FAULTS INSEPARABLE FROM STABLES. 



253 



rightful obligation. Man is blessed with reason, and is constituted, in 

 this world, the only judge of his own actions. So high a privilege should 

 bind him to be even more than just in his decisions ! 



To return. The reader will observe that, in the sketch No. 1, the 

 bones rest one upon the other. That arrangement ensues when the 



No.l. 



No, 2. 



THB STRESS ENBtJBED BY THE DIFFERENT STRUCTITRES WHICH COMPOSE THE LEG OF THE HORSE IS 

 DEPENDENT UPON THE POSITION OF THE FOOT. 



animal descends an incline. There can exist no man but must have en- 

 joyed the ease which is imparted by walking down a slop-e. Every person 

 must also be acquainted with the fatigue consequent upon ascending an 

 acclivity. The effect is generally explained by stating that, in one case 

 progression is favored by, while in the other it is made in opposition to, 

 gravitation. Such a cause, certainly, is in operation ; but the different 

 structures on which the strain reposes, when moving in opposite direc- 

 tions, to the author's mind supply a better Illustration of the fact. 



Do not muscles, and does not tendon participate in the burden which 

 is upheld by bone? Assuredly they do ; but in various degrees. No 

 limb can move unless some muscle contracts. Every muscle in the body 

 arises from bone, and is inserted into bone by the interposition of liga- 

 mentous fiber. Before a member can be elevated or depressed, some 

 muscle must drag, from some bone, that it may move some other bone 

 more distantly situated. Then, tendon cannot escape strain, since in no 

 possible attitude is every portion of the frame in absolute rest. Motor 

 muscles, however, generally exist in pairs. They are spoken of as ele- 

 vators and as depressors, or as flexors and as extensors. Their uses are 

 opposite, but not opposed. When one set works, the other is inactive. 

 niiThe bones in the sketch, indicated by No. 2, evidently press against 



