A CONTRIBUTION TO THE STUDY OF THE SCOTTISH SKULL. 



431 



Where the angle 



A" is 83°, angle ' 



'B"is94° 



95° 



89° 



97° 



91° 



87° 



93° 



89° 



94° 



83° 



88° 



82° 



84° 



82° 



89° 



88° 



82° 



While the angle " B" is less variable than the angle " A," it may have as low a 

 value as 82°, and values of 84°, 85°, and 86° also occur ; 84° twice, 85° five times, 

 and 86° three times. The highest value of the angle in the 100 skulls, however, 

 is 95°, which occurs only on a single occasion. In the case of the angle " A" we find 

 that the angle of 82° occurs in 3 per cent., 83° in 2 per cent., while the highest value 

 is 99°, which occurs in one specimen, though the angle 97° occurs twice. 



It would seem, therefore, that even in such a homogeneous series as the present 

 one the lambda-bregma line need not necessarily be parallel to the basion-nasion 

 line, while the angle formed by the bregma-prosthion line may vary considerably from 

 a right angle. The angle " B " never attains to the value of 100°, however, which would 

 bring it within the range of anthropoid measurement. In spite of the circumstance 

 that the angle "B" shows considerable variation, it is an interesting fact that the 

 mean angle is practically 90° (8978°). 



The relationship as shown to exist between these respective lines should un- 

 doubtedly be of value as an aid to reconstruction ; but its value is restricted for the 

 same reason as is the relationship, pointed out by Klaatsch, between the basion- 

 bregma and glabella-lambda line, viz. it involves the assumption that the relationship 

 which exists between certain dimensions in one type of skull will hold in another type, 

 an assumption for which there is no authority in the present state of our knowledge. 



4. Schwalbe's Method of Measurement of the Cranial Vault. 



Having completed my examination of the series of male Scottish skulls by 

 Klaatsch's method, it was suggested to me by Professor Bryce that I should apply 

 the methods of Schwalbe to the same series. The measurements introduced by 

 Schwalbe have the object of expressing certain morphological features of the vault, 

 more especially of the frontal bone, and were used primarily to elucidate the 

 characters of the fossil skulls of Homo primigenius (52 and 53). In recent, years 

 Professor Berry of Melbourne and his collaborators have used this method of 

 measurements in their studies of native Tasmanian and Australian crania, and have 

 added certain biometrical methods of their own in an endeavour to place these crania 

 in their proper morphological horizon. In my selection of measurements and indices 



