CiAccio^ on the Nerves of the Cornea, 
89 
gular_, pentagonal^ or quadrilateral form, but sometimes they 
are seen exhibiting other shapes. The bundles of fibres, 
from the intermingling of which the meshes are produced, 
are of different sizes, and disposed in curved lines. Very 
often, from various parts of the meshes, fibres more or less 
fine are seen to arise, which cross the field of the meshes in dif- 
ferent directions ; and after a tortuous course, and continually 
change of plane, either unite with other fibres, which pro- 
ceed from distant bundles, or with the bundles themselves. 
These fibres, which, from their thinness, would lead us to 
consider them as single, are never found in this state, but 
are made up of at least two fibres, and generally more. 
4. Pleocus with narrow meshes. — From what I have ob- 
served, I feel sure that the nerves distributed to the human 
cornea terminate in a very extensive plexus with narrow 
meshes. The plexus is not formed by single, separate nerve- 
fibres, but by bundles, which are in direct continuation with 
the smallest branches, into which the trunks, by repeated 
division, are reduced. In some of my specimens these 
branches may be seen crossing the corneal tissue in difi'erent 
directions, and may be followed for a long distance, before 
they are observed to divide into the bundles before mentioned. 
As the fibres which compose the bundles are extremely 
pale and transparent, and are also greatly softened and 
changed very soon after death, considerable difficulty exists 
in the investigation of this plexus, which can only be seen 
in good specimens prepared in a particular way. 
These different kinds of networks and plexuses, which have 
been described, extend throughout the anterior part of the 
cornea, and gradually cease towards the posterior portion. 
It must be observed that the various bundles forming these 
networks and plexuses are frequently changing the planes 
and direction of their ramifications, so that each separate 
bundle during the whole of its course comes into contact 
with several other bundles. I have before stated that the 
principal trunks of nerves, on entering the cornea, are very 
near to its posterior surface, and pass in an oblique direction, 
repeatedly dividing, and at length reach the anterior surface. 
In this fact, which seems to me to admit of no further dis- 
pute, is found the explanation why, in the w^hole space over 
which the networks and plexuses extend, the different 
branches which enter into their formation are of unequal size, 
and the finest branches are found in that part of them which 
lies immediately beneath the anterior elastica lamina of the 
cornea. 
