CRANIOLOGY OF THE PEOPLE OF SCOTLAND. 603 



category. If an index 98 be taken as marking the upper limit of orthognathism, 

 seventy-two skulls belonged to this group, whilst twenty-four had indices from 98 

 to 103 and were mesognathous. The Scottish skulls are therefore characterised by an 

 almost complete absence of prognathism. 



It is sometimes stated that in the same race or people the women show a relatively 

 greater prognathic character than the men. This can scarcely be said of the Scottish 

 skulls, for the difference between the two sexes was only fractional, so that for all 

 practical purposes they may be regarded as identical. 



Orbital Index. — Broca paid much attention to the determination of the height and 

 width of the orbit and to the computation of an index of their relative proportions. 

 The width was measured from the dacryon, or point of junction of the frontal, lachrymal 

 and ascending process of the maxilla, to the most distant point on the edge of the outer 

 border of the orbit. These measurements were taken in one hundred and twenty-four 

 skulls. The greatest width in eighty-four males was 46 mm., the least was 35 mm., 

 and the mean was 39 mm. ; in forty females the greatest width was 41 mm., the least was 

 35, and the mean was 37'4 mm. The greatest height in the males was 41 mm., the 

 least was 28 mm., and the mean was 34 mm. ; in the females the greatest height was 

 37 mm., the least was 29 mm., and the mean was 33 mm. 



The orbital index is obtained as follows : 



orbital height x 100 

 orbital width 



The index was computed in one hundred and twenty-five skulls, of which eighty-four 

 were men and forty-one were women. It ranged from 737 to 105*1, and the 

 mean was 86 "4. 



In grouping skulls in their orbital and nasal indices I have in this, as in my previous 

 craniological memoirs, adopted the terms employed by Broca and Flower, as well as their 

 numerical divisions of the groups. An orbit is said to be microseme when the height is 

 low in relation to the width and the index is below 84. Thirty-three skulls came into 

 this group. On the other hand, when the height and width closely approximate so that 

 the base is rounded and the index is 89 and upwards, the orbit is megaseme, and to 

 this group fifty-seven specimens belonged, and in three of these the index was 100 or 

 upwards. Orbits are named mesoseme when the index is between 84 and 89, and thirty- 

 three skulls fell into this category. In Scottish skulls the rule was for the orbit to be 

 high in relation to the width, and somewhat rounded in outline, though exceptions 

 not unfrequently occurred. My observations on the orbital index in the skulls of 

 numerous races have satisfied me that it presents a great range of variation in the 

 same race, and that it possesses only a secondary value as a race character. 



Nasal Index. — The relation between the height of the nose, measured from the 

 nasion to the lower border of the apertura pyriformis, and the greatest width of that 

 aperture, constitutes one of the most important anthropological characters of the face. 



TRANS. ROY. SOC. EUIN., VOL. XL. PART III. (NO. 24). 4 u 



