188 THE EXTERIOR OF THE HORSE. 



strongly inclined forward, gives the fore-legs an oblique direction 

 backward, vvhicli permits them to push against the collar, to which the 

 shoulders are energetically applied. It is by the extension of all their 

 articular angles, previously semi-flexed, that the fore-legs accomplish 

 this result. When they are directed obliquely and in an inverse direc- 

 tion, as is seen sometimes at the beginning of the eifort of traction, the 

 force which they exercise upon the trunk, and therefore against the 

 collar, is at its minimum. Traction forward can be favorably executed 

 only when the foot, directed backward, is fixed against the roughnesses 

 of the ground. This is observed in the draught-horse as he moves his 

 load ; when the soil, the point of support, gives way, the feet suddenly 

 glide backward. 



Aside from these functions, the anterior member is, as all admit, 

 nothing more than a column of support and an apparatus of dispersion 

 and compensation. From its mode of attachment to the trunk and the 

 disposition of the segments composing it, the fore-leg is adapted in a 

 remarkable manner to this double function. Fixed to the side of the 

 thorax by means of muscles and aponeuroses, it has all the articular 

 angles quite open, except that one of them, the radio-metacarpal, is 

 even entirely effaced. It opposes to the body-weight and to the loco- 

 motory reactions resistances, more particularly mechanical, whose pas- 

 siveness eases the muscular strain. The bones, the ligaments, and the 

 tendons, more than their muscular portions, resist the pressure and con- 

 cussion of locomotion. 



The posterior members are widely different in construction and 

 function. Much less of a support to the trunk, and well situated in 

 relation to the centre of gravity, they are articulated solidly with the 

 coxfB without endangering their integrity. By the inclination of their 

 different segments, they push against the trunk at a given moment 

 when the former are straightened, one piece upon the other ; thus the 

 angles are obliterated, and the hind-legs communicate to the body the 

 needed force or velocity. The muscles, being obliged to contract in 

 order to oppose the tendency towards closing of the angles of locomo- 

 tion, are more voluminous and numerous than those of the fore-leg ; 

 they are therefore able to sustain without fatigue the part of the body- 

 weight which the osseous framework intrusts to them. 



They are therefore, first of all, the agents of propulsion. They 

 act with the greatest efficacy and power against the trunk, to which 

 they are attached, at the moment when their line of direction (a line 

 which unites the superior centre of movement to the foot) points ob- 

 liquely downward and backward. Inclined in an inverse direction 



