ANTERIOR MEMBER. 



209 



The line AE, which indicates the direction of the elevators of the 

 shoulder AB, is more perpendicular to this segment, and consequently 

 more powerful than is its homologue CE, which is attached to the 

 shoulder CD. But it can be seen that the mechanical inconveniences 

 resulting from the latter conformation Avill be mitigated to a certain 

 degree by a more horizontal direction of the neck EF. It is also ob- 

 served that horses with straight shoulders, and which have to employ 

 great force, carry their necks very low, so as to increase the power of 

 the muscles by giving them the best incidence, and to enable the centre 

 of gravity to be more easily displaced forward. 



The Scapulo-humeral Angle. — The obliquity of the shoul- 

 der, an element to be desired for velocity, tends to eifect a reduction 

 of the dimension of the scapulo-humeml angle. This circumstance 

 would, consequently, restrain the extent of play of the latter, if the 

 humerus, by a more vertical position, did not preserve a normal separa- 

 tion of these two segments. 



Whatever may be the value of this direction of the humerus, it 

 never attains such a degree as to give to this angle the same obtuseness 

 which the other angles of locomotion have, excepting the coxo-femoral. 

 Normally, in running- and trotting-horses, the scapulo-humeral angle 

 is much more acute than any of the others. The consideration of 

 this fact alone is, however, not suffi- 

 cient to establish our position. It is 

 necessary that the arm itself have s^od 

 direction ; in a word, that the angle 

 remain well situated in relation to the 

 vertical axis of the member. 



Our measurements have shown us, 

 in fact (Fig. 62), the angles A OD and 

 AOC, as well as the angles BOD and 



Boa 



It may be said that a large scapulo- 

 humeral angle can coexist with an 

 oblique shoulder, and, vice versa, a 

 small one with a straight shoulder. 



It can be understood by this time 

 why so many beautiful or ideally per- 

 fect shoulders fail to fulfil the expec- 

 tations which are based upon them, and how, also, the inclination of 

 the arm constitutes, to a certain point, a compensation for a straight 

 shoulder. In the latter case, the animal ma}' still be capable of great 



14 



Fig. 62. 



