抄録
During the course of the study on the developmental process of oral cavity in the human embryo, the authors found unexpectedlly an epithelial pearl appearing in the Lamina propria of P. vallatae in the human embryo 9 and 10 months old. The results were summarized as follows. 1) The epithelial pearl in the 9 month embryo showed the typical features with its longitudinal diameter of 510 micron, and its width of 430 micron. 2) On the histological finding of the epithelial pearl. The outer layer consisted of one or two layers of columnar epithelail cells, and within it, there appeared a concentric circle of very thin squamous cell layer, and a part the center is degenerated to horny or corneous layer with scattering nuclei, and another part to the so-called chylous condition.
