41 8 NORMAL HISTOLOGY AND ORGANOGRAPHY. 



TUNICA MEDIA. 



i. The Choroid Coat. The choroid is the vascular 

 tunic of the eye, and may be divided into four layers. 

 From without inward these are named: i, lamina 

 suprachoroidea ; 2, lamina vasculosa Halleri; 3, 

 lamina choriocapillaris ; 4, glassy layer, or vitreous 

 membrane. This entire tunic is derived from the 



Solera. . 



Lamina supra- 

 choroidea. 



Lamina vascu- 

 losa Halleri. 



Lamina chorio- 

 capillaris. 

 Glassy layer. 



Fig. 289. Section through the human choroid (Bohm and Davidoff). 



mesoderm and is largely composed of connective- 

 tissue elements. 



The Lamina Suprachoroidea. This layer is closely 

 applied to the sclera, and is composed of a loose 

 fabric of areolar tissue in whose meshes are con- 

 nective-tissue cells and lymph spaces lined with 

 endothelium, known as perichordeal lymph spaces. 



