These studies represent investigations to determine ionic and hormonal mechanisms responsible for motor movements Mimosine, an alkaloid found in these species, which was proposed in these studies to be in part responsible for movement, was administered in rico. Plants were also treated with agents known to disrupt either K efflux(tetraethylammoniumchloride), Na +,K adenosine triphosphatase(ouabaiuk or Ca influx(verapami) to determine the ionic species involved in the tactile response of the Mimosu. Additionally, the alpha and beta adrenergic receptor blocking agents were also used. All the ionic blockers employed produced a slower response movement, as well as growth retardation. Phentolamine inhibited leaflet closing, but propranolol had