THE SENSES 



78i 



membrane is formed by the expanded feet of the fibres of Miiller, 

 JhVk rUn f I a SCaffoldln or framework through nearly the whole 

 thickness of the retina terminating at the outer limiting membrane. 

 External to the layer of nerve-fibres is the stratum of large ganglion 

 cells, whose axons they are; next to this the inner molecular layer, 

 made up largely of the branching dendrites of these cells. The fifth 

 layer is the inner granular or nuclear layer, containing many fusiform 



Rods. 



Cones. 



FIG. 287. THE RETINA. 



FIG. 288. DIAGRAM OF STRUCTURE OF 

 RETINA (BOWDITCH, AFTER CAJAL). 



Figs. 287, 288. i, internal limiting mem- 

 brane ; 2, H, layer of nerve-fibres ; 3, G, layer 

 of ganglion cells ; 4, F, internal molecular 

 layer ; 5, E, internal nuclear layer ; 6, C, ex- 

 ternal molecular layer ; 7, B, external nuclear 

 layer; 8, external limiting membrane; 9, A, 

 layer of rods and cones ; 10, pigmented epi- 

 thelium. 



' granule ' cells which send out axons into the fourth, and dendrites 

 into the sixth, or outer molecular layer, and are thus connected with 

 the ganglion cells of the third layer on the one hand, and with the 

 seventh or outer nuctear layer on the other. The seventh stratum 

 receives its name from the large number of nuclei which it contains. 

 These are connected with the rods and cones of the ninth layer, 

 which is divided from the seventh by the external limiting mem- 

 brane. At ihefovea centralis the rods are entirely absent, and the 



