The fine structure of the dorsal lingual epithelium of the scincine lizard Chalcides ocellatus Forskal (Scincidae, Sauria, Reptilia). I. Histogenesis of the lingual epithelium

Abstract

The purpose of the present study is to illustrate the histogenesis of the lingual epithelium of scincine lizard Chalcides ocellatus from the beginning of the appearance of the tongue at the floor of the buccal cavity to the truly functional tongue. Light microscopic examination revealed that the tongue of the embryo at the first chosen stage, was composed of a lamina epithelialis of stratified cuboidal cells, surrounding a core of mesenchymal cells. A peridermal layer surrounds the lamina epithelialis. A condensation of deeply staining mesenchymal cells was noticed underneath the lamina epithelialis. The interaction between these two layers was discussed in detail. The differentiation of the peridermal layer was studied in detail both by the light and scanning electron microscope. The dissociation of this layer at the chosen late stage before delivery was noticed by the aid of the SEM as ruptured cells cover the surface of the tongue. A few number of macrophage cells was observed also at different stage of phagocytosis. Therefore the light and the SEM findings seem to be complementary. In addition the differentiation of the lingual glands and lingual papillae was observed.


KEY WORDS: Chalcides ocellatus, reptiles, SEM, tongue, histogenesis, peridermis, macrophage.


Egyptian Journal of Biology Vol.3(2) 2001: 12-19