will be seen the infundibula are almost gone, a speck alone denotes their latest trace; nevertheless, the next wood-cut, which exhibits the tables at the sixteenth year, will show that the absence of the infundibula is not to be relied upon. Still the advance in age is, though feebly, indicated. The central incisor has assumed a form which is peculiarly characteristic of age in the horse. It is seldom that at sixteen years all the tables take so marked a shape, but some of them, and generally those in the centre, will, at this period, be symbolical of the truth. [Illustration] Had it not been for the very conspicuous indication of the central tables, the others in the former wood-cut might have been reasonably decided to be more juvenile in their aspect. 55. _At twenty years old, the form of the mouth has changed, and the lower teeth are imperfectly seen from the front._ This circumstance springs from the more horizontal direction which the teeth have now assumed, and the acuteness of the angle which they consequently form when closed. The engraving also depicts that alteration in position which disables a person, standing in front, from well seeing both rows of incisors when the lips are separated. When the upper incisors are fairly presented to the sight, a partial view only of the lower teeth is obtained, and as the age advances even that is lost. Further inspection also shows additional changes in position, shape, and tint. The grooves are broad, deep, and well marked by their dark colour. Between the upper incisors there are interspaces in which the food has accumulated and become black, giving to the mouth the appearance represented in the coloured plate. The upper tush, which is now of a brownish hue, may be worn to the gum, and the lower continue long and surrounded by tartar, or both may be reduced to mere stumps. The tongue protrudes greatly; the membrane of the mouth seems hard; and no longer vascular, it is thrown into wrinkles. The edge of the lower jaw is sensibly retracted, and its sides are flattened or narrowed. The general appearance indicates the decay of nature. Here again, however, nothing is positive, save the yellowness of the teeth and the protrusion of the tongue. The general character of the animal is of more value than the indications of the mouth; and, persons familiar with horses can, sometimes by this, guess the age of an animal with the same approach to accuracy, which most people exhibit, when pronouncing the extent of an individual's life, by simply looking at a man's face. In neither instance, perhaps, could the basis of the opinion, which possibly shall approach very close to correctness, be accurately stated. Proof, as to the evidence upon which a conclusion is in such cases based, cannot be anticipated, and to the inquiry how they were able to tell the age, each would probably answer, by the "looks," but neither would be capable of precisely defining in what these "looks" consisted.