350 THE VITEEOUS HUMOUR, BY PROF. A. IWANOFF. 



verse sections of the vitreous of eyes hardened in Mailer's fluid, split 

 into layers which run parallel to the surface, and with the aid of high 

 powers, after tinting with carmine, a finely granular mass makes its 

 appearance in these layers, in the posterior part of this organ, together 

 with a few scattered fine fibres. Anteriorly, towards the ora serrata 

 the fibres become more abundant, and pursue a wavy course parallel 

 to the surface. Even here, however, no traces of membranes are 

 visible. 



These statements respecting the structure of the vitreous have 

 received fresh confirmation from the researches of Stilling,! which 

 possess the advantage of having been exclusively made on the fresh 

 vitreous, and are not therefore open to the objection that the 

 conclusions arrived at are due to appearances artificially produced. 

 According to Stilling, if sections be made through the fresh vitreous 

 parallel to the optic axis, and a few drops of carmine be allowed to fall 

 on the cut surface, a number of concentric furrows, varying from six to 

 twelve, are formed in the periphery, whilst the centre, or nucleus, 

 remains free from colour. The furrow forming the boundary between 

 the cortex and the nucleus is, as a rule, the deepest, and is most 

 quickly filled. Stilling does no-t give the relations of the cortex and 

 nucleus quite correctly, since he was only aible to apply his method to 

 the determination of the coarser anatomy of the parts. He states that 

 the cortex invests that part of the nucleus situated behind the ora 

 serrata, so that the lens and zonula lie npon the latter alone. But, 

 as we have seen above, the cortical portion, the several layers of 

 which are closely compressed at the ora serrata, completely surrounds 

 the nucleus, as is correctly shown in the illustrations of Hannover 

 and Finkbeiner. 



After Henle had demonstrated that mo hyaloid membrane existed, he 

 endeavoured to explain the existence of the membrane that, in his 

 opinion, is found in the shallow groove covering the vitreous at this 

 point, by assuming that the limitans, before it reaches the ora serrata, 

 increases in thickness, and at the same time becomes altered in struc- 

 ture. He considered that it partially breaks up into fibres, which either 

 pursue an irregularly tortuous course, like those of elastic tissue, or are 

 parallel and wavy, like those of connective tissue ; in either case, how- 

 ever, being always remarkable for their extraordinary tenuity : and 

 further, wiiilst the principal portion of these fibres or fasciculi of fibres 



* Stilling, Eine Studie uber den Bau des Glaskorpers, Archiv fiir 

 Anatomie, Band xv., Heft iv. 



