. Text book of zoology. Zoology. Glass 6. Mammalia. Order 6. Proboseidea. 511 common membrane. The snout is produced into a long trunk, bearing tbe nares and, in the Indian Elephant, a finger-like process at the tip; it is a prehensile organ, and conveys food (plants) to the mouth; water is sucked up into it and squirted into the mouth, towards which the tip can be directed. The pinnse are large dependent flaps. The mammse (two) are close to the forelegs. The head is borne upon a short thick neck, and is of colossal size; the cranium small; extensive air sacs in the bones of the head. Incisors
. Text book of zoology. Zoology. Glass 6. Mammalia. Order 6. Proboseidea. 511 common membrane. The snout is produced into a long trunk, bearing tbe nares and, in the Indian Elephant, a finger-like process at the tip; it is a prehensile organ, and conveys food (plants) to the mouth; water is sucked up into it and squirted into the mouth, towards which the tip can be directed. The pinnse are large dependent flaps. The mammse (two) are close to the forelegs. The head is borne upon a short thick neck, and is of colossal size; the cranium small; extensive air sacs in the bones of the head. Incisors absent from the lower, one on each side in the upper jaw; this, in the males especially, is modified to form a long tusk which is curved forwards, and is practically devoid of enamel; it projects some distance from the mouth, and grows continuously throughout life. Canines are absent. The molars are large, with high crowns and short roots; the crown is made up of a varying number of compressed transverse plates coated with enamel, and. Fig. 409. Molar teeth in longitudinal section. A, B different species of Mastodon, C Elephant; diagrammatic, cement removed; d dentine, e enamel, k pulp cavity, r root.— Orig. bound together with an abundant supply of cement. There is never more than one, or at most, two, teeth in use at the same time in each half of the jaw : as one tooth is worn away another comes forward and gradually takes its place; the anterior end comes into use, whilst the posterior part is still within the jaw: it is therefore worn away first, so that at last only the posterior end remains. Altogether sis molars appear in this way on each side; the first to arise being the smallest.* There are only two living species: the Indian Elephant {E. indicus), with the molar-plates numerous and much compressed; with relatively small pinn^ j it is both wild and * The six molars of the Elephant are : dp', df,', dp', m}, m?, m-'; the premolars are wanting in living forms, but rud
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1896
