THE VISUAL PIGMENTS 



unknowable way, to the sensations of vision, i.e. form, brightness, 

 colour and saturation. 



FIELDS OF STUDY 



In the study of vision proper, that is of the processes which ensue 

 as the result of the formation of an image on the retina, diverse 

 methods have been used. In much of the work the main object has 



ii^fel-PPP 





AKk'KAM 



Fig. 1.2. Diagrammatic section of the primate retina. 



Layers: 1, pigment epithelium; 2 (a), (6), rod and cone layer; 3, outer 

 limiting membrane; 4 (a), (b), outer nuclear layer; 5 (a), (b), (c), 

 outer plexiform layer; 6 (a), (b), (c), (d), inner nuclear layer; 7, inner 

 plexiform layer; 8, ganglion cell layer; 9, optic nerve fibres ; 10 inner 

 limiting membrane. 



Nerve cells: (a), rods; (6), cones; (c), horizontal cells ; (c?), (e), (/), (//), 

 bipolar cells; (/), (0, amacrine cells; (w), («), (o), (/?), (s), ganglion 

 cells; (tt), 'radial fibres' of Miiller. 



(Polyak, 1941) 



4 



