THE SKKLETON. 



21) 



both legs. The same efl'ect wLicbthe muscles of the 

 Lose, iu connectiou with the Aehill-chord, perform ou 

 the lever of the hock, the extensor tendons •will 

 |!erform on the lever of the elbow. The muscles of 

 tho hose draw the lever of the hock toward the thigh 

 bone, and, the thigh bone being simultaneously 

 moved biu'kwiird by the muscles of the croup, all the 

 upper joints will bo oponed. 



This sudden extension of the leg represents the 

 propelling activity of the hind leg, the hock joint 

 forming the near and the ground tho more remote ful- 

 crum. The same is the case with the fore leg. The 

 extensors acting ou the elbow, at the same time the 

 fihoulder joint being opened at the front side by the 

 long flexor of the fore arm, the same sudden elonga- 



