A CONTRIBUTION TO THE STUDY OF THE SCOTTISH SKULL. 



363 



and female skulls, show the great uniformity in the relatively long and narrow 

 character of the Scottish face. 



For the series of 100 female Scottish skulls we can construct the following table, 

 according to the magnitude of the palato-alveolar index, subdividing them into three 

 groups as in the male : — 



Table XVIII. 



Class. 



West Scottish Series. 



Turner's Series. 



F. (100). 



M. (400). 



M. & F. (500). 



M. &F. 



Hyperdolichuranic . . . . 

 Dolichuranic ..... 

 Mesuranic ..... 

 Brachyuranic ..... 

 Hyperbrachyuranic .... 



per cent. 

 15 

 19 

 18 

 22 

 26 



per cent. 

 13-8 

 24-0 

 213 

 20-3 

 20-5 



per cent. 

 14 

 23 

 20-6 

 20-6 

 21-6 



per cent. 

 13-4 

 24-4 

 18-3 

 20-7 

 23-1 



What strikes one on surveying the above table is the near approach to equality 

 in the numbers of the different groups contained in the various classes. The hyper- 

 dolichuranic class contains a smaller proportion than is contained in the other classes, 

 but the latter are remarkably similar, only slight variations occurring from group 

 to group. 



In the series of 100 female skulls the mean value of the opisthio-nasal length, or 

 Cleland's base line, is 126'98 mm., which is considerably shorter than the mean 

 length of the base line of 100 male skulls. In the female series the mean length of 

 the sagittal arc is 363'15 mm., and the mean value for the proportion of base to arch 

 in the 100 skulls is as 1 to 2'859, which proportion of base to arch is slightly less in 

 the female than in the male, where the proportion for 100 is as 1 to 2'819. This 

 larger proportion of the arch to the base in the female skull . is held to be the rule 

 by Welcker (16) and Ecker (17). 1 shall return to this subject when considering 

 the variability of the skull. 



In the 100 female skulls I have measured the lengths of the frontal, parietal, and 

 occipital segments of the total sagittal arc, and find the following mean values : — 



Frontal segment, mean value 

 Parietal segment ,, ,, 

 Occipital segment ,, 

 Total arc 



126'96 mm. 

 121*4 „ 

 11476 „ 

 363-15 „ 



In the series of 100 the occipital arc is greater than the frontal in 8 per cent. 



of the cases and equal in 1 per cent. ; the occipital is greater than the parietal in 



20 per cent, and equal in 4 per cent. ; the frontal is greater than the parietal in 



70 per cent, and equal in 5 per cent. 



TRANS. ROY. SOC. EDIN., VOL. LI, PART II (NO. 9). 



52 



