MAN. 
13 
withdrawal o£ the front limbs from the function of progression, 
and their modification into grasping and feeling organs ; at the 
same time the hind-limbs are developed sufficiently to be 
capable, by themselves, of supporting and moving the whole 
weight of the body. The direction of the hind-limbs is in a 
straight line with the axis of the vertebral column, instead of at 
right angles to it, as in other Mammals ; the thumb is so 
attached to the wrist-bones as to be completely opposable to the 
other four digits, while the great toe is fixed parallel to the 
other toes, so that the foot is quite flat beneath, with little 
power of grasping, but forming a base on which the body may, 
be balanced. The tail is only represented by the rotrya-, an 
immovable bone composed of from three to five united vertebrae. 
Fig. 6. Fig. 7. 
Skull of a Caucasian. Skull of a Tasmanian. 
Man^s skull differs from that of the other Mammals by the 
great size of the brain-case, and the proportional reduction of 
the bones of the face, the result of the high development of the 
brain and the disuse of the jaws and teeth as weapons of offence 
and defence. It therefore follows that those races of mankind 
which have prominent jaws and small brain-cases are of a lower 
type than those in which the jaws are more reduced in size and 
the brain-case is larger. Australians and Tasmanians, for 
example, have a very small brain-cavity, thick skull-bones. 
