1877.] the Cornea in the Process of Inflammation. 493 



observers hare alleged that proliferation of the fixed corpuscles of that 

 tissue also occurs ; in other words, that the so-termed leucocytes are 

 not entirely immigrant, but that some of them are formed in the inflamed 

 tissues. It is stated by those who take this view of the process, that in 

 a few hours after the establishment of inflammation the fixed corpuscles 

 begin to alter, that their processes are partially retracted and thickened, 

 their outline becoming more distinct, and that at a later period small 

 spherical bodies appear in their substance by a process of endogenous 

 cell-formation ; that with the progress of inflammation these changes 

 increase, the corpuscles losing their stellate form, and assuming the cha- 

 racter of endogenous mother-cells which divide by fission. 



These observations have all apparently been made upon corneas 

 excised and examined in serum or other fluid, or upon laminse of corneas 

 prepared by the gold method. 



Cohnheim and others have denied that the changes are objective, and 

 attribute all the appearances to an active immigration of leucocytes. 

 A principal objection to this conclusion has been founded on the grounds 

 that the observations commenced too late, when the asserted changes had 

 already occurred. 



In the ordinary methods of preparation, the appearances presented 

 during the second and third day of the inflammation are such as might 

 readily be conceived to arise from proliferation of the elements of the 

 tissue ; and it is unquestionably matter of great difliculty to determine 

 with certainty whether this does occur or not. The purpose of the pre- 

 sent note is to describe a mode of investigating these appearances, by the 

 emplojnnent of which satisfactory evidence may be obtained that the 

 process essentially consists in the penetration of colourless corpuscles 

 (migratory cells), in a state of active cell-division, into the cell-spaces of 

 the cornea, where they overlie and obscure the cornea-cells in such a 

 way that, in preparations made by the usual methods, they appear to be 

 incorporated with them. If, however, a method is employed by which 

 the ground-substance can be destroyed (as, e.g., by potash) and the cor- 

 puscles separated by teasing, it is shown that they are perfectly unaltered, 

 the migratory or wander cells only undergoing cell-division ; so that it 

 is by the presence of the latter alone that the difference between a nor- 

 mal and an inflamed cornea can be recognized. 



The appearances presented by these corpuscles in corneas prepared by 

 the ordinary methods, when supposed to be undergoing proliferation, 

 have been so often described and figured that they need not be further 

 referred to here. 



Methods adopted in these experiments. — Inflammation was induced 

 either by touching the surface with a fine point of nitrate of silver in 

 the usual way (in which case the ensuing process arrives at its height in 

 about 48 hours, and then gradually subsides, so that by the fourth or 

 fifth day its effects have disappeared) or (when it was desired that the 



