A CONTRIBUTION TO THE STUDY OF THE SCOTTISH SKULL. 



425 



longitudinal depressions in the vault of the former and the relatively narrow keeled 

 shape of the latter, are not brought out in median sagittal tracings, and considerable 

 value would be added to the method by taking horizontal tracings at the glabella- 

 lambda plane and vertical transverse tracings at right angles to the above-mentioned 

 plane passing up from the basion. 



I have done this in a few specimens, making use of the apparatus devised by 

 Professor Bryce, which enables one to take a tracing of any desired contour in any 

 horizontal or vertical plane. By this means the other characters of the brain-box in 

 the Australian, Scottish, and Tasmanian are well shown, e.g. the character and slope 

 of the vault, etc., as well as 'the relations of breadth and height. By associating or 



sX 



^ 



/' yr 



I'.yr 



z.. 







^Ns\\ 



>^» 









M 



^c 







y' 



1 ' 



N> 





.is 





' ' 



Fie. 10. — Diagram showing sagittal cranial contours and quadrilateral figures of mean Tasmanian skull 

 and mean West Scottish skull superimposed. Glabella-lambda line as base. 



West Scottish — continuous line. Tasmanian — interrupted line. 



combining the measurements derived from the sagittal tracing with those obtained 

 from the vertical and horizontal tracings, one can obtain a complete picture or model 

 of the cranial box or calvaria, and so from the values obtained derive more assistance 

 in reconstructing the facial part of a skull when the calvaria is alone available, and 

 thus be able to come to more definite conclusions and with a greater likelihood of 

 accuracy than if the figures in the sagittal plane are alone made use of. 



This method of Klaatsch is fitted for the study and comparison of median 

 sagittal contours of different skulls or types of skull by superposition on a common 

 base, in this case the glabella-lambda line. I have constructed four quadrilateral 

 figures, giving to the various chords lengths equal to the mean values shown by the 

 Scottish series of skulls, and with the zentrum angle 92 '5° — the mean value of the 

 angle for the 100 Scottish skulls. By the addition to each quadrilateral figure of the 

 other triangles in Klaatsch's scheme, making their respective heights equal to the 

 mean heights of the Scottish series, I have obtained a sufficient number of points to 



