The secondary tongue of Salamandra salamandra: histochemical and ultrastructural aspects of the developing lingual epithelium.

The development of the lingual epithelium of Salamandra salamandra was investigated with emphasis on histochemical and ultrastructural aspects. The temporal and spatial occurrence and the typical appearance of various cell types; i.e. pavement cells, replacement pavement cells, basal cells, mitochondria rich cells, goblet cells and glandular cells have been analysed and documented in detail from the young larval stage up to the metamorphosed animal (2 months after metamorphosis). It is shown that anatomical re- and de novo-constructions related to the formation of the secretory tongue led to distinct changes in the cellular equipment of the epithelium of the tongue, including various histochemical properties. Finally, functional aspects of the morphological characteristics are discussed in detail and compared with respective findings in other species.