6 ACCOUNT OF THE FORAMEN CENTRALE 
the choroid has at this point a slight projection in- 
wards *. 
I have stated that the fold of the retina is sometimes 
totally unconnected with the foramen centrale^ but may be 
found occasionally proceeding from the point of insertion 
of the optic nerve outwards. When there are more than 
one, they resemble radii drawn from the centre of a circle 
towards its circumference. Sometimes a large deep fold 
proceeds from the optic nerve towards the edge of the 
transparent point, and from it outwards in a straight un- 
interrupted line. It would seem, therefore, that the forma- 
tion of these folds is accidental, in so far as regards their 
presenccj or absence, or situation ; but that they do not 
depend for their production, as has been supposed, on any 
mechanical disturbance of the internal parts of the eye-ball 
after death. 
Two specimens of the Lacerta superciltosa were ex- 
amined, and one of the variety called Smitata: in all these 
the above anatomical appearances were remarkably dis- 
tinct ; and being comparatively larger than in man, did not 
require, in order to be perfectly seen, the aid of magnify- 
ing glasses. 
Three specimens of a small lizard, agreeing in descrip- 
tion with the Lacerta Calotes of naturalists, were examined. 
In these the eye-ball is somewhat less than in the super- 
ciliosa; but in all other points, as the distribution of the 
retina, the existence of the transparent point, deep and ex- 
tensive folds of the retina, &c., the animals entirely agree. 
In a very small specimen of the Lacerta striata, I ob- 
served the retina folded in a remarkable manner, and, by 
the aid of a strong glass, I thought I perceived a small 
* There is in my possession a very beautiful preparation illustrative of 
■-&is long disputed point. 
