the 

 choroid. 



The deeply-pigmented tissue 

 cf the innermost layer of the sclera, next the subscleral space, 

 constitutes the lamina fusca, and is covered with the endothe- 



C 



Section of human eyeball taken midway be- 

 tween equator and posterior pole : S, sclera ; p, 

 lamina fusca and lamina suprachoroidea ; P, peri- 

 scleral tissue ; C, choroid ; R, retina with its layers 

 indicated by figures. 



