Unusual cell ultrastructure in ventral epidermis of the African reed frog Hyperolius viridiflavus, (Anura; Hyperoliidae).

The stratum corneum of the epidermis of Hyperolius viridiflavus contains several replacement layers. The outer layer is covered by mucopolysaccharide secretion. H. viridiflavus in their dry phase do not moult the sloughed off layers; these remain attached to the stratum corneum. Long and slender pillar-like cells situated under the stratum corneum extend through the stratum granulosum, stratum germinativum, and the basement membrane into the dermis. These cells abound in tonofilaments. Flask-shaped cells rich in mitochondria, reaching under the stratum corneum, extend into the stratum granulosum. They show delicate, membranous infoldings in their neck-like apical part. Granule-cells, arranged in 2 or 3 layers are situated in the stratum granulosum between the stratum corneum and germinativum. The germinative cells are large and separated from each other by wide intercellular spaces. ATPase activity was localized cytochemically in the baso-lateral cell membranes bordering with the intercellular spaces under the stratum corneum.