| Abstract: | SYNOPSIS. The adult Tokophrya infusionum does not possess cilia, but has 20–30 barren basal bodies arranged in 6 short rows adjacent to the contractile vacuole pore. During reproduction, which is by internal budding, the contractile vacuole sinks into the parent along with the invaginating membranes that form the embryo and the wall of the brood pouch. The 6 rows of basal bodies radiate away from the pore and elongate to form 5 long ciliary rows, that encircle the anterior half of the embryo, and 1 short row at the posterior end. The contractile vacuole pore, along with several barren basal bodies, remains in the parent when the embryo is completed. The pore rises to the surface when the embryo is born. New basal bodies are then formed in the parent to replace those which were incorporated into the embryo, and formation of another embryo may begin. The cilia of the embryo are partially resorbed 10 min after the start of metamorphosis, with depolymerization of the ciliary microtubules. Later, the cilia and most of the basal bodies disappear completely, except for a group of barren basal bodies near the embryo's contractile vacuole pore, which form 6 rows and serve as an anlage for the basal bodies and cilia that arise during embryogenesis. There is, therefore, an organized infraciliature in Suctoria throughout their life cycle, and a distinct continuity of basal bodies across the generations. |
