VISION. 



78? 



The first layer consists of neuraxons from the ganglionic cells 

 of the second layer. The second layer consists of a lot of multi- 

 polar nerve-cells, and their neuraxons run inward to form most of 

 the fibers of the optic nerve. The dendrons of these multipolar 

 cells are branched and terminate in the inner molecular layer, of 

 which this third layer is chiefly composed. The fourth inner nuclear 

 layer is made up chiefly of round and oval cells with a peripheral 

 neuraxon and a central neuraxon. 



The peripheral neuraxon arborizes around the dendrons of a 

 ganglionic cell in the inner molecular layer. 



The fifth outer molecular layer is made up of the arborizations 

 of the neuraxons of the visual cells of the outer nuclear layer. 

 * - 



paracenfral 

 lobule 



corpus 



f. of Rolando 

 intraparietal fissure 



f. of Sylviut 

 parallel fissure 



A B 



Fig. 338. Diagram of Occipital Region of Right Cerebral Hemispheres. 



(BALL.) 

 A, From inner, and B, from outer aspect. 



The sixth layer, the outer nuclear layer, is the layer of bipolar 

 visual cells. Their central neuraxons end in arborizations in the 

 outer molecular layer about the dendrons of the bipolar cells of the 

 inner nuclear layer. The peripheral processes of these cells are the 

 rods and cones of the retina, which are similar to the dendrons of 

 other nerve-cells. 



The seventh layer of rods and cones are the dendrons of the 

 visual cells. 



The eighth layer is the pigment-layer of the retina. 



The retina is essentially formed by a number of nerve-cell 

 chains, the elements of which are arranged in three series from with- 

 out in. The first is the rod and the cone ; the second is the bipolar 

 cell, which interlaces with the peripheral dendrons of the ganglonic 

 cells. The third element is the ganglion-cell. 



