FIGURE 1 FIGURE 2 . . Enamel . « Dentine .. Enamel . , Dentine PHOTOMICROGRAPHS show cross-section contrast be- tween a hypoplastic tooth (Fig. 1) and a well-calcified tooth (Fig. 2). In former, note roughened, pigmented enamel and dentine honeycombed with minute interglobular spaces— inviting bacterial invasion. Calcification is now known to depend on adequate vitamin D in the diet—at ail ages. mann’s Yeast assures helps the mother maintain an adequate reserve of calcium and phosphorus, so essential in arresting the onslaughts of caries in her own teeth and in laying the foundation for well-formed, uncrowded teeth in the child. The fetal teeth begin to form in the seven- teenth week of pregnancy. From then until the end of the nursing period, the child’s tooth for- mation depends entirely on the mother. Even after weaning, the beneficial effects of a reserve store of vitamin D acquired from the mother during lactation may be observed. Helps Child Tooth and Jaw Formation The structure of the permanent teeth is, of course, influenced to a large extent by the early calcification of the deciduous teeth, in which the mother’s diet during pregnancy and lactation was such an important factor. It has now been demonstrated (as reported in