56 THE HUMAN BODY. 



in an opposite direction to the work of nature, he has 

 explained the proceeding by which she bent the articulation 

 of the elbow forward and that of the knee backward. 



The articulations of the lower limb permit to it a great 

 variety and extent of movement. Under the action of 

 powerful muscles it folds back upon itself or becomes a 

 rigid column, raising or lowering with rapidity and facility 

 the body of which it supports the weight. In walking it is 

 carried forward or backward, and by turns extended or bent; 

 it turns on its axis or changes from the vertical in order to 

 maintain the equilibrium by the direction of the foot or to 

 enlarge the base of support. It can raise itself laterally almost 

 to a right angle with the body, and in front it approaches it 

 still more nearly. In fencing it bends or is extended, raises 

 and lowers the body, and carries it backward and forward by 

 movements which succeed each other almost as rapidly as 

 those of the arms. But it is especially in the varying steps 

 of a skilful dancer that we can admire the perfection of this 

 mechanism, and all the suppleness, strength, and agility that 

 exercise can give to it. 



