An experimental study was performed to observe the epithelial-mesenchymal interacion in the developing odontogenic tissue of 10-18 days rat embryos. Several results were obtained with the histochemical study of this experimentss.
1. Through invagination of dental lamina, P A S mucicarmine staining of middle and basal cells was shown to have weak reaction. but in mesenchymal cells, these staining was reacted with diffus form.
2. In accordance with the differentiation of enamel organ, these odontogenic tissue was being to form mesenchymal condensation, it was alse shown that the intermesenchymal cell was stained deeply with colloidal iron and alcian blue.