Horses' teeth : a treatise on their mode of development, anatomy, microscopy, pathology, and dentistry; compared with the teeth of many other land and marine animals, both living and extinct ; with a vocabulary and copious extracts from the works of odontologists and veterinarians / by William H. Clarke.

  • Clarke, William H.
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Horses' teeth : a treatise on their mode of development, anatomy, microscopy, pathology, and dentistry; compared with the teeth of many other land and marine animals, both living and extinct ; with a vocabulary and copious extracts from the works of odontologists and veterinarians / by William H. Clarke. Source: Wellcome Collection.

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    of compartments or cells, and extremely minute tubes. The earthy particles have a twofold arrangement, be- ing either blended Avith the animal matter of the in- terspaces and parietes of the tubes, or contained in a minute granular state in their cavities. The density of the dentine arises principally from the proportion of earth in the first of these states of combination. The tubes contain, near the formative pulp, filament- ary processes of that part, and convey a colorless fluid, probably transuded ‘plasma.’ They thus relate not only to the mechanical conditions of the tooth, but to the vitality and nutrition of the dentine. This tissue has feAV or no canals large enough to admit capillary vessels with the red particles of blood, and it has been therefore called ‘ unvascular dentine.’ “ Cement ahvays closely corresponds in texture vvd th the osseous tissue of the same animal; and AvhencA'cr it occurs of different thickness, as upon the teeth of the horse, sloth, or ruminant, it is also traversed, like bone, by vascular canals. When the osseous tissue is excavated, as in dentigerous vertebrates above fishes, by minute radiated cells, forming, with their contents, the ‘ corpuscles of Purkinje,’ these are likewise present, of similar size and form, in the cement, and are its chief characteristic as a constituent of the tooth. The hardening material of the cement is partly segregated and combined with the parietes of tlie radiated cells and canals, and is partly contained in disgregated granules in the cells, which are thus rendered Avhite and opaque, vieAved by reflected light. The relative density of the dentine and cement varies according to the proportion of the earthy material, and chiefly of that part Avhich is combined Avith the animal matter in the Avails of the cavities, as compared Avitli the size