432 
Variation and Correlation of the Human Skull 
modern % Copts) the means are based. Compare for example the (/" Naqadas in 
capacity (C), horizontal circumference {U), sagittal circumference {8), vertical cir- 
cumference (Q), breadth of face {GB), nasal height {NH), nasal breadth {NB), 
orbital breadth* (Oj), orbital height (O2), palate length palate breadth {0^, 
profile length {GL), profile angle (P), height-breadth index (100 HjB), nasal 
index (100 NBjNH), orbital index (100 O.JO,), and palate index (100 G^jGJ), 
with the like quantities for the Thebans, and it seems impossible to hold that we 
are dealing with really different races or even with a mixture of races. Evidence 
in the same direction if less definite may be drawn from the auricular height {OH), 
the skull-base {LB), the height-breadth index {HjB) and having regard to 
Maciver's measurements and those on the Copts, the zygomatic breadth {J). 
Turning to the females we reach much the same results ; in several cases where 
the Naqada appear to differ slightly from the Thebans, they are seen to be inter- 
mediate between the latter and the Copts or Maciver's measurements show us how 
a slight difference in sample or method of measurement brings Naqadas into line 
with Thebans or Copts or both. The Germans and Aino, and in many cases the 
Negroes show us how widely divergent different races can be from a group like the 
Naqada-Theban-Copt series. Compare for example the Germans and Aino with 
the Egyptian group in ^ skull circumferences {U, S, Q) and the Negroes and 
the Egyptian group in nasal breadth, orbital height, length of profile, or palate 
index. In some respects, indeed, the modern Negro is closer to the later Egyptians, 
Thebans or Copts, than to the Naqadas. He stands on the whole nearer to the 
Egyptian group than to races like the German or Aino, but it seems impossible to 
assert that he is closer to the Naqadas than to the later Egyptians. If the historic 
Egyptians are to be treated as distinct from the Negroes, then certainly the 
Naqadas are. Skulls of a negroid type may be found among our material, and 
possibly competent type-craniologists would have cast them out at once, but our 
general averages are quite sufficient to show that we are dealing with distinct 
races, and one which 6000 or 7000 years ago was as distinct from the Negro as it 
is to-day. 
If we accept the general proposition that the Naqadas, Thebans and Copts are 
for a number of characters so closely related that we are bound to consider them as 
in bulk the same stock, we are still forced to the conclusion that in certain 
characters a progressive evolution has taken place, for these characters have 
substantially changed. If it be asserted that the change is due to racial mixture, 
then the fact that other characters have remained practically stationary is very 
difficult of interpretation, for the result of mixture would be to alter these also. 
On the other hand, the comparatively small correlations of the parts of the skuUJ 
show that if certain characters in the .skull be modified by selection, the change 
in other characters need not be significant, if the latter have not themselves been 
directly selected. The most noteworthy of these changing characters are the 
* See remarks, p. 431. + See remarks, p. 430. 
J See the section on correlation below. 
