. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. four years; four teeth hare been shed and renewed. (After Youatt.) Fin. five years; all the incisors have been shed and re- newed; the middle pair much worn. (After Youatt.) ally obliterated in the first, or mid-incisors, at the sixth year ; in the second incisors at the seventh year, and in the third, or outer incisors, in the eighth year, in the lower jaw. It remains longer in those of the upper jaw, and in both the place of the " mark " con- tinues for some years to be indicated by the dark-coloured ce
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. four years; four teeth hare been shed and renewed. (After Youatt.) Fin. five years; all the incisors have been shed and re- newed; the middle pair much worn. (After Youatt.) ally obliterated in the first, or mid-incisors, at the sixth year ; in the second incisors at the seventh year, and in the third, or outer incisors, in the eighth year, in the lower jaw. It remains longer in those of the upper jaw, and in both the place of the " mark " con- tinues for some years to be indicated by the dark-coloured cement, even to about sixteen years old. At this period the worn summits of the incisors present a subtriangular form. The canine teeth are small in the horse, and rudimentary in the mare ; the unworn crown is remarkable for the folding in of the anterior and posterior margins of enamel, which here includes an extremely thin layer of dentine. The representative of the first premolar in the first set of teeth is a very small and simple rudiment, and is soon shed. The three normal premolars are as large and complex as the true molars, the anterior one being usually the largest of the series in the upper jaw. Salivary Glands. — The salivary apparatus in the Solipeda is very extensive, perhaps more so than in any other class of quadrupeds, con- sisting of large glandular masses divided into numerous lobes and lobules of a pale colour, and but loosely connected together by cellular tissue. The Parotid Glands in the horse constitute a secreting apparatus, the bulk of which is extremely remarkable. Each of these glands extends from the external meatus auditoreus along the side of the head and of the lower jaw, as far forwards as the masseter muscle, and at the same time stretching deeply in- wards as far as the side of the trachea. This enormous glandular organ may be considered as composed of three principal portions : each furnishing its excretory duct, which, however, soon unite t
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