. History of Hereford cattle : proven conclusively the oldest of improved breeds . Hereford cattle. <ir2o 6. CALF'S TEETH AT 11 MONTHS. tooth. permanent space. "At the age of six months the fourth molar is well developed, but it is in close contact with the angle of the jaw, and the posterior sur- face is not quite free from the covering of the gum. "Between six and twelve months old there are no important dental changes, the incisor teeth become worn, and as the jaws increase in size there is more space left between them, but it is not possible to assert from the state of the inc
. History of Hereford cattle : proven conclusively the oldest of improved breeds . Hereford cattle. <ir2o 6. CALF'S TEETH AT 11 MONTHS. tooth. permanent space. "At the age of six months the fourth molar is well developed, but it is in close contact with the angle of the jaw, and the posterior sur- face is not quite free from the covering of the gum. "Between six and twelve months old there are no important dental changes, the incisor teeth become worn, and as the jaws increase in size there is more space left between them, but it is not possible to assert from the state of the incisor teeth whether an animal is under or over the age of one year. (Fig. 7.) "Shortly after one year the fifth molar be- gins to make its appearance, and at fifteen months it is well up. The appearance which the fifth molar presents at this age is very much like that of the fourth molar at the age of six months. The new tooth is in close contact with the angle of the jaw, and the gum covers the extreme posterior part of its surface. "No change occurs in the incisors, except that which is caused by the wear of the teeth and the growth of the jaw, until the age of one year and eight or nine months, at which time the two central teeth are loose, and the first broad teeth sometimes begin to project through the gum. In very forward animals the central permanent incisors are cut at the age of a year and seven months, but they are never level with the other incisors before one year and ten njonths, and their perfect development is in- dicative of the age of two years. "The illustration (Fig. 10) was taken from a Shorthorn heifer at the age of one year and ten months, and may be accepted as indicative of the general appearance of the incisors at that age. "While the first pair of permanent incisors are advancing to take the place of the tem- porary teeth, the sixth and last permanent molars push their way through the gum, and at the age of two years are in position.
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Keywords: ., bookcentury1900, bookcollectionbiod, bookdecade1900, bookyear1902
