426 THE ANTIQUITY OF MAN 
the upper or first frontal convolution ? Undoubtedly 
it is the latter, for three reasons, (i) If it is not the first 
frontal convolution, then this convolution was missing 
in the Piltdown brain — an improbable supposition. (2) It 
will be noted that the coronal suture (C.S., fig. 158) crosses 
this convolution unchanged in direction, indicating that 
it has not reached the middle line. (3) If we regard this 
elevation as lying in the middle line, it is impossible to fit 
the parts of the skull so as to give the right and left halves 
an approximate degree of symmetry. To my mind there 
is no doubt that the shallow groove, marked by an arrow 
in fig, 158, represents the position of the middle line. 
A trace of the marginal elevation of the right frontal lobe 
is apparent at the point of the frontal fragment. Further, 
it will be found that at the margins of the lateral sinus 
of modern skulls, the vessels which supply the skull and 
outer covering of the brain terminate in a peculiar fringe 
of fine tributaries. The impress of this vascular fringe 
is apparent on the left side of the median groove on the 
original brain cast. We have evidently to deal with a 
condition similar to that seen in anthropoid brain casts, 
where the longitudinal sinus is represented by a groove 
or depression between the adjacent marginal elevations 
of the frontal lobes. The median elevation is absent — 
not yet developed. 
At the hinder end of the left parietal fragment of 
the brain cast we meet another clear indication of the 
longitudinal sinus. The incurved margin at the hinder 
angle of the parietal fragment represents the lateral 
boundary of the sinus to which attention has already been 
drawn. On the incurved margin can be seen a trace 
of the vascular fringework already described (fig. 158). 
If we suppose that the arrow in fig. 158 represents the 
true position of the middle line in front of the lambda, 
then all the parts fall into conformity with those seen in 
brain casts of men and anthropoids. 
Thus an examination of the brain cast confirms the 
conclusion reached from an examination of the skull, 
namely, that a mistake was made in the identification of 
