Submicroscopic Structure of the Cellulose in the Cell-Walls of Spirogyra and Nitella

The cellulose structure of the cell-walls of Spirogyra setiformis and of Nitella mucronata was studied by means of the electron microscope. In Spirogyra the main direction of orientation of the microfibrils is axial on the outer surface and transverse on the inner surface, which is in line with growth according to the multinet theory. The transverse walls have a random microfibrillar orientation and differ from transverse walls from filaments of land plants in the lack of plasmodesmata. In Nitella the outer surface of the cell-wall shows a pre-dominant axial orientation of the microfibrils. This is in line with the findings of others who used other species and with multinet growth.