抄録
In order to procure thorough knowledge upon the development of an organ, besides the histogenesis and the development of the external form, the growth pattern of the organ should also be taken into account. Up to the present time, most investigators 1) have dealt with the occluso-apical growth of dental germs and that only in regard to the hard tissues, i.e. enamel and dentine. Although the mesio-distal extension of calcified tissue has been measured 2), that of the epithelial part has never been considered. The aim of the present study is, therefore, to decide whether, (in the growth pattern of the incisor and canine germs), the mesio-distal growth of the epithelial part of the dental germs takes place evenly during the course of the fetal period or whether it occurs at certain developmental stages.
