[Ultrastructural study of the dogfish mature egg-capsule gland zones secreting proteic and glycoproteic material (author's transl)]. / Etude ultrastructurale des zones à sécrétions protéiques et glycoprotéiques de la glande nidamentaire de la roussette, à maturité.

The ultrastructural study of the zones (D, E, F1) of a dogfish mature egg-shell gland secreting proteic and glycoproteic material brings evidence of a wide range of secretions. Besides the two types of grain found in each of the two zones D and E (respectively spiralled and heterogeneous) a second type of heterogeneous grain as well as a fourth one composed of tiny dense particles are present in zone E. A fifth type of grain is revealed in zone F1. The Golgi apparatus is undoubtly involved in the formation of F1 grains and of both heterogeneous grains, but seems to be irrelevant to zone E secretion of dense grains. As regards spiralled grains there is no evidence of the first stage of their formation in the mature gland. After this first ultrastructural study, the grains specifically involved in the formation of the collagenic protein cannot yet be positively identified.