308 
A Study of the Negro Skull 
sexes in separate lists. That there is something very anomalous in the position 
of the Congo males is clear ; not only is this one of the two exceptions to the rule 
that the female stands above the male in the list, but the highest negro male 
series is associated with a female series at the very bottom of the list. It should 
however be noted that the other case of interchanged sex order occurs in the 
1864 Gaboon series, a series very closely allied to the Congo crania. The affinity 
already noted between the prehistoric, historic and modern Egyptians and the 
Gaboon Congo crania is also emphasised in this series. Modern advanced races 
of man tend to a considerable excess of cranial breadth over height, primitive and 
prehistoric races like the Naqada and Aino to an equality of these diameters ; the 
negroid races tend to fall below equality and exhibit an excess of cranial height 
over breadth. The index 100 (B — H)jL may be used to measure this characteristic, 
and if it has not yet been given a name— and I am not aware that it has — might 
be called the acroplatic index. 
Of the measures of the mandible we can say but little, because so few com- 
parative measures exist. Macdonell gives measures of the Whitechapel mandibles, 
but was unable to sex them satisfactorily, so that they are at present almost 
useless for comparative purposes*. Shrubsall gives condylar and angle widths 
for 19 Kaffir mandibles. Benington provides four characters for the two Gaboon 
series ; there were no mandibles with the Congo crania. All we can do is to put 
against these negro mandible measurements those of Fawcett on the prehistoric 
Egyptians and Koganei on the Aino. We have the following results : 
w 2 
h 
6 
? 
6 
? 
$ 
? 
6 
? 
Aino ... 
Naqada 
Gaboon, 1864 
Gaboon, 1880 
Northern Negro 
Kaffir 
102-0 
110-5 
112-5 
121-0 
117- 0 
118- 5 
95-5 
106-5 
110-0 
106-0 
93- 5 
94- 0 
99-0 
97-0 
96-0 
87-5 
90-0 
90-0 
34-0 
33-0 
32-5 
31-5 
32-5 
31-5 
30-5 
28-0 
44-5 
44-5 
47-5 
43-0 
45- 5 
46- 5 
English, Whitechapel 
113-0 
95-5 
31-0 
43-5 
This table shows that in every respect (W 1 , W 2 and/) the negro mandible is 
broader than that of either Aino or prehistoric Egyptian, but that he has a less 
depth (h) of mandible, i.e., crudely described, less chin. 
Another interesting index in the case of the negro is the alveolar index, 
or the ratio of the profile length to the base of the skull ; it is, like the profile 
angle, a partial measure of the prognathism. 
* See Biometrika, Vol. vm. p. 213. 
