Freiburger historische Bestände - digital

122 Cumiingham Memoirs.

very accurately in the foetus with the sulcus prsecentralis Reillii of the
insula.

Fig. 31.—The lateral view of an adult skull. The cranial wall has been drilled along the internal sutural
lines. These can therefore be compared with the external sutural lines. The extent to
which the squamous projections of the temporal, alisphenoid and parietal bones overlap the
margins of the contiguous bones is seen.

IX. Sylvian Point.—The point at which the trunk of the Sylvian
fissure appears on the outer surface of the cerebral hemisphere may be
termed the " Sylvian Point." The relative position of this point is very
different in the brain of man and in the brain of the ape. It was found to
vary also to a considerable extent in the different apes examined. In the
following Table the lateral length of the hemisphere is taken as 100, and
the figures given indicate the position of the Sylvian Point with reference
to the anterior end of the cerebrum. In the human brain the " Sylvian
Point " is placed relatively further forwards upon the side of the cerebral
hemisphere than in the ape's brain. In the European brain the fronto-
Sylvian index is 32*7, whereas in the orang and the majority of the other
apes examined it is rather more than 34. It is important to note that in