88 _ Trans. Acad. Sci. of St. Louis. 
the sections well enough preserved to show that there 
are usually three layers of epithelial cells. The cells of 
the basal layer are more or less cuboid, the next layer 
consists of flatter cells, and in the outer layer they are 
still more flattened. In the eyes of the adult specimens 
where the corneal surface was well protected the corneal 
epithelium is preserved intact and shows the same 
arrangement. 
The corneal tissue proper shows a lamellated structure 
with fixed corneal cells. I have not been able to find 
any anterior uniform layer corresponding to Bowman’s 
layer, nor a posterior membrane corresponding to that 
of Descemet in the human eye. On account of the 
extreme shallowness of the anterior chamber in most 
of my sections, in consequence of which the anterior sur- 
face of the iris and the anterior pole of the crystalline 
lens seem fairly agglutinated to the posterior surface of 
the cornea, it was only with difficulty that I could con- 
vinee myself that the posterior surface of the cornea is 
lined with a layer of endothelial cells. These cells 
appear large and flat and have a large oval nucleus. They 
resemble so much the capsular epithelial cells of the 
adjacent crystalline lens that this, also, helps to render 
it more difficult to differentiate them. 
The sclerotic is quite thin and shows nothing particular 
aside from a small amount of cartilage tissue which I 
find not only in the larvae, but also in some of my adult 
specimens. 
As stated above, the very darkly pigmented uveal tract 
is in all of my sections more or less mutilated and dis- 
integrated, and quite frequently the choroid is split in 
two unequal parts, the inner one adhering to the retina. 
It was, therefore, impossible to study the structural con- 
ditions with anything like accuracy and completeness. 
In none of my sections have I found a trace of a blood- 
vessel in this membrane, which in the human eye is the 
vascular coat. The ciliary body appears simply like a 
few folds and corrugations of darkly pigmented tissue in 
