482 
Dr Duckworth, Report on the brain of a 
The optic nerves, chiasma, and tracts are present but small. 
The external geniculate body is absent from the right hemisphere, 
or atrophied so far as to be unrecognisable: in the left hemisphere 
the external geniculate body is much smaller than usual, though 
still distinct. 
No obviously abnormal conditions were found in the remaining 
cranial nerves. 
The surface anatomy of the cerebral gyri and sulci will be 
discussed in the following paragraphs. 
Central region. 
The Sylvian fissure is present and does not differ markedly 
from the normal type as regards its posterior limb. (It must 
be mentioned that a distinct gyrus separates the hinder end of 
this fissure from that part of the cortex which has been involved 
in the haemorrhagic effusion. Therefore the middle cerebral artery 
was probably not involved in this part of its course. More probably 
one of the end-branches, lying on the cortical surface and given 
off after the emergence of the terminal trunks from the depths 
of the Sylvian fissure, was ruptured.) 
The temporal operculum is well-developed. But though the 
orbital operculum is normal, the parietal (now in part destroyed) 
and the frontal opercula were defective in development and did 
not extend sufficiently far over the insula to conceal it. The 
insula is thus exposed, but the nature of this exposure is such 
that it cannot be compared with that in apes. In the latter, the 
frontal operculum is small and the orbital operculum practically 
non-existent. Here both frontal and orbital opercula are distinct 
although the former is not fully developed. Hence the condition 
is a retention of that normally attained at the termination of the 
eighth month of intra-uterine existence. 
The fissure of Sylvius sends off one orbital branch, which 
however does not cut quite through the operculum. It probably 
represents the inner of the two usual sulci in this position. Another 
sulcus given off from the Sylvian fissure and cutting through the 
opercular lip to separate frontal and orbital opercula, is identified 
with the anterior ascending limb of the fissure of Sylvius. This 
identification is open to criticism, for the sulcus is directed obliquely 
backwards and upwards and the frontal operculum bounded by it 
is of unusually great width. 
Much difficulty is found in identifying the central sulcus. 
My interpretation is that this sulcus is not continuous throughout 
its length. And I believe that upper and lower components can 
be recognised, while between the two the cortex is marked by 
sulci directed in the long axis of the hemisphere. The furrow 
thus regarded as the lower part of the central sulcus is however 
