31. _Some judges depend upon the tushes as indicative of the age_, and taken in conjunction with the other parts they afford corroborative evidence; singly, however, they should not be relied upon, nor should too much weight at any time be placed upon their appearance. In the first place, the tushes are cut irregularly; they may appear in the mouth between the second and third, and they may not pierce the gums so late even as the eighth year; the periods named being of course the extremes. As a general rule, however, they come up between the fourth and fifth year. The custom, however, which Nature so frequently disregards, can afford no positive guide to the judgment, and the wear which may begin thus early or late, should not be too particularly insisted upon. The tushes when they first show are shaped somewhat like a spear head, smooth and rounded on their external surfaces, but grooved on the side which touches the tongue, pointed at their extremities, and sharp at their edges. The inclination of the young tush is oblique, standing forward, and the situation is comparatively near to the incisors. As the animal's age advances, the tushes retract, the grooves on the inner surfaces wear out, and the space which separates them from the incisors increases: all observations, however, concerning the tushes, must be accepted with much allowance, for these teeth are very irregular. As a general rule, the lower tush becomes blunt, or rounded at its point and edges, and also of considerable length, while the upper is often so diminished as to be worn almost to the level of the gum. In stallions, kept only for service, the lower tush, however, frequently attains a great length, presenting the appearance depicted in the coloured engravings of the mouths at twelve and sixteen years. In those plates, the reader will observe the tushes no longer point in a forward direction, but have a decided inclination outward, and somewhat backward also. Another indication of extreme age is also worthy of notice, although, if too absolutely relied upon, it may occasionally mislead. Tartar, not generally found in any quantity upon the other teeth in the horse, accumulates around the tush, and in very old animals almost conceals it. This excessive deposit I have rarely observed in horses of moderate age.