title: Perspective on Function of Free Space in Ion Uptake by Roots.
abstract: An observed effect of longitudinal flow rate through corn roots on phosphate transport is shown to be inconsistent with diffusion theory. R. C. Smith's results confirm rather the existence of a diffusion barrier between the xylem and the free space external to the central cylinder of the root.
authors.forename: L
authors.initials: L
authors.lastname: Bernstein
authors.forename: W R
authors.initials: WR
authors.lastname: Gardner