68 



THE HUMAN BODY. 



skeleton.* In Fig. 28 are shown some of the muscles of 

 the arm. Their anatomical names 

 we need not trouble about ; but it 

 will- be seen that some (8, 11, 12) 

 pass from arm to forearm: others, 

 as 16, 15, 14, 13, 17, 18, start from 

 the forearm bones and pass to the 

 bones of the hands ; near the 

 wrist they end in slender tendons, 

 which are bound down into place 

 by a stout cross band of con- 

 nective tissue. The skin has 

 been dissected away from the back 

 of the middle finger to show the 

 endings of tendons on its pha- 

 langes. 



The belly of a muscle is its 



What portion of a muscle is its 

 working part? 



FIG. 28. The muscles on the 

 back of the hand, forearm, and 

 lower half of the arm, as ex- 

 posed on dissecting away the 



* The parts of a muscle may readily be seen 

 in that which forms the calf of a frog's leg 

 Put a teaspoonful of ether in a quart of water, 

 immerse a frog in it, and cover the vessel. In a. 

 minute the animal will be quite insensible ; its 

 head can then be cut off and its spinal cord 

 destroyed by running a pin along it, without 

 causing the animal any pain. Now make cir- 

 cular cuts through the skin at the top of the 

 thighs and then peel the skin off like a pair of 

 hose : it will come quite easily except about the 

 knee-joint, where it may be necessary to carefully 

 divide one or two tough bands. On the skinned 

 leg many muscles will be observed, and the long 

 slender tendons which run to the toes. The 

 calf muscle will be seen to end below in a 

 strong tendon near the heel. If this be divided, 

 and the muscle turned upwards, it will be found 

 to have at the upper end of its thick rounded 

 belly a pair of short tendons. 



