56 THE EMBRYOLOGY OF THE EYE. 



external to this stratum is a second in which 

 the cells stain faintly (Fig. 15, C). These 

 faintly staining cells disappear to give place 

 to the reticulum. 



Near the ora serrata the nerve-fibre layer is 

 very thin, and only in this region can the sup- 

 porting fibres of Mliller be studied with any 

 degree of clearness. At a late stage coarse 

 fibres may here be seen spreading out into a 

 cone shape and inserted into the limitans in- 

 terna, which previously has existed as a simple 

 membrane. In this cone-shaped foot, both in 

 the foetus and in the grown animal, we may 

 here and there distinguish a very faintly stain- 

 ing nucleus. 



As the ganglion-cell grows, its nucleus in- 

 creases greatly in size and comes to stain more 

 faintly. Among the ganglion-cells there are 

 from the beginning small bipolar cells which 

 take a deep stain. These small cells have an 

 oval nucleus with its long axis in the direction 

 in which Miiller's fibres run. Somewhat simi- 

 lar cells which stain less deeply lie in the 



