DIFFICULTIES OF RECONSTRUCTION 349 
massive. In the modern sample, represented in fig. 117, 
the greatest width of the skull is 1 34 mm. ; in the Piltdown 
skutl this measurement is a little under 150 mm. ; in Dr 
Smith Woodward's reconstruction the greatest width is 
also 150 mm. If we deduct 10 mm. from this amount 
on account of the great thickness of the bony walls, the 
width measurement of the Piltdown skull is still 140 mm. 
— 6 mm. more than in the modern skull represented in 
fig. 117. As regards height of the cerebral chamber — 
the height of the roof of the skull above the horizontal 
or subcerebral plane — there is not much difference 
between the ancient and modern example, if we allow for 
the greater thickness of the Piltdown skull. The roof of 
the skull in our example of modern man falls short of 
the loo-mm. line ; the roof of the Piltdown should just 
reach that line. If the length of the skulls were approxi- 
mately equal, it is clear that the ancient brain should be 
the larger. The Piltdown brain was, as regards bulk, 
about the average for modern races. 
The reader may very properly offer the criticism that 
the conclusion as regards the width and size of the 
Piltdown skull turns on that small fragment of the 
occipital bone. He may well ask for confirmatory 
evidence. Substantiation of the conclusions reached can 
be obtained by a totally different method — one which 
carries us right into the principles of skull reconstruction. 
If a cut is made across a skull so as to expose its walls 
in a vertical cross-section as in fig. 120, the composition 
of the bony wall enclosing the brain is seen to be simple. 
The base of the skull at this point is made up of three 
bony elements — a bar of bone in the middle, a pyramid 
of bone, the petrous part of the temporal, on each side 
of it. The lateral walls and roof are formed by two 
enclosing bones — the squama of the temporal and the 
parietal bone on either side. Now, as may be seen from 
fig. 120, the brain cavity of anthropoid apes and of men 
is enclosed by corresponding bones, but in the ape the 
parietal bones and the plate of the temporal are small 
in size. As regards the size of the bones in the base of 
