M. L. TiLDBSLEY 
179 
packing, the skull was filled five times in succession by me, and the seed packed 
again each time in the measuring-glass; after which it was weighed. This operation 
was also performed by Professor Pearson. 
Prepared Skull. 
Weight of seed 
Cm.^ of seed 
in grams 
K. Pearson ... 
1325 
1065-45 
M. L. Tildesley 
1325 
1071 00 
1325 
1062-55 
1320 
1063-50 
1325 
1064-30 
1325 
1060-30 
Totals 
7945 
6387-10 
Mean 
1324-17 
1064-52 
The skull was then filled with water and the water measured in the measuring- 
glass: this, which should be the true capacity of the skull, came out at 1365 cm^. 
We thus arrived at the equation : 
Volume of 1000 grs. of seed = ^'^^qq^-q o^^ ^^-^ ^ ff^^l ^^^'^ 
The result obtained by Macdonnell on this skull was that 1000 cm.^ contain 
764-63 grs. of seed. The seed we used bad been kept for a large number of years, 
and was probably slightly more shrunken than that used by him, and would there- 
fore give a denser packing. 
H and H'. The height of the skull from the basion was measured by Macdonnell 
to the bregma, not vertically as by Fawcett. In this he was followed by Benington* 
and Thomson^. His H is also the H used by Flower and Turner. J have therefore 
taken, for the purposes of com|)arison with their results, both these measurements, 
calling Macdonnell's H, H'. 
Q and Q' . We may note that Macdonnell has also measured his Q over the 
bregma, instead of in the vertical plane, following, he says, Virchow and Turner, 
and Benington does the same, but also takes the vertical Q under the title Q^. 
Thomson abandoned the bregmatic Q, but added Q'%, taken off the craniophor, 
from the upper margin of one auricular passage to the upper margin of the other. 
I have done as Thomson has done. With regard to the determination of the position 
of the apex in defective skulls where the orbits or auricular passages were missing, 
so that the skull could not be adjusted accurately to the Frankfurt horizontal on 
the craniophor: Macdonnell said he put it at 2-3 cms. behind the bregma. This evi- 
dently varies for different races, since the mean distance for both males and females 
of our series was just under 15 mms. I have therefore estimated the apex at 15 mms. 
behind the bregma where it could not be properly determined, and if the orbits 
* Biometrika, Vol. vm. p. 296. 
t Ihid. Vol. XI. p. 84. 
% Ihid. Vol. XI. p. 85. 
