516 L. BOLK 



In the coronal suture, however, it appears to be of a more 

 irregular character, as follows from the fact that in cases of 

 partial concrescence at one time a certain point of the suture is 

 obliterated, at another time again a different point. In the 

 five cases of partial concrescence I found the following con- 

 ditions: once the right half was totally obliterated and of the 

 left half the lower part; once only the right half was totally 

 obliterated; once the upper part of the right haK, once the upper 

 part of the left half and once the lower part of the left half. 

 The contrast with the sagittal suture in which the synostosis 

 regularly appears in the occipital half is indeed very mani- 

 fest. 



Rarer still than the non-complicated synostosis of the coronal 

 suture is that of the parieto-temporal (squamosal) sutures, 

 On the whole I only encountered three infantile skulls of my col- 

 lection in which this was the case: i.e., two in Group I and one 

 in Group II. Twice the middle part of this suture on the left 

 side of the skull was obliterated, and once the hindmost part 

 of the suture on both sides. These cases do not call for a 

 special consideration. 



A premature synostosis of the fronto-sphenoidal suture I 

 found four times in infantile skulls belonging to the first, second, 

 fourth and sixth groups. It was a remarkable thing that the 

 process appeared symmetrically, in all these cases the synos- 

 tosis being noted on both sides. This does not seem to me to 

 be of a special significance, for the suture between the sphenoidal 

 and parietal bone I only found obliterated once unilaterally 

 (left side) in an infantile skull from Group III. I found, more- 

 over, in this same group a skull in which a part of the left half 

 of the lambdoid suture has disappeared. 



These are the cases in which a synostosis, total or partial, of 

 only one single suture was seen. Before we pass to the exami- 

 nation of the more complicated cases I will give a table (5) 

 containing the facts heretofore stated. 



This table shows very clearly the typical place occupied more 

 particularly by the masto-occipital suture but also by the 

 sagittal suture with regard to the premature obliteration. 



