OBLITERATION OF SUTURES IN SKULL 503 
Summarizing the preceding results our investigation leads 
us to the following conclusions with reference to the masto- 
occipital suture. In the infantile skull there is found a premature 
closure of the suture between the mastoid and occipital bone 
either on one or on both sides in about 10 per cent of the cases. 
This process is not pathological but ought to be considered as 
merely physiological. The beginning of the coalescence between 
.the two bones is restricted to earlier stages. After the child 
has reached its seventh year it has but little chance to be sub- 
ject to the said premature synostosis. 
In the preceding pages we only considered the skulls in 
which exclusively the masto-occipital suture was closed and 
all others were intact. There were, however, in my collection 
of infants' skulls a certain number showing a more complicated 
condition in which premature obliteration was seen in more than 
one suture. For the sake of brevity we will postpone the ex- 
amination of these cases until after the description of the skulls 
with a single obliteration. 
THE PREMATURE OBLITERATION OF THE SAGITTAL SUTURE 
In this suture too my investigation resulted in unexpected 
results, the frequency of premature closing being more consid- 
erable than I anticipated. 
The premature closure of this suture has attracted the atten- 
tion of many anatomists, more so than the masto-occipital 
suture. The frequency of the latter's synostosis was till now an 
unknown fact in the anatomy of the skull. In general it was 
acknowledged- that a premature closure of the sagittal suture 
occurred occasionally, although investigations with statements 
are as yet wanting. The cause of this difference between two 
homologous phenomena" is near at hand. In case of closure 
of the sagittal suture, the possibility arises of a deformity of 
the skull, more considerable the sooner in life the process com- 
mences. This anomaly is known as scapho-cephaly (which 
name was introduced by von Baer), because when excessively 
deformed the skull becomes boat-shaped. A premature coales- 
