254 
A First Study of the Burmese Skull 
To test, by the method of mean squared contingency, whether this kind of 
asymmetry is associated with either of the other two I made out the following 
tables : 
Greater Frontal Prominence 
o 
Right 
Equal 
Left 
Totals 
Right 
29 
41 
20 
90 
Equal 
10 
15 
8 
33 
Left 
1 
2 
4 
7 
Totals 
40 
58 
32 
130 
Greater Occipital Prominence 
Right Equal Left Totals 
Right 23 17 50 90 
Equal 7 11 15 33 
Left 4 2 17 
Totals 34 30 66 130 
These gave the following results : 
Greater Sylvian Depression on one side with Greater Frontal Prominence on 
same side : Cg = • 1 794. 
Greater Sylvian Depression on one side with Greater Occipital Prominence on 
opposite side: = -2348. 
For 130 in a sample, with this number of categories, mean Cg when there is no 
contingency is -1728 ± -0592. As even the greater of our results differs from this 
by hardly more than the probable error, the results cannot be said to indicate any 
certain association between Sylvian asymmetry and asymmetry of the frontal and 
occipital bones. 
Another point in which there is frequently a marked difference between the 
two sides of the cranium is to be found in the grooves on the inner side of the 
occipital bone which accommodate the lateral sinuses. Le Double* found that out 
of 200 European skulls, the superior longitudinal sinus was directly continued into 
the right lateral sinus in 137 cases, into the left lateral sinus in 29 cases, and in the 
rest neither could claim any advantage over the other. 
One hundred and thirty-five of our Burmese crania were available for examina- 
tion on this point. There were 94 in which the right lateral groove was the more 
obvious continuation of the superior longitudinal groove (and in this case usually 
* Train des Variations des Os du Crane, p. 16 (1903). 
^ 2 
^ 33 
