OBLITERATION OF SUTURES IN SKULL 505 
any sign of scaphocephalic deformation in my collection is too 
large to accept this point of View. But as mentioned before I 
will return to this question later on. 
The number of skulls with premature closure of the sagittal 
suture was a fairly large one. After finding this fact the ques- 
tion arose whether this process should be considered either 
pathological or physiological. 
To justify the putting of this question some observations may 
precede upon the variability of the closure of this suture in the 
adult. The opinions of the writers diverge greatly as to the 
age in which the normal obliteration of the sagittal suture com- 
mences. According to Tapmord the process begins normally 
at the age of 40 to 45 years, a conclusion also accepted by Ribbe. 
In the text book of human anatomy the average age of the 
closure is given as about 50 years. Dwight, on the contrary, 
lays stress upon the fact that the obliteration commences be- 
tween the twentieth to thirtieth year, although the individual 
variability is considerable, while the process can occasionally 
be postponed till a fairly old age. In his admirable paper, 
already mentioned, Fredericg shows that in 22 out of 34 human 
skulls, varying between 20 to 30 years, the suture commences 
to disappear. In this connection the author cited an observation 
of Schwalbe, who always found the sagittal suture either 
partially or entirely coalesced after the fortieth year. 
The process of obliteration however can proceed very slowly, 
and it even happens that in skulls 80 years of age, the two 
parietal bones are not yet totally united. Based upon the re- 
sults of the investigations of Schwalbe and Fredericg, the 
following point of View presents itself. It is proved, and we 
need not doubt the reality of the fact, that the beginning of the 
obliteration of the sagittal suture is seen fairly often between 
the twentieth and thirtieth year. But this fact was found by 
merely examining skulls older than 20 years. Until the present 
time young skulls have not yet been investigated as to the 
occurrence of the closure of the sagittal suture. And if it 
becomes clear in the course of such an examination, that such 
a closure in infantile skulls is not an exception, then I must 
