4i6 THE ANTIQUITY OF MAN 
almost alike. The impress of the longitudinal blood- 
sinus can be detected along the whole length of the vault 
of the brain between the two hemispheres. As it courses 
down to the occipital region, it is continued between the 
right occipital lobe above and the right half of the 
cerebellum below as the right lateral sinus. The left 
occipital pole is rather larger than the right pole. The 
right half of the cerebellum is rather larger than the left 
half. There is thus some indication of a specialisation 
of function in the occipital region of even a gorilla's brain 
— a region connected with the function of sight. The 
medulla emerges between the lateral lobes of the cere- 
bellum to become continuous with the spinal cord. The 
outline of the occipital bone is shown ; its right and left 
halves are approximately symmetrical. Further, it will be 
noticed that in width the gorilla brain just reaches the 
50-mm. lateral vertical lines. In height, the right and 
left halves of the cerebrum fail to reach the 60-mm. level. 
In fig. 152 the brain cast from an Australian skull — 
the same specimen as was represented from the side — is 
drawn from exactly the same point of view as was 
adopted in the case of the gorilla ; there is a marked 
contrast in shape and size between the two. The vault of 
the modern human brain cast is not flattened from above 
downwards, as in the gorilla and as in Neanderthal man, 
but is lofty and peaked, rising almost to the loo-mm, 
level. In the gorilla the sides of the brain cast bulged 
outwards, but here, in the Australian brain cast, they are 
compressed and reach well beyond the 50-mm. verticals, 
almost to the 70-mm. lines. In both, however, there is 
about the same degree of asymmetry ; the left occipital 
lobe and the right cerebellar are the larger. The longi- 
tudinal sinus behaves in the same way in both. Before 
reaching the hinder ends of the parietal bones, the sinus 
leaves on the brain cast a long, oval elevation, with a 
sharply depressed lateral border. Then it passes between 
the occipital lobes and turns to the right as the right 
lateral blood-sinus. It will be noted that the lateral 
sinus and occipital poles descend well below the horizontal 
