424 
THE ANTIQUITY OF MAN 
sharp, lateral, depressed margins of the same kind as we 
saw in brain casts of modern man. 
To make our study of the median line of the brain 
cast complete it is necessary to examine the primitive 
arrangement seen in a brain cast taken from the skull of 
a young gorilla (fig. 157). In this instance we can trace 
Fig. 157. — Brain cast from the skull of a young gorilla viewed from above, to 
show the markings for the longitudinal blood-sinus. 
the impression for the longitudinal sinus, lying in a groove 
or depression between the adjacent margins of the cerebral 
hemispheres. The vascular median elevation, which was 
so apparent in the brain cast of modern man, and to a 
less degree in that of Neanderthal man, is absent in the 
bregmatic region. We must suppose, then, that the 
primitive condition for the sinus is that represented in 
the irorilla. 
