Fine structure of cellulose microfibrils in poplar gelatinous layer and Valonia

Summary Fine structure of cellulose microfibrils in poplar (Populus euramericana) gelatious layer and Valonia cell walls was observed in the electron microscope by using disintegration and ultrathin section techniques with various electron stains. Staining of the gelatinous layer in poplar showed that the microfibrils had a paracrystalline region surrounding a crystalline core, but such a region was negligible in Valonia. From the facts that kinks and shortened microfibrils were observed after mechanical and hydrolysis treatments, respectively, and that the microfibrils were unaffected by negative staining, it was concluded that the microfibril core is uniformly crystalline in the longitudinal direction although there may be some crystalline dislocations.The authors are indebted to Dr. Y. Yokohama (Marine Biological Laboratory, Tokyo University of Education) for supplying the samples and to Mr. Y. Tachida (Sanyo-Kokusaku Pulp Co.) for the technical assistance of the glow discharge apparatus.