129 
May 13, 1851. 
John Edward Gray, Esq., F.R.S., in the Chair. 
The following papers were read :— 
1. OBsERVATIONS ON THE Eye OF THE MOLE, IN A LETTER 
ADDRESSED TO W. Spence, Esaq., F.R.S. 
By Joun Davy, M.D., F.R.S. 
In a letter with which you favoured me some weeks ago, you 
made mention of Schiddte’s ‘ Faunze Subterraneze Specimen,’ and 
of the interesting discoveries described in it of several species of 
eyeless animals, the inhabitants of caves into which the sun’s rays 
never penetrate, and where, in utter darkness, visual organs would 
consequently be useless. 
Reflecting on the subject, I thought it worth while to examine with 
some care the eyes of the common Mole, an animal that spends the 
greater portion of its time beneath the surface of the earth, and seems 
in its general organization specially adapted for a subterraneous life. 
I shall chiefly notice what, in the dissections I have made, appears 
to be peculiar. 
The first peculiarity that arrests attention is, that the eyes of the 
Mole are not contained in bony sockets, but lie unprotected by any 
bony prominences in the cellular tissue, beneath the common integu- 
ments ; and, in consequence, were this animal an extinct one, and its 
skeleton found in a fossil state, there being no orbit, the palzeontolo- 
gist might be led to infer that it is a species destitute of eyes. 
The next peculiarity I would mention is in regard to eye-lashes. 
These too it seems to be destitute of. The hair in which the eyes 
are buried, and by which they are defended, seems to be the common 
fur of the head. I could detect in that immediately surrounding 
them no hairs of larger dimensions, or in any respect different from 
those of which its fine fur is composed. 
The apertures for the admission of light constitute another pecu- 
liarity. When the fur is removed from the skin surrounding the 
eyes, a minute aperture appears over each, about ;;th of an inch in 
length when closed, and, in this state, linear and straight, but cir- 
cular when fully expanded. The extreme margins of these openings 
in the integuments being covered with fur, there is no well-marked 
appearance of eyelids,—indeed, it may be a question, whether the 
Mole, in strictness, can be said to possess these appendages. From 
the observations I have made, I am disposed however to infer that it 
does possess them, but imperfect ;—imperfect, not having been able 
to detect beneath the marginal cutis any vestige of ciliary cartilages, 
and yet having found in the surrounding subcutaneous cellular tissue 
muscular fibres so arranged as if designed for closure, resembling an 
orbieular muscle, and probably designed for and performing the part 
of such a muscle. 
No. CCXXVII.—ProcreEpInGs oF THE ZOOLOGICAL SOCIETY. 
