6 JUDGING HORSES 



of the jaw apph' their power to the center of the jaw bone, 

 the fulcrum is at the point where the under jaw joins the 

 head, while the application of the power is at the teeth, 



2. Action of the Muscles. In considering the leverage, 

 the attachment of the muscles and their nature are impor- 

 tant. As the muscles consist of bundles of fibers, it is easy 

 to understand that when these fibers are long, thej' possess 

 more elasticity than when they are short. The long muscle 

 with long leverage, added to b}' length of the bones is more 

 favorable for quick action or speed, while the heavier muscle 

 is more favorable for draft or power. The attachment of the 

 muscles to the skeleton is also an important feature. When 

 the muscles by means of the tendons are attached to promi- 

 nences thus enabling them to work some distance from the 

 bones that furnish the leverage, it is easy to see that the 

 action of the muscles would be more efiective. Hence, in 

 most joints there are prominences to give the muscles the 

 most favorable attachment. 



In this connection it will be interesting to study the pro- 

 portions of the bones of the skeleton to find reasons for the 

 advantages which are supposed to originate with difierent 

 proportions. In general we look for short bones in those 

 parts where the function is simply the transmission of power; 

 while we desire greater length in those [parts where the mus- 

 cles, the source of power or speed, are to be found. In the 

 front leg for instance, it is desirable to have the distance long 

 from the elbow to the knee, with the proportions showing a 

 much greater distance from the knee to the fetlock joint for the 

 reason that the distance over which the power travels should 

 be as short as possible that it may be economized and but 

 little of it lost in transmission. 



3. Function of the Nervous System. In studying the 

 horse as a mechanism, more than bone and muscle should be 

 included. The stimulation for action comes from the nerve 

 power or force. The nerve power is represented centrally 



