Eveline Y. Thomson 
131 
To sum up : the comparison we have made suffices to show that cranial type 
contours can be of great service; they are justified by the generally good con- 
cordance they give when tested against average measurements of the skull made 
in the ordinary manner. But if they are to serve for the purpose of accurate 
measurement and for more than a rough comparison of race with race, we think 
a considerably improved technique will be essential and if, as we believe, it is 
desirable to compare the contours of the individual crania step by step with their 
actual measurements, then the contour drawing will not relieve us from the usual 
craniometric processes, but at first serve only as a control. In particular the 
difficulties which have arisen in our own case centre especially round : («) a better 
agreement in the position of the auricular point as determined (i) by the 
craniophor and (ii) on the transverse and sagittal contours; {b) in the better 
location of the opisthion and alveolar point on the sagittal contour. 
These do not seem substantial difficulties, but they need practice and caution. 
The basion can always be inserted from the nasio-basionic length and basio- 
bregmatic lengths {LB and H) ; the opisthion from the foraminal length and the 
lambda opisthionic chord {f»d and S'^). The alveolar point is then determined 
by the upper face height {GH') and the profile length (GL). To avoid the 
contour determination of the auricular point, we might mark the apex (^4) of the 
individual skull when on the craniophor as well as the gamma. Then on the type 
contour by drawing a line through the average apex perpendicular to the average 
Ny, and plotting off along this line the mean auricular height (OH), we should 
obtain an auricular point which would agree with the cranial measure ents. 
The parallel to Ny through the auricular point thus determined would give the 
standard horizontal plane, and the profile angles by contour and measurement 
should now coincide. 
A marked feature of the type Moriori sagittal contours for both male and 
female is evident on inspection — the auricular point is vertically above the basion. 
It is not true for individual crania, but it may be true for type crania (i.e. on the 
average) for other races than the Moriori. If so the vertical through the basion 
would give the apex and the auricular point could be determined from the mean 
auricular height, and control would be easier to establish. In general the basi- 
auricular line as an approximate or average vertical of the head deserves 
consideration*. 
* It is proposed shortly to observe skull by skull the difference between the contour and the direct 
measurements with a view to improving technique. The English male sagittal type contour when the 
basion and alveolar points were added as above suggested gave a profile angle of 86°-3, according 
reasonably with the msasured angle 86°- 1, but the same method applied to the Congo Batetelu 
cross-section only gave a profile angle of 81°-2 as against 82°-8 measured directly on the crania. The 
actual marking of apex and gamma when the skull is on the craniophor and the transfer of these 
marked points to the contour will undoubtedly aid in ascertaining what is needful to bring contour 
measurement and direct measurement systems into full unison. At the same time it must be 
remembered that the characters of a mean or type contour cannot be demonstrated theoretically to 
coincide absolutely with the means of characters not used in constructing the contour. 
9—2 
