ATTITUDES. 439 



cases, is reduced to a triangle, which renders the equilibrium less stable. 

 Nevertheless, if the body remain immobile and the members change 

 their relative positions alternately, it is possible for the horse to pre- 

 serve this attitude for a long time, and even to sleep without being 

 obliged to lie down. 



The anterior members do not alternate with each other in their 

 position. Nevertheless, if the fatigue be great, they are alternately , 

 lifted up and replaced in position by a sort of slow and regular 

 stamping movement, which eases the muscles and gives intermittence 

 to their contraction, that intermittence without which it could not 

 continue. 



As soon as a member becomes tired out, or is the seat of some 

 pathological alteration, it will take longer and more frequent rests, and 

 changes its ordinary direction. It is thus that the posterior limbs are 

 displaced forward, with the foot generally flat upon the ground and 

 the fetlock strongly projected forward, knuckled, as if the muscular 

 system were powerless to maintain the osseous segments in their normal 

 relations (see page 295). The fore-limbs, on their part, seek to deviate 

 from the centre of gravity ; they also incline forward, and sometimes 

 a little outward, in a semi-flexed state, which is vulgarly expressed by 

 saying that the horse points, stands like a dancing-master. 



In forced station, on the contrary, the four members are obliged 

 to support the body, and are symmetrically disposed in each biped in 

 order to receive a proportional share of the body-weight. The base 

 of support is no longer triangular ; it becomes an elongated or shortened 

 parallelogram, according to the direction of the locomotory column 

 in relation to the vertical axis. The distance comprised between the 

 anterior and posterior bipeds is, in this case, equal to three-fourths of 

 the height of the horse. 



As the separation of the two fore-feet is sensibly greater than that 

 of the hind-feet, it follows from this that the polygon constituted by 

 the base of support is, in reality, a trapezoid and not a rectangle, which 

 M. Duhousset has demonstrated. This is a fortunate disposition, the 

 effect of which is to maintain the equilibrium in front, that is to say, 

 at the place where the natural supports of the trunk are more bur- 

 dened and more liable, on account of their proximity to the cervico- 

 cephalic regions, to allow the line of gravitation to fall outside of the 

 base of support. 



Forced standing is always fatiguing, although the body may not 

 execute any apparent movement, because this attitude implies that the 

 muscular contraction is continued without the necessary intermissions. 



