HRDLICKA | PHYSICAL ANTHROPOLOGY OF THE LENAPE 45 
Middle lacerated foramina. Posterior lacerated foramina.—As 
repeatedly pointed out by the writer on former occasions, the middle 
lacerated foramina are structures of some importance. They are 
very small in the anthropoid apes, generally small in negro skulls, 
submedium to medium in the yellow-brown races and in less devel- 
oped whites, and reach their maximum spaciousness in civilized 
modern white men. These differences are connected with the increase 
in the size of the brain. A growing brain not accompanied with a 
proportionate or equally rapid increase in the bony structures of the 
base of the skull (which seems to be most frequently the case) will 
cause a spreading and bulging of the basal parts, one result of which 
will be the increased size of the middle lacerated foramina. In the 
Munsee, in only two of the nineteen skulls in which the basal 
region is sufficiently well preserved for examination, the foramina 
about equal in size the average in whites; in nearly half of the remain- 
ing skulls they are submedium, and in slightly more than half they 
are small. 
XXXV. MUNSEECRANIA: MIDDLE LACERATED FORAMINA; POSTERIOR LACERATED 
FORAMINA 
7 males 12 females |) | 7 males 12 females 
‘ Per Reena es VP EXOTe Palmer ~ Per 
Cases pent Cases Centll| Cases Cant Cases eat 
Medium (about as ay- - Of equal size......-.- 1 14 il 8 
erage in whites) - - -- 1 14 1 8 || Right larger .....-.--- 5 71 8 67 
Submedium....-....-- 5 71 3 PS NW 1G fs) (el beh eXs) eee a 1 14 3 25 
Smallest eeos sats - 1 14 8 67 
The posterior lacerated or jugular foramina are of interest chiefly 
because of their frequent and often marked inequality in size, which 
signifies inequality in the size of the lateral sinuses and especially 
of the internal jugular veins. The right foramen is frequently 
larger than the left, a phenomenon which has been associated with 
the prevailing right-handedness in man. In the nineteen Munsee 
skulls in which the foramina could be examined, they are of about 
equal size in only two instances; the right is larger in thirteen, or in 
two-thirds of the cases, while the left is the larger in only four in- 
stances. As the proportion of left-handed persons among the Indians 
averages only about three per cent, it is evident that in some 
instances the relation between a larger jugular canal and habitual 
greater use of the arm of the same side would not maintain; besides, 
we know the motor centers for the right arm and hand to be on the 
left side of the brain. Possibly greater blood pressure on the right 
side in right-handed persons, due directly and mechanically to the 
