Fig. 6.

Ovotestis of younger snails. (A) Thin elongated periacinar cell (white arrow), located close to the acinar outer wall (black arrow). The tip of the threads is either free or connected to the developing spermatogenic cells. (B) Enlarged view of interacinar portion showing acinar boundary and RER. (C) A part of interacinar space showing membrane-bound vesicles. (D) Cytoplasm of periacinar cell possess RER stack (arrow) and membrane-bound secretory vesicles. Note the fibrous junction between periacinar cell and acinar boundary. Arrow head indicates a portion of nucleus of a spermatogenic cell. (E) Associations of periacinar cell and its surroundings with fibrous structures (white arrow).

ad = acinar boundary; RER = rough endoplasmic reticulum; sd = spermatid.