PARENCHYMATOUS KERATITIS. 



341 



formly throughout the whole cornea, but was limited 

 to a definite portion of the tissue. This portion is so 

 characteristic in reference to the different explanations 

 possible, that the case, I think, presents especial inter- 

 est theoretically. 



It turned out namely that the opacity began in the 

 immediate proximity of the posterior surface and at the 

 circumference of the cornea, close to the membrane of 

 Descemet [posterior elastic lamina of Bowman] at the 

 point where the iris is attached. Thence the opacity, 

 assuming almost the shape of a flight of steps, mounted 

 up into the cornea till within a certain distance of the 

 external surface. Then it proceeded at the same level, 

 till it descended upon the other side again in a similar 

 manner. Thus an opaque bow was formed throughout 

 the whole substance of the cornea, without reaching the 

 external (anterior) surface and without encroaching 

 upon the central parts of the posterior surface. If we 



FIG. 99. 



imagine the nutrition of the cornea to proceed from the 

 aqueous humour, the opacity did not assume the form 



Fig. 99. Parenchymatous keratitis. A, A, Anterior (external), J?, B, posterior 

 (internal) side of the cornea. C, O. The clouded zone with enlarged cornea-cor- 

 puscles. 18 diameters. 



