418 



PRACTICAL ANATOMY. 



7. The inner molecular layer is a thick layer, gran- 

 ular in appearance, which is formed of a dense net-work 

 of fibres, imbedded in which are some ganglion cells. 



8. Ganglion cell-layer, a single layer of large flask- 

 shaped cells, having an inner pole, which communicates 



with an optic-nerve fibre, 

 and several external 

 branched poles, which 

 pass into the inner molec- 

 ular layer. 



9. Optic-nerve fibre- 

 layer consists of a layer 

 of naked axis-cylinders, 

 which pierce all the other 

 layers of the retina. 

 They radiate from the 

 disk, and also form fre- 

 quent plexuses. Some 

 communicate with the 

 ganglion cells, others 

 pass outward through 

 the molecular layer. 



10. The membrana 

 limitans interim is 

 formed of cellular tissue. 



The retina is sup- 

 ported by a connective- 

 tissue stroma, arranged between the internal and external 

 limiting membranes. Between these pass columns of 

 connective tissue, from which pass off skeletal supporting 

 fibres. 



The Humors of the Eye. The aqueus fills both 

 the anterior and posterior chambers of the eye. It 

 contains a trace of chloride of sodium, is alkaline in 



FIG. 180. VERTICAL, SECTION OF HUMAN 

 RETINA. 



a, rods and cones ; b. external, j, internal limiting 

 membranes ; c, external, and f, internal nuclear layers ; 

 e, external, and g. internal granular layers; k, blood- 

 vessel and nerve-cells ; i, nerve-fibres. 



