CHAPTER XXIV 
IRAIN OF FOSSIL MAN 
In the previous chapters I have thrust the tedious and 
technical details relating to the reconstruction of the 
Piltdown skull before the reader, but our real objective 
is to see what sort of brain was enclosed within it. The 
cranial wall is moulded to fit the brain. Hence when 
the skull is rightly reconstructed — but not until then — 
it provides us with a means of telling the size and shape 
of the brain. So exactly does the brain fill its cavity that 
the impress of its various parts — of its lobes and convolu- 
tions — are preserved. When a cast is taken of the 
interior of the cranial cavity, we see before us a rough 
image of the organ which guides mankind through the 
intricacies of life and reveals the world in which men live. 
In the case of the Piltdown skull, considerable parts of 
the cranial walls are missing, but enough are preserved 
to show us not only the general form and size, but also 
to give us definite information relating to the mental 
capacity of its original owner. 
We all agree that a man with a big head or a large 
brain is not necessarily an exceptionally clever man. 
Those, however, who have studied the brain as experts 
are firmly convinced that unless a man has a certain size 
of brain he cannot think and act as ordinary men do. 
Professor Elliot Smith is of opinion that a brain must 
reach a weight of 950 grammes (or about 1000 c.c. in 
volume) before it can serve the ordinary needs of a human 
existence — before it can become the seat of even a low 
form of human intelligence. If we accept this definition, 
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