ANATOMY IN A NUTSHELL. 



381 



interstitial cement substance and each space contains cells, the conical corpuscles 

 which are stellate in shape. (3) A homogenous elastic lamina. (4) A single 

 layer of endothelial cells forming part of the lining membrane of the anterior 

 chamber of the eye-ball. 



Besides these four strata we have the anterior and posterior elastic 

 lamina. The anterior clastic lamina (n embrane of Bowman) is the uppermost 

 layer of the corneal stroma immediately beneath the conjunctival epithelium. 

 The posterior elastic lamina (membrane of Descemet or Demours) is the pos- 

 terior lining membrane of the cornea. Its function is to preserve the correct 

 curvature of the cornea proper. The nerves are numerous and are derived from 

 the ciliary. It is non-vascular. 



LESSON CVII. 



The choroid consists of two layers, an outer and an inner. The inner layer 

 or tunica Ruyschiana is formed by the capillary endings of the vessels of the 

 outer coat. They pass forward to within one-eighth of an inch of the cornea 



PLATE CXIX. 



EXTERNAL ROOT FROM TEMPORAL LOE 



INTERNAL ROOT FROM GYRUS FORNICATUS. 



The Olfactory ok First Cranial Nerve. 



joining those of the ciliary processes. The choroid consists of blood vessels 

 Connected together by loose connective tissue and containing large branched 

 and pigmented cells. Externally it is connected to the selenitic by loose con- 

 i:< ctive t issue forming lymphatic spaces. It is a continuation of the pigmentary 

 feells of the retina. The choroid is thickest behind where it is pierced by the 

 optic nerve. The outer layer contains the larger branches of the vessles. The 

 Bhoii ciliary arteries after piercing the sclerotic close to the optic nerve pass 

 forward and inward to < nd in the inner lay< r of the choroid. The venae vorti- 

 B< -;r. which are four or five in number, are formed by numerous smaller veins 

 and lie external to the arteri< s. They pierce th< sclerotic midway be1 ween the 

 cornea and the optic nerve. The venae vorticosae form the two ophthalmic 

 veins which join to form the common ophthalmic v< in. The common ophthal- 

 mic vein passes from the orbit through the internal inferior angle of the sphen- 



