276 THE RETINA, BY MAX SCHULTZE. 



ent in character from the radially directed rows of fibres seen 

 in the more peripherally situated parts of the retina. 



Some differences of opinion prevail respecting the membrana 

 limitans interim, which I believe depend on the different thick- 

 ness and resistance it presents at various parts of the retina in 

 Man and different animals, and its frequent coalescence with 

 the vitreous. Kolliker* observes, in regard to this point, that 

 the remarkable softness and destructibility of the radial fibres 

 in contrast to the resistance of the limitans, is opposed to the 

 idea of their identity of structure, and he consequently consi- 

 ders the limitans as a special tissue to be ranked amongst the 

 vitreous membranes. In opposition to this, however, it may be 

 remarked that other vitreous membranes, as the anterior elastic 

 lamina of the cornea, or the internal layer of the choroid, also 

 fuse with their supporting tissue, and may be held to originate 

 with and out of this, though presenting essential differences in 

 their relations to solvents. I am unable to discover any other 

 kind of membrana limitans interna besides the above described, 

 on which account I place its identity of structure with the sup- 

 porting reticular or spongy connective tissue in the foreground, 

 though fully recognizing the importance of the separability 

 of the limitans, and the difference in resistance between it 

 and the spongy subjacent layer, especially at the yellow spot. 

 Henle also regards the limitans interna as an independent 

 membrane, to the outer surface of which the radial supporting 

 fibres, with their expanded extremities, are applied, f He 

 calls it the limitans hyaloidea, to show that it is identical with 

 the special membrane of the vitreous, described by many au- 

 thors. The conditions of hypertrophy of the connecting sub- 

 stance which take place in atrophy of the nervous constituents 

 of the retina are very instructive for the purpose of demon- 

 strating the connection of the supporting fibres with the 

 limitans interna, as they have been described in one case by 

 Iwanoff, J where the hypertrophy of the radial fibres occasioned 

 circumscribed enlargements extending into the vitreous. 



* Geu-ebelehre, 5th Edition, p. 681. 



t Eingeu-eidelehre, p. 658. 



$ Grafe's Arcfiiv, Band xi., Abtheil i., p. 141, Taf. 3 and 4. 



