On Corpuscles of the Cornea, de. By G. F. Dowdeswell. 289 
formation ; that with the progress of inflammation these changes 
increase, the corpuscles losing their stellate form, and assuming the 
character 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 lamine 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 leuco- 
cytes. 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 pre- 
sented 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 
difficulty to determine with certainty whether this does occur or 
not. ‘The purpose of the present note is to describe a mode of in- 
vestigating these appearances, by the employment of which satis- 
factory 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 corpuscles 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 normal and an inflamed cornea can be 
recognized. 
The appearances presented by these corpuscles in corneas pre- 
pared 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 Haperiments.—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 forty-eight hours,.and then gradually sub- 
sides, so that by the fourth or fifth day its effects have disappeared), 
or (when it was desired that the process should be of longer dura- 
tion) by a seton of silk thread. The animal having been killed at 
the proper period, and its cornea excised and immersed in half per 
cent. solution of gold chloride for sixty minutes, and exposed in a 
light warm place, when sufficiently coloured a small portion of the 
inflamed part is placed in a solution of potash till the ground- 
substance 1s completely dissolved. Care is requisite to hit off the 
