Crystallite Features of Valonia cellulose by Electron Diffraction and Dark‐Field Electron Microscopy

Individual cellulose crystallites from the cell wall of Valonia ventricosa have been studied by electron diffraction and observed by dark‐field electron microscopy. These two techniques reveal that the crystalline zones which run along the fibrils are above 1000 Å in length without any longitudinal periodicity. The width of the crystallites covers the width of the microfibrils and ranges from 140 to 180Å without persistent 35 Å subunits. In several instances, the crystalline zones terminate in the manner of a fork with two arms of 30 to 40 Å in width.