232 THE RETINA, BY MAX SCHULTZE. 



of the retina of the Frog can be so detached in specimens pre- 

 pared with alcohol, that the ganglion cells come away with 

 them,* and the connection of the latter with the optic fibres 

 can thus be most distinctly brought into view. The majority 

 of the cells then appear to be unipolar. Manz nevertheless 

 admits that the numerous and probably peripherically directed 

 processes of these cells, demonstrable by other methods, are 

 broken off in this mode of preparation. We only know, there- 

 fore, in respect to these processes of the ganglion cells of the 

 retina which do not disappear in the optic-fibre layer, that -a 

 portion run towards the granulated layer. Anastomoses of 

 the cells with each other, effected by thick processes, have been 

 depicted by Corti in the Elephant. It remains to be shown 

 whether such connecting processes, which have not been again 

 observed, are to be regarded as normal. 



As in the optic-fibre layer, so also between the ganglion cells, 

 the radiating supporting fibres form a kind of framework, which 

 will be subsequently described. 



Section of the optic nerve in animals is followed, according 

 to W. Krause, by fatty degeneration of the ganglion cells.'f' 

 In the eyes of blind persons in whom the disappearance of 

 the layer of nerve fibres of the optic nerve can be anatomically 

 demonstrated, there is usually also atrophy or complete absence 

 of the ganglion cells, as is seen especially in glaucoma resulting 

 from an increase of the intra-ocular pressure. 



The peculiar appearance of the internal granulated (mole- 

 cular) layer of the retina is due to the admixture of a very 

 fine plexus of spongy connective tissue, given off from the 

 hereafter-to-be-described radial supporting fibres, with im- 

 measurably minute nerve fibrils. The latter, as Pacini J and 

 Remak first pointed out, form an essential constituent of this 

 layer. They may be isolated in properly macerated retinae 



* H. Miiller (Zeitschrift fur wiss. Zool. , Band viii. , p. 21), even at that 

 date (1856), remarked in regard to the retina of Fishes, that " if the ner- 

 vous fibre layer were raised from the inner surface of the retina with 

 forceps, a portion of the cells was easily detached with them." 



t Membrana fenestrata, p. 38. 



I Nuove ricerche sulla tessitura intima della retina. Bologna, 1844. 



Medicinische Centralzeituny, 1854. No. 1. 



