VISION. 



'83 



elongated. They are divided into two parts, the outer segment and 

 the inner. The outer segment is doubly refracting, contains the 

 visual purple, and breaks up into many superposed discs when acted 



Fig. 334. Diagram of the Structure of the Human Retina According 

 to Golgi's Method. (GREEFF.) 



I, Pigment epithelium layer. II, Rods and cones. Ill, Granules of the visual 

 cells. IV, Outer plexiform layer. V, Layer of horizontal cells. VI, Layer of 

 bipolar cells. VII, Layer of amakrine cells. VIII, Inner plexiform layer. IX. 

 Ganglion cell layer. X, Layer of nerve fiber. 1, Diffuse amakrine cell. 2, 

 Diffuse ganglion cell. 3, Centrifugal nerve fiber. 4, Amakrine association fiber. 

 5, Neuroglia cells. 6, Muller's radial fibers. 



upon by certain reagents. The inner segment is spindle-shaped, 

 granular, and singly refractive. The ellipsoid of Kraus is in the 

 outer part of the inner segment, and exhibits a fibrous structure. 



