to be excitatory transmitters and 7- aminobutyric acid, glycine, taurine, and alanine are thought to be inhibitory neurotransmitters. Contractile protein or fibrils in the vacuole membrane may be activated by an ATP-ATPase system and calcium efflux, which in turn is metabolically activated, presumably through ions or amino acids, by the initial stimulus. The movements for contraction are chain like in mimosa like that of animal