140 L. W. G. Bilchiu'r: 



suits procured by these luethods on the same skulls illustrate the 

 difliculty of obtaining a precise estimate of the degree of progna- 

 thism.'' 



With the exception of Keith's method, all were introduced prior to 

 the invention and general adoption of the dioptrograph and dia- 

 graph, and it is questionable whether all that is claimed by the 

 authors quoted for their special methods cannot really be better 

 done now with t*lie diagraph. In any case, the perpetual multiplication 

 of new methods and special instruments for the same purpose, renders 

 it almost impossible to collect sufficient data for the comparative in- 

 vestigation of tlie several races. For all these reasons, therefore, 

 I have thought it advisable to confine myself to dioptrographic trac- 

 ings, which, fur the Tasmanian, have now been rendered available to 

 all by Berry and Robertson, and to record the degree of prognathism 

 by Flower's method. This procedure has the great advantage over 

 and above all the others herein discussed, that it enables me to insti- 

 tute a series of comparative observations of the Tasmanian with 

 other races. Personally, I am of opinion that in this way only 

 will any real progress be made in the complex science of the 

 craniolog}- of race. 



Tlie material upon which the present research is based will be 

 found in Berry and Robertson's "' Dioptrographic Tracings in Four 

 Normae of Fifty-Two Tasmanian Crania " (30). All the observations 

 recorded herein are calculated from the median sagittal tracings, 

 shown in No)-ma A, and are as follow : — 

 1 The basi-nasal length. 



2. The basi-prosthionic length. 



3. Gnathic index. 



4. The nasi-prosth ionic length. 



."). Ihe glabella prosthion basion angle. 

 G. The jjrosthion glabella basion angle. 



Of these observations, the first three comprise the data necessary 

 for the estimation of prognathism by Flower's method, and the last 

 three are supplementary measurements, upon which to estimate the 

 general projection and height of the face. 



As stated elsewhere (31), it was not possibk- to record all of the 

 observations on every skull. Number -tS, being a juvenile subject, the 

 measurements recorded on it have been uniformly omitted from the 

 final results. The results of Numbers 4 and (^ have also been oinitted 

 where they concern the prosthion. 



In Table I. are set forth the individual observations upon the 

 crania referred to. 



In the two columns on the Icji are recorded the original numbers 

 and their serial numbers. In the columns to the rijjht the several 



