79 
anatomical structure of the eye. 
it. I have much pleasure in stating, that what he represented 
in the quadruped, corresponds with Mr. Bauer's drawings 
from the human eye, made before Mr. Maunoir’s Treatise 
on the artificial pupil was shown to him. The capsule of the 
crystalline lens is made up of two hemispheres of different 
texture, in which the lens is completely enclosed ; the anterior 
portion is more dense than the other. The posterior Is so 
thin, as to appear a continuation of the capsule of the vitre- 
ous humor, but from its curling up when cut, it must partake 
of the same nature as the anterior portion. The vitreous 
humor consists of a very delicate gelatinous substance, ex- 
ceedingly elastic, abundantly supplied with branches of ves- 
sels. Arteries are sometimes met with carrying red blood, 
and in a degree capable of being injected. 
The fibres of the lens have the appearance of hairs like 
those formed in spun glass. 
The situation of the marsupium is shown both in the eagle 
and goose, and the difference of its radius of curvature at the 
bottom of the eye on its two sides, is as to ^th of an 
inch. 
EXPLANATION OF THE PLATES. 
Plate VI. 
Fig. i. Front view of the human eye, extracted from its 
orbit ; natural size. 
Fig. 2. Side view of the same; natural size. 
Eig. 3* Vertical section of the same; magnified three dia- 
meters. 
Fig. 4. External side view of the human eye, the sclerotic 
coat and cornea being removed, showing the bundles of ves- 
sels which arise from the sclerotic coat, and go towards the 
ciliary ligament ; magnified three diameters 
