POSTERIOR MEMBER. 251 



favors speed ; should it become more inclined, it closes the angles, 

 shortens the member, draws the body down to the ground, and favors 

 the muscular insertions and the production of force. 



It is easy to understand that the more the tibia is inclined on the 

 femur the more perpendicular is the insertion of the muscles upon 

 their lever-arm and the more effective are their contractions. These 

 two segments are never so oblique upon each other as to form a right 

 angle, even when the member is in station. Although normally very 

 obtuse, the more closed the femoro-tibial angle is the more favorably 

 is it disposed for all the manifestations of force. It renders the buttock 

 shorter without preventing it from being strongly muscled ; it diminishes 

 the height of the animal without interfering with an increase of its 

 bulk. Besides, is not this the form which this angle assumes when 

 the draught-horse is called upon to move his load and to display great 

 force ? Does he not incline the croup, the thigh, the leg, and the canon, 

 close all the angles, bring the body to the ground, correct the muscular 

 insertions, and, in a word, adapt his locomotory apparatus to the new 

 conditions which are imposed on him ? 



In the rapid motor, the angle of the stifle should offer a greater 

 amplitude. If, indeed, on the one hand we should seek in the abdomi- 

 nal limb for a certain horizontality of the croup with a view of aug- 

 menting the power and extent of the contraction of the muscles, the 

 case is quite different with the inferior segments, the femur, tibia, and 

 canon, which require but little obliquity to move one upon the other 

 with a great amplitude when the foot is raised from the ground. It 

 is for this reason that the femoro-tibial angle is much more open in 

 the running-horse than in any other. A tibia excessively inclined in 

 relation with the femur would not reach its limit of extension quickly 

 enough ; too much time would he taken up, and the extension would 

 not be terminated before the foot had touched the ground again. We 

 have seen in discussing the thigh that the femoro-tibial angle is about 

 145 to 150 degrees in horses endowed with speed. This is a quality 

 which we have recognized in the best running-horses, and which we 

 will give only as a simple datum on which our judgment can be based, 

 for this angle varies according to the type of the horse examined. 



In order to subserve speed, it is necessary, besides, that the tibio- 

 tarsal angle be very wide, another condition which implies a small 

 inclination of the direction of the leg. The canon can then be more 

 strongly flexed, pass over more space, and take a long stride, particu- 

 larly if the tibia be long and well muscled. Moreover, when the foot 

 gets on to the ground again, the extension of the hock is at its full on 



