1910-11.] Anatomy of the Head of the Australian Aboriginal. 611 
In the case of head number two the estimated cubic capacity worked out 
by this method yielded a result of 1198 c.c. After the discovery that the 
brain was useless it was removed and the sections built up again in order 
to reconstruct the head for storage purposes. Whilst doing this it suddenly 
occurred to me that by filling up the skull cavity with shot I should be 
enabled to submit the method of estimation to a somewhat rigorous test as 
to its accuracy or otherwise. The several sections were therefore displaced 
and again rebuilt, but this time with a thin layer of vaseline between every 
section, with the dual object of restoring the tissue lost by the saw cuts and 
at the same time of making the reconstructed head impervious to water. 
The skull was then cubed some six times with both water and shot, with 
the nett result that with both an actual cubic capacity of 1000 c.c. was 
obtained. There was thus a difference between the estimated and the actual 
cubic capacity of 198 c.c., which is more than the 4 per cent, difference to 
which Lee claims that her method reduces the error. 
As it was impossible to carry out the like procedure on the remaining 
two heads, on account of the brain investigations, and struck as I was with 
the possibilities opened out by this chance experiment, I arranged with Dr 
J. H. Anderson, my senior assistant, to carry out an elaborate investigation 
into the whole subject, and his results have already been published. (50 
and 51.) 
Schwalbe’s Fronto-biorbital Index. 
In view of the well-known fact that in the crania of Pithecanthropus 
erectus, Homo primigenius, and Homo fossilis there is a well-marked con- 
striction at the frontal end of the skull, due to the extreme narrowness of 
the minimum frontal diameter, an examination of Schwalbe’s “ fronto- 
biorbital index ” (39), for these three Australian heads become of some 
importance, particularly as Schwalbe remarks, “ besonders bedaure ich, dass 
mir fur die Australierneger nur ein einziger Schadel vorliegt und dass ich 
diese Lucke auch aus Krause’s Arbeit nicht ausftillen kann, da auch dieser 
den ausseres biorbitalen Durchmesser nicht berticksichtigt.” 
Schwalbe’s “ fronto-biorbital index ” seeks to compare the minimum 
frontal diameter with the external orbital diameter, the latter being taken 
as 100. It is expressed by the following formula : — 
Minimum frontal diameter x 100 
External orbital diameter 
In Pithecanthropus erectus this index is 82. In Homo primigenius it 
ranges from 84*3 in Spy 1 to 88'8 in Neanderthal. In four Kalmucks it 
