6. _The description of the teeth_ cannot be rendered pleasing; but as it is a necessary part of the subject, the reader must exert his patience, while the matter is briefly discussed. Teeth are anatomically classed with bones, which in many respects they resemble. A tooth is divided into two parts, or into _crown_ and _fang_. The _crown_ is that portion which projects above the gum into the mouth; therefore so much as can be seen while the animal lives, is the crown of the tooth. The _fang_, the end of which is called the _root_, is that part of the tooth which is hidden from view, and is inserted into the jaw. For the convenience of description, however, other portions of the tooth have received distinct names, and the _neck_ and _table_ are spoken of. The neck is that portion of the tooth which is immediately surrounded by the gum. The _table_ is the upper surface, or the part which touches the corresponding tooth of the opposing jaw when the mouth is closed. Such is the division made, and it will hereafter be found to assist the description of the various changes which the teeth undergo. 7. _The teeth are situated_ in the maxillary bones, in which certain osseous cups, like indentations or holes, called the alveolar cavities, are developed for their reception. Each tooth has its separate cavity, and however close the crowns may appear, nevertheless each fang is divided from those before and behind by bony plates. The alveolar cavity always corresponds to the fang. As the fang alters in form, or diminishes in length, so does the shape of the cavity simultaneously change; and should the tooth be removed, the space, no longer needed, is filled up; the alveolar cavity being obliterated by a growth of bony matter. 8. _Teeth are organised_, that is, they possess nerves, arteries, veins, and absorbents, or are endowed with those vessels needed to resist decay, and to promote nutrition. That a tooth possesses nerves, no one who has submitted to have these members filed by the dentist, or who has endured the tooth-ache, can for an instant doubt; and that they are even, in some degree, susceptible of external impressions, the sensation produced by certain acids seems to render probable. The growth they exhibit shows they are gifted with arteries and veins; and these vessels can be traced directly to and from, though not unto, their substance. The existence of absorbents some have doubted; but the removal by nature of the fangs of the temporary teeth, clearly testifies the presence of these vessels.