Monthly Microscopical"! 
Journal, Nov. 1, 1869. j 
Histology of the Eye. 
229 
Fig. 1. 
not yet differentiated; but at full term it is very distinct. 
In the adult cornea, in which its average thickness is about 
T^Voth of an inch, it is always remarkably conspicuous by its 
transparent structurelessness, 
which marks it off from the 
epithelium in front and the 
lamellated corneal tissue be- 
hind it. The front of the 
lamina bearing the epithe- 
lium is perfectly even ; while 
the posterior surface is slightly 
irregular, owing to the pro- 
duction of fibres which pass 
slantingly from it into the 
lamellated tissue, and tie the 
lamina to this so closely that 
it is inseparable from it by 
dissection, except in very 
minute pieces. These tie- 
fibres, originally described by 
Mr. feowman, are, I believe 
with him, of the same nature 
as the lamina — a modified 
connective \ substance ; and 
they are perfectly distinct 
from the nerve-fibres, the 
tracks of which a recent 
author supposes them to be. 
The peripheral relations of the anteri<|jr elastic lamina are very 
simple. It becomes suddenly thinned at a short distance in front 
of the foremost conjunctival vessels, and thence runs backwards 
over the loose submucous tissue as the basement-membrane of the 
conjunctiva bulbi. 
The next structure is tbe lamellated cornea, one of the group 
of connective substances. It is mainly composed of two elementary 
tissues- — one cellular, the other a modification of common connective 
or white fibrous tissue. Their microscopic characters and the pro- 
portions in which they occur are not the same at all ages. At its 
first appearance, the cornea, embryology teaches, is purely a cell- 
tissue; and, in the earliest human foetal cornea which I have 
examined (at the fourth month), the cell or corpuscular tissue has 
greatly preponderated. At full term, the disproportion is less : the 
cells have still simple shapes ; but they are separated by a larger 
quantity of interstitial tissue, which is very distinctly fibrillated. 
In the adult's cornea, the fibrous tissue dominates ; and the cor- 
puscles are large-branched cells, cohering in nets of variable sizes, 
Suppuration of Anterior Corneal Epithelium. 
