STUDIES ON THE STRUCTURE OF VEGETABLE FIBRES. V.

ON A LONGITUDINAL GROWTH STRUCTURE OF VEGETABLE FIBRES.

Abstract

At the time of studying the spiral structures of the vegetable fibres by swelling method, the author often observed transverse lines or clefts on straw and cotton fibres. While the further observations have proved that all sorts of fibres show, without exception, these lines or clefts perpendicular to the fibre axis. In the following some typical examples of these phenomena have been shown (cf. photomicrographs in Japanese original in this number).
Fig. 1 shows a kôzo fibre swollen by a weak xanthation in which transverse lines (marked with ×) perpendicular to the fibre axis are observed, and Fig. 2 a swollen kôzo fibre with clefts perpendicular to the fibre axis. The author call these lines and cleavage planes N-lines and N-planes respectively for convenience sake. In Fig. 3 are shown thin pieces cleft along the N-planes. Under microscope the dispersed cleft pieces are very beautiful and remind us so many scattered coins. Fig. 6 shows time independent existence of the N-lines and the lines due to the spiral structure. In Fig. 4 and Fig. 5 are shown a swollen mitsumata fibre and cotten fibres (acetylcellulose) with many clefts produced along the N-planes respectively.
Hydro- and oxycellulose fibres and long heated fibres are easy to show these lines or clefts on swelling. It is clear rhat, in the thermal or chemical treatments of cellulose fibres, they are firstly attacked at the N-plane parts and that the decrease of strength of any modified fibre is due to the weakening of these parts.
At any rate there is no doubt that the transversal N-plane part shows a longitudinal growth structure of a fibre and we know that the fibrillae of vegetable fibres are composed of a great many short elements.