108 MECHANISM OF THE BONES. 



Fig. 17. 



A part of the hip joint is here taken off, for the purpose of ex- 

 hibiting the round ligament a, which is seen connecting the 

 head of the thigh bone with the bottom of the socket. It al- 

 lows considerable latitude of motion, at the same time it is 

 the great safeguard against dislocation. It is hardly imagina- 

 ble how great a force is necessary to stretch, still more to 

 break this ligament ; — yet so flexible is it as to oppose no im- 

 pediment to the suppleness of the joint. 



T. We will now close the description of the bones 

 and joints, with another striking instance of wisdom 

 and design in the formation of the foot. 



THE FOOT. 



A. The foot is composed of twenty-six little 

 bones, united together by gristle, a very elastic sub- 

 stance under a hard pressure. So many joints impart 

 the advantage of a spring — and of enabling the foot 

 to conform itself to the surfaces of objects upon which 

 we tread. Any one must be sensible of the incon- 



