292 



THE EXTERIOR OF THE HORSE. 



tends (Fig. 98) to press on the sesamoid bones, A, and tends to effect 

 a closing of the angle PBC. 



The ligamentous apparatus, however, and the tendons \\'hich exist 



behind this angle, constantly re- 

 sist this tendency and, by their 

 tenacity as Avell as their elas- 

 ticity, transform the articular 

 joint into a veritable elastic 

 spring admirably adapted to the 

 sustentation of the body, the 

 dispersion of the reactions, and 

 the impulsion of the mass. 



The suspensory ligament of 

 the fetlock, being resisting and 

 elastic, thanks to the k\\ mus- 

 cular fasciculi which enter into 

 Its composition, yields more or 

 less, according to the intensity 

 of traction which it undergoes, 

 to the lowering of the great sesa- 

 moids, and through its attach- 

 ments upon the bones of the canon distributes upon the latter a portion 

 of the pressure of the weight of the body, in such a measure as is 

 compatible with their integrity. 



As to the cord T, of the flexor tendons, though much less elastic, 

 it acts in the same manner upon the extremity of the lever-arm AB^ 

 in order to limit to some extent the movement of descent of the fet- 

 lock and prevent the elasticity of its suspensory ligament from being 

 strained beyond its limits. But as it is continuous, superiorly, with 

 the fleshy portion of the corresponding muscles, and as an intermission 

 in the action of all these contractile organs is necessary, there exists, 

 behind and below the carpal and the tarsal articulations, a strong lig- 

 amentous band emanating from the posterior capsular ligaments of the 

 latter, which permits the flexor tendons to perform the role of passive 

 organs of suspension, by giving them a function completely independent 

 of their respective muscular portions. The carpal and the tarsal check 

 ligaments therefore transfer to the superior part of the canon bone the 

 remaining pressure of the body-weight which has not been completely 

 overcome by the elasticity of the suspensory ligament of the fetlock. 

 Hence their force of resistance is in relation with the intensity of the 

 tractions which they must support, and it is for this reason that the 



