424 A Study of the Nasal Bridge in the Anthropoid Apes 
when we pass from intraracial to interracial correlations is a thing previously not 
unknown. Thus in 1903 in a paper* on interracial and intraracial correlations, 
Jacob, Lee and Pearson showed that while with individuals a long cranium is likely 
to be a broad cranium, yet interracially a compensating factor comes in, a long- 
headed race is likely to be a narrow-headed race. Thus it is quite conceivable that 
capacity of the cranium — depending on many anatomical units — may be of far 
more evolutionary importance than the measure of any single " anatomical unit " 
of the skull. We have referred at length to these matters here, because there is 
a growing idea — fostered probably by the idea of Mendelian " units," that the 
measurement of "anatomical units" — or the measurement between "anatomical 
points" — is of primary importance in craniology. Whether craniologists measure 
the same thing or not is immensely important, the correlation between anatomical 
units is also of great value as determining what combinations of simple units form 
evolutionary factors. But very little service is done by insisting too largely on 
anatomical unity in and for itself. Evolution depends largely on physiological 
fitness, and organs of physiological importance are rarely compounded of either 
single anatomical or of single Mendelian units. 
If we now turn to the index correlations of (DS—SS)/DG — i.e. height of 
maxillary portion of nose by its breadth — with SS/SC — i.e. height of nasal bones 
portion by its breadth — our results are less uniform. Putting the male Gorillas on 
one side for a moment there are only two of the correlations which can be said to 
be significant, namely, possibky the male Chimpanzee and the female English, and 
these are of opposite signs. The means for male races and for female races are 
— 0(35 and + "Oil, and these would be of no service for prediction. With regard 
to the Gorilla result, this arises principally from three males with the very high 
simotic indices of 88, 106 and 103. It is conceivable that the material is not really 
homogeneous ; the arithmetic has been carefully repeated without change in 
values. If we take these indices to measure the cuneal or wedge-shaped properties 
of the two portions of the nose, we should sa}^ that individually there is very little 
relation between the ratio of height to breadth in the simotic and maxillary 
portions of the nasal bridge ; the only exception to this rule being the male 
Gorilla. On the other, hand the cuneal characters are positively and sensibly cor- 
related (+"370 to + '393) interracially, an obtuso-cuneal nasal part being also 
associated with an obtuso-cuneal maxillary part and an acuto-cuneal nasal part 
with an acuto-cuneal maxillary part. 
We have already discussed the maxillary nasal angle <j>, the complement of 
which roughly measures the angle between the maxillary wall of the nose at the 
bridge and the sagittal plane of the skull. We can introduce a similar angle 
to measure roughly the angle between the nasal bone- and the simotic chord. We 
may take (see Fig. (i), p. 420) : 
tan<£' = SS/Q SG) 
= 2 Simotic Index. 
* Biometrika, Vol. n. p. 355. For the first introduction of the ideas of intraracial and interracial 
correlation, see Biometrika, Vol. i. p. 460. 
