The rate of mitosis and the probability of the plane of mitosis have been determined for every cell of the cap meristem. of Zea. Overall rates decrease from the central files outwards and from the proximal to the distal tiers. This also applies to transverse divisions, but highest rates in the longitudinal plane occur nearer the periphery of the proximal tier. All the cells show some probability of dividing in both planes and the transition from predominantly transverse divisions at the axis to mostly longitudinal divisions near the periphery is smooth.
The meristem is very sensitive to the way the plants are treated not only in the aggregate rate of cell production, but also in the disposition of cell production across the meristem.