564 



FILAMENTS OF MULLER. 



[sect. 226. 



Fig. 234. 



the fibres of Muller, which, when they cover one another, and 



especially when they are distended by 

 water, produce the appearance of roundish 

 angular bodies, lying parallel to each 

 other. Now, the truncated terminations 

 of the fibres of Muller abut upon the 

 outer surface of the membrana limitans, 

 and pieces of the latter membrane, espe- 

 cially in chromic acid preparations, may 

 not unfrequently be obtained in connec- 

 tion with these fibres ; the connection of 

 the two, however, is by no means intimate, 

 for the radiating fibre-system can generally 

 be detached with facility from the limitary 

 membrane, especially in fresh prepara- 

 tions, or in such as have been treated 

 with re-agents. 



The signification of this radiating fibre- 

 system, and even its anatomical relations 

 to the other elements of the retina, is 

 still, in many respects, very obscure. This 

 only is certain, as I formerly supposed 

 (Compt. Rend., 1853, Oct.), and as IT. 

 Mi'dler and myself (see my Gratulations- 

 schrift an Tiedernann, p. 12, and my Micr. 

 Anat., ii. 2, p. 703) have also recently de- 

 monstrated by direct observation, that at 

 the yellow spot, the fibres of Muller which 

 leave the cones, enter into connection with one of the granules of the 

 inner layer and with one of the nerve-cells of the retina. It is 

 very probable that at other places, filaments proceeding from the 

 cones have similar connexions. We have no positive observations 

 on the filaments of the rods ; and it is not to be forgotten, that 

 many histologists are inclined to dispute the nervous nature of . 

 many of the radiating elements of the retina. 



The vessels of the retina are derived from the art. centralis 

 retince, which, situated in the optic nerve, enters the eye, and 

 commences its distribution from the middle of the colliculus by 

 four or five main branches. Lying at first beneath the membrana 

 limitans only, they pass through the lamina of nervous fibres into 

 the layer of grey nervous substance, where they are distributed 

 with beautiful arborescent ramifications as far as the ora serrata ; 



Diagram to represent the con- 

 nection of the cells, rods, and 

 fibres of Mutter, according to my 

 view of them. a. A nerve-cell ; 

 h. optic fibre ; c. outer process of 

 the cell, connected with an inner 

 granule d; e. fibre of Muller, 

 proceeding from this to an outer 

 granule/, and thence to a rod g ; 

 h. internal extremity of the fibre 

 of Muller, with the enlarge- 

 ment i. 



