Some hippologists have said that the coxo-femoral 

 angle should be as small as possible, so as to open wider 

 at the moment of propulsion. This is not absolutely 

 true; the truth is that the coxo-femoral angle should 

 have all freedom to close, in order to have the same free- 

 dom in the opposite direction. A croup close to the hori- 

 zontal with a thigh close to vertical will satisfy this dou- 

 ble condition in the best way. 



In absence of chronophotographic plates of the horse 

 at racing speed, it is very difficult to determine exactly 

 what the direction of the femur should be at the stand 

 still. We must, therefore, be satisfied with measure- 

 ments ; those of MM. Goubaux and Barrier are very valu- 

 able because they were made before 1884, consequently 

 more than thirty years ago, at a time when the best race 

 horses were stayers. These authors found that the croup 

 of the race horse of that time was close to horizontal 

 (about 30°), and that the slope of the femur was about 

 80°, a direction almost vertical. 



The femur approaching horizontality is generally 

 short, otherwise the play of the stifle would be interfered 

 with by the flank and the plumb of the hind quar- 

 ter would be defective. Still the femur should not 

 be vertical. It is important that all the muscles of 

 the hind quarter should assist in absorbing the 

 shock of gravity at the level of each joint. If 

 the femur were vertical the rump muscles and the 

 ischio-tibials would have nothing to do in main- 

 taining the opening of the coxo-femoral angle, the weight 

 would be integrally transmitted to the stifle joint, and 

 would throw increased work upon the tibial-extensor, in 

 opposing the closing of the angle at the stifle. It can be 

 added that a vertical femur would make a femoral-flexor 

 longer than the ischio-tibial muscles which would be un- 

 reasonable. 



.so 



