Illustrating this subject is the annexed figure of a horse which has been hurt upon the off fore foot; the figure is supposed to be desirous of progressing, or to be in the act of bringing the hind limbs forward. The entire weight having for a certain space to rest upon a single support, some time is spent in accurately balancing the body before this action is hazarded. The slightest mistake would necessitate a fall, of which it has been observed the sick horse is endued with a particular dread. Therefore, after a certain time spent in preparation, the legs are, with much muscular exertion, lifted from the ground, and the sufferer hops onward. The wretchedness of the quadruped, however, is not complete until one or both hind legs are implicated. From some hidden cause, the anguish of the animal, great as it may be, is not perfected while the lameness resides in front. The horse, suffering in a fore limb, has even laid on flesh during the period of enforced idleness. But when the posterior extremities are injured, the constitution is involved. The body wastes rapidly, and every fiber within the huge framework seems to quiver with sensibility. [Illustration: THE MANNER OF ADVANCING THE HIND MEMBERS WHEN ONE POSTERIOR FOOT IS INJURED.] If the creature, thus disabled in one leg, is obliged to advance, the chief difficulty is to so place the sound limb upon the earth that the balance shall not be destroyed. There are the two fore legs to rest upon, and the head to act as a kind of counterpoise; therefore there is little impediment to raising of the trunk; but the obstacle consists in the peril to be surmounted when the sound member reaches the ground. A certain shock has then to be sustained, and the fear apparently is lest the slightest want of preparation should bring the body to the earth. [Illustration: A HORSE, HAVING ONE HIND LEG RENDERED USELESS, BY A SUDDEN EFFORT ADVANCES THE FORE LIMBS.] The next motion delineated necessitates the greatest care and the mightiest exertion. There are several signs which declare such to be the case. To advance the two sound fore legs is an effort of despair always preceded by a pause. During the time the feet are from the earth, the entire weight, unrelieved by the slightest counterpoise, must be supported by one sound limb. The muscles on that side have to raise the trunk, or to perform double labor, for the step invariably is a species of leap. The body has not only to be lifted, but the strain must be maintained to continue or rectify the balance. A pause of more than ordinary length declares the magnitude of the approaching struggle. The teeth are clinched; the head is thrown backward; a deep inspiration is inhaled; the muscles are powerfully excited; and, with a spasmodic suddenness, the feet are projected onward.