The next indication of advancing age is given by the gums growing more vascular, even now looking inflamed, while a yellow deposit (the nature of which is not well understood) may be seen upon the neck of the tooth, and the central incisors of the upper jaw, if felt, may probably be found loose. In another or about the sixth month, one of the central incisors is removed. It does not fall out, as is generally stated, but while the animal is feeding, the tooth is, as by accident, wrenched off. The gum bleeds, and being slightly lacerated, looks sore and angry for some time. The sharp edge of the new brown-coated permanent incisor is now seen protruding. In a week or two the remaining milk central incisor of the upper jaw is, by a seeming accident, forced out; and the mouth now has an irregular appearance, the edges of the upper central incisors not being level with the tables of the lateral milk teeth. The lower central incisors, when the upper milk teeth are lost, generally are loose, and their gums inflamed; but a month or sometimes six weeks may elapse before these are gone: by that time the upper permanent teeth have grown considerably. When the central milk incisors have disappeared, the molars begin to change, and those of the upper jaw are the first uncovered; not in any regular order, or the two teeth on the same day, but generally the first molar before the second, the wolf's teeth mostly departing at the same time. A week or two subsequent, the first two permanent molars of the lower jaw are laid bare, so that at or about the ninth month, the horse has all those teeth, which denote the animal to be three years old, fairly in the mouth; that is, he has between the second and third year cut four horse incisors and eight permanent molars. Lest the description should not be perfectly clear, or such as to enable the reader to readily understand which teeth by this time are shed, a drawing of the head of an adult animal, which forms the frontispiece of this work, was designed. It will enable the reader to form some notion of the extent of the horse's mouth and likewise of the positions of the teeth. Near to the teeth will be seen figures which do not denote the periods when these organs first appear, but the time at which they are fairly up, or to some extent exhibit wear. In that engraving no further notice is taken of the milk teeth than is conveyed by the small star associated with such of the figures as indicate the places from which they have been displaced: thus the figures 1, 2, and the last 4, having no star, indicate that those molars are developed only as permanent teeth. The figures 3*, 3*, 3*, having stars, denote that milk teeth originally occupied the situations where these teeth are shown: those figures will be seen above and below the central incisors and the first two molars of either jaw; and as but one side of the face could be displayed, of course the number has to be doubled, the colt