. Elementary text-book of zoology. Zoology. hoof -like nails. They all feed on vegetable, usually hard substances,. especially on stalks, roots, seeds, and fruits. Only a few are omnivorous. There are two large chisel-shaped, somewhat curved incisors (tig. 696), which possess enamel only on their anterior surfaces. The posterior surface is, therefore, quickly worn away by use, and the more so since the arrangement of the narrow, laterally compressed glenoid cavity necessitates an antero-posterior movement of the lower jaw during mastication. The wearing away is compensated by a proportionate,
. Elementary text-book of zoology. Zoology. hoof -like nails. They all feed on vegetable, usually hard substances,. especially on stalks, roots, seeds, and fruits. Only a few are omnivorous. There are two large chisel-shaped, somewhat curved incisors (tig. 696), which possess enamel only on their anterior surfaces. The posterior surface is, therefore, quickly worn away by use, and the more so since the arrangement of the narrow, laterally compressed glenoid cavity necessitates an antero-posterior movement of the lower jaw during mastication. The wearing away is compensated by a proportionate, continous growth of the tooth. The "Tinders, which are separated from the incisors by a wide gap, possess usually transversely arranged folds of enamel, and are only tubercula- ted when the animal is omnivorous. When these teeth are being used the lower jaw is drawn so far back that the incisors are not rubbed one another, and the lower jaw is moved backwards and FIG. 696.—Skull of Cncettts rnt;/(iris (after Giebel; Broim's Classen und Ordnuug- en).. 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 Claus, Carl, 1835-1899; Sedgwick, Adam, 1854-1913; Sinclair, F. G. (Frederick Granville), b. 1858. New York : Macmillan
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1884
