224 THE EXTERIOR OF THE HORSE. 



ratio with the distance passed over in a unit of time ; but the exten- 

 sion of the canon taking place after the flexion of the forearm, the 

 quantity of movement of the latter will tend to augment that which 

 the antibrachial muscles will communicate to the canon, in order to 

 favor the rapid and extensive projection of the inferior part of the 

 member. 



It is, therefore, also necessary to seek for a great development of the 

 forearm in the parts where the muscles are situated, since the degree 

 of muscular shortening gives the measure of the angular displacements 

 of the bones. For this reason it is preferable to have a short canon 

 in relation with the forearm. From a point of view of locomotion, it 

 is just to say that, of these two segments, the one is active and the 

 other passive ; the first, by its mobility, overcomes the inertia of the 

 second. 



Finally, with a short forearm, the displacement of the knee is 

 effected upward instead of its being projected forward in the direction 

 of movement. The arm of the lever (radius) of the resistance (weight 

 of canon) diminishes, whilst the intensity of the power (flexors of the 

 radius) remains the same, which favors so much the latter and gives to 

 it more facility to elevate the knee. With a long radius, the arm of 

 the lever (radius) of the resistance (weight of the canon) augments, 

 and the power (extensors of the metacarpus) remains invariable, a con- 

 dition which favors this bone again and disposes it more favorably for 

 the extension of the canon. This is the reason w r hy, in the first case, 

 the knee-action is exaggerated, the members badly employed and not 

 properly advanced ; also why, in the second case, the knee is not unduly 

 elevated, the segments being at the same time well projected forward. 

 The animal thus acquires more speed without increasing the rapidity 

 of his efforts and without compromising the integrity of the locomotory 

 apparatus. 



Width. It suffices not that the forearm should merely be long, 

 but it should also be wide, this wideness being an indicator of the 

 volume of the muscles. 



This width is measured from before to behind below the elbow, 

 viewing the horse in profile, at a point always a little superior to the 

 widest part of the tibial region, x and at the level of the most prominent 

 portion of its anterior muscles ; it is, finally, on the same level as that 

 of the tibial region at the point where the latter receives the insertion 

 of the fold of the buttock. 



The forearm has such a conformation in well-formed horses, which 

 qualifies it imde y muscular, well muscled. 



