. American animals: a popular guide to the mammals of North America north of Mexico, with intimate biographies of the more familiar species. Mammals -- North America. Sections of Teeth. i An incisor or tusk of Elephant, with open pulp cavity at base. 2 Human molar with broad crown and two roots 3 Molar of Ox, showing deeply folded enamel surface with cement filling up the depressions. (After LYDEKKER). A tooth grows from a soft "pulp" and in its early stage is open at the base, the cavity being occupied by the pulp. Some teeth remain this way and continue to grow on indefi- nitely wh
. American animals: a popular guide to the mammals of North America north of Mexico, with intimate biographies of the more familiar species. Mammals -- North America. Sections of Teeth. i An incisor or tusk of Elephant, with open pulp cavity at base. 2 Human molar with broad crown and two roots 3 Molar of Ox, showing deeply folded enamel surface with cement filling up the depressions. (After LYDEKKER). A tooth grows from a soft "pulp" and in its early stage is open at the base, the cavity being occupied by the pulp. Some teeth remain this way and continue to grow on indefi- nitely while they wear away more or less at their tips. Such are the tusks of elephants and the incisor teeth of rats and other gnawing animals. Other teeth, on the contrary, gradually close up at the base, forming one or more roots or fangs, the rem- nant of the pulp being contained in the inside of the tooth. Such teeth do not increase in growth after the roots are formed. The substances that make up teeth are three: (i) dentine or ivory which forms the bulk of the tooth, (2) enamel, a very hard bluish-white substance which covers the outer surface, and (3) cement, a bone like substance which fills up the cavities. 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 Stone, Witmer, 1866-1939; Cram, William Everett, 1871-. New York : Doubleday, Page & Co.
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License: Licensed
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1904
