The horse having completed his fifth year, will have a black cavity in every tooth _above_ and _below_: but the inner edge of the five year old tooth at the corners, is not completely grown up till the last half of the sixth year, as may be seen by a reference to the Plate, Fig. 3; "_Rising Six_." When the horse is about four or five months beyond his sixth year, which is called _six off_, the black mark in the centrical teeth fill up by degrees; those standing next, fill up next in the same way; and in faint succession one pair to the other, till, at the seventh year, (when the horse is said to be _aged_,) the mark is fairly retained in only the corner teeth, which continues to decline during the year, and is generally obliterated by the time the horse is eight years old. The tushes begin to appear about four, or between that and the fifth year; they display themselves one above and one below, on each side, at a little distance from the corner teeth, without having been preceded by any colt's teeth in _that spot_ since they were foaled. After a horse is eight years old, his age can only be guessed at by the length, and worn edges, of his teeth; which may always be nearly ascertained by any person a little accustomed to the examination. TENDONS—are the elastic covering of the muscles, composed of an infinity of fibres, which, in their aggregate, form a substance of great strength, and appropriate contraction and elongation, for all the purposes of expansion and flexibility. The tendons in a horse most liable to injury and accident, are those passing down the shank-bone of the fore-legs, from nearly the back of the knee, to their seat of insertion at the fetlock joint, which are in general known by the name of the _back sinews_. These, and the accidents to which they are liable, have been so fully treated on under the heads of LAMENESS and SPRAINS, that enlarging here would only prove a repetition superfluous and unnecessary. A wounded or punctured tendon, by thorn, stub, stable-prong, or with any other instrument, is always attended with excruciating pain, and violent inflammation, producing the most dangerous symptoms. In such cases it has been too much the practice to have immediate recourse to turpentine, and other spirituous applications, which is only adding _fuel_ to the FIRE, and rendering the _remedy_ worse than the DISEASE. Warm, mild fomentations, emollient poultices, gentle digestives upon lint covered with tow, and recourse to the most judicious and experienced practitioner to be obtained, constitute the only sound basis upon which even _hope_ of recovery can be entertained; as most cases of the kind, if serious and severe, have a very unfavourable termination; those few subjects who seem completely restored, being ever after incapable of any work of consequence, ranking only as invalids.