420 A Study of the Nasal Bridge in the Anthropoid Apes 
be borne in mind that the mesodacryal subtense consists of two portions, the first 
part due to the nasal bones is the simotic subtense, the second part is due to the 
maxillary bones. If we subtract the simotic subtense from the mesodacryal sub- 
tense (DS) — (88), we have a measure of the part of the nose due solely to the 
maxillary bones, and we may correlate this with (SS) the part due to the nasal 
bones. There will be no spurious correlation in this as in correlating (DS) and 
(SS) directly. Further we may form an index {(DS) - (8S)\/(DG) and correlate 
this with the simotic index (SS)j(SC), although in doing this (SG) must be 
considered in a certain sense as contained in (DC). The spurious correlation, 
however, is unlikely to be as great in this as in (SS) and (DS), for the maxillary 
walls of the nose can approach so close that there is no (SC) at all, as in the case 
of many Orangs and in some Negro skulls*. 
SS 
DS-SS 
Fig. (i). 
(10) The Maxillary and Simotic Nasal Angles, and . 
The value of DC — SC may be used to obtain a measure of the flatness of the 
maxillary walls of the nose. Clearly (see figure above) 
tan (j) = (DS- SS)/± (DC - SC). 
We term </> the maxillary nasal angle and its complement 90°— measures 
approximately the angle the maxillary wall of the nose makes with the median 
plane of the skull. Table XXI records the values of the nasal maxillary angle (p 
for the races dealt with; they are obtained not from the calculation of <fi from 
individual crania, but by the rougher process of using the mean values of the 
mesodacryal and simotic subtenses and chord in the above formula*)". The table 
emphasises again the relation of the Veddahs and the higher races to Orang and 
Hylobates, while it indicates the relation of the Negro races to the African anthro- 
poids. At some points the female order is not in accord with the male, but the 
smallness of many of the series dealt with seems sufficient to explain the source 
of these differences. Some races have clearly a marked sexual difference, but it is 
not always one way and the means show no very great difference ; more data and 
longer series would be needful to be certain of a persistent sexual differentiation. 
* E.g. Gaboon 1864, Nos. 10, 11, 81, and Congo 70 : see Biometrika, Vol. vm. p. 319, and see 
especially the remarks in Tables of measurements. In one gibbon the simotic subtense was actually 
negative or the nasal bones depressed. 
f Table XXIV a gives the values of <p and their variabilities for a small number of selected races. It 
will be seen that the differences due to the two methods are not great. The short method will give 
results close enough for any conclusions which are in the least likely to be drawn from such small series. 
