[ 7 «] 
IX. Croonian Lecture . On the anatomical structure of the Eye ; 
illustrated by microscopical drawings , executed by F. Bauer, 
Esq. By Sir Everard Home, Bart. V. P. R. S. 
Read November 15, 1821. 
Having found an extraordinary advantage from Mr. 
Bauer's microscopical observations, when applied to anato- 
mical investigations of other organs of animals, I requested 
him to give me his assistance in the examination of the diffe- 
rent parts of the eye in the human species, quadrupeds, and 
birds. 
In the first place, I wished him to ascertain whether the 
marsupium in the bird's eye is muscular; as I had advanced 
such an opinion in the Lecture for 1795. After the most 
careful examination, he has decided that it is not ; but is a fine 
vascular membrane, as represented in the annexed drawing, 
which Dr. Young had long considered it The real struc- 
ture of the marsupium being thus completely established, I 
was led to inquire what parts, contained within the globe of 
the eye, are possessed of muscular fibres. Mr. Bauer, on 
examining the ciliary processes, found that the anterior layer 
is made up of about 80 processes, lying directly behind the 
iris, and with it firmly attached at the base to the choroid 
and sclerotic coat : these are membranous, very vascular, and 
the surface next the lens concave ; that next the iris, convex. 
They are distinctly shown in the annexed drawings. 
