M. L. TiLDKSLEY 
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bregmatic height by a large pair of callipers. The points on the border should ac- 
cordingly be so chosen that they provide a resting point for the vertical or hori- 
zontal measuring instrument, i.e. the points should be about central on the curved 
rim where the surface changes its direction from horizontal to vertical. 
Auricular Point. The ambiguities attaching to this "point" have been fruitful 
in the provision of difficulties, and reduce the value for comparative purposes of 
a good deal of material. The difficulties have been much discussed already, but I 
cannot forbear to make my own contribution to the discussion, in the hope of 
assisting somewhat in the solution of the working problem. The main fact, of course, 
is that the "auricular point" like most other cranial points is not a point, but an 
area, only it happens to be nearly the worst of its kind and less susceptible of a 
definition by which different workers will identify approximately the same position 
for it. I will summarise the history of this in our own Laboratory. 
From the beginning of craniometric work here the Frankfurt Concordat was 
taken as the basis of our method of measurement, though it has had to be 
modified in some details — as few as possible — and more exactly defined in others. 
The Concordat gives the auricular point as that point on the upper rim of the 
auricular orifice which lies immediately above the centre of the orifice when the 
skull is adjusted to the Frankfurt horizontal plane. When the skull is placed 
on a Ranke's craniophor its auricular height is taken from the ear-plugs on 
which it rests; naturally to achieve stability it is the highest point in the 
vertical section* through the point of contact with the roof of the orifice upon 
which the skull rests. But this point may vary with the depth to which the 
ear-plugs are inserted; and in any case it is not possible to guarantee that this 
point is immediately above the centre of the orifice, whatever the centre of an 
irregular trumpet-shaped cavity may be: the section of the orifice might be an 
obhque oval (such as Le Double refers tof, and I have myself found). Probably, 
however, the difference, if any, due to this cause would be slight. Fawcett found 
it needful to drop "the centre of the orifice" and modified the definition of the 
auricular points to "the highest points of the upper rims of the auricular pas- 
sagesj." The application of this definition — and probably of any definition by which 
one could attempt to indicate exactly this exceedingly difficult point — is not simple 
in a considerable number of skulls, at any rate in my series, owing to the fact that 
their auricular orifice has no very definite rim. The auricular passage is roofed by 
the squamous portion of the temporal bone, and the curve upwards and outwards 
towards the zygomatic ridge is sometimes so smooth that it is hard to say at what 
point there is a greater change in direction than at any other: this leaves a good 
deal of room for personal equation in determining the point, and unavoidably so. Of 
course in many other skulls there is a definite break in direction, giving a distinct 
upper rim, and all stages are to be found between these two extremes. I do not 
claim to add anything to the definitions, which I have tried to apply in deter- 
mining my "auricular points." In this connection I may, however, mention one 
* By "vertical section" is here to be understood one parallel to the sagittal plane of tlie skull, 
•j- Variations des Os du Crane, p. 325. % Biometrika, Vol. i. p. 413. 
Biometrika xm 12 
