Mr. Home's Account of an Orifice , See. 333 
from Mr. Maunoir, an eminent surgeon at Geneva, which 
contains, I believe, the material information published by Mr. 
Soemmering ; I shall therefore transcribe that part of the letter, 
which is as follows. 
“ The war being an obstacle to a free communication be- 
“ tween England and the Continent, you are not, perhaps, ac- 
“ quainted with a new discovery in the anatomy of the human 
“ eye, made by a professor of Mentz, Mr. Soemmering ; permit 
“ me, therefore, to say something on the subject. He was dis— 
“ secting, in the bottom of a vessel filled with a transparent 
“ liquid, the eyes of a young man who had been drowned, and 
“ was struck on seeing, near the insertion of the optic nerve on 
“ the retina, a yellow round spot, and a small hole in the mid- 
“ die, through which he could see the dark choroides , (looking 
“ at the surface of the retina which covers the vitreous hu- 
“ mour.) He dissected other human eyes, and constantly, 
" when the dissection was carefully made, found the hole of 
the retina seemingly at the posterior end of the visual ra- 
“ dius, nearly two lines on the temporal side of the optic nerve* 
and the hole surrounded by the yellow zone, of above three 
“ lines in diameter. The hole of the retina is not directly seen, 
“ being covered with a fold of the retina itself. An anatomist 
“ of Paris dissected many eyes of quadrupeds and birds, and 
“ found the yellow spot and hole in no animal but the human 
“ kind. 
“ Should you think that nature has intended this hole to 
“ grow large when the eye is opposed to a strong light, and 
“ thereby cause a great part of the rays to fall on the choroid, 
“ and vice versa , when the eye is in darkness ? And the want of 
s ‘ such a construction in animals, is it owing to a greater power 
