THE MUSCLES. 43 



nodding of the head, the fulcrum being at the articulation of 

 the skull with the first vertebra. The second kind of lever, 

 where the weight is between the power and the fulcrum, is 

 also uncommon in the body. An instance of this is seen 

 when the body stands on the toes. In this case the fulcrum 

 is at the point where the front of the foot rests upon the 

 ground, the body forms the weight, and the large muscles of 

 the calf of the leg constitute the power. In assuming this 

 position the calf of the leg becomes hard and firm. The third 

 kind of lever, where the power is between the fulcrum and 

 the weight, largely prevails in the human body. In this form 

 of lever the power is applied at a disadvantage, but it is the 

 only kind suitable with a view to economy of space and com- 

 pactness of body. This variety of lever is well shown in the 

 flexion of joints. The bending of the elbow is by the action 

 of the biceps, which is attached above by two heads to the 

 scapula, and below to the radius, a short distance from its 

 head. The forearm and hand are the weight, which is in- 

 creased by any object the hand may hold. The fulcrum is 

 'the elbow joint. 



In walking, rowing and swimming most of the voluntary 

 -muscles are at work, and with healthy, properly developed 

 muscles we see exhibited the perfection of motion, power 

 and grace. 



6. Tendons. The strong, flexible, inelastic cords or bands 

 which we see playing along the back of the hand when we 

 move the fingers, are called tendons. Follow them up the 

 limb, and we find they each belong to a muscle. In fact, 

 each tendon in the body is a sort of rope, by which the 

 muscle pulls upon the part it is intended to move. It is an 

 arrangement by which muscles can be placed in unexposed 

 positions and nicely grouped, so as to give symmetry to the 

 limb. These cords take up less room in the hands and fin- 

 gers, for instance, and do away with the bulky appearance 



