418 THE CORNEA, BY ALEXANDER ROLLETT. 



Lightbody, * to the effect that perivascular lymph spaces 

 surround the marginal loops of the cornea, have not been 

 corroborated as a normal condition by C. F. M tiller f or by 

 Schwalbe. J Neither C. F. Muller nor Schweigger-Seidel || were 

 successful in discovering any mode of exit for the fluid driven 

 into the substance of the cornea by puncture-injections ; but 

 Leberlf has observed the entrance of injected fluids into the 

 lymphatics of the conjunctiva. 



Lastly, it may here be observed that in simple puncture- 

 injections into the cornea, the injected fluid may make its way 

 along the trunks of the nerves,** and this may also occur from 

 the extravasation of injection fluids driven into the bloodvessels. 

 In this way are to be explained, according to C. F. Miiller,tt 

 the vascular-like figures observed by Teichmannin the injected 

 cornea, J{ and the vasa serosa described by J. Arnold and by 

 Niemetschek.|||| 



THE MEMBRANE OF DESCEMET. 



The membrane of Descemet forms a very sharply defined 

 layer in vertical sections of the cornea ; its thickness increases 

 in Man with the advance of years. In the newly born child 

 H. Miillerf If found its thickness to amount to 0*005 0*007 of 

 a millimeter; in the adult and at the centre, to O'OOG O'OOS of 

 a millimeter ; at the margin, from 0*01 to 0'012 of a milli- 

 meter ; in old people, in the centre, to O'Ol ; and at the margin, 

 to 0-0150-02 of a millimeter. It is detached with difficulty 

 from the fresh cornea, but with facility from a cornea treated 

 with permanganate of potash, or with a ten per cent, solution 

 of common salt. 



* Journal of Anatomy and Physiology, 1867, p. 35, et seq. 



t C. F. Muller, loc. cit., p. 147. 



J Archiv fur Mikroskopische Anatomic, Band vi. , p. 264. 



C. F. Muller, loc. cit., p. 146. 



|| Schweigger-Seidel, loc. cit., pp. 324 and 325. 



IT Klinische Monatsbldtter fur Augenheilkunde, 1866, p. 17. 



** C. F. Muller, loc. cit., p. 142. 



ft C. F. Muller, loc. cit. 



JJ Teichmann, Das Saugadersystem. 



J. Arnold, loc. cit. 



Illl Prager Vierteljahresschrift, Band in., 1864, p. 48. 



1HT Archiv fur Ophthalmologie, Band ii., Abtheil. ii., p. 48. 



