210 THE EXTERIOR OF THE HORSE. 



speed, but he does not receive the benefits which should result from 

 the fixation of the scapulo-humeral angle in advance. Whenever the 

 anterior member is advanced, the point of the shoulder is not suffi- 

 ciently elevated to permit the other segments to attain their maximum 

 degree of movement. As a natural consequence of this, the gait is 

 deficient, the feet are but little elevated from the ground, the steps are 

 short, and the movements rapid. 



The scapulo-humeral angle in horses of the best conformation is 

 not 90 degrees (as is generally but incorrectly supposed) ; and, aforUoriy 

 the inclination upon the horizon of the two segments constituting it 

 is more than 45 degrees. In the articular angles, the axes of move- 

 ment of the branches should meet in the probable centre of the articu- 

 lation. The central point of the scapulo-humeral union is not, as has 

 been commonly believed, the point of the arm (the summit of the 

 trochiter and trochin). Its situation is more posterior, and corresponds 

 externally to the convexity of the great trochanter over which the 

 tendon of the sub-spinatus muscle glides. It is at this point that the 

 axes of the scapula and the humerus meet, and the angle formed by 

 these lines can be measured in the living animal when the bones are 

 placed in their normal position in relation with the median line. 



Our measurements have given us 55 degrees as a mean inclination 

 of the scapula in horses possessed of speed, and 65 to 70 degrees in 

 those used for slow and heavy work. The beautiful models of rapid 

 draught-horses do not differ sensibly, in this relation, from the champion 

 of the race-course, and we do not hesitate to affirm this fact in opposi- 

 tion to those obstinate partisans of the oblique shoulder, who value it 

 only in the race-horse, and declare it a defect in the draught-horse. The 

 unpublished observations on this topic which Professor I^aulanie has 

 kindly communicated to us, although less numerous than ours, fully 

 corroborate our own. According to our distinguished colleague, the 

 mean scapular inclination is 57 degrees, the extreme measurements 

 varying from 50 to 66 degrees. 



The scapulo-humeral angle has been determined by us to have a 

 mean dimension of 115 degrees, and we have seen it vary from 110 to 

 130 degrees in all types of horses. 



Resume. — It results from the preceding statements that the direc- 

 tion of the shoulder is in intimate relation with the speed. It is 

 desirable to have it as much inclined as possible, because its obliquity 

 will admit of a greater extension of the humerus ; it will permit the 

 member to be raised higher and to complete the extension before placing 

 the foot on the soil ; it will more strongly project the foot, and will be 



