Abstract
The structure and the cellulose microfibril orientation of cell walls of cortical fibre cells, parenchymatous cells and vessels were observed with the technique of microscopic chemistry and polarized microscopy. The cell wall of the cortical fibre is composed of three layers, and the vessel has two kinds, dominant and recessive, of microfibril orientation, as illustrated in Fig. 1 (p. 603). It is important that, in all cases, the cellulose microfibrils cross each other at the angle of about 84°or about 58°Notes. Photos. 1-10. Cortical fibre cell. Photo. 1. Transverse section. The outer layer (S1) is formed first, and followed by the middle layer (S2) and the inner layer (S3). Photos. 1A', 1B' and 1C' are photographed between crossed nicols. PW Primary wall. Photos. 2 and 3 are the transverse sections of the middle layer and the outer layer, respectively, swollen with cuprammonium. The middle layer shows several lamellae. Photos. 4 and 5. The cortical fibre cells swollen with sulfuric acid, show the helices of the outer layer. Photos. 6 and 6'. Surface view of a single wall of the outer layer. Photo. 6 is the wall stainde with iodine, and 6' is photographed between crossed nicols. The axes of pits and striations run in the same direction. Photo. 7. Surface view of a single wall of the middle layer. Photo. 8. Surface view of a single wall of the inner layer. ST Station. Photo. 9. The inner layer's helices of the cortical fibre swollen strongly with cuprammonium. Photos. 11-15. Parenchymatous cell. Photo. 11. The transverse section of a cell wall, swollen with sulfuric acid and stained with iodine, shows many lamellae. Photo. 11 is photographed through polarizer. The dichroism of iodine can be recognized. Photo. 11' is photographed between crossed nicols. Photos. 13 and 14. Surface view of a vertical single wall bearing two sets of striations crossing each other at the angle of about 84°. Photo. 15. Surface view of a horizontal single wall having striations running at random. Photos. 16 and 17. Annular vessel. Photos. 16' and 17' are photographed between crossed nicols. Microfibrils run horizontally in the hollow rings. Photos. 18 and 19. Pitted vessel. Photos. 18A and 19A are focused on the basal plane, 18B and 19B at the top. The direction of pit axes shows that microfibrils run downward along an S helix. Photo. 20. The cell wall of a vessel, swollen with sulfuric acid, shows several lamellae. Photo. 21. Surface view of a single wall of the vessel. Two sets of striations cross each other at the angle of about 84°in 21 A and B, and at the angle of 58°in 21C and D.
