THE SKULL AS A BASIS FOR RACE CLASSIFICATION. 19 
in the Norma occipitalis. The change in the direction of 
the foramen magnum in Man is due to the backward 
growth of the cerebrum and the need for maintaining the 
balance of the skull upon the summit of the spinal column. 
Note also the form of the Hard Palate and the Dentary 
Arch, and the state of the teeth, for information with regard 
to age and habits. 
CAPACITY OF THE SKULL. 
The object aimed at by this mode of examination is to 
obtain a convenient indication of the development 
of the brain. It must be remembered, however, 
that the skull contains meninges, blood-vessels, sinuses, 
the beginnings of cranial nerves, and the cerebro-spinal fluid, 
in addition to the brain, and it has been suggested that 
10% should be deducted from the capacity in order to allow 
for these objects. 
It is not easy to take the capacity of a skull by any 
method which is quite free from error, or to get constant 
results by whatever method one adopts. The aim of the 
operator is to fill the cranium quite full of some substance, 
which may then be poured out into a graduated glass 
vessel for measurement. Of course, special precautions 
require to be taken for the purpose of ensuring equal 
pressure during both of these operations. Therefore, the 
substance employed should not permit of any compression, 
and the routine of the operation must be rigidly adhered to 
in the most minute details. It is preferable to have a large 
series of data recorded by the same operator. 
Of the substances which have been employed, sand and 
seed are quite unreliable, because they permit of com- 
pression: water is inconvenient for many reasons, although 
recently an attempt has been made to confine it in a thin india- 
rubber bag placed within the cranium and slowly distended. 
The best substance is chilled shot, number 8, and the rate 
at which the shot flows into the skull, as well as its rate of 
flow from the skull into the graduated measure, must be 
constant, so that for this purpose it should flow through a 
funnel whose outlet is 20 mm. in diameter. Even when 
