THE HORSE. 695 



In aged horses this mark disappears altogether, owing to the wearing down of the tooth 

 below the extent of this enamel fold. This occurs in the lower mid-incisor when the horse 

 is six years of age, in the next pair at seven, and the outer pair at eight years. This 

 &quot;mark &quot; remains considerably longer in the upper teeth. 



The grinding teeth are long, and have heavy, square crowns composed of enamel, den 

 tine, and cement intermingled, so that when worn down they present an uneven and ridgy 

 surface, owing to the enamel and dentine being so much harder than the cement. There are 

 two sets, the temporary or milk teeth, which are the first, and the permanent teeth which 

 succeed them. The canines are wanting in the colt, and generally in mares, as previously 

 stated. The following facts relative to this subject are derived mainly from Youatt s noted 

 work on the horse. 



The germs of the teeth are visible in the jaw seven or eight months before the birth 

 of the foal. At the time of birth, the first and second grinders have made their appearance, 

 and seem very large in proportion to the size of the jaw. &quot;When the colt is seven or eight days 

 old, the two center nippers or incisors appear at the end of the jaw. During the first month, 

 the third grinder appears on the upper and lower jaw, and soon after, and usually by or 

 before six weeks have expired, another incisor comes by the side of the first two, on each 

 jaw. When the colt is two months of age, the center incisors or nippers will have grown 

 their full length, and between the second and third month the second ones attain the same 

 level. Between the sixth and ninth month another pair of incisors appear by the side of the 

 others, making six on each jaw, after which the only apparent difference in these teeth, 

 until between the second and third years, is in the wear. At six months of age, the four 

 incisors are worn to a level. 



At the Expiration of the First Year, or shortly after, a fourth grinder is seen, and 

 the colt then has six nippers and four grinders in each jaw, above and below, which will enable 

 one to determine its age at this period. When it has attained the age of a year and a half, 

 the mark in the central incisors will be considerably shorter and fainter; that in the two 

 other pairs will be somewhat changed, and all of them will be worn flat. 



At Two Years this change will lie still more apparent. When about this age a* fifth 

 grinder will be seen, and the new process of shedding the milk or temporary set commences. 

 The necessity of this is readily seen, since the first set are only adapted to the size of the jaw 

 and necessities of the colt, but as these bones expand with the increased growth of the animal 

 the teeth become separated too far apart from each other to be useful, and a larger set 

 will be required to occupy the space, and also to meet the demands of the system. 



By the gradual growth and pushing up from below of the permanent teeth, the fangs 

 of the first set are absorbed until the second teeth are near the surface of the gum, when the 

 former drop out. When the second teeth appear by the side of the first, they will be 

 absorbed partially their entire length, will become narrow, and will be pushed out of place. 

 These should always be drawn to give the permanent teeth room, and to prevent injury to 

 the mouth or cheek, which sometimes happens if this is neglected. 



At this period the colt should be fed cut or mashed feed, as he will be liable to find 

 difficulty in eating. 



At Three Years of Age the sixth grinder is generally through, or if not, its appear 

 ance is indicated by the swelling of the gum at that point. 



From three and a half to four years of age, the central nippers will have reached nearly 

 their full growth, the second pair will just be making their appearance above the gum, or a 

 space will be left where the first ones stood. The corner ones will be greatly diminished in 

 breadth, and worn down so that the &quot;mark&quot; will be small and faint. At this time, the 

 second pair of grinders will also be shed. 



