[Characteristics of the follicular epithelium in the fishes with demersal roe. Concerning the classification of unilaminate monomorphous follicular epithelium of the vertebrates].

Follicular epithelium of Hemichromis during the periods of small and slow oocyte growth changes from flattened prismatic into high prismatic; during the periods of fast oocyte growth, the follicular epithelial cells undergo secretory specialization. Secretion is of apocrine type and forms the second oocyte tunica. According to the literature data analyzed and the author's investigation, in the development of unilaminate monomorphous follicular epithelii, it should be distinguished: a) period of primary transformation with characteristic intensive proliferation of epithelial cells, their morphologic transformation, upward growth of epithelium and increase of its physiological activity; b) period of secondary transformation either at the expense of secondary follicular epithelial flattening, or by means of secretory specialization of its cells. It is suggested to name unilaminate monomorphous follicular epithelii in vertebrates according to their construction at the end of the primary and by the character of the secondary transformation. Thus, follicular epithelium of Hemichromis can be defined as highly prismatic with secondary specialization.