In the first chapter of his work, Fauchard speaks “of the structure, position, and connection of the teeth; of their origin and of their growth.” He distinguishes in each tooth a body, a root, and a neck, making the remark, however, that this last is to be considered as forming part of the body. According to the author, the name of “crown” can only be applied suitably to the body of the molar teeth, but not to that of the incisors or of the canines, which has no resemblance with a crown. Although in the adult the number of the teeth is normally thirty-two, it may be that some persons have, nevertheless, thirty-one, thirty, twenty-nine, or even only twenty-eight teeth, and this independently of any eventual loss, but for the simple reason that the wisdom teeth are often cut very late in life (even after fifty years of age), or do not all come forth, or sometimes are never cut at all. The author refers to some cases of a supernumerary tooth situated in general between the two superior central incisors and similar in form to the lateral incisors. He also observed two individuals who had each thirty-four teeth, sixteen in the lower and eighteen in the upper jaw, and in these cases the two supernumeraries were situated behind the incisors. Fauchard declares the popular opinion expressed also by some ancient authors, of the milk teeth having no roots, to be false. The roots of these teeth, he says, are gradually worn away before the latter are shed, when the permanent teeth are just on the point of coming through; however, if it so happens that one or more of the milk teeth be extracted some time before the period in which they are usually shed, their roots are found to be as long and as strong in proportion to the body as those of the permanent teeth. In children one finds, besides the twenty deciduous teeth, the germs of the thirty-two permanent ones, for which reason it may be said that children have in all thirty-two teeth without counting the germs that may sometimes be found at the extremities of the roots of the large molars. As, however, the existence of such germs is an exceptional fact, the twelve large molars, if extracted, are not ordinarily regenerated. This may be possible, however, if the germs in question exist, and, indeed, the author observed two persons in both of whom a large molar had been regenerated in the place of the one which had to be extracted.