THE PERIPHERY OF THE CORNEA. 4o7 



interruption. But on account of the extreme tenuity of the 

 fibrils, both of the cornea and of the sclerotic, this appearance 

 is not to be altogether trusted. Even if they were not con- 

 tinuous with each other, it would be very difficult to separate 

 the two sets of fibres from each other, and to be quite sure of 

 their real mode of termination. 



I think it probable that the tissues are only intimately 

 intercalated with each other; for if, by means of simple puncture 

 injection, we break down the corneal tissue in the mode above 

 described, as far as to the periphery, and again extract the in- 

 jected fluid, we see the corneal tissue presenting a spongy 

 appearance, and running out in the form of thin laminae 

 intercalated with thin layers of dense sclerotic tissue. 



The difference in their chemical characters is a feature that 

 in particular renders it improbable that there is a direct con- 

 tinuity between the fibres of the cornea and those of the 

 connective tissue. Sections of portions of the membranous 

 capsule of the eye, containing the limbus corner, that have 

 been boiled in acetic acid and dried, are well adapted for 

 staining both with carmine and picric acid;* and from an 

 examination of such specimens it may be demonstrated that 

 the cornea becomes stained of a yellow colour, whilst the 

 sclerotic, like all connective tissue, stains red. In the cornea 

 the corpuscles alone appear of a red colour. 



The membrane of Descemet (c c', fig. 393) becomes attenuated 

 at the margin (c'), and indeed in Man is so at a considerable 

 distance from the angle of the anterior chamber of the eye. 

 It does not, however, cease abruptly at the margin, but ifc con- 

 nected with peculiar fibres, f which are at first irregular, 

 and interlace at their borders, J after which they project with 

 broader or more slender processes, and ultimately form an 

 annulus at the border of the membrane of Descemet, on the 

 outer surface of which the gradually attenuating termination 

 of the membrane still continues to lie. With this marginal 



* Schwarz, Sitzungsberichte der Wiener Akademie, Band lv., Abtheil. i., 

 p. 676. 



f Henle, loc. cit., pp. 607 and 626. 



I Schwalbe, Archiv fur Mikroskopische Anatomie, Band vi., p. 278. 

 Iwanoff and Eollett, Archiv fur Ophthalmologie, Band xv., p. 49. 



