. Text book of zoology. Zoology. 486 Vertehrata. young animals it is scarcely indicated; the enamel (except in teeth growing from persistent pulps) appears to be completely developed only when the tooth comes into use. Before falling out, the milk teeth are usually absorbed to a certain extent in the lower portions by special cells lying in the sun-ounding connective tissue. The number of teeth will be indicated here according to the following plan: i I (= 3 incisors above, 2 below on each side), c i (= 1 canine above, 0 below), m f (^ 6 molars above, 5 below), or pm f (=: 3 premolars above, 3
. Text book of zoology. Zoology. 486 Vertehrata. young animals it is scarcely indicated; the enamel (except in teeth growing from persistent pulps) appears to be completely developed only when the tooth comes into use. Before falling out, the milk teeth are usually absorbed to a certain extent in the lower portions by special cells lying in the sun-ounding connective tissue. The number of teeth will be indicated here according to the following plan: i I (= 3 incisors above, 2 below on each side), c i (= 1 canine above, 0 below), m f (^ 6 molars above, 5 below), or pm f (=: 3 premolars above, 3 below), m f (^ 3 molars above, 2 below). If the actual teeth present are to be expressed, the following formula is used, the signs above the line indicating the teeth of the upper jaw, those below, those of the lower jaw: P" P' Some of the Mammalia are altogether edentulous^ but where this is the case with the adult {, Whale-bone Whale) teeth may- have been present in embryonic life; or even in youth, such are, however, never cut; they are absorbed. The presence of an upper and a lower lip is characteristic of the Mammalia. These are large, muscular folds of skin covering the edges of the jaws and continuous with each other laterally; #''f"^*^-V. tn hg. Fig. 396. Longitudinal section through the head and neck of a Dog, decreased. b hyoid, e opening of eustachian canal into the pharynx, g train (only suggested), h frontal sinus, hg hard palate, Tc epiglottis (lies above the edge of the soft palate), I lyssa {cf. foot note, p. 487)), m turbinals, p anterior, p' posterior edge of the pharynx, r spinal cord, s vocal cords, sp CBSophagiis, t tonsil (see foot note, p. 487), tr trachea, v soft palate, z tongiie, 2 axis, 4 fourth cervical vertebra.— Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original wor
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1896
