A CONTRIBUTION TO THE STUDY OF THE SCOTTISH SKULL. 



357 



palato-alveolar breadth was less than the length in 12 cases only, i.e. 3 per cent., 

 whereas in Turner's series this occurred in 3 specimens or 3 '6 per cent. 



There are a few other measurements in this series which we can compare with 

 the corresponding dimensions in Turner's series. 



E.g. Minimum frontal diameter with a mean value of 9 6 "42 mm. 

 Interstephanic diameter ,, ,, 117'93 



Asterionic diameter 

 Intermalar diameter 

 Transverse base 

 Transverse arc 



109-68 



90-12 



115-13 



311-10 



With regard to some of these measurements in his Scottish series of skulls 

 Turner (l) makes the following statement : " As a general rule the frontal Stephanie 

 diameter materially exceeded the minimum frontal ; the asterionic diameter, except 

 in one skull, was greater than the minimum frontal, but as a rule it was less than 

 the Stephanie, although there were several exceptions." The results in the present 

 series are in accord with Turner's results, as will be evident from an analysis of the 

 above mean values. 



Material for comparison with the present series is supplied by Turner's memoir 

 for other two dimensions of the undivided skull, namely, the length of the base of 

 Cleland, i.e. the opisthio-nasal length, that of the sagittal arc, and their relationship 

 to one another. The mean length of the base line in the group of male skulls 

 (22 in number) examined by Turner was 134"3 mm., and that of the sagittal 

 arc was 376'5 mm. The average base line in the series "K" was 135*3 mm. (for the 

 405 male skulls it was 134*5 mm.), and the sagittal arc in the same series was 

 382'3 mm. In the series of 100 the mean relation of the base line to the arc was 

 1 to 2"819. This is slightly greater than the figure given for Scottish skulls by 

 Cleland; which was 1 to 2'72 ; the latter also gives 1 to 2 '67 for French skulls, 1 to 

 2'80 for German, and 1 to 2'89 for Irish. In a series of 5 male skulls measured by 

 Turner the relation of the base line to the arc was as 1 to 2 '7 8. In a larger series 

 of 15 the relation was as 1 to 2'8. In a series of 20 male Australian aboriginals, 

 dolichocephalic in type, the mean base line was 139'8 mm. and that of the arc 

 380'4 mm. ; the proportion of base line to arc being as 1 to 2*72. We observe that 

 the mean arcs in the dolichocephalic West Scottish series and in the Australian 

 aboriginal group are approximately equal, while the difference in the relative pro- 

 portions of base line to arc is mainly due to the longer base line in the lower type, 

 the Australian, and not so much to the slight degree of mean difference in the arc. 

 It was long ago pointed out by Cleland (15) in his well-known memoir on the skull 

 that " uncivilised or lower forms are in general characterised by the possession of a 

 relatively longer base line, while the length of the arc is very variable." 



