ORIGIN OF THE MIGRATING OR WANDERING CELLS. 391 



manifold varieties in the inflammatory appearances occur, as 

 Strieker* has pointed out, and, which is a matter of great im- 

 portance, it may be shown very decisively that in certain cases, 

 at a time when the corneal corpuscles around the ulcerated spot 

 exhibit either very slight indications of proliferation, or none at 

 all, a moderate degree of infiltration of pus may commence from 

 the margin, which may in other cases be entirely absent. In the 

 former case appearances are presented similar to those which 

 have been described and illustrated by Cohnheim in his account 

 of the relations existing between the corneal corpuscles and 

 those of pus. 



It is thus placed beyond all question that pus corpuscles can 

 originate from the corneal corpuscles ; yet, however satisfactory 

 a proof this constitutes in favour of the protoplasmic nature 

 of the latter, it is equally certain that purulent infiltration of 

 the cornea may occur without the corneal corpuscles in any 

 way participating in the process. 



Two sources must be admitted for the migrating cells of the 

 cornea, and unless a given inflammation has been followed 

 through all its stages, from its very first commencement to the 

 particular moment when the changes it produces are subjected 

 to examination, it is not easy to say how many proceed from the 

 one, and how many from the other source, or how many from 

 the fission of previously present migrating cells, f 



The origin of the migrating cells present in the healthy 

 non-inflamed cornea from the corneal corpuscles has not been 

 demonstrated. The cells which form the small pustules in 

 keratitis phlyctenularis, which lie between the anterior epi- 

 thelium and the corneal tissue, and which reach their destina- 

 tion by travelling along the side of the nerves,:}: appear only 

 to be migrating cells that have escaped from the blood. 



THE FIBRILLAR SUBSTANCE (FIBRILLAR PORTION OF THE 



MATRIX) OF THE CORNEA. The fibrillar substance of the 

 cornea forms the principal portion of its mass. 



* Studien, p. 34. 

 + Strieker, loc. cit., p. 18. 



t Iwanoff, Klinische Monatsblatt fur Augenheilkunde, Jahrgang vii., 

 p. 462. 



