MAN FROM THE FARTHEST PAST 
lower jaws of apes actually have a small depression at 
this point; and in the older prehistoric human skulls, we 
find a condition intermediate between modern man and 
the ape. 
The teeth, in their size and shape, including that of their 
roots, in the way they are set in the Jaw, and in many 
other features, likewise contain evidence of great sig- 
nificance to the 
anatomist and 
the prehis- 
torian. 
As our far- 
distant ances- 
tors gradually 
attained amore 
upright pos- 
ture, their fossil 
skeletons reveal 
that further 
anatomical and 
struct mnas 
changes took 
place in their 
bodies. The 
head began to 
be balanced 
on the spinal 
Fic. 10. Thigh bone of modern man (left), of Neander- column > oe us 
thal man (center), and of gorilla (right). After Keith stead of being 
thrust far 
forward (Fig. 9). To accomplish this balancing, the back 
of the head, or occiput, grew out backward, the jaws were 
drawn in and became less massive, the forehead became 
higher, and the whole face more nearly vertical. At the 
same time equal or even greater changes went on in the 
rest of the skeleton, notably in the pelvic bones. In'a 
creature going on all fours, the weight of the internal 
[ 48 ] 
