404 THE ANTIQUITY OF MAN 
and apparently treasures the memory of sounds and 
associates particular sounds with particular meanings. 
This part of the brain must also be regarded as con- 
cerned in speech. 
The occipital lobe is connected with sight. On the 
occipital pole itself, and on the surface which lies buried 
in the fissure between the two hemispheres of the brain, 
is the area where impressions streaming in from the eyes 
reach the horizon of our consciousness. Spread out on 
the surface of the brain, in front of the visual area of the 
occipital pole, are others which are known as association 
areas — evidently connected with the elaboration and 
interpretation of the visual impressions which reach the 
brain. The parietal lobe constitutes the central part of 
each hemisphere of the brain ; it lies behind the frontal 
lobe, above the temporal, in front of the occipital. The 
part of the parietal lobe lying just behind the central 
fissure — the post-central convolution — receives sensory 
impressions coming from the skin and body generally 
(fig. 145), but the greater part of this lobe seems to 
serve the higher purposes of the human brain — the 
purposes of memory and interpretation. For instance, 
the part which lies above the hinder end of the fissure of 
Sylvius seems to be concerned in the interpretation of 
written or printed words. At least, in many cases of 
" word-blindness " — cases where words can be read but 
not understood — this area of the parietal lobe is found to 
have been destroyed by disease. The " word-interpret- 
ing " centre is placed in this association area, which 
often rises above the surrounding parts of the brain into 
a distinct elevation or eminence. Enough has been said 
to show that, imperfect as our present knowledge of the 
brain is, we may hope to obtain some light on the mental 
status of fossil man by a careful study of brain casts. 
Indeed, I firmly believe that the day will come when we 
can estimate the functional value of every convolution of 
the brain. 
Having thus formed a broad picture of the chief 
features to be seen on the brain cast of a modern skull. 
