THE EYE. 243 



then pass outward into the next layer to join the 

 ganglion-cells. These, which have the general 

 characters of branching nerve-cells, send numerous 

 processes into the internal molecular layer, where 

 they break up into an extremely delicate fibrillar 

 network associated with the connective-tissue 

 framework. Most of the nuclei in the internal 

 nuclear layer are believed to belong to small nerve- 

 cells, while the larger ones belong to the connective- 

 tissue framework. In the external molecular layer 

 again, we have a delicate network of nerve-fibrils 

 intermingled with connective tissue. The nuclei of 

 the external nuclear layer seem to belong exclusively 

 to nerve-elements, and are directly connected, by 

 processes which pass through the openings in the 

 external limiting membrane, with the rods and cones. 



Of the rods and cones, which within the limits 

 of this book cannot even in a general way be ade- 

 quately described, the rods are the longer, are usu- 

 ally somewhat pointed at the inner extremity where 

 they join the nerve-elements of the outer nuclear 

 layer; the cones are shorter, are connected also with 

 nerve-elements within, and terminate externally in 

 pointed or rounded extremities. 



The connective-tissue elements of the retina con- 

 sist, in certain layers, of broad, irregular radial fibres 

 forming frequent inosculations, and, in the molecular 

 layers, of a delicate reticulum, within which the nerve 

 fibrils ramify. 



