Contradictory Data on Spiral Structures in the Secondary Cell Wall of Fibers of Flax, Hemp, and Ramie

Abstract

Althought the microscopy of the well-known textile fibers flax, hemp, and ramie is familiar to many people and the spiral structure of their cell-wall layers is mentioned in many textbooks, the study of the original literature on this point disclosed many contradictory data. However, there cannot exist essential differences between the samples studied by the different authors, since there are no conflicting data on the direction of twist shown by the fibers on wetting or drying, nor on the optical behavior when studied with a polarization microscope. A reinvestigation revealed that in flax there are not two, but three, layers with different spiral structure. Since usually either the outer or the inner one is very difficult to discern, previous authors described two of them, either the two outer or the two inner ones. In ramie and in hemp fibers the spiral structure of two outer layers is identical with those of flax, although the slope of the spirals and the thickness of the layers, of course, differ. If here, too, a third, innermost layer with different spiral structure could be found, the conflicting data in the literature would be understandable.