The fine structure of the collenchyma cell wall.

An investigation of the fine structure of the cell wall was carried out on representative species of four morphological forms of collenchyma, viz. annular, angular, plate and lacunate. In all forms lamellae were observed in which the orientation of cellulose microfibrills was transverse. These lamellae alternated throughout the thickness of the wall with lamellae in which the orientation of cellulose microfibrils was longitudinal. The distribution of pectic substances within the wall, when stained with ruthenium red and by the alkaline hydroxylamine-ferric chloride method of Reeve (1958), was generally not observed in lamellate form although instances of lamellae with high pectic content were observed.