10 Proceedings of the Royal Society of Edinburgh. [Sess. 
As judged by the standard deviation of the cephalic index, it is very 
clear that the Australian male is less variable than the highly advanced 
modern races, but more variable than the more primitive peoples and 
those which are slightly in advance of the primitive condition. 
Conclusions. 
1. That the methods of modern statistical investigation must be adopted 
in all future estimations for making intra-racial and inter-racial comparisons. 
2. That, from the difficulty of separating the skulls into sexes, it would 
be advisable to have resulting values obtained for crania of races without 
reference to sex. 
3. That the Australians are not as homogeneous or pure as some 
series which are regarded as homogeneous, but are less heterogeneous- 
than some other races, and the relationship of their cranial measurements, 
as indicated by the coefficient of correlation, is low, but is higher than 
most modern, though lower than primitive, races. 
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(5) Galton, Francis, Biometrika , vol. i. 
(6) Galton, Francis, National Inheritance. 
(7) Pearson, Karl, The Chances of Death, vol. i. pp. 256-372. 
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(9) Pearson, Karl, “Correlation Values of Length, Breadth, and Height, and 
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(10) Pearson, Karl, Note on Dr Keith's Review of Professor Arthur Thomson’^ 
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