ON THE PREMATURE OBLITERATION OF SUTURES 

 IN THE HUMAN SKULL 



L. BOLK 



From the Anatomical Institute, University of Amsterdam (Holland) 



INTRODUCTION 



In the developmental history of the human skull, there is a 

 period in which the phenomena of development are as yet fairly 

 unknown to us: viz., the phase of life included between the third 

 year and the adult state. The reason of this is quite clear. It 

 is impossible to acquire a perfect knowledge of an object of such 

 intricate structure as the human skull, unless investigation is 

 made of a very great nmnber of infantile skulls. Now, the 

 number of non-adult skulls, except those belonging to children 

 of one and two years old, found in the anatomical institutes is 

 generally quite restricted. This was the case with the anatomi- 

 cal institute of the University of Amsterdam, until two years 

 ago, when it became the possessor of about two thousand infan- 

 tile human skulls. This collection may be utilized for inves- 

 tigations of many totally different natures and my intention is 

 to communicate occasionally in this journal the results of some 

 investigations worked out by myself or by my pupils on the ma- 

 terial of this splendid collection. 



The present paper will refer to the sutures of the cerebral 

 part of the skull. 



It is a well known fact, that the bones of the human skull 

 coalesce either during the developmental period or in a more 

 advanced phase of life. In the first case, coalescence takes place 

 for the greater part during the foetal period, in the second case 

 at a date varying extraordinarily for each suture. Therefore 

 in human life a phase exists during which skull-bones do not 

 unite, beginning about the fourth year, when the metopic suture 



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