410 
not produce much which could amplify or modify the com- 
plete statement of Cohnheim on this subject. I shall only 
allow myself to make some remarks upon the structural con- 
ditions. These remarks apply both to the plexus of the 
broad nerve-fibres, and to the subepithelial networks of the 
fine ones. 
If the nerves are followed from their entry into the cornea 
uncut where they forma plexus in the tissue by the successive 
division and anastomosis of their branches, it is found on the 
one hand that the neurolemma, with its oblong nuclei, is 
prolonged from the trunk on to the branches, and on the 
other that the individual nerve fibrils of the trunk at the same 
time lose the medullary sheaths, but do not do so at corre- 
sponding points in their course. The branches, moreover, of 
the same trunk do not lose their sheaths at corresponding 
points in their course. In the non-medullated parts it may 
be recognised that the colourless or pale reddish neurolemma 
contains only bundles of delicate filaments, with varicosities 
at more or less regular intervals, which filaments may run 
more or less parallel to each other, or twine round one 
another in spirals. At the points at which a bundle of this 
kind divides into smaller bundles, or at which fibres branch 
off laterally, there exist enlargements of triangular form, the 
neurolemma being prolonged from the trunk on to all the 
branches. 
The filaments of the branches of this plexus, which are to 
be met with in all parts of the cornea propria, are conse- 
quently to be regarded as bundles of fine fibrils, which were 
separated so long as they formed a series of single axis- 
cylinders. 
In addition to the points already mentioned as to the 
arrangement of the non-medullated fibrils, another peculiarity 
is to be noticed. The fibrils form within the neurolemma, 
particularly at the points of enlargement, a mesh-work of 
extraordinary closeness, which is produced by the bifurcation 
and coalescence of neighbouring fibrils. The interspaces 
are rhomboid or oblong. 
In the anterior superficial layers of the corneal tissue, 
minute bundles of fibrils spring from the plexus, which lose 
themselves in the subepithelial network. Cohnheim has 
explained in the most complete manner the differences which 
this network presents in the central, peripheral, and middle 
parts of the cornea. Cohnheim’s research is so well known, 
that it is scarcely necessary to give quotations. I will 
content myself with adding to his description, that as well 
on the central as on the intermediate zone, between centre 
