Spontaneous Movements in Plants Studied as a Random Walk Process

A theory to describe spontaneous curvatures performed by different plant materials on the clinostat is put forward. The movements are proposed to follow the assumptions of a random walk process (statistically randomly distributed movements) and thus to give curvatures following the equations E(α) = 0 V(α) = constant * time where α is the curvature from the starting direction, E(α) is the expectation of α and V(α) is the variance ofα. These equations are experimentally shown to be valid for Lepidium roots and Helianthus hypocotyls. Results for roots reported in the literature are recalculated and are shown to support the theory.