AbstractThe contraction ofStentorandBlepharisma, in response to mechanical and electrical stimulation and ofSpirostomumin response to mechanical stimulation is described. All three species respond to electrical stimulation by contraction of the cytoplasm, beginning at the anodal end regardless of orientation of the animal. The differences in contractile ability and shapes during contraction are discussed in relation to body form and microanatomy.StentorandSpirostomumalso respond to mechanical stimulation. Dropping a weight on the slide causes contraction of the whole body ofSpirostomum, but not ofStentor. Stimulation of the oral region ofStentorby means of a vibrating needle causes a contraction of the entire body, but this sensitivity is limited to the oral region.Blepharismadoes not respond to mechanical stimulation.SpirostomumandStentorundergo rapid spontaneous contractions, butBlepharismadoes not contract spontaneously.
展开▼
