514 



THE HUMAN BODY. 



the cells of this layer send processes between the rods and 

 cones. The processes contain dark pigment and in eyes 

 which have been exposed to bright light reach a long way, 

 sometimes even as far as the external limiting membrane. 

 If, however, the animal have been kept in the dark for some 



10 



FIG. 144. A section through the retina from its anterior or inner surface, 1, in 

 contact with the hyaloid membrane, to its outer, 10, in contact with the chqroicl. 

 1, internal limiting membrane; 2, nerve-fibre layer; 3, nerve-cell layer; 4, inner 

 molecular layer: 5, inner nuclear layer; 6, outer molecular layer; 7, rod and cone 

 fibres or outer nuclear layer; 8, external limiting membrane; 9, rod and cone 

 layer; 10, pigment-cell layer. 



time before its eye is removed, the processes of the pigment- 

 cells are short and extend only a short distance between the 

 outer ends of the rods. In addition, certain fibres run verti- 

 cally through the retina from the inner to the outer limiting 

 membrane; they are known as the radial fibres of Mutter 



