ANTERIOR MEMBER. 223 



action will be less disposed to stumble, will more easily overcome 

 obstacles in his way, and will be fitted for special varieties of work, 

 but will never be possessed of great speed. 



Horses provided with long forearms move their members closely 

 along the ground, and thus offer less safety to the rider on uneven 

 roads. An intelligent handling and a rational training will nearly 

 always cause a disappearance, or at least an attenuation, of most of 

 these disadvantages of a long forearm. 



b. Length in Relation with the Canon. Nearly all authors 

 agree that the radio-metacarpal segment should owe its length to the 

 forearm or its superior section, and not to that of the canon. In 

 other words, from a point of view of speed, the conformation should 

 be such as to present a long forearm and a short canon. 



The relative length of these regions varies in a small proportion 

 when they are measured in a large number of horses of the same 

 height at the withers. But the few centimetres by which these figures 

 differ are sufficient to produce a very marked effect on the value of the 

 movements at the extremity of the member. 



Professor Neumann l was the first one to remark that if the metacarpus be 

 considered just before the foot is raised, when the region is inclined downward 

 and backward, it will be seen that the latter plays the role of a lever, upon the 

 superior extremity of which the weight of the body is decomposed into two 

 secondary forces : the one, perpendicular to the canon, tends to carry the knee 

 forward ; the other, parallel to this segment, indicates the intensity with which 

 the foot presses against its point of support, the ground. The latter force, 

 antagonized by the resistance of the soil, offers but little of interest to us in 

 the present discussion. The former force acts behind on the arm of a lever, the 

 metacarpus, antagonized in front by the extensor muscles of this region. It 

 follows, then, that the shorter this arm the less will be the eifect of the force in 

 question and the less the fatigue of these muscles in combating the tendency to 

 flexion. 



A member with a long forearm will support the body more easily 

 during contact for a longer time without a greater expenditure of 

 force, and will incline itself more before being raised from the ground, 

 a condition which will enable the foot to describe a larger arc and 

 increase the length of the step. 



If the inferior extremity of such a forearm, having reached its 

 limit of inclination, be now flexed, it will describe, for an equal angu- 

 lar displacement, a greater quantity of movement, and the latter is 

 always proportional to the speed acquired, which is itself in direct 



1 G. Neumann, De 1'avant-bras du cheval et de 1'influence de sa longueur sur la rapidity des 

 allures, in Journal de me'decine veterinaire militaire, t. xi., annee 1873, 1874, p. 157. 



