M. L. TiLDESLEY 
183 
occurred at a distance from this perpendicular of 5 mms. or less in 239 ont of 
my 259 cases; in the remaining 20 it did exceed that. Except in the case of 
these 20, therefore, no difference would have been made by my inserting the 
ear-plugs less far, and the difference made for these few individuals would have 
a very slight effect on the mean value for my series. In another series it might 
have more, in others less. 
The other direct measurement involving the auricular points was the trans- 
verse arc Q which Fawcett* defines as the "cross circumference of the skull 
measured in a vertical plane from the upper rim of one auricular passage to that 
of the other," a definition which is repeated by Benington (his Q-^) and by 
Thomson^. We find, however, a note to Thomson's definition which says that "Q 
is taken with the tape over the skull, and measured from the top of one ear-rod to 
the top of the other." 
Q\ on the other hand, "the same measure taken when the skull is ott' the 
craniophor," is terminated on each side by the selected auricular points. As the 
note states, — owing to the recessing of the margins of the auricular passages — 
is not quite the same as (^," i.e. in the individual measurements, where the differ- 
ence is seen to be as much as 4 or 5 mms. in some cases (the excess sometimes 
being in favour of Q, sometimes of Q') ; though the mean values of Q and Q' obtained 
for the Moriori skulls are extremely close together, there being only 0-2 mm. 
difference between them for both males and females. 
In my own series the individual differences were of the same order, though 
more numerous, and the mean value of Q (the craniophor measurement) was 
1-8 mms. shorter for males and 2-2 mms. for females. These differences can be 
practically accounted for by the recessing of the margins of the auricular passages: 
the transverse contours show the zygomatic ridges at a mean height of 3-0 mms. 
((J and ?) above the auricular points (selected) and projecting 3-'l mms. beyond 
them in the males, 3-3 mms. in the females, so that the mean distance between 
the two on the skull is 4-5 mms. {$ and 5). For Q' , taken the craniophor, the 
tape traverses this 4-5 mms. distance; I have interjjreted Thomson's note to mean 
a vertical drop to the ear-rod from the zygomatic ridge, which gives a mean dis- 
tance of 3-0 mms. This would lead us to expect mean difference of 1-5 mms. for 
my series between Q and Q' , a difference quite reasonably close to what I have 
obtained. In the case of the Moriori crania the constants for this region of the 
skull would probably differ from those of the Burmese; indeed the peculiar con- 
formation of the Moriori skull in the region above the auricular orifice was one of 
its distinguishing racial characters. On the other hand, it is possible that there 
may also have been some difference between the interpretation put by Thomson 
and myself on the definition of the auricular point, as we have already seen that 
in many skulls there is room for a considerable personal equation in identifying 
the "upper rim of the auricular passage." 
* Biomelrika, Vol. i. p. 416. f Ibid. Vol. viii. p. 296. % Ibid. Vol. xi. p. 85. 
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