102 Royal Kociety :— 
On raising the anterior lobes gently from the base of the skull, 
it was ascertained that no nerves saga be the brain with the bone 
anterior to the fifth pair. The base of the brain also exhibited an 
entire absence of the optic nerves pee. a vestige in a very minute 
eae A as A ribed by Mr. Solly. 
ining the internal surface of the base of the skull, the 
usual SRT for the optic nerves are found to be wanting, a con- 
dition which is observed with facility in the dried specimens in 
the Museum of the Royal College of Surgeons. Among these there 
is one in which there is a vestige of an optic foramen on the left side 
of the head, while on the opposite side the surface is smooth and 
perfect 
In the arrangement of the details which have been given above 
of the appearances observed in the course of the examination, atten- 
tion has been directed to three points in particular, gener to the 
condition of that part of the optic nerve which is situated externally 
re 
to the skull which exists as a mere t d of connective tissue ; 
secondly, to the eye itself, and the structures withi it 
as necessary to consider them in their efficiency for opt - 
the ke of the brain from which the optic nerves take their oe = 
The following description of the various structures in the 
Mole will be more general than the above account of them in de 
jacent, a part of the globe of the eye is exposed. When the whole 
side of the face and the temporal region are dissected, the eye is 
found to be in close proximity to the large branch of the facial 
ne 
head of the jade iet cornea V trebalücin) 5 the sclerotic perfectly 
distinct, and of dense white pee: © bas iris apparent through the 
cornea, "with a clear pupillary apert 
etween the eye and the facial nerve a small portion of the optic 
nerve is seen in the superficial dissection, and appears to form an 
upright peduncle for the globe. 
is necessary to divide the seventh pair in order to examine the 
deeper parts of the orbit. When the dissection is completed, and 
the optic nerve exposed in its whole extent, from the eye to the base . 
of the cranium, the branches of the fifth pair of nerves are brought 
into view. The main branch of the second division of the fifth nerve 
eep dissection of the orbit, as I observed nothing u unusual to re- 
quire particular notice. There are some minute muscles attached 
to the globe which do not admit of separation into distinct parts, 
but completely surround the oai half of the globe. 
To trace the optic nerve through its foramen to the brain was 
successfully accomplished in only a denies After exposing 
sre Ee de NES. P NITIDIS 
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