ON METOPISM 29 



Furthermore it is clear that even among the Europeans the 

 ratio is not at all constant in crania of the inhabitants of the Mid- 

 European region (Bavarians, Alsatians and Swiss), and in the Slavs 

 the frontal bone seems to oe divided less frequently than n crania 

 of the inhabitants of the North-European regions (Hamburgher, 

 Scotch, and, as will be demonstrated further on, also Amsterdam- 

 ian). I draw special attention to this fact, which does not agree 

 with the not seldom expressed contention, that metopism occurs 

 more frequently in brachycephalic than in dolichocephalic skulls. 

 As far as I am aware, it was Welcker who first pointed out this 

 idea. And it is found in most treatises on metopism. But I 

 think in most of these it is a mere statement of a current opinion, 

 and not a result of definite investigation. The results of research 

 do not confirm this hypothesis. This will be demonstrated by 

 my own research in the course of this paper, and the investiga- 

 tions of Bryce on Scottish crania give similar results. As is well 

 known these are very dolichocephalic, and yet the author found 

 9.5 per cent metopical skulls among them. Therefore among 

 the dolichocephalic Scotchmen the metopical skulls are more nu- 

 merous than is the case among the more broad-headed inhab- 

 itants of the Mid-European region. This contradicts the 

 assumed prevalence of metopism in brachycephalic skulls. 



Before finishing these introductory remarks it is necessary to 

 give a brief account of some of the principal points in the com- 

 parative anatomy of the frontal suture. A knowledge of these 

 points is necessary for the thorough understanding of my expla- 

 nation of metopism, which, as already mentioned, differs from the 

 current one. That the frontal bone in the human embryo arises 

 by two points of ossification situated symmetrically is due to the 

 fact that originally this bone was a paired one. As a rule this 

 condition persists not only in the lower vertebrates, but even 

 among mammals there are many groups in which the metopical 

 suture does not disappear. In Prosimiae as a rule the frontal 

 suture persists as long as the other sutures of the skull. In case 

 of an early closure of the system the frontal suture also disappears 

 earl}^, in case of a persistence of the system till an advanced 

 age, the frontal suture also persists. There is considerable va- 



