THE BRAIN OF FOSSIL MAN 421 
the middle line. The opening out of the vault completely 
alters our estimate of the Piltdown brain. In the original 
cast (fig. 153) the parietal eminences are situated almost 
on the upper aspect of the vault ; the interparietal 
depression approaches within 20 mm. of the middle line 
of the vault (fig. 153). When the vault is opened out, 
the parietal eminences and interparietal depressions 
assume almost the same relationship as in modern man 
(compare figs. 152 and 154). We have seen that the 
parietal lobe of the brain — of which the eminence forms 
a central part — is the seat of higher or association centres. 
The anomalous closing of the vault in the original brain 
cast deprived Piltdown man of a very large area of the 
parietal lobes — deprived him of one of the areas which 
are characteristic of the human brain. 
There is still another aspect of the brain we must 
examine before we are in a position to give a definite 
opinion on the cerebral endowment of fossil man. In 
fig. 155 a view of the upper or vault aspect of the brain 
cast from the skull of a native Australian is represented. 
It is especially important to note the various features seen 
along the middle line of the vault from front to back, for 
much of the difference of opinion regarding the Piltdown 
brain centres round a correct identification of the middle 
line. In the Australian cast (fig. 155) the middle line at 
the very front of the vault is marked by a groove between 
the right and left frontal lobes. Very soon, however, 
this groove, in which the longitudinal sinus lies, dis- 
appears, and is replaced, before the bregma is reached, by 
a wide elevation or ridge on which no distinct impress of 
the median blood-sinus is visible (fig. 155). This median 
frontal elevation, with a slight groove running along its 
summit, is continued backwards under the anterior two- 
thirds of the parietal bones. There, the wider elevation 
disappears, and is replaced by a narrow, oval ridge — the 
first clear trace of the great longitudinal blood-sinus to 
be seen on the vault of the brain cast. A little distance 
in front of the lambda this narrow, well-defined ridge 
disappears (fig. 155). The wider elevation, running along 
