OBLITERATION OF SUTURES IN SKULL 521 



literation occurs in cases of more extensive premature closure, 

 the veiy interesting fact presents itself that it is the squamosal 

 suture. To demonstrate this fact, I recall that amongst 1820 

 infantile skulls there were only three in which only the suture 

 mentioned showed signs of obliteration, forming a striking 

 difference with the sagittal suture, in which this appeared 47 

 times. On the other hand I find amongst 18 skulls with more 

 extensive and irregular premature obliteration not less than 

 11 in which the suture squamosa was no longer intact, and 

 only 9 in which the sutura sagittalis was partially or totally 

 obliterated. I call attention to this fact because it speaks in 

 favor of my opinion that the isolated obliteration of the sagittal 

 suture is caused by a special cause. 



Finally I shall proceed to give a general view of the sutural 

 obliteration in our collection of skulls considered as a whole. 

 In this collection, consisting of 1820 skulls, I found a prema- 

 ture obliteration either in a single suture or in more, in no less 

 than 343 skulls. This amounts to 19 per cent. This result, 

 due largely to the very frequent obliteration of the masto- 

 occipital suture, I did not expect, neither should it have been 

 expected by anybody. 



In the preceding paragraphs I pointed out how frequently 

 only a single suture in a skull showed a more or less extensive 

 obliteration, while all others remained intact. This, of course, 

 did not give a real idea as to the number of times in which each 

 of the sutures amongst the 1820 skulls really was obliterated, 

 because amongst these, the cases in which more than one suture 

 showed signs of obliteration, were not counted. In the table 

 7 I give a short summary which shows how many times 

 each suture was obliterated either totally or partially. If this 

 occurred, as is possible in paired sutures, on both sides, the case 

 is only once counted. 



The extraordinary frequency of the obliteration in the masto- 

 occipital suture is very obvious, and no less that of the sagittal 

 suture. To estimate the frequency correctly one has to com- 

 pare, of course, the bilateral sutures with each other, and also 

 the unpaired. Then the difference between the sutura masto- 



