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A course of lectures on dental physiology and surgery. Delivered at the Middlesex Hospital School of Medicine / [Sir John Tomes].

  • John Tomes
Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: A course of lectures on dental physiology and surgery. Delivered at the Middlesex Hospital School of Medicine / [Sir John Tomes]. Source: Wellcome Collection.

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    to approach each other; by this combination of movements, the animal saws the three-lined wound with which we are most of us familiar. In many insects hard horny plates occupy the oral orifice, and perform the office of incisor teeth, while the cesophagus is provided with short strong teeth, which perform the function of molars, as instanced in the grasshoppers and others. The proventriculus in all mandibulated insects is armed with nu- merous horny teeth, which vary in form, number, and arrange- ment, in the different species; some being flat, others corru- gated on the surface, and some conical and recurved. In structure the teeth of insects are similar to the external skeleton *. In the division mol/usca, of which the common snail is a member, we have a flat curved plate for incising, with which the creature divides the vegetable matter upon which it feeds. In the same order some of the vegetable-feeding species are furnished with dental organs in the stomach. In fishes the teeth are implanted in the vomer, in the palate, and pharyngeal bones, in the branchial arches, and os hyoides, as well as in the maxillary and inter-maxillary bones. In the mammalians the dental organs are alone found arranged in single lines in the maxillary and inter-maxillary bones. Thus we find, by examining various members of the animal kingdom, teeth occupying every point of the anterior part of the alimentary canal. | Teeth are used either as organs for the mastication or pre- hension of food. They are also used as organs of offence and defence, and sometimes aid slightly in locomotion, and in man assist in articulation; but these latter may be considered as accessory uses only. It admits of question whether the bills of birds should be regarded as dental organs; the evidence seems in favour that they should, since they are situated at the anterior orifice of * BurmistEr’s Lntomology.
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