The macronucleus is central, and the contractile vacuole posterior and terminal.
They are contractile, and propagated by spontaneous division, or fission.
contractile vacuole, single or double, usually connected with a sac-like reservoir.
The polype is remarkable for the protrusion and contractile power of its lips.
The contractile vacuoles are quite varied and from one to many in number, the number increasing with the size of the individual.
For some hours after death the limbs retain their contractile power.
The contractile wave may be blocked by poisons in another way.
There is one central nucleus and usually one contractile vacuole.
The macronucleus is almost central; the contractile vacuole posterior.
The contractile vacuole is close to the base of the flagella.
contractile con·trac·tile (kən-trāk'təl, -tīl')
Capable of contracting or causing contraction, as a tissue.