464 
Variation and Correlation of the Human Skull 
Weldon, who spent several days in going through the material with a view to 
noting anatomical peculiarities and selecting typical crania for reproduction, 
Lastly to Professor Flinders Petrie we owe not only the information acknowledged 
earlier, but the skulls themselves. 
If the professed craniologist should feel aggrieved that such splendid material 
should have fallen at first into mathematical hands, he may console himself with 
the knowledge that the crania will be available for further work when they 
ultimately reach the Anatomical Museum at Cambridge. He must also remember 
that the material was dug up and brought to this country with this direct purpose 
in view — that it should be used for the illustration of statistical methods as 
applied to craniometry, — and that however little sympathy he may have with these 
methods, without them the present material would certainly not have been 
brought to England when and how it was. Let us hope that he will in the end 
pardon the method and even the errors of this paper for the sake of such material 
as it has indirectly made available for craniological purposes. 
(11) Summary of Conclusions. 
(a) Craniometry cannot in future content itself with either the raw 
measurements, tables of mere averages, or graphical exhibition of correlation 
results, but must adopt the methods of modern statistical investigation, tabu- 
lating means, variabilities, correlations, and their probable errors in order to draw 
safe inferences and make racial comparisons. 
(b) The prehistoric Egyptians as represented by the Naqada crania appear 
to be as homogeneous as most short series which pass muster as racial unities. 
(c) The Naqada race does not appear substantially nearer to the Negro — as 
judged by his modern representative — than the historic Egyptian as sampled in 
the Theban mummies or than the modern Copt. 
(d) In some features only the Naqada crania are " primitive or inferior," in 
others they are " advanced or modern." In some characters they resemble the 
Negro, in others the European. 
(e) The close resemblance in the majority of characters of Naqadas, Thebans 
and Copts leads one to believe that one is examining substantially the same race 
at intervals during 8000 years. 
{/) The progressive divergence in certain characters of these three series of 
crania ought, we hold, to be attributed to an evolution tending in a fixed direction. 
If this be so we have an actual measure of the rate at which evolution can modify 
characters. 
(g) The relationship between cranial characters as exhibited by their 
coefficients of correlation in the case of the Naqada and other races is seen to be 
low, and to vary much from race to race. It is therefore very doubtful how far it 
