Cell wall texture and cortical microtubules in growing staminal hairs of Tradescantia virginiana

Cell wall texture and orientation of cortical microtubules of staminal hairs of Tradescantia virginiana were studied. A new method for determining of the microfibril orientation was applied. On the outer surface of the cell wall the microfibrils undergo a shift from preferentially transverse in young cells to preferentially axial in older cells. On the inner surface microfibrils are deposited in transverse direction throughout the growth period of the hair. The same applies to the cortical microtubules. The results are in agreement with the multinet growth hypothesis of Roelofsen and Houwink.